2-NRLF 767 M4S r, /:;' ffl o o o t I w W ^ D a 3 PRACTICAL DATA FOR THE CYANIDE PLANT Published by the McGrow - Hill Book. Company Ne^vYork ook.Departrnervts of tKe McGraw Publishing Company Hill Publishing Company Publishers of Books for Electrical World The Engineering and Mining Journal TKe Engineering Record rower and The Engineer Electric Railway Journal American Machinist PRACTICAL DATA FOR THE CYANIDE PLANT BY HERBERT A. MEGRAW B.S., A.I.M.E. Mining and Metallurgical Engineer McGRAW-HILL BOOK COMPANY 239 WEST 39TH STREET, NEW YORK 6 BOUVERIE STREET, LONDON, E.G. 1910 Copyright, 1910, by the McGRAw-HiLL BOOK COMPANY The Plimpton Press Norwood Mass. U.S.A. INTRODUCTION THE inspiration for the publication of this volume was in the realization that, while theory and practice of the cyanide process has been ably explained in the standard works on the subject, no attempt has yet been made to collect the practical data, formulae, tables, usual methods etc., in one small and convenient volume which might be carried about by the "Man on Shift." The work is frankly a compilation, with some few diversions from standard practice which long experience has shown to be advisable. It is intended to assist the shift man in understanding the basic reasons for the operations he performs every day, and to give him convenient access to the data he may have to use from time to time. The experienced worker also, it is hoped, will find the work a con- venience to him on his travels, containing, as it does, matter which could only be had from a number of standard books on the subject aside from his personal notes. The author fully realizes the deficiencies of the work and request* communications from those who feel inclined to suggest the advisa- bility of additions or improvements. The author sincerely hopes that the volume may be an aid and a convenience to the "Man on Shift," to whose especial use he has dedicated his work. H. A. MEGRAW. SAN Luis DE LA PAZ, GTO., MEXICO. July, IQIO. 91 CONTENTS PAGE CRUSHING AND GRINDING . . . . . , ... . . i THE CYANIDE PLANT . . . . . . * * v. . . '. . 10 SLIMES . 13 PRECIPITATION 24 Solutions Stoichiometry Preliminary Experiments on Ores Trouble Data FORMULAS IN MENSURATION 43 TABLES OF GENERAL WEIGHTS AND MEASURES .... 49 GENERAL REFERENCE TABLES . . . . 51 Squares Roots Logarithms, etc. TY PRACTICAL DATA FOR THE GENERAL CYANIDING is the term generally applied to the art of extracting metals from their ores by the chemical process, depending upon the chemical solubility of the metals in solutions of the alkaline cyanides. The cyanides generally used are those of sodium or potassium. Cyaniding, in the general use of the term, includes the processes of solution of the metal, its recovery from the solution and its conse- quent transformation into a form of bullion readily marketable. In dealing with the subject, then, we are to include the methods of dis- solving the metal, separating the pregnant solution from the residue of ore, precipitation of the metals from the solution, preparation of the remaining solution for re-use, and the refining of the precipitate. As it is necessary for an ore to be treated in some way to prepare it for the dissolving process, it might be well to consider what methods are followed to put the ore into the most suitable form for readily giving up its values to the dissolving solution. CRUSHING AND GRINDING As the object of cyaniding is to dissolve, as far as possible, all the precious metals in combination or free in the ore, naturally the first step in preparation is to break the ore into such small particles that the dissolving solution will be able to reach and act upon every par- ticle of the metal. These processes of breaking are usually included in the terms crushing and grinding. It is practised to a more or less degree with all kinds of ore, the exact point where it may be left off depending upon the physical and chemical characteristics of each ore to be treated. It will be readily seen that a very open or porous rock will permit solutions to penetrate each atom of rock with less preliminary breaking than an ore which is hard and solid. Instances are on record where a low-grade ore has been treated in percolation tanks after having been broken only by means of a finely set rock crusher to cubes of \ to inch in size. The majority of the ores of the precious metals are, however, hard and impenetrable, so that the best results are obtained by very fine subdivision. Grind- ing and crushing are accomplished by so many mechanical devices that it would be impossible to enumerate them, and the following are mentioned as the most usual methods of practice: Rock crushers are almost universally used for preliminary break- ing. These are, the Blake type, which accomplishes breaking by means of a moving jaw, swung at the top and operated by toggles. This gives a product of varied size, due. to the fact that the size of the discharge opening is constantly changing. The Dodge type, similar to the Blake, except that the jaw is swung from the bottom, maintaining a practically constant discharge opening and therefore CYANIDE DATA FIG. i. Blake Rock Crusher FIG. 2, Roll Jaw Crusher CRUSHING AND GRINDING 3 discharging a more uniform product. Its capacity is less than the Blake for that same reason. The Roll Jaw type, in which the mov- able jaw is convex and rolls through a small arc, similar in effect to the passing of a heavy wheel over the rock to be crushed. This motion gives a constant product with good clearing function and large capacity. The Gyratory type, which grinds by means of a verti- cally placed, grooved crushing unit revolving in a horizontal plane and crushing rock by compression against the stationary walls en- closing the revolving unit. Machines of this class are followed by secondary crushing machines of which by far the most popular is the gravity stamp. This machine consists of a vertically placed stem carrying at its lower end a boss head into which the stem is fitted, a shoe of cast iron or steel being in turn fitted into the boss head. This shoe takes the wear of crush- ing the ore and may be renewed when worn out. The stamp is raised and dropped by means of a double cam fixed to a horizontal revolving shaft. These cams engage a tappet which is keyed to the stamp stem. The stem itself works in guides which keep it in place. Usually five of these stems are grouped together and allowed to fall with their shoe ends enclosed in a box or mortar of cast iron. This mortar also contains the dies upon which the ore is fed and where it is broken by means of the impact of the falling stem with its weight of shoe, boss head, tappet, and the stem itself. Stamps in use now usually weigh from 750 to 1200 Ibs., although in some camps it is the tendency to increase the weight up to as much as 1400 Ibs. for each stamp. The stamp is one of the original machines designed for the crushing of ores and its form has changed little from the original design. It is generally admitted to be an inefficient and expensive machine, but engineers have not yet been able to agree on anything which promises better results. Other machines which have been more or less used for the same purpose are the Chilian mill, in various forms, which is a roller, or series of rollers, moving on a circular track and crushing ore by means of the weight of the rollers themselves. The Huntington mill, which is a series of rollers revolving Jiorizontally against a ver- tical track or die, and crushing by virtue of the centrifugal force gen- erated by means of the speed of revolution, in addition to the weight of the crushing members. The Bryan mill is a modified chilian mill and is used in many places as a primary grinder. The machine which seems to promise most beneficial results in the contest against stamps is the chilian mill in some form. Most of the modern forms of this mill are high-speed machines, however, and these are expen- sive in repairs and not particularly efficient. The slow-speed mill, on the contrary, has many advantages which make it a particularly efficient and economical machine. In reducing ore still further, fine grinding, or sliming, is becoming more and more the most modern form of practice. With the ad- vent of methods which make it possible and even simple to treat very finely ground ore, or slime, it is becoming an axiom that, "the finer the grinding, the better the result." For fine grinding there seems to be an universal concurrence of opinion in favor of the tube CYANIDE DATA FIGS. 3 AND 4. Styles of Gyratory Crusher CRUSHING AND GRINDING 5 mill. This machine is a tube or pipe of plate steel revolving on trunnions or rollers, driven by a proper driving mechanism at a rate of speed depending on conditions. This tube is partly filled with hard pebbles or coarse hard ore, the grinding being performed FIG. 5. Usual Stamp Construction with Suspended Automatic Feeder by the action of the pebbles against each other, which reduces the pulp fed into the mill, through a hollow bearing, in a very satisfac- tory manner. It is a prime requisite to keep the wear on the walls of the machine to as low a point as possible, and with this object in view to find a lining medium which will represent as little expense CYANIDE DATA FIG. 6. " Lane" Slow- Speed Chilian Mill FIG. 7. High-Speed Chilian Mill CRUSHING AND GRINDING FIGS. 8 AND 9. Perspective and Sectional View of Huntington Mill 8 CYANIDE DATA in the form of wear as possible. Many lining mediums have been devised, the most satisfactory of which at present are the silex lining FIG. 10. View of Center Discharge Tube Mill and the El Oro lining. The latter is a lining of cast iron in the form of grooves longitudinally placed, into which the pebbles or other FIG. 12. Interior View of Tube Mill with "El Oro" Lining grinding medium become firmly lodged, forming a lining themselves. This lining replaces itself automatically whenever one of the pebbles CRUSHING AND GRINDING 10 CYANIDE DATA or stones becomes so small that it cannot hold its place in the lining, another and larger stone soon becoming lodged in the vacant space. The ore being sufficiently subdivided, it is then either sent directly to the cyanide treatment plant, or it is first concentrated and then subjected to the cyanide treatment. Concentration is the removal from the ore of that portion which is the heaviest. This process depends upon the settling properties of the different portions of the ore through a sheet of water. The particles having the highest specific gravity settle first, the remainder following in the order of the specific gravity of the different particles. As that portion of the ore which contains the most metal has the highest specific gravity, it follows that those particles which settle first are the richest. This portion is removed from the run of the mill and treated separately. It may be either sold to the smelting firms or treated by a separate and distinct process at the mill, the course to be followed depending largely upon the geographical location of the mine. THE CYANIDE PLANT TAKING the ore from the concentrators or from the grinding plant, the cyaniding department is then entrusted with the duty of extract- ing all values economically possible from the ore. The exact method of accomplishing this end differs widely in different plants. As the cyanide process, like any other art, has been and is being developed and improved upon from time to time, it is quite natural to see modern plants, representing the most improved practice, in operation in immediate proximity with older plants whose practice, while finan- cially successful, does not represent all that can be done. This will undoubtedly continue to be the case until the limits of development have been reached and there is no hope of further progress. It is necessary, then, to consider some of the methods which are still in use as well as the most modern applications. * In the first place, when pulp is delivered to the ordinary reduction plant, it consists of a mixture of coarsely crushed material and a portion, in amount depending upon the method of crushing, of very fine material. Ordinarily all grades between the two extremes are represented, except in the most modern plants, where all the pulp is reduced to the finest possible point of subdivision. There is a line of division, however, which is used to divide the whole into two classes, called sand and slime. It is a very difficult matter to give an accurate definition of the point where sand ends and slime begins, but for purposes of practical use it may be said that clean sand, of whatever fineness, is susceptible to the leaching or percolation process. On the contrary, settled slime is very difficult to leach; in fact most slimes when settled are quite impenetrable. This point is the one which has caused so much difficulty in the development of the cyanide process and which made it necessary, for successful results, to sep- arate carefully the leachable and unleachable content of a ground ore, and to treat the two products separately. The separation is made by various means, all depending, however, upon the more rapid settling of sand in water. One favorite and very good method THE CYANIDE PLANT II has been to use a sand treatment tank with an annular launder or gutter around the top of the tank. This tank is filled with water or solution, according to which is used in crushing, and then the flow of pulp from the grinding plant is allowed to flow into the tank. It is better to introduce the pulp by means of a distributing device such as the Butters and Mein distributor, which has the advantage of filling the tank evenly from center to circumference. As the pulp enters, the sand, being heavier, settles immediately to the bottom, while the slime, being fine and light, overflows with the excess of solution into the annular launder and is carried to the place where its collection is effected. It is best in many cases to perform a pre- liminary separation upon the pulp before it is delivered to the sand tank. This may be performed by the use of a settling cone, from which most of the slime is overflowed and the sand drawn out of the bottom of the cone. The Dorr classifier is also largely used for this purpose and is a very efficient contrivance. It consists basi- cally of a series of rakes in an inclined bottomed box. The pulp is delivered into the lower end of the box, and the coarse sand which settles promptly is carried up the incline by the rakes until it is finally delivered clear of the pulp into a launder which takes it to the sand plant. The slime overflows from the lower part of the box and is delivered to the slime plant. The motion of the rake, which is inter- mittent, is very efficient in washing out the main part of the slime from the sand and delivering a fairly clean sand product for the sand plant. The sand tank filled with solution washes out what slime remains, and the resultant sand charge is in good condition for the percolation treatment. FIG. 13. Sand Leaching Tank The tank or vat in which the sand is treated contains a false bottom made of a lattice work of wood strips which supports a filter mat made of coco matting, jute, or canvas. This filter retains the sand charge in the tank while permitting the solution with its dissolved values to pass freely through. The solution is drawn off through pipes fixed in the tank below the filter bottom. In treating sands it is important to know accurately the quantity of material the tank may contain at any time. To do this, in a round tank, it is only necessary to know the weight of a cubic foot of the 12 CYANIDE DATA u u FIGS. 14 AND 15. Types of Filter Bottoms for Sand Leaching Tanks SLIMES 13 sand as laid down in the tank. By deducting from this the moisture contained we have the weight of a cubic foot of dry sand under the conditions obtaining in the tank. In a tank having a known content for each vertical foot (see table, p. 52) the distance of the surface of the sand charge from the top of the tank is measured and deducted from the total content of the tank. It is usually convenient to have a small box made which will hold just one cubic foot. This should be filled with the moist sand as nearly as possible like the sand laid down in the tank. Very often the box can be placed in the tank while it is filling and thus a very fair sample of its density can be obtained. This box is weighed, the moisture in the sample of sand determined, and the weight of both the box and the moisture deducted, thus leaving the weight of one cubic foot of dry sand under the con- ditions obtaining in the tank. Knowing the cubic content occupied by the sand, the tonnage of the tank follows. The most approved and efficient method of treating sand is to add the solution in separate baths, the strong solution being added first, and as soon as the leachings show that the maximum strength has been reached throughout the charge, weaker solution is used. This is gradually made weaker and weaker until the last baths are of clear water which displaces the pregnant solution and all dissolved values. Between each bath of solution it is advisable to allow the charge to leach as dry as possible. This permits the passage of air throughout the charge and materially assists the next bath to dissolve further values. In some cases this process is assisted by means of a vacuum pump which draws the air positively through the mass of the charge. Sand charges, after treatment, are discharged in the most economi- cal way possible under the circumstances. If water is available it is much the cheapest way to thoroughly saturate the charge and then discharge it with water under head from a hose. In this way the tank may be quickly and cheaply emptied. Where water is scarce other methods have to be resorted to. Discharging by hand shoveling is the most expensive way of doing the work, but where the plant is small and water scarce, it must be used. The Blaisdell excavating apparatus for automatically discharging sand tanks is very excellent and closely approaches the cost of hydraulic sluicing, but the machinery is expensive and not applicable to the small plant. The machine is practically a rotary plow with disc cutters suspended by arms fixed to a central revolving shaft. This shaft is lowered as the plow discs cut their way through the charge. The sand is forced toward the center of the tank and discharged through a central opening in the bottom. SLIMES THE slime, or very fine, non-leachable portion of the ore is carried to the slime plant where special means are taken to separate it from the superfluous water and collect the thickened slime in charges for treatment. Large cones are often used for dewatering the slime. These cones deliver a product containing from 50 to 75% water or more, as is considered necessary in treatment. Where crushing is performed in solution it is not necessary to take out such a large per- CYANIDE DATA centage of the water or solution, as treatment can be performed in the same solution by adding sufficient cyanide to raise the solution to the strength necessary for proper treatment. Slime is very often collected in the same tank in which treatment is performed. The full stream of pulp is allowed to fall into the tank, generally through a box reaching down into the tank, or behind a baffle board. The current in the tank being very slow, the slime settles to the bottom, clear solution being allowed to overflow from the tank. This clear solution may be, and very often is, returned directly from this point to the crushing plant, where it is used over again. A solution thus used will in time accumulate considerable quantities of dissolved values. To reduce these, the mill solution is at stated intervals passed through the precipitation boxes, thence back again to the crushing plant. In thus collecting slime in the treatment tanks, a certain proportion must be observed between the flow and the size of the collecting tank; otherwise, if the stream is too great, the overflow will carry more or less of the lighter slime with it. The addition of a proper amount of lime to the solutions current in the mill will give the slime a tendency to settle more rapidly and leave a clearer supernatant solution. The size of vats or tanks giving a clear overflow when receiving slime pulp is given by Julian and Smart (Cyaniding Gold and Silver Ores), as follows: Diameter ol tank. Cubic feet of slime pulp delivered per minute. 20 fe et 18. 25 25- 30 34= 35 40 45 45-5 60. 78. 5o v IOO. The treatment of slimes has been developed from a point where it was not possible to treat them at all, many mills having discarded this product for years, to the present-day practice where they are the simplest and most economical form of ore to treat and where results are the best obtainable by practice. The slime after having been collected in a charge of a suitable amount is then treated with cyanide solution of the strength found by experiment to be best adapted to it. As it is imposssible to successfully leach slime, the only remaining way is to keep it in motion .during the time when extraction is proceeding. The more thoroughly the charge is kept in agitation, the better will be the final result. At first this agitation was attempted by keeping the charge of slime stirred up with a current of compressed air, the air being directed through a hose and small pipe by a man whose duty it was to see that the slime SLIMES 15 was kept in continual motion as far as possible. This procedure gave results, but proved to be expensive, and efforts were soon made to keep the charge in motion mechanically. From this was devel- oped the mechanical stirring gear which has been so widely used. This consists of a vertical shaft in the center of the tank carrying horizontal arms near the bottom of the tank, the shaft being revolved by means of gears from a horizontal shaft passing over the line of tanks. This method also gave good results, an improvement on the previous methods. Later a scheme was devised by which the FIG. 16. Agitating Slime with Compressed Air through Hose central shaft was made hollow and compressed air was introduced through it to pipes carried by the radial arms, thus adding air agita- tion and, to a certain degree, oxygen also to the charge. This idea also had merit and was successful. It probably led the way to the most modern practice of to-day, which is the use of the Brown or Pachuca tank. This tank is a tall cylinder having a cone bottom. In the center of the tank is a tube which reaches not quite to the top of the tank, and terminates a short distance from the bottom of the cone. Into the lower end of this tube is introduced a small pipe carrying compressed air. The air introduced at this point lightens i6 CYANIDE DATA the material in the central pipe and causes it to overflow at tne top, and consequently drawing in more pulp to replace it at the bottom of the tank. This action is practically that of the air lift. By this system it is possible to keep a charge in thorough motion during the time it is being treated, and the cost is considerably less than that of the most approved mechanical agitators. The angle at the apex of the cone bottom is made as acute as is possible in order to avoid any settling of the charge on the walls of the cone and at the FIG. 17. Slime Tank with Mechanical Agitator bottom. It has been suggested that water pipes be installed in the tank at this point, so that, should settling occur for any reason, water can be added under pressure and so loosen the settled charge to such a point that the air lift may begin to work. After the lift is at work it will soon bring into motion any material that may remain settled. Slimes usually require to be treated with solution of much less strength than sands, as the material is so much more finely divided. In consequence of this fine division also, much less time is necessary SLIMES FIG. 18. " Brown " or " Pachuca ' Slime Agitation Tank l8 CYANIDE DATA for treatment. In these two items is contained a large part of the reason why slime is cheaper to treat than sand. The saving is so great, all considered, that it largely overbalances the increased cost of grinding. In treating slime, it is necessary, as with sands, to know accurately the quantity of dry slime each tank contains. In calculating this tonnage the specific gravity of the dry slime and that ofthe charge must be known. The former is calculated in the laboratory by experiment. The latter can be obtained at any moment* by the use of a graduated measuring flask whose weight has been determined. Filling the flask with a sample of the pulp under treatment and weigh- ing it, thus finding the weight of the slime pulp itself, without the bottle, and comparing this weight with the weight of the same volume of water, the specific gravity of the charge is arrived at. Taking one cubic foot of water, weighing 62.5 Ibs. as a unit, 62.5 times the volume of water in one cubic foot of charge will equal the weight of the water in that amount. And the specific gravity of the dry slime times 62.5 equals the weight of one cubic foot. Multiplying this by the volume of dry slime in one cubic foot of charge gives the weight of slime in this amount. The sum of the weights of water and slime in one cubic foot of charge will be equal to the weight of the charge per cubic foot, which is the specific gravity of the charge multiplied by 62.5. Expressing this algebraically: Let E equal specific gravity of dry slime < P " " charge " X tl volume of slime in one cubic foot of charge u y tt water Then 62.5 Y + (E 62.5) X = P 62.5 But X+Y-i, then Y-i =X Substituting for Y its value in the equation, we have the formula 62.5 (i-X)+ (P62.5) X = P62.5 Example, Let E 2.5 and P = 1.3 Then 62.5 (i -X) + (2.5 X 62.5) X = 81.25 62.5 (i X)+ 156.25^ = 81.25 93.75 X = 81.25- 62.5 - 18.75 or X = .2 So that in a slime charge whose specific gravity is 1.3, two tenths of each cubic foot is dry slime. As dry slime of specific gravity of 2.5 weighs 156.25 Ibs. per cubic foot, it follows that there are 31.25 Ibs. of dry slime for each cubic foot of charge. The specific gravity of dry slime from quartz ores will closely approximate 2.5 as an average, so that this figure may have a wide application. Therefore the table, page 58, has been calculated using this figure, for all percentages of dry slime in charge. This table will be found very useful for practical operation, as it makes it the matter of a moment to calculate the tonnage of a charge. Should the specific SLIMES 2O CYANIDE DATA gravity of the slime under treatment vary much from this figure it will be advantageous to make a similar table for regular use in the slime plant. Before discharging the slime charge it is necessary to wash out, as far as possible, the values in solution. Formerly this was accom- plished by giving a water wash and then settling the charge for a long time in special settling tanks, decanting off the cleared solution from time to time as it became possible. At its best this method was wasteful, as a good deal of cyanide and some values in solution had to be run to waste with the slime tailings. Recently, however, the filtering of these tailings has become standard practice, resulting in a large saving of cyanide values in solution and time. The first Canvas Separating strips ' FIG. 20. Moore Filter Leaf of these filters to come into successful use was that designed by George Moore and the machine is known as the Moore Vacuum Filter. A very large number of these machines are in use in many parts of the world. Following this lead, many other types of filter have been devised, most of them depending on the same principle, that of vacuum. Among these probably the most popular has been that designed by the staff of Chas. Butters & Co. and known as the Butters Filter. The Burt filter is another of the successful ones. Its principle is like the others except that the mass is filtered by means of pressure instead of vacuum. The basic principle of these filters is the use of a frame or leaf, made of coco matting with a layer of canvas sewed on each side, and the whole covering a frame of small SLIMES 21 22 CYANIDE DATA iron pipe perforated with small holes. One end of this pipe is con- nected with a vacuum pump and the frame is immersed in the pulp to be filtered. The vacuum causes the clear solution to be drawn through the mat and the solid slime pulp forms a cake on the outside of the mat. A number of these leaves are used in a unit box or tank, depending upon the amount of slime to be filtered. The Ridgway FIG. 22. " Burt " Rapid Slime Filter filter operates on the same principle, but is rotary and continuous. It accomplishes good work but is a rather complicated machine. The filter designed by Hunt is a circular rotary continuous machine, using sand as a medium of filtering, thus avoiding the expense of repairing cloths. This machine seems to be a particularly efficient and economical machine and its use may offer advantages over any other type at present in use. SLIMES CYANIDE DATA FIG. 24. Hunt Continuous Slime Filter The solution from both sand and slime tanks is carried to the pre- cipitation department, where the valuable metal is separated from the solution and collected. Solution from slime treatment, whether the result of settling or nitration, usually has to be further clarified before it is in proper condition to proceed to the precipitation depart- ment. This is usually accomplished by passing the solution through sand filters which take out the last trace of slime and send the solu- tion perfectly clear to the precipitators. PRECIPITATION THERE are three methods of precipitation in general use at present and most plants have adopted one of these or a combination of two or more of them. The most general way, by far, is precipitation on zinc shavings. By this method the solution is passed through long narrow boxes which are divided off into compartments in such a way that the solution rises through the mass of zinc shavings and flows down between them. In this process the zinc replaces the gold and silver in solution, the latter being precipitated loosely on the zinc in the form of a black slime or sludge. The zinc shavings are supported a few inches from the bottom of the box on a screen which allows the solution to pass freely through while holding the zinc in place. The space below the screens is utilized to allow the settle- ment of the precipitated slime of gold and silver. A very modern and efficient method of precipitation is that devised by Merrill and in use at the Homestake plant, South Dakota. This process uses zinc fume or dust in place of the shavings. This zinc dust is metallic zinc in the form of an extremely fine powder. On account of the extreme fineness its precipitating action on solutions of gold and silver cyanides is almost instantaneous. Therefore in order that there shall be no re-solution of the precipitated metal, the whole solution PRECIPITATION is pumped through a filter press at once, where the precipitate and any unused zinc is taken out of the solution immediately. The great advantage of this process is that no zinc boxes are required and the labor of cleaning up is saved. Also it produces, at every clean-up, g M the entire amount of metal which has been recovered. On the con- trary, zinc shavings hold a large amount of values which cannot be recovered until the zinc is entirely used up. The third process now in use is the electrical precipitation process originated by Siemens-Halske of Berlin. This process has been 26 CYANIDE DATA used extensively in South Africa. The idea is simply the precipita- tion or plating of the metals in solution upon a cathode by means of a current of low density. This process has been modified by the staff of Chas. Butters & Co., by which company the process has been used for years. The modification consists in increasing the current density to a point where the metal no longer plates itself on the cathode, but precipitates in the form of a slime of the metal and falls to the bottom of the box. Iron anodes and lead foil cathodes are used. The current density used in this process is about .3 amperes per square foot of anode. The advantage of this system is that a large bulk of precipitate can be handled without the expense of the consumption of zinc usual with shavings. The electric current also precipitates whatever metal may be in the solution and is not affected by solutions not altogether clear. When a clean-up is to be made in the ordinary zinc shaving plant, the flow is turned off the boxes to be cleaned and the zinc shaken thoroughly to clear it of all precipitate which may be shaken off. This precipitate is then allowed to settle and an opening in the bottom of the box is opened and the content of the box run to sump. This flow from the box is usually passed through a screen to free the pre- cipitate from any pieces of coarse zinc which may have passed into the bottom of the compartment. The finer the screen the cleaner the resulting bullion. The precipitate is then pumped through a small filter press which rids it of the solution. The cake formed is partially dried, fluxed and melted in crucibles. The broken zinc which is caught on the screen is either treated with acid, and melted, or better, is placed in trays having a fine screen bottom and placed in the flow- of strong solution where the zinc is used up and aids in precipitation until it finally is absorbed by the solution. The precipitate to be melted is not thoroughly dried in order to avoid losses in dusting. The flux used for the precipitate depends entirely on the nature of the metal and varies in different localities. A flux which has been used with good results for gold-silver precipi- tate which has been washed through a 4o-mesh screen is as follows. Precipitate, 100 % Borax Glass IO % Soda (bicarb.) 5 % Silica (sand) 2 % Sometimes where there is more zinc in the precipitate it is well to add a small portion of niter to the flux. The first pourings from the crucibles usually deliver slabs of metal of different sizes and these are re melted into bars of whatever weight may be required. Solutions IN treating ores by the cyanide process it is necessary to make up solutions of a strength which has been proved most satisfactory. This strength of solution is one by the use of which it has been found that the economical limit of extraction can be reached in a given time. PRECIPITATION 27 It is not true that a very strong solution will necessarily be more effi- cient than a much weaker one. In fact the contrary seems more likely to be true within limits. In treating ores whose values are economically in gold only, it has been the custom to use solutions containing from .02 to .1 % KCN. Silver ores require stronger solu- tions for the reasons that to be workable at all a silver ore must have a much larger weight of metal than a gold ore, and also because the chemical reactions of cyanide solutions with silver require a larger portion of the former to effect solution. The strength to be used depends entirely upon the nature and quantity of the metal contained and also to a great degree upon the other constituents of the ore which may have an effect upon it. The proper solution to be used is determined by experiment before commercial treatment is attempted. Having determined the strength to be used the next step is to make the solutions. To make a tank full of solution of a determined strength, first find the capacity of the tank in tons of water. Calculate the capacity of each vertical inch of the tank. The per cent to which the solution is to be made up, multiplied by 20 (in a 2000 Ib. ton) gives the number of pounds of KCN to be added to each ton of water. Multiplying by the number of tons of water contained in the tank will give the number of pounds of KCN to be added to the tank to make the solution. Expressing this algebraically: Let L equal the number of inches in the tank. Let X equal the strength to be made up and Y equal the present strength of the solution' in the tank. Let A equal the number of tons per inch in the tank. Then X Y = N, which is the difference between the actual and required strength and there- fore the percentage which is to be added to the solution. Then AL X 20 N = Ibs. KCN to be added. When the solution is to be made up with water, Y = O. In computing in metric tons, simply multiply the percentage to be added by the number of tons to be made up. The result is in kilos. Thus, i ton equals 1000 kilos. 1000 x .3% = 3.000 kilos KCN to be added. In using sodium cyanide, NaCN, which is now largely used on the score of economy, it is necessary to calculate its value in terms of KCN, as all percentages are calculated and expressed in terms of the salt originally used. Commercial NaCN contains from 125 to 130% KCN. To find the strength of sodium cyanide in terms of KCN, make up a small quantity of solution of the proportion of i gram of the cyanide to 100 cc. of distilled water. If pure KCN were used this solution would be i % KCN. Titrate this solution with standard silver nitrate (AgNO 3 ) as noted below, and the result will show the strength of the sodium cyanide. From this data it is a simple cal- culation to find the weight of sodium cyanide to be used to make the solutions in terms of per cent, of KCN. To test the strength of cyanide solutions, the general method is by titrating with standard silver nitrate solution. This solution is 28 CYANIDE DATA made up of such strength that i cc. of the standard nitrate solution represents i % KCN. 13.07 grams of pure crystal AgNO 3 added to i liter of distilled water will give a solution of such strength. Very often in testing weak solutions of cyanide it is convenient to have the standard solution made up to half this strength. In order that the end point of the reaction of the silver nitrate with cyanide solutions may be made clear, an indicator is generally used, consisting of a few drops of a 10% solution of potassium iodide (KI). This renders the precipitate heavier and imparts a yellow opalescent tint which may be readily recognized with practice. In order to familiarize oneself with this color, add two drops of KI solution to 10 cc. of dis- tilled water and then from a burette add a drop of silver nitrate solu- tion. The yellow color will appear immediately. In solutions which have been in use for some time and contain other elements which might mask the reaction it is a good plan to add a liberal quantity of dis- tilled water, say 20 cc. to the 10 cc. of cyanide solution under test. This dilutes the solution to such a point that the reaction may be easily recognized. This test shows the free or available cyanide in the solution. Should it be required to estimate the total cyanide in solution, add 10 cc. of sodium hydrate (NaOH) solution (20 grams to liter) to 50 cc. of solution to be tested and titrate as above. All cyanide solutions used in treating ores contain a certain amount of lime. This lime is added for two reasons, first, to counteract any acid tendencies in the ore which might consume cyanide, and second to aid settlement of the slime. In silver ores this addition of lime is particularly necessary. The addition of lime, however, is often car- ried to a point far beyond that necessary and even so far as to become an actual detriment to treatment. The small amount of lime neces- sary to counteract the acidity of the ore is generally quite sufficient to carry out the settling function satisfactorily. According to experi- ments made by Sharwood (Jour. Chem. Met. & Min. Soc. S. A.) lime higher than .3 Ib. per ton of solution actually retards the solution of gold to a great extent. To test for the amount of free lime in solution, either oxalic acid or sulphuric acid may be used. The former is made up in a tenth normal solution. Each cc. of this solution used in 50 cc. of the cyan- ide solution to be tested represents .008 % CaO. This test is to be performed after the titration with silver nitrate in order that the KCN may not be titrated as lime. In using sulphuric acid for titrating for lime, a tenth normal solu- tion is used. The titration is made in this case after titrating with silver nitrate, as in the case of oxalic acid, 10 cc. of the cyanide solution being used. After the titration with silver nitrate, an excess of potassium ferrocyanide is added, and the titration made with the N sulphuric acid, i cc. of this solution equals .0112 % CaO. In the cases of both oxalic and sulphuric acids, an indicator is used to show the point where the solution ceases to be alkaline. The indicator most used is phenol-phthalein, a few drops being added just before titrating. This solution is made by dissolving phenol-phthalein in alcohol to saturation and then adding distilled water until a perma- PRECIPITATION 29 nent precipitate is thrown down. In alkaline solutions this indicator has a purple red color. In acid solutions it is colorless. A normal solution is one of which one liter contains a quantity of the substance, expressed in grams, chemically equivalent to one gram of hydrogen. In cases where the solution is to be made from a salt which contains water of crystallization, the weight of the combined water must be taken into consideration. As in the case of oxalic acid: H 2 C 2 O 4 + 2H 2 O H 2 = 2 C 2 = 24 O 4 = 64 2H 2 O = 36 H 2 = i 2 6 H = 63 Thus 63 grams oxalic acid to one liter distilled water makes a normal solution of oxalic acid. In other words, the sum of the atomic weights of the elements comprising the formula of the compound, divided by the number of atoms of hydrogen contained, or to which it is equiv- alent, is equal to the number of grams of the substance to be added to one liter of water to make a normal solution. In treating gold ores the reaction taking place between the gold and potassium cyanide is expressed in the equation known as Eisner's equation : 4 Au + 8KCN + O = 4KAu (CN) 2 This equation shows the proportion of gold soluble in cyanide solu- tion and also shows the necessity of sufficient oxidation to complete the reaction. In the case of silver the reactions are much more com- plicated. The oxygen does not play the direct part in the solution of silver as in gold, but the indirect reactions taking place show that the oxygen is quite as necessary, if not more so. The reactions do not take place as promptly as in the case of gold, probably because the silver is always in combination with other elements and the requisites for the completion of the reactions are not at hand to be used promptly. The reactions given for the solution of silver sulphide in cyanide solu tions are given by Sharwood (Min. & Sci. Press, Sept 26, 1908) as follows: 96 KCN + Ag 2 S = 2 KAg (CN) 2 + 92 KCN + K 2 S This is in the proportion of 28.9 KCN to i Ag and represents the dissolving without oxidation. The K 2 S formed in solution is probably changed during slow oxidation to potassium thiocyanate and potas- sium hydrate, K 2 S + KCN + O = KCNS + 2 KOH It has been shown that if silver sulphide ores are treated with cyanide solutions a soluble double cyanide of the silver with K or Na is formed with K 2 S or Na 2 S as shown above. Now it is a fact that in the pres- ence of soluble sulphides the silver will not remain completely in solution and extraction will not be good. In order to eliminate these 30 CYANIDE DATA soluble sulphides, a soluble salt of some element whose sulphide is insoluble must be added to the solution. Lead salts are conveniently used and generally in the form of the acetate, although litharge may be used with good effect. The following reactions are given by Caldecott (Jour. Chem. Met. & Min. Soc. S. A., March, 1908) show- ing the reactions following the use of lead salts: 4NaCN = 2 NaAg(CN) 2 + This reaction showing the formation of sodium sulphide: 2 Na 2 S +2O= Na^oOa + Na 2 O Na 2 S 2 O 3 + Na 2 O + 2O 2 = 2Na 2 SO 4 and Na 2 S + NaCN + O = NaCNS + Na 2 O showing the formation of thiocyanate. The lead acetate added to the solution yields lead oxide, the reac- tions with which are, Na 2 S + PbO = PbS + Na 2 O The lead sulphide is insoluble and it is precipitated and removed from the solution. Then follows: PbS + NaCN + O - NaCNS + PbO Here the thiocyanate is again formed in solution, taking the sulphur atoms, and the lead oxide is liberated and is free for further use in repeating the above cycle of reactions. The NaCNS formed is useless for further dissolving. This is one of the reasons for the higher con- sumption of cyanide when silver is being treated. In the majority of cases the above reactions are hampered for several reasons, and the dissolving and consequent extraction of the silver values is slow. Probably the large amount of oxygen needed to complete the reactions is not available promptly and the reactions have to proceed with a speed depending upon how fast the requisite oxygen can be supplied. There are many different expressions of opinion on the subject of the reactions taking place when silver ores are treated, so that the above reactions cannot be offered with absolute certainty of truth, but they do represent the evolved opinions of those most familiar with the situation and who have given it mgst careful attention and study. Stoichiometry WHILE it is not within the scope of this work to go very deeply into chemical science or calculation, at the same time it is a wise plan for every one working with the practice of cyaniding, which depends directly upon chemical knowledge, to know something about the cal- culations of chemical reactions in order that he may be able to under- stand the principles governing them and be able to solve a few simple problems which may present themselves at any time. PRECIPITATION 31 Stoichiometry is simply the arithmetic of chemistry. Its practice involves only a knowledge of chemical reactions and basic arithmetic. Most of the problems arising can be solved by the rules of simple pro- portion. A few examples will best show the application and principle of the work. Calculation of percentage from weight: Suppose one gram of iron ore is taken for assay. The weight of iron obtained is .02 gram. What is the percentage of iron in the ore? Weight taken : weight found : : 100 : X i : .02 : : 100 : X X =2% Calculation of percentage from chemical formula: This class of problem is also solved by proportion, using in the first two terms the weights of the constituents in question and in the last two their corresponding percentages. The formula for silver nitrate is AgNOa. What is the per cent, of silver contained in the compound? Thus using the atomic weights : Weight of compound : weight of element : : 100 : X 170 : 108 : : 100 : X X = 63.5 % In the same way the percentage of each constituent may be found. Should it be required to find the weight of silver in a certain known weight of the compound, it is only necessary to multiply the known weight by the percentage found as above. This applies to any chemi- cal compound the formula of which is known. In the same way the percentage of any chemical compound which forms part of another compound may be found. Thus should it be required to find the percentage of CaO in CaCO 3 the same rule is followed, using the weight of the compound CaO in the second term of the proportion as shown above. Calculations for making up and using standard solutions: Let it be required to make a solution of sodium bromide for precipitating silver of such strength that i cc. will exactly precipitate o.oi gram of silver. From the equation, AgNO 3 + NaBr = AgBr + NaNO 3 it is evident that i atom of Br precipitates i atom of Ag. Hence follows the proportion, 108 : 103 : : o.oi : X X = 0.009537 This follows from the proportion of the atomic weights of silver and sodium bromide. X in this case is the amount of NaBr to be added to each cc. of the standard solution to be made. Therefore if 1000 cc. or i liter of the solution is to be made up, it will require 1000 times X or 9.537 grams NaBr. A similar calculation is used in making up the solution of silver nitrate with which to titrate the cyanide solutions. Here the ultimate reaction may be expressed as follows: 32 CYANIDE DATA AgNO 3 + 2 KCN - KAg(CN) a + KNO 3 Here we wish to make our standard solution of such strength that the silver contained in i cc. will be exactly dissolved in a KCN solu- tion, 10 cc. of which will represent .1 % KCN. Therefore first we must find out what weight of KCN is contained in 10 cc. of .1 %. This is readily seen to be .01 gram KCN. One atom of silver nitrate requires two atoms of potassium cyanide, according to the reaction expressed in the equation. Using the atomic weights of the two compounds, we have 2 KCN : AgNO 3 130 : 170 : : .01 : X X = .01307 which is the amount of silver nitrate to be added to each cc. of water to make the standard solution, or if 1000 cc. are to be made, 13.07 grams are to be used. These calculations are about the only ones which will be required in cyaniding work, or will serve as a type for similar calculations which may be required. To those interested in further investigation of the subject, it may be said that any standard work on quantitative analysis will give further details along this line. Preliminary Experiments on Ores IN order to determine the most efficient methods of procedure in treating by cyanide solutions, it is most important that preliminary experiments be made upon the ore in question. All possible methods should be tried in every possible way, as it is only by careful and repeated tests that conclusions valuable in after practical work can be derived. Possibly the most important factor in testing work is the selection of the sample upon which the experiments are made. It is abso- lutely necessary that this sample should represent not only the grade of ore which will be at hand in the completed plant, but it must also represent all the other conditions which will be met with in practice. Its chemical constituents should represent an average of the ore to be treated. It should have neither more nor less of the elements which tend to impede solution and those which tend to assist the opera- tion. In short, unless the sample typifies what may be expected in working practice, the experiments are useless, or worse than useless, misleading. Examples are not lacking of plants built under a mis- apprehension as to the class of ore available and having to be entirely rebuilt or changed at a great expense when practical work is begun. Therefore it behooves the experimenter to use every possible means to assure himself that the sample upon which he makes his tests is really a true sample in every sense of the word. The method of taking the sample depends entirely upon the source from which it comes. If one is dealing with a proposition which is milling ore and concentrating or amalgamating, it is then a simple matter to procure an even sample of the material to be experimented upon by sampling the tailings over a period of from one week to three months, taking the samples at regular intervals. In this case it is PRECIPITATION 33 hardly possible to go astray on the work, providing the mill is treating ore of grade and character which is expected to continue. Where there is no mill and samples have to be taken directly from the mine, it is well to extract a portion of ore from each part of the mine and experiment upon each section separately, except where the ore in the mine is fairly regular, when the samples from different parts of the mine can be put together and thoroughly mixed. The larger the sample, the better and more representative the resultant sample will be. The thoroughly mixed sample, which should contain from five to one hundred tons, according to the size of the mine and the consequent magnitude of the plant, should be reduced to an even size of rock, breaking up all large boulders or rocks. The pile should then be mixed again and reduced, either by taking out one shovel in every five, or better, by cutting the pile in quarters and rejecting half of the sample, opposite quarters, at the first reduction. The sample should then be further reduced in size and the quartering process resorted to again. At this rate, when the sample is reduced to about half a ton, the size of the largest piece should not be over \" y or such size as will pass through a half-inch ring. When the sample is reduced to a quarter ton the whole should be so crushed to pass through a screen having openings \" square. At this point the sample can be thoroughly mixed again by shoveling over several times and the sample for test can be extracted. In cases where the plant in view is to be large and important, it is well to install sufficient sampling machinery so that a large tonnage may be crushed, thus securing a sample well representative of all the possibilities to be met with. It is a wise policy to erect a small mill so that experi- ments may reproduce, as far as possible, results obtained in actual practice. It is true that laboratory results are fairly representative of results which may be obtained on a large scale, probably more so in the cyanide process than in any other mode of reduction, but the character of the sample is the one point where large quantity makes for accuracy. If it is desired to construct a plant in which the sand and slime is to be treated separately, the sample should be so crushed as to give a part of it in slime and a part in sand. This is a very difficult thing to do on a small scale, and the only way to get a true idea of what crushing will produce is to really crush the ore in the way it is to be done in the future mill, on a smaller scale, of course. If this is not possible, it is well to crush the sample on a bucking board, screening the product after each separate bucking so that the percentage of slime will not be abnormal, as it is likely to be if the whole sample is bucked over until the coarsest particles pass the required screen. After bucking, the whole sample can be separated into sand and slime by passing it through a 2oo-mesh screen, that part which passes through the screen being held as slime and that which does not pass through the screen being treated as sand. In making experiments upon the sand, it is well to take out several samples of a weight convenient for test, sizing each sample through a screen of different mesh in order to make experiments upon each grade. For instance, one sample might be passed through a 60- 34 CYANIDE DATA mesh screen, another through a 40, another through a 30, and another through a 20 mesh. In every case the crushing 'should be done with all possible care to ensure all the product, as far as possible, being of practically the same screen grade. Experiments may be performed on leaching in an ordinary bell jar, in the bottom of which a filter mat may be arranged by folding a piece of jute or cotton material so as to fill the bottom of the jar and not allow the sand under treat- ment to pass through. Before attempting to add the cyanide solu- tions, a test should be made in order to find out the amount of lime necessary in order to neutralize the acid tendencies of the ore. This may be done by adding to the weighed ores in a bottle an equal weight of water in which is dissolved a known weight of lime. Several bottles may be prepared each containing a different quantity of lime. These bottles are shaken up for several hours and allowed to stand for several hours more. At the end of this time they may be tested for the amount of lime still remaining in the solution. Testing all the bottles thus, an idea of the amount of CaO consumed by the ore is readily ascertained. An amount slightly in excess of this should be added to the sands under test. The excess must not be too great, or it will have a deterrent effect upon the extraction of gold. The solutions should not show over 0.3 Ib. per ton of solution, after the ore has consumed all it will. The dry lime is mixed with the sand before treatment in the pro- portion found necessary, and treatment is then instituted. Each sample for the leaching test should be treated with solution of differ- ent strengths in order to find out which is the best adapted for the extraction. Solution should be used eventually which is no stronger than that absolutely necessary for best results. It makes a difference whether the ore contains silver enough to make it commercially important, or whether it is a straight gold ore. In the latter case solution containing .05 to .1% KCN will probably be strong enough and from two to ten days' treatment will be required, depending upon the value of the ore. When silver is treated, solution of .6 to i. % KCN will be required and the time will probably be length- ened to from six to twenty days, depending upon the grade of the ore and the combinations in which the silver exists. All strengths of solution should be experimented with and all times between reason- able limits. The first few tests will generally show the limits between which good results can be obtained. After having obtained good results the same experiment under same conditions should be repeated again and again in order to absolutely verify results. In adding the solution to sands, the first wash should be of strong solution enough to completely cover the charge when it is thoroughly saturated. This solution should be allowed to stand for some time, having the tube leading from the bottom of the bell jar, under the filter mat, closed so that no solution can escape. The solution should be allowed to stand thus for from four to six hours. The tube should then be opened slightly and the solution allowed to run off slowly, so that it will take about ten hours to run off, leaving the charge with- out any solution which will run off of its own accord. The charge is then allowed to stand in this condition for from four to six hours PRECIPITATION 35 in order to assist aeration, when another wash of solution should be applied. At this point it is well to mention that better results are obtained in practice in the large tank than can possibly be attained in the laboratory, for the reason that the receding solution in the tank draws after it a volume of air which materially assists the next bath to dissolve further values. The solution draining off from the charge should be tested for KCN and lime and charges of strong solution should be added until the teachings show practically the same strength as the applied solution, showing that no further cyanide consuming effect is to be expected from the ore. Then weaker solution should be added, gradually diminishing in strength until the final wash or two is clear water in order to wash out all dissolved values. The charge should then be taken out of the jar, dried carefully and as- sayed. The teachings from each test should also be collected and assayed as a check against the tailing assay. In this way, by dint of many careful experiments under different conditions, a very good idea of what may be expected in practice may be determined. In making the experiments upon the slimes, the amount of lime necessary is determined in the same way. The solutions required in treating slimes will be found to be less than those required in sand, in per cent. KCN, and the time required will be also less, due to the very fine division of the particles of the ore. As slime cannot be leached, agitation must be resorted to. A simple way to make agitation tests is to place the slime with its solution, after having added the necessary lime, in a large bottle and agitate the bottle by fastening it to some moving piece of machinery, such as a slowly revolving wheel or a Wilfley concentrator, or any moving piece in which the speed is not so great that the charge will be held in one place by centrifugal force. The amount of solution necessary for a given amount of ore varies from 3 to i, to 5 to i. Experiments should be made with all proportions of solution of all possible strengths and with different times of treatment. In treating slimes it is well to treat with several washes of solution. After the treat- ment of the first twenty-four hours the solution is tested, the bottle allowed to rest until the slime has settled and the supernatant solu- tion is clear. This is then decanted off and a fresh bath of solu- tion added. The second bath may be decanted off after twelve hours of treatment and a third wash added, to be later decanted again. The number of baths, like the strength of solution, depends upon the character of the ore, and its value, and is only deter- mined by repeated experiment. In agitating the bottle containing the charge, the machine which operates it should be stopped from time to time and the cork removed in order that fresh air may be available. In treating both sand and slime it is important that the solutions be at all times carefully titrated for strength KCN and a calculation made to determine the total consumption of cyanide per ton of ore treated. This is an important point and has large effect upon the total cost of treatment. The results from the different methods should be all tabulated and compared, checking in each case by assaying the total solution re- sulting from the treatment. 36 CYANIDE DATA In cases where the treatment is to be made on slime alone, grinding the whole ore to the point where it can all be treated by agitation, it is only necessary to crush the original sample all to a slime and proceed with treatment as with the slimes above. It is always well to repeat the experiments on a slightly larger scale where it is possible. To this end leaching tanks can be made for treating sands by cutting a barrel in half and putting a filter mat in the bottom of the half. A pipe is fitted in the bottom of the barrel under the filter mat, with a valve by means of which the leaching can be controlled. A small zinc box can be also made if it is desired to experiment with the pre- cipitation, and the teachings from the sands run through the box. With slimes a half barrel can also be used and agitation can be ac- complished by a mechanical stirrer or by means of air jets placed in the barrel. A Pachuca tank on a small scale can be very readily made of sheet metal, very light metal will do, and a tank 18" in diame- ter and 48" deep will give very good results. Only by very careful and conscientious work can dependable results be obtained. In order that results should be of value no pains should be spared to be exact in every operation and to reproduce to the finest possible point conditions which will obtain in actual practice. In very large operations it is an extremely wise plan to build first a small plant in which actual working operations are dupli- cated. This plant may later become a part or unit in the larger in- stallation, or even if it has to be discarded entirely, it is money well spent in order to be absolutely sure of results. Trouble IN the regular work of cyaniding, there are liable to occur times when things go wrong and it seems almost impossible to account for the causes of the trouble. In such cases it is a matter of careful study and close application to discover the causes which lead to bad results and, once found, it is comparatively a simple matter to remove the cause of the difficulty. It is a good thing to know some of the things which may happen and which have happened, and thus have a few hints upon which to base observations when things go wrong on the plant. In the first place it often happens that the slimes will suddenly refuse to settle properly. Of course the first thing to do in such a case is to make sure that the proper quantity of lime has been added regularly. Operatives may happen to omit the regular addition of the lime for a short time and the results will certainly be evident on the plant very quickly. Usually this omission will be accompanied by an abnormal consumption of cyanide, due to not having the required protective alkalinity in the solutions. It is necessary in these cases to be sure the lime is being added regularly. Another cause which may bring about the same result is the use of faulty lime. Cases have occurred where lime has contained large quanti- ties of reducing agents, while the percentage of CaO has remained about normal. Sometimes the amount of reducing agents may be so large that it may render inoperative any alkalinity due to the lime content. A lime may be very easily tested for this condition PRECIPITATION 37 by making up a solution of cyanide in clear water, testing it, and then adding a small quantity of the lime in question. This is agitated for a few minutes, filtered off and the solution tested again. Any drop in the percentage of cyanide in the solution is then clearly due to the action of the lime. This condition must be at once looked after and the lime discarded. Other substances than lime have the same coagulating effect upon slimes and may be used to electrolyze them. Of course any of these materials must be used with judgment as there are certain cases in which certain ones may not be safely used. Careful experiment will, however, lead to a correct knowledge of their effects. Julian and Smart (Cyaniding Gold and Silver Ores) give the following table of the relative efficiencies of different chemicals : Substance. Quantity required by weight to produce equal effect, or relative efficiency. Aluminum sulphate 100 Alum (Potash) 14? Ferric Iron 221 Alum (Ammonium) 2Z2 (Am Chrom Iron ) 2Q? Lime 6^4. Magnesia 748 Alum (Pot. Chrom.) (K8. Calcium chloride I OQZ " carbonate I 215. sulphate 2 870. IVIagnesium sulphate 3j.6o Sodium chloride At: ooo sulphate 6 1 700 In cases where the lime is good and the addition to the solution found to be regular, it may be that the ore contains reducing agents which the lime cannot eliminate. In this case it may be easily proved by taking a small portion of the solution from the pulp under examina- tion and acidifying it with a few drops of sulphuric acid and then addinjg a few drops of potassium permanganate solution from a burette. Should there be no reducing agents present the solution under test will assume the characteristic pink color given by the permanganate, and will hold the color. Should there be^ reducing agents, however, the color will disappear with the addition of the first drop of permanganate and a brown precipitate may result. A comparison of the quantity of permanganate added before the pink color is constant will give an idea of the quantity of reducing agent present. Reducing agents may be eliminated by oxidation of the pulp. This is accomplished by agitation with air or with chemical oxidizing agents. Probably the most efficient and prompt chemical agent is bleaching powder, or calcium hypochlorite, Ca(OCl)2. A 38 CYANIDE DATA small quantity of this agent added to the pulp will usually be sufficient to thoroughly oxidize any reducing agents present. In treating accumulated tailings, trouble has been encountered due to small particles of charcoal or partly decomposed organic matter. The former is common in Mexico where charcoal is the universal fuel. Charcoal is an active precipitant and a very poor extraction will be the result where there is an appreciable quantity of this matter in the ore or tailing. It should be carefully screened out before attempting treatment. Organic matter is an active cyanicide and should be eliminated as far as possible. Screening will take out the greater part of the organic matter which is not completely decomposed, the remainder should then be carefully neutralized by the use of chemical. Lime is generally used for the purpose, but bleaching powder may be used with good effect to oxidize the acids formed and render them innocuous. The use of lime in the cyanide plant is one of the causes of some poor results, the cause for which baffles the mill man. Lime is often used in a most haphazard way, without rhyme or reason, and it is the cause of as much trouble as it is good. The most economical way to use the lime is to make it up by slaking in a small quantity in warm water and feeding the resulting lime water to the solution requiring it. Lime slaked carefully in this way will give 20 % more soluble CaO than when the dry lump, air slaked, is fed directly to cold solution. It is also more effective. A small quan- tity of lime is usually of a great deal more service than a large quantity. An excess of lime over that necessary to settle slimes is usually waste. Sharwood (Chem. Met. Min. Soc. S. A., April, 1908) shows that lime in solution to a greater extent than 0.3 Ib. per ton of solution is decidedly injurious to the extraction of gold. Lime should be used with care and judgment, and usually a series of experi- ments to determine its best mode of use would be very beneficial. It is even true that some slimes settle better without lime than with it. Some difficulty in treatment may be found after a plant has been running a long time as a result of foul solutions. In such a case it will probably be found well to precipitate the zinc from the solutions by some one of the methods suggested for the purpose. Orr's method is useful for this purpose. Its principle is the precipitation of the zinc by means of the addition of fused chloride of zinc, thus throwing down the insoluble single cyanide of zinc. This is allowed to settle, the supernatant solution drawn off and allowed to waste if necessary as it contains no cyanide. The precipitate is then dissolved in a solution of an alkaline hydrate and the zinc precipitated from it as sulphide by means of fused sulphide of Na, K, or other alkaline metal. This gives a clear solution with regeneration of the useful cyanide and gets rid of the excess of zinc. The latter may be thrown aw r ay or reduced to metal, as seems most economical under the conditions. The temperature of the pulp has a direct effect upon results. This is due largely to the influence of the viscosity of the solution, which decreases as the temperature increases. In the case of slimes it is true that the greater the proportion of solution to the weight of dry slime treated, the better will be the extraction and general result. PRECIPITATION 39 This is, however, a rule that cannot be absolutely applied in every case, for there are instances where it is not true, but in the general run of ores it will be found to apply. It is, of course, impossible to increase the proportion of solution used beyond a certain point which will be found to be the economical limit. And below this limit it is often found that a dilution much less will give results, due to less time of treatment and general convenience, which will be more effective. The amount of dilution had best be determined by care- ful experiment. The point should be found where the viscosity of the solution will be low enough to allow a thorough mixing of the solution with the ores, so that a particle of cyanide may come in contact with and act upon every particle of metal in the ore. A raise of temperature lowers the viscosity of the solution and allows mixture to take place more freely. This is limited by economy as well as by the point of temperature where the heat will tend to decom- pose the cyanide, causing an expense greater than the saving attained by higher extraction. In treating sands by percolation bad results can often be found due to imperfect percolation. In order that leaching results be good it is necessary that the sand should be in a perfectly homogeneous state so that solution will percolate uniformly through the mass. If portions are left which contain more coarse sand than other parts, the main volume of the treating solution will tend to pass through those portions to the detriment of the remaining parts of the tank. Slimes should not be permitted in the sand tank and the sands of whatever fineness should be thoroughly mixed so that percolation will proceed at a perfectly even rate throughout the whole mass in the tank. In some cases where there is no slime plant, it is desired to add as much slime to the leaching tank as possible. In this case much depends upon the character of the slime. In many cases as much as 10 % of slime can be added to the leaching tank without bad results, provided, however, that the slime is thoroughly mixed with the sand so that the density of the charge may be thoroughly even throughout. The exact quantity of slime which may be mixed with the sand can be determined only by careful experiment, and after ascertaining the quantity which may be used, the greatest care must be taken to assure thorough mixing. In precipitating on zinc shavings the strength of the solutions precipitated have a good deal to do with the efficiency. Strong solutions give uniformly good results. Very weak solutions do not give such good results and are apt to be erratic. The minimum strength of solution which can be depended upon to give good extrac- tion cannot be stated with any degree of definity, as other circum- stances seem to have effects upon it. However, Yates (Jour. Chem. & Met. S. A., Vol. i, p. 257) gives a minimum of 0.008% KCN, below which uniformly good precipitation cannot be expected. The amount of zinc shavings necessary for correct precipitation varies from \ to i\ tons of solution per 24 hours for every cubic foot of zinc shaving. The richer the solution is in metal, the less zinc will be consumed per unit of metal recovered. 40 CYANIDE DATA In cases where there is much copper in the solution precipitation on zinc will be bad. Copper is likely to precipitate in a solid, firm coating on the zinc, which prevents further action. In such cases the remedy is to use the electrical precipitation process, either wholly or in part. Should the latter mode be preferred, the first compart- ments may be precipitated by electricity and the remainder by zinc. This process will be effective in removing all the objectional elements from the solution at once. The use of lead acetate in treating silver ores has the effect of increasing the efficiency of precipitation, but also increases the con- sumption of zinc. The acetate should not be used beyond the actual amount necessary for proper extraction. In melting precipitate from the zinc boxes it is well to be perfectly sure in the first place that the flux used is that best suited to the securing of good results. A few sample charges mixed up on a small scale and melted in the assay furnace will settle that question at once. The flux should be such that it will allow the mass to melt readily and promptly and give a good liquid slag free from shots of bullion. A great deal depends upon the furnace in which the melting takes place. It should not be too large, for a large fire requires frequent replenishing with fuel and with each addition the heat is appreciably lowered. The fuel should be added in small quantities frequently rather than large quantities at long intervals. In this way the heat is preserved without great drops in temperature. Before pouring a crucible, whether it contains the slag meltings of bullion only, or bullion for bars, care should be taken that the heat is amply sufficient to maintain the contents of the crucible in a perfectly liquid state for the time necessary to pour the contents into the molds. Bullion which is poured too cold is sure to make an ugly looking bar and the assay at different points will differ widely. A properly poured bar will be perfectly mixed and will have practically the same value at whatever point a sample may be taken. The slag from the meltings should be saved and when sufficient has been accumulated should be ground fine in the mill or other grinding machine, concentrated and remelted. The concentrates will have to have a special flux while the tailings can be either treated at the plant or shipped to the smelter. After grinding the slag, a large portion of metal shot and pieces from the crucibles will be found in the mortar of the mill in which the grinding has been done. This should be carefully fluxed and melted also. The crucibles in which the melting has been done should be saved and ground up with the slag after they have worn out. Experience has shown that the crucibles are likely to have buttons of metal all through them. The only way to fully recover this material is to grind the crucibles and concentrate and melt the material with the slag. Data ALTHOUGH the standard works on chemistry and assaying include many methods for assaying cyanide solutions, it is well to have at hand a method which is reliable and which may be referred to at PRECIPITATION 41 any time. The following procedure is reliable and seems to be prompt and simple. It was published in the Mining and Scientific Press, June 8, 1907, and is an adaptation of the method of Alfred Chiddey. Take 292 cc. (10 assay tons) of solution to be assayed in a large beaker; add 5 grams zinc shavings and 40 cc. of a 20 % solution of ordinary commercial lead acetate. Bring to a boil and place in a fume closet or an open window and add 400 cc. commercial HC1. When action nearly ceases, boil again. Pour off the waste solution and squeeze the wad of spongy lead into a cube, place it between filter papers and squeeze it dry by standing on it. By folding the cubes of lead in pieces of lead foil the weight can be increased to about 10 grams each, giving better cupellation and preventing any pieces of lead from being detached from the main bulk, if any moisture happens to be left in the cubes. It has been found that solutions obtained in treating pan amalgamation tailings containing mercury sometimes cause the lead to become too brittle to wad together nicely in a cube, and this has been overcome by using less solution and more lead acetate. In cases of accidental cyanide poisoning, a remedy has been de- vised and published in the Queensland Government Mining Journal. The remedy is as follows: One ounce of 23 % solution of ferrous sulphate, i ounce of 5 % solu- tion of caustic potash, 30 grains of powdered magnesium oxide. These ingredients are to be kept separately in sealed tubes which may be broken and the contents mixed at any time they may be needed. It is believed that this mixture will prove an effective anti- dote if administered at once, but a very few minutes' delay may prove fatal. The specific gravity of a ground ore, whether sand, slime, or con- centrate, may be determined with a fair degree of accuracy by the use of the following formula: W Sp - Gr ' - (W + A)-K where W is the weight of pulp taken. A is the weight of the bottle filled with distilled water. K is the weight of the bottle and pulp with water filled to graduation. This is performed with a standard graduated flask or bottle of any convenient capacity. The bottle is weighed first with water filled up to the mark of its graduated capacity. The sample of weighed pulp is filled into this bottb when empty, the bottle filled up to the graduation mark with distilled water and the whole weighed again, thus giving the date required in the formula. New concrete may be made to take a coat of oil paint by first treating it with a 20 % solution of ammonium carbonate, applied with a brush or sprayed. The resulting carbonate of lime formed will dry hard in a short time, and not being hygroscopic, paint may be safely applied to the surface. This information is of use in pre- 42 CYANIDE DATA paring concrete foundations or floors where it may be considered advisable to apply a coat of paint. Centrifugal force may be calculated as follows: Multiply the square of the number of revolutions per minute by the diameter of the circle in feet and divide the product by 5217. This is the cen- trifugal force when the weight of the body is i. This figure mul- tiplied by the weight of the body is the centrifugal force required. The weight of i cubic foot of gas at any given temperature and pressure is found by first calculating the weight of one cubic foot of dry air at the same temperature and pressure, and then multiply- ing this weight by the specific gravity of the gas referred to air as a standard. For calculating the weight of one cubic foot of air at any pressure and temperature, let W equal the weight required B " " barometric pressure in inches t temperature in degrees Fahrenheit. Then: w ^S X B 495' Table, page 52, shows the specific gravity of some gases referred to air as a standard. To find the diameter of a pump cylinder to move a given quantity of water per minute (100 feet of piston being the speed) , divide the num- ber of gallons by 4, extract the square root, and the result will be the diameter of the pump cylinder in inches. For calculating the data referring to driving pulleys: To find the speed when the diameter of the driven is given, multiply the diam- ter of the driver by its revolution per minute and divide the product by the diameter of the driven. The diameter and revolutions of the driver being given, to find the diameter of the driven to make a given number of revolutions, multiply the diameter of the driver by its revolutions and divide the product by the number of revolutions which the driven is to run. To ascertain the size of the driver, multiply the diameter of the driven by its number of revolutions and divide the product by the revolutions of the driver. The result is the diameter of the driver. Fluxes for soldering or welding: Iron or Steel Borax or Sal Ammoniac Tinned Iron Resin or Chloride of Zinc Copper and Brass Sal Ammoniac or Chloride of Zinc Zinc Chloride of Zinc Lead '. . .Tallow or resin Lead and Tin Pipes Resin and Sweet Oil Nitric acid will produce a black spot on steel; the darker the spot the harder the steel. Iron, on the contrary, remains bright under the acid treatment. FORMULAS IN MENSURATION 43 To ascertain the horse-power necessary to drive elevators, multiply the number of pounds lifted per minute by the hight of the elevator and divide the product by 33,000. The result will give the theoretical horse-power necessary, to which should be added 50 per cent, for friction losses. A foot-pound is the work performed in lifting one pound one foot high in one minute. A horse-power equals 33,000 foot pounds, or the work performed in raising 33,000 Ibs. one foot in one minute, or in raising i Ib. 33,000 feet per minute. To find the weight of rail required for one mile of track, divide the weight of the rail per yard by 7 and multiply by n. Thus for 56 Ib. rail, ^V 6 " = 8, 8 X n = 88 tons for one mile of single track. Assay ton is the name given to a weight of 29.166 grams, which is ToVo" f tne number of Troy ounces in one ton of 2000 Ibs. If a sample of i assay ton is taken for assay and the resultant bead weighed in milligrams, each milligram represents i ounce per ton. Should it be required to weigh the pulp in grams, the following principle will be found useful. 29,166 Troy ounces equal one ton. The value of one ounce pure gold is $20.67. Therefore one ton gold has a value of $602,861. If 100 grams are taken for assay and the bead weighed in milligrams, from the proportion i mg. : 100,000 mg. : : X : $602,861 then, X or i mg. equals $6.00 per ton. FORMULAS IN MENSURATION To find the area of a parallelogram, multiply the length of one side by the perpendicular distance from that side to the one opposite. To find the diagonal of a square, multiply the length of one side by 1.41421. To find a square equal to a given circle, multiply the diameter of the circle by .886227. Result is side of required square. To find the area of a triange, multiply its base by one-half the altitude. To find the altitude of an equila trial triangle, multiply length of one side by .866025. To find area of a triangle, given two sides and included angle. Multiply the two sides together, multiply product by the natural sine of included angle, and divide product by 2. To find the area of an triangle, given three sides. Add the three sides together, divide the sum by 2. From this half sum subtract each side separately. Multiply the half sum and the three remainders continuously together. Extract the square root of the product. 44 CYANIDE DATA To find the three angles of a triangle, given its three sides. C Divide the triangle into two right triangles by erecting a per- pendicular from its base to the upper angle. Find length of sides AD and DB by proportion. AB : AC + CB :: AC - CB : AD - DB thus obtaining the value of AD DB But AD + DB is known as one side, so that the value of both AD and DB are found. AD = ( AD ~ DB ^ + (AD + DB) 2 and DB = AB - AD Then cos A = -j-^ and cos B = and angle C = 180 (angle A + angle B). To find the third side and two angles, given two sides and the included angle. Divide into two right triangles. Find the altitude CD CD where A is given by formula Sin A = ^,, or similarly for B if A C/ given. Then find the third side by formula J& = CD2 _|_ ALP Then find remaining angles as in preceding formula. To find two sides, given one side and two adjacent angles. The third angle equals 180 sum of two given angles. The third angle is opposite the given side. Then Sin angle opposite given side : given side : : sine of either other given angle : its opposite side. To find area of a trapezoid, multiply the perpendicular height by half the sum of the two parallel sides. To find the area of a trapezium. Divide the figure into two tri- angles. Find the area of each according to formula already given, and add the two areas together. To find the area of a polygon whose sides are given. Divide into a number of triangles equal to the number of sides by connecting each angle to the centre. Find the area of each triangle and add them together. To find circumference of a circle, multiply the diameter by 3.1416. FORMULAS IN MENSURATION 45 To find the area of a circle, multiply the square of the diameter by .7854. Or multiply the square of the circumference by .07958. To find the surface of a cube, multiply the area of one side by 6. To find the surface of a parallelepiped, add together twice the area of the base, twice the area of the side, and twice the area of the end. To find the cubic contents of a cube or parallelepiped, multiply the area of the base by the perpendicular hight. To find the contents of a prism, multiply the area of the base by the altitude. To find the surface of a cylinder, multiply the circumference of the base by the altitude. To find the contents of a cylinder, multiply the area of the base by the altitude. To find the surface of a pyramid, multiply the perimeter of the base by half the slant hight and add the area of the base. To find the contents of a pyramid, multiply the area of the base by one third the altitude. The last two formulas apply equally to the cone. In this case the perimeter of the base is the same as the circumference of the base. To find the convex surface of a frustum of a pyramid or cone, multiply half the sum of the perimeters or circumferences of the two bases by the slant hight. To find the entire surface add to this the area of the two bases. To find the contents of a frustum, add together the sum of the area of the two bases, and the square root of their product, and multiply this result by one third the altitude of the frustum. CYANIDE DATA COMPARISON or VALUE OF SILVER IN OUNCES TROY AND KILOGRAMS When Silver is Worth in New York Per Oz. i Kilo, is Worth U. S. Currency When Silver is Worth in New York Per Oz. i Kilo, is Worth U. S. Currency When Silver is Worth in New York Per Oz. i Kilo, is Worth U. S. Currency 50 cts. $16.0750 55} cts. $I7.9237 6if cts. $19.7321 5oi 16.1152 55! 17.9639 6lJ 19.7723 50* 16.1554 56 18.0040 6i| 19.8125 5o| 16.1956 56i 18.0442 6ij 19.8527 Soi 16.2358 56i 18.0844 6tf 19.8929 5t 16.2760 56f 18.1246 62 19.9330 si 16.3162 56 18.1648 62j 19.9732 Sol 16.3564 561 18.2050 62j 20.134 Si 16.3965 56f 18.2452 62f 20.0536 Si* 16.4367 561 18.2854 6 2 J 20.0938 sit 16.4769 57 J 8-3255 62f 20.1340 Sif 16.5171 57i 18.3657 62f 20.1742 Sii 16.5573 57i 18.4059 62! 20.2144 Sif 16.5975 57f 18.4461 63 20.2545 Sif 16.6377 57^ 18.4863 6 3 i 20.2947 5if 16.6779 57} 18.5265 63i 20.3349 52 16.7180 571 18.5667 63! 20.3751 5*1 16.7582 57i 18.6069 63* 20.4153 5^ 16.7984 58 18.6470 63! 20.4455 Sif 16.8386 58i 18.6872 63f 20.4957 523 16.8788 58i 18.7274 63i 20-5359 rr^ 5 2 8 16.9190 58f 18.7676 64 20.5760 52| 16.9592 58i 18.8078 64* 20.6162 S2S 16.9994 58f 18.8480 64i 20.6564 53 17-0395 58f 18.8882 6 4 f 20.6966 S3i 17.0797 58| 18.9284 64^ 20.7368 53i 17.1199 59 18.9685 6 4 f 20.7770 S3l 17.1601 59* 19.0087 6 4 f 20.8172 53i 17.2003 59i 19.0489 64! 20.8574 53s 17.2405 59t 19.0891 65 20.8975 53f 17.2807 59i 19.1293 6 5 J 20.9377 53l 17.3209 59f 19.1695 65i 20.9779 54 17.3610 59f 19.2097 6 5 f 21.0181 54i 17.4012 59! 19.2499 6 5 i 21.0583 54i 17.4414 60 19.2900 65! 21.0985 54l 17.4816 6o| 19.3302 6 5 f 21.1387 54i 17.5218 6oJ 19.3704 6 5 I 21.1789 541 17.5620 6of 19.4106 66 21.2190 54f 17.6022 6oi 19.4508 66| 21.2592 54! 17.6424 6of . 19.4910 66i 21.2994 55 17.6825 6of 19-5312 66f 21.3396 sst 17.7227 6o| I9.57U 66^ 21.3798 ssf 17.7629 61 19.6115 66f 21.4200 ssl 17.8031 6ii 19.6517 66f 21.4602 55i 17.8433 6il 19.6919 66! 21.5004 ssl 17-8835 COMPARISON OF VALUE ' OF SILVER 47 COMPARISON OF VALUE OF SILVER IN OUNCES TROY AND KILOGRAMS When Silver is Worth in New York Per Oz. i Kilo, is Worth U. S. Currency When Silver is Worth in New York Per Oz. i Kilo, is Worth U. S. Currency When Silver is Worth in New York Per Oz. i Kilo, is Worth U. S. Currency 67 cts. $21.5405 72! cts. $23.3892 82 cts. $26.364 6;i 21.5807 72j 23.4294 82i 26.444 67! 21.6209 73 23-4695 82| 26.524 67! 21.6611 73* 23.3097 82i 26.605 67^ 21.7013 73i - 23-5499 83 26.685 67! 21.7415 73l 23.5901 83i 26.765 67! 21.7817 73i 23.6303 83^ 26.846 67! 21.8219 731 23.6705 83f 26.926 68 21.8620 73f 23.7107 84 27.007 67i 21.9022 73J 23-7509 84i 27.087 67i 21.9424 74 23.7910 84^ 27.167 68f 21.9826 74i 23-83I5 84! 27.248 68 22.0223 74i 23.8720 85 27.328 68| 22.0630 74! 23.9120 85i 27.408 68f 22.1032 M 23.9520 85* 27.489 681 22.1434 74f 23-9925 85! 27.569 69 22.1835 Hi 24.0330 86 27.650 6 9 i 22.2237 741 24.0730 861 27.730 6 9 | 22.2639 75 24.1130 86^ 27.810 6 9 f 22.3041 75i 24.1930 86f 27.891 69} 22.3443 75^ 24.2740 87 27.971 69! 22.3845 75i 24.3540 87i 28.052 69! 22.4247 76 24-4350 87l 28.132 69! 22.4649 76t 24.515 87f 28.212 70 22.5050 76^ 24-595 88 28.293 7oi 22.5452 76f 24.676 88i 28.373 7oi 22.^854 77 24.756 88^ 28.453 7of 22.6256 77i 24.836 88f 28.533 7o 22.6658 77i 24.917 89 28.614 7o| 22.7060 77f 24.997 89^ 28.695 7of 22.7462 78 25.078 89^ 28.775 7of 22.7864 78i 25-158 8 9 f 28.855 7i 22.8265 78 25-238 90 28.936 71* 22.8667 78f 25.3I9 9oi 29.016 m 22.9069 79 25.399 9} 29.096 7if 22.9471 79t 25-479 9of 29.177 74 22.9873 79^ 25.560 9i 29.257 7if 23.0275 79f 25.640 9ii 29.338 7if 23.0677 80 25.721 94 29.418 7if 23.1079 8o| 25.801 9if 29.498 72 23.1480 8oi 25.881 92 29.579 72i 23.1882 8of 25.962 9*4 29.659 7*f 23.2248 81 26.042 9 2 i 29.739 72f 23.2686 8ii 26.122 92! 29.820 725 23.3088 8^ 26.203 72| 23-3490 8i-2- 26.283 CYANIDE DATA COMPARISON or VALUE OF SILVER IN OUNCES TROY AND KILOGRAMS When When When Silver is i Kilo, is Silver is i Kilo, is Silver is i Kilo, is Worth in Worth U. S. Worth in Worth U. S. Worth in Worth U. S. New York Currency New York Currency New York Currency Per Oz. Per Oz. Per Oz. 93 Cts. $29.900 95i cts. $30.704 98 31.508 93i 29.981 95f 30.784 981 3L588 93* 30.061 96 30.865 98i 31.668 93f 30.141 96i 30.945 98f 31-749 94 30.222 96 3I-025 99 31.829 941 30.302 96! 31.106 99i 31.910 94i 30.382 97 31.186 99i 31.990 94t 30-463 97i 31.267 991 32.070 95 30-543 97* 31-347 100 32.151 95i 30.624 97f 3I-427 AREA i square millimeter = i square centimeter = i square decimeter = i square meter or centare = i square decameter = i hectare = i square kilometer i square myriameter .001550 sq. in. .155003 sq. in. 15.503 sq. in. 10.764101 sq. ft. .024711 acre. 2.47110 acres. 247.110 acres. 38.61090 sq. miles. VOLUME i cubic centimeter = i centiliter i deciliter i liter i decaliter i hectoliter = i kiloliter = i myrialiter .0610254 cu. in. .610254 cu. in. 6.10254 cu. in. 61.0254 cu. in. .353156 cu. ft. 3.53156 cu. ft. 35.3156 = 353- x 56 cu. ft. ABBREVIATIONS USED IN METRIC SYSTEM milligram = mg. cubic centimeter centigram = eg. centiliter deciliter liter decaliter hectoliter cubic meter decigram = dg. gram = g. decagram = Dg. hectogram = Hg. kilogram = Kg. myriagram = Mg. myrialiter Quintal = Q. : cc. *millimeter = mm. = cl. *centimeter = cm. dl. *decimeter = dm. ' 1. *meter = m. Dl. *decameter = Dm. HI. *hectometer = Hm. = cm. *kilometer = Km. = Me. *myriameter = mm. * In measures of area, these abbreviations take the prefix "sq." UNITED STATES WEIGHTS AND MEASURES 49 WEIGHTS AND MEASURES USUAL IN THE UNITED STATES TROY WEIGHT APOTHECARIES WEIGHT 24 grains = i pennyweight (dwt.) 20 grains = i scruple. 20 pennyweights = i ounce (oz.) 3 scruples = i dram. 12 ounces = i pound (Ib.) 8 drams = i ounce. 12 ounces = i pound. AVOIRDUPOIS WEIGHT 2 7-34375 grains = i dram. 1 6 drams = i ounce (oz.) 16 ounces = i pound (Ib.) 28 pounds = i quarter 4 quarters = i hundredweight (cwt.) 20 hundredweight = i ton. i stone = 14 pounds, i quintal = 100 pounds i short ton = 2000 pounds, i long ton = 2240 pounds. In Troy, Apothecaries and Avoirdupois weight, the grains are the same. LENGTH 12 inches 3 feet 6 feet 66 feet 10 chains foot. yard. fathom. chain. furlong. 8 furlongs = i mile = 5,280 feet. AREA 144 square inches = square foot. 9 square feet = 30^ square yards = An nprrhes = 3H ( -"* i '- . perches 4 roods 640 acres square yard, perch, rood, acre, square mile. VOLUME 1728 cubic inches = i cubic foot. 27 cubic feet = i cubic yard. 1 cord of wood =128 cubic feet or 8X4X4 feet. LIQUID DRY 4 gills = i pint. 2 pints = i quart. 2 pints = i quart. 4 quarts = i gallon. 4 quarts = i gallon. 2 gallons = i peck. 31^ gallons = i barrel. 4 pecks = i bushel. 63 gallons = i hogshead. 2 hogsheads = i pipe. 2 pipes = i tun. CYANIDE DATA TABLE i Marco i Troy ounce i Troy ounce i Avoirdupois ounce = 1000 Kilograms i ton avoirdupois = i pound avoirdupois = i ton avoirdupois = i Gram = OF EQUIVALENTS 7.39864 troy ounces. 31.10348 grams. 430.00000 grains troy. 28.3495 grams. 2204.62 pounds avoirdupois. 907.1849 kilograms. 453.59242 grams. 29166.67 Troy ounces. 15.43236 grains Troy. TO CONVERT Oz. troy per av. ton Oz. troy Oz. troy Oz. avoirdupois Lbs. avoirdupois Metric tons Kilos per metric ton Kilograms Kilograms Grams Tons avoirdupois Tons metric Millimeters Centimeters Meters Meters Meters Kilometers Kilometers Square millimeters Square centimeters Square meters Square kilometers Hectara Cubic centimeters Cubic centimeters Cubic centimeters Cubic meters Cubic meters Cubic meters Liters Liters Liters CONVERSION TABLE INTO Kilos per metric ton Oz. avoirdupois Kilograms Oz. troy Kilograms Av. tons 2000 Ibs. Oz. troy per av. ton Lbs. av. Troy oz. Troy oz. Tons metric Tons avoirdupois Inches Inches Inches Feet Yards Miles Feet Sq. inches Sq. inches Sq. feet Acres Acres Cubic inches Fluid drams Fluid ounces Cubic feet Cubic yards Gallons Cubic inches Gallons Fluid ounces MULTIPLY BY 0.034286 1.09714 0.03110348 0.911457 0.45359243 I.I023I 29.166 2.20462. 32.15074 0.032150 .9071849 I.OI23I 0.03937 0-3937 39-37 3.281 1.094 .621 3280.7 0.0155 o.i55 10.764 247.1 2.471 16.383 3-69 29.57 35.315 1.308 264.2 61.022 .2642 33.84 INTERNATIONAL ATOMIC WEIGHTS INTERNATIONAL ATOMIC WEIGHTS, 1910 Symbol Atomic Weight Symbol Atomic Weight Aluminum . . . Antimony .... Argon Al Sb A 27.1 120.2 -2Q Q Molybdenum .... Neodymium Neon Mo Nd Ne 96.0 144-3 20. o Arsenic As 7/1 n6 Nickel Ni S8.68 Barium Ba 137.37 Nitrogen .... N 14.01 Bismuth Bi 208 o Osmium Os IOO.Q Boron B II. O Oxygen O 16.00 Bromine Br 7Q Q2 Palladium Pd. 106.7 Cadmium .... Caesium Cd Cs 112.40 I32.8l Phosphorus Platinum . P Pt 31.0 IQC.O Calcium Carbon Cerium Ca C Ce 40.09 12.00 140.25 Potassium Praseodymium . . Radium K Pr Ra 39.10 140.6 226.4 Chlorine Cl 3^.46 Rhodium Rh 102.9 Chromium Cr ^2 O Rubidium Rb 8q.4S Cobalt Co =58.07 Ruthenium Ru 101.7 Columbium . . . Cb 93-5 Samarium Sa 150.4 Copper Cu 63.^7 Scandium Sc 44.1 Dysprosium . . Dy 162.5 Selenium Se 79.2 Erbium Er 167.4 Silicon Si 28.3 Europium . Eu I ^.O Silver Ag 107.88 Fluorine F 19.0 Sodium . Na 23.00 Gadolinium . . . Gd 157.3 Strontium Sr 87.62 Gallium Ga 69.9 Sulphur s 32.07 Germanium . . Ge 72.5 Tantalum Ta 181.0 Glucinum ..-'. . Gold Gl Au 9.1 197.2 Tellurium Terbium Te Tb 127-5 159.2 Helium He 4 o Thallium Tl 204.0 Hydrogen H 1.008 Thorium Th 232.42 Indium In 114 8 Thulium Tm i68x Iodine I 126.92 Tin Sn 119.0 Iridium Ir 103. 1 Titanium Ti 48.1 Iron . . Fe ^ 8^ Tungsten W 184.0 Krypton Kr 83.0 Uranium u 238.5 Lanthanum . . . La 139.0 Vanadium . . . V 51.2 Lead Lithium Lutecium .... Magnesium . . . Pb Li Lu Mg 207.10 7.00 174.0 24.32 Xenon Ytterbium (Neoytterbium) Yttrium Xe Yb Yt 130.7 172.0 89.0 Manganese . . . Mercury Mn Hg 54-93 200. o Zinc Zirconium Zn Zr 65.37 90.6 * A new element has been reported discovered at the University of Tokio. It has been called nipporium, symbol Np, atomic weight 100. It exists in the rare mineral thorite, in which it occurs as a yellow or red crystal hard enough to cut glass These crystals are a double silicate of nipporium and zirconium. CYANIDE DATA SPECIFIC GRAVITY OF SOME GASES USING AIR AS STANDARD Name of Gas Symbol Sp. Gr. Air I OOOO Carbonic acid CO 2 I ^20 Sulphureted hydrogen H S I OOI 2 Olefiant . . C 2 H 4 o?8 Carbonic oxide CO .067 Steam H 2 O 623 s Marsh gas CH 4 crn Oxygen . o 1.1056 Nitrogen N O71 1 Hydrogen H .06926 CAPACITY OF ROUND TANKS Diameter in Feet Inside Contents in Cubic Feet For Each Foot Depth Capacity in Lbs. Water For Each Foot in Depth 5 I9-635 1,227.18 6 28.274 1767.12 7 38.485 2495-3I 8 50.266 3141.62 9 63.617 3976.06 10 78.540 4908.75 12 113.100 7068.75 15 176.710 11,044.37 18 254.470 15,904.37 20 314.160 19,635.00 22 380.130 23,758.12 25 490.870 30,679.37 26 530-930 33,232.12 28 6I5-750 38,484.37 3 706.860 44,178.75 32 804.250 50,265.62 34 907.920 57,045.00 35 962.110 60,131.87 36 1017.880 63,587.50 38 1134.110 70,881.87 40 1256.640 78,540.00 42 1385.440 86,590.00 44 1520.530 95,033.12 45 1590.430 99,401.87 46 1661.900 103,868.75 48 1809.560 113,097.50 So 1963.500 122,718.75 METALS IN KCN SOLUTIONS 53 ELECTRO-MOTIVE SERIES OF METALS AND MINERALS IN KCN SOLUTIONS PROF. S. B. CHRISTY, TRANS. AM. INST. MIN. ENG. SEPT., 1899 KCN = 6.5% Volts Ttf KCN - 0.65% Volts if o KCN = 0.065% Volts T O w es oi co co -"tf- to too t->- t^-od ON d O M > 3*^ (N *" * w t^-00 OO ON C> O M ! t^-^-^-^^t-^-' 5 t T t^-^^- < ^-'^' ! t'=t-' ( t^-^-'^-^-^-to ^ Q^S co^Mdcx)^Ndtoio^coc^MddoNodi>.t^\dtoio'. o^ 1 " , & ' ij 2rt >Q O CO NO ^ w O CO CO O ^O ^^t'^'^'^t"''t'Tj-Tt'^O CO CO _^^,.. __MCSCO^ -T J' 1O !> i>CO ON O IH (N CO TJ- tovd t^-CO O H g ^-s^-s p^ p^ w <5^^ o S *n"C S ^ iOO t^ONO w co^O f^ONO * J O t>> D O O COCO CO C^ O t^ COCO i>- to ON "^ IH CO O O CS CO CO '-9 1 EH J^ g O H M t^" O O ^CO O O O 1-1 t^O ON ^}" O ONCO ON O O O 4) ^ rl " ^ H ^^ ^ ^ "^ W ^^ ^~ S ^"^^ co i? 2 ^^ * "* * ^ W +> "S r -COCO O*d\C) O u ^,^0, OO*-iM(NcOcOTh to tOO *^ t^-CO ONO*O *-* ^ ^ cO 1 ^" 1 qqqqqqqqqqqqqqqqMMHMMMf O M CS CO ^ lOO t^OO ON O M W PO ^ toO t^OO ON O H ( "cZ WEIGHTS AND VOLUMES OF SLIME PULP 59 ON O M CN co ^ lOO f>- O\ O M CM T}- iO*O C/6 O\ M CN ^ 10 t^. ON O -''''''' < ' vO *>- o u-> M o O vOiOV5iOiOiOiOiOiOiOioOVO 1/ ^ V O ^OOOO^OvOOOvOvOO t^- q 10 ON focx) rooq cooq roq^-^qo d ^ ^- to t^ <> M ^O^t^O^nL ro^O MMMMCSCSWC^CNC^CVl^rOCOCOCOfO'^-'^-'^l-^l-'^ . *O 1/5 OO OO CO CO Q^ M CO IOOO OONONO^O\O\i-i M COd O w M CN c-i cococo^-'^-iouovovo t>-r^.co c>d\d oq M co ^ooo q fo ^oo q ^90 o M ^f^ ^ ^^-2 9 ! ^^ M ^9 ^7" 9 ^7 O - M M O O O O O\CXD OO i-tM(Nco'^-rt to\o r^-co GOOOwcu p < ^" ^o iotoior}-TJ-'^-TJ-Tt - cocococococs -r^cx5 ON C> O O w co M O O-.OO r^vO O 10 10 to 10 to too t- t-^CO ^ M 5.5 to 6.0 Magnetite (iron oxide) 4.9 to 5.2 Pyrite (iron bisulphide) 4.8 to' 5. 2 Marcastite (iron sulphide) 4.6 to 4.8 ZINC Smithsonite (zinc carbonate) 4.4 to 4.4 Sphalerite (zinc blende) 3.9 to 4.2 Willemite (zinc silicate) ' 3.9 to 4.1 GANGUE Barite (heavy spar) 4.3 to 4.7 Manganese Garnet 4.1 to 4.5 Iron Garnet 3.9 to 4.4 Lime Garnet 3.4 to 3.5 Fluorite (Fluorspar) 3.0 to 3.2 Anhydrite (Gypsum) 2.8 to 2.9 Dolomite (magnesian limestone) 2.8 to 2.9 Quartz 2.5 to 2.8 Calcite (lime carbonate) 2.5 to 2.7 Kaolinite (Kaolin) 2.4 to 2.6 62 CYANIDE DATA METALLIC CONTENTS or PURE ORES Magnetite (magnetic iron ore) Iron, 72.0 per cent. Hematite (red oxide of iron) Iron, 70.0 per cent. Iron Pyrite Iron, 46.6 per cent. Cuprite (red oxide of copper) Copper, 88.8 per cent. Malachite (green carbonate of copper) . . Copper, 62.0 per cent. Az.urite (blue carbonate of copper) Copper, 61.0 per cent. Bornite (purple or peacock copper) Iron, 15 per cent.; Copper, 58.0 per cent. Chalcopyrite (copper pyrite) Iron, 30 per cent.; Copper, 34.0 per cent. Chalcocite (copper glance) Copper, 78.0 per cent. Galena (lead sulphide) Lead, 86.6 per cent. Cerussite (lead carbonate) Lead, 70.0 per cent. Zinc Blende (zinc sulphide) Zinc, 67.0 per cent. WEIGHTS OF FLAT STEEL PER LINEAL FOOT Width in 1 1 Inches 1 Thickness in Inches A i i 3 B i I 5 B 1 i 1 f 1 i I .21 43 638 .850 i. 06 .28 i-49 1.70 2.12 2-55 2.98 ii .24 48 .720 955 1.20 43 1.68 1.92 2-39 2.87 3-35 3.88 ij .27 53 797 i. 06 i-33 59 1.86 2.12 2.65 3-i9 3-72 4.25 it 30 59 875 1.17 1.46 .76 2.05 2-34 2.92 3-51 4.09 4.68 ii 32 .64 957 1.28 i-59 .92 2.23 2-55 3.19 3-83 4-47 5.10 if 35 .69 1.04 1-38 1-73 2.08 2.42 2.77 3-46 4.15 4-84 5-53 if 38 75 i. ii i-49 1.86 2.23 2.60 2.98 3-72 4-47 5.20 5-95 2 43 85 1.28 1.70 2.12 2-55 2.98 3-40 4.25 5.10 5-95 6.80 2i .48 .96 i-44 1.91 2-39 2.87 3-35 3-83 4.78 5-75 6.69 7.65 2 i 53 .06 i-59 2.12 2.6 5 3-i9 3-72 4-25 5-31 6.38 7-44 8.50 2 t 59 17 i-75 2-34 2.92 3-5i 4.09 4.67 5.84 7.02 8.18 9-35 3 .64 .28 1.91 2-55 3-19 3-83 4.46 5.10 6.38 7-65 8-93 IO.2O 3i .69 38 2.07 2. 7 6 3-45 4-i5 4-83 5-53 6.91 8.29 9.67 11.05 3| 75 49 2.23 2.98 3-72 4-47 5.20 5-95 7-44 8-93 10.41 II.9O 31 .80 .60 2-39 3-19 3-99 4.78 5-58 6.38 7-97 9-57 ii. 16 12-75 4 85 .70 2-55 3-40 4-25 5.10 5-95 6.80 8.50 IO.2O 11.90 13.60 4i .96 .92 2.87 3.83 4.78 5-74 6.70 7.65 9-57 11.48 13-39 I5.30 5 1.07 2.13 3-i9 4.25 5-3i 6.38 7-44 8.50 10.63 12-75 14-87 I7.OO 5i 1.17 2-34 3-5i 4.67 5-84 7.02 8.18 9-35 11.69 14.05 16.36 18.70 6 1.28 2-55 3-83 5.10 6.38 7<6 5 8-93 10.20 12.75 I5-30 17-85 2O.4O 7 i-49 2.98 4.46 5-95 7-44 8-93 10.41 II.9O 14.87 17.85 20.83 23.80 8 1.70 3-40 5.10 6.80 8.50 IO.2O 11.90 13.60 17.00 2O.4O 23.80 27.2O WEIGHTS AND GRAVITIES OF MATERIALS 63 WEIGHT AND SPECIFIC GRAVITY or VARIOUS MATERIALS Material Weight per Cubic Feet Average Pounds Specific Gravity Average Brick common I oo to 125 1.6 to 2 Brick pressed 1 3 J. 2 16 Brick fire ISO 2.4 Brickwork in mortar no Brickwork in cement 112 Cement Portland, loose . 78 Cement Rosendale loose 60 Clay no I.Q Coal anthracite Q2 1? T < Coal, bituminous 8A I.7C Coal cannel 7O I 272 Coke 46 Concrete, in cement 137 2 2 Concrete, ordinary I IO I O Earth 77 tO I 2 S IS 2 1"O "2 Galena 6 1 to 7 C Granite, gray l63 2 6 2 Granite, red i6s 2 62 Gypsum . . IA3 2 286 Iron pyrites 4tT to C C J^imestone 168 o tu 5-5 2 7 Lime, quick r? RA-J Marble 168 2 7 Masonry, ashlar. 1 60 Masonry, rubble 1 80 Mortar, average 1 06 I 7 Quartz . . i6s 2 6^ Sand, river 117 i 88 Sand, coarse ... IOO i 6n Sandstone I SO 2 A Silica 2 S Slate, American . I7S 2 8 Slate, Welsh . 1 80 2 88 Sulphur 12 S 2 64 CYANIDE DATA WEIGHT AND SPECIFIC GRAVITY OF LIQUIDS Specific Gravity Weight Per Cubic Inch Pounds Weight Per Gallon Pounds Water, distilled, 60 degrees Fahrenheit ... i. Water, sea 1.03 Water, Dead Sea 1.24 Acid, Acetic 1.062 Acid, Nitric 1.217 Acid, Sulphuric 1.841 Acid, Muriatic 1.2 Alcohol, pure 792 Alcohol, proof 916 Alcohol of commerce 833 Oil, Linseed 940 Oil, Olive 915 Oil, Turpentine 870 Oil, whale 923 Petroleum 878 .036 037 045 .038 .044 .067 043 .029 033 .030 034 033 .031 033 .032 8-35 8-55 10.4 8.78 10.16 15-48 9-93 6.7 7.62 6-93 7.85 7.62 7.16 7.65 7-39 WEIGHTS AND GRAVITIES OF MATERIALS 65 WEIGHT AND SPECIFIC GRAVITY or METALS Metal Specific Gravity Range According to Several Authorities Specific Gravity Approx. Mean Value Used in Calcula- tion of Weight Weight Per Cubic Foot Pounds Weight Per Cubic Inch Pounds Aluminum 2.56 to 2.71 2.67 166.5 .0963 Antimony 6.66 to 6.86 6,76 421.6 .2439 Bismuth Brass: Copper, Zinc ] 80 20 70 3PJ .... 60 40 1 Bronze! {t n PP-'V} Cadmium 9.74 to 9.90 7.8 to 8.6 8.25 to 8.96 8.6 to 8.7 9.82 8.60 8.40 8.36 8.20 8.853 8.65 612.4 536.3 523.8 521.3 5II-4 552. 539. 3454 3103 3031 .3017 2959 3195 .3121 Calcium 1.58 Chromium . 5.0 Cobalt 8.5 to 8.6 Gold, pure 19.245 to 19.361 19.258 1200.9 .6949 Copper 8.69 to 8.92 8.853 552. .3195 Iridium 22,38 to 23. 1396. .8076 Jron, cast 6.85 to 7.48 7.218 450. .2604 Iron wrought 7.4 to 7.9 7.70 480. .2779 Lead 11.07 to 11.44 11.38 709.7 .4106 Manganese 7. to 8. 8. 499. .2887 Magnesium 1.69 to 1.75 1.75 109. .0641 f ^2 . 13.60 to 13.62 13.62 849.3 .4915 Mercury { 60 13.58 13.58 846.8 .4900 [ 212 f 13.37 to 13.38 13.38 834.4 .4828 Nickel 8.279 to 8.93 8.8 548.7 .3175 Platinum 20.33 to 22.07 21.5 1347. .7758 Potassium 0.865 Silver : . . . . 10.474 to 10.511 10.505 655.1 .3791 Sodium O O7 Steel 7 60 tO 7 O32 7.8^4 489.6 .2834 Tin 7.291 to 7.409 7.350 458.3 .2652 Titanium r 3 Tungsten 17 to 17.6 Zinc . . 6.86 to 7. 20 7. 4.36.< .2526 In the first column of figures the lowest are usually those of cast metals, which are more or less porous; the highest are of metals finely rolled or drawn into wire. 66 CYANIDE DATA JOISTS, SCANTLINGS AND TIMBER CONTENTS IN FEET Size, Inches Lengths 10 12 14 16 18 20 22 24 I X 10 S 10 "f 13* 15 i6 i8J 20 I X 12 IO 12 H 16 18 20 22 24 I X 14 nf 14 i6| i8| 21 23*' 25! 28 I X 16 13* 16 i8| 21* 24 26| 29* 32 ijX 8 8| 10 iif I3i 15 i6f i8i 20 ii X 10 IT 5 I M| i*A i6f i8f 20| tfi 2 5 ii X 12 J 15 171 20 22i 25 27i 30 ii X 6 7i 9 xoj 12 I3i 15 i6i 18 ii X 8 IO 12 14 16 18 20 22 24 ii x 10 wl 15 i7i 20 22* 25 ?i 30 ii X 12 15 1 8 21 24 27 30 33 36 2 X 4 61 8 9* io| 12 i3i I4 16 2 X 6 10 12 14 16 18 20 22 24 2X8 13* 16 i8f 21* 24 26f 29* 32 2 X 10 i6f 20 23* 26f 30 33i 36f 40 2 X 12 20 24 28 32 36 40 44 48 2 X 14 23i 28 32 37i 42 46f 5ii 56 2 X 16 26f 32 37i 42 48 53i 58! 64 2i X 12 25 30 35 40 45 50 ' 55 60 2^ X 14 29* 35 4of 46f 52^ 58* 64^ 70 2i X 16 33i 40 46f 53i 60 66f 73* 80 3X6 15 18 21 24 27 30 33 36 3X8 20 24 28 32 36 40 44 48 3 X 10 25 30 35 40 45 50 55 60 3 X 12 30 36 42 48 54 60 66 72 3 X 14 35 42 49 56 63 70 77 84 3 X 16 40 48 56 64 72 80 88 96 4X4 13* 16 i8f 21* 24 26f 29i 32 4X6 20 24 28 32 36 40 44 48 4X8 4 X 10 26f 33i 32 40 37i 46f 42 53i 48 60 53! 66f 58! 73i 64 80 4 X 12 40 48 56 64 72 80 88 96 4 X 14 46! 56 65i 74f 84 93i I02 112 6X6 30 36 42 48 54 60 66 72 6X8 40 48 56 64 72 80 88 96 6 X 10 So 60 70 80 90 IOO no 1 2O CONTENTS OF TIMBER, IN FEET 67 JOISTS, SCANTLINGS AND TIMBER CONTENTS IN FEET Continued Size, Inches Lengths 18 24 6 X 12 60 72 84 96 1 08 120 132 144 6 X 14 70 84 98 112 126 I4O 154 168 6 X 16 80 96 112 128 144 1 60 176 192 8X8 531 64 74 85i 96 io6 H7l 128 8 X 10 66f 80 93i io6| 1 20 i33i 146! 160 8 X 12 80 96 114 128 144 1 60 176 192 8 X 14 93i 112 130! i49i 168 i86f 205^ 224 10 X 10 83* IOO n6f i33i 150 i66f 183* 200 10 X 12 100 120 140 1 60 180 200 220 240 10 X 14 n6f I4O i6 3 J i86f 2IO 233i 256! 280 10 X 16 i33i 1 60 i86f 213* 240 266f 2931 320 12 X 12 1 20 144 168 192 216 240 264 288 12 X 14 140 168 196 224 252 280 308 336 12 X 16 1 60 192 224 256 288 320 352 384 14 X 14 i6 3 i 196 228f 261} 294 326! 359i 392 14 X 16 i86f 224 26l| 2 9 8| 336 373? 4iof 448 CYANIDE DATA TABLE SHOWING THE RELATIVE VOLUMES OF COMPRESSED AIR AT VARIOUS PRESSURES Volume of Volume of Gage Pressure Pounds Free Air Correspond- ing to One Cubic Foot of Air Correspond- ing Volume of One Cubic Foot of Free Air at Given Gage Pressure Pounds Free Air Correspond- ing to One Cubic Foot of Air at Correspond- ing Volume of One Cubic Foot of Free Air at Given at Given Pressure Given Pressure Pressure Pressure O I.OO I.OO 70 5.762 1735 I 1.068 .9356 75 6.102 .1638 2 1.136 .8802 80 6.442 .1550 3 1.204 8305 85 6.782 .1474 4 1.273 .7861 90 . 7.122 .1404 5 i-34 .7462 95 7.462 .1340 10 1.68 5951 IOO 7.802 .1281 15 2.02 .4949 no 8.483 .1178 20 2.36 .4236 120 9.170 .1090 25 2.7 3703 I 3 9-843 .1016 30 3-04 .3288 I4O 10.52 .0950 35 3.38 2957 150 11.20 .0892 40 3-72 .2687 1 60 11.88 .0841 45 4.06 .2462 170 12.56 .0796 50 . 4-40 .2272 1 80 13.24 0755 55 4-74 .2109 190 13.92 .0712 60 5.08 .1967 2OO 14.60 .0684 65 5-42 .1844 TABLE OF AIR COMPRESSIONS 69 TABLE SHOWING HORSE-POWER DEVELOPED TO COMPRESS 100 CUBIC FEET FREE AIR FROM ATMOSPHERE TO VARIOUS PRESSURES Gage Pressure Pounds One-stage Compression D. H. P. Gage Pressure Pounds Two-stage Compression D. H. P. Four-stage Compression D. H. P. IO 3-60 60 11.70 10.80 15 5.03 80 13.70 12.50 20 6.28 100 15.40 14.20 25 7.42 200 2 1. 2O 18.75 30 8.47 300 24.50 2 1. 80 35 9.42 400 27.70 24.OO 40 10.30 500 29-75 25.90 45 11.14 600 31.70 27.50 50 11.90 700 33-50 28.90 55 12.67 800 34-90 30.00 60 I3-4I 900 36.30 31.00 70 14.72 IOOO 37.80 31.80 80 15-94 1200 39-70 33.30 90 17.06 I6OO 43-oo 35.65 TOO 18.15 2OOO 45-50 37.80 25OO 39.06 3000 40.15 The above table does not take into consideration jacket-cooling or friction of machine. Initial temperature of air at beginning of each compression is 60 degrees. CYANIDE DATA CIRCUMFERENCES AND AREAS OF CIRCLES E 9 3 Circum. Area. 8 d 5 Circum. Area | 3 Circu . Area A .1963 .00307 8 25.132 50.265 55 172.788 2375.83 1 .3927 .01227 9 28.274 63.617 56 175.929 2463.01 ft .5890 .02761 10 31.416 78.540 57 179.071 255I-76 i .7854 .04909 ii 34.558 95.033 58 182.212 2642.08 A .9817 .07670 12 37.699 113.097 50 185.354 2733-97 f 1.1781 .1104 13 40.840 132.732 60 188.496 2827.43 A 1-3744 .1503 14 43.982 I53.938 61 191.637 2922.47 i 1.5708 .1963 15 47.124 176.715 62 194.779 3019.07 * I.777I .2485 16 50-265 201.062 63 197.920 3H7.25 I-9635 .3068 17 53407 226.980 64 201.062 3216.99 H 2.1598 .3712 18 56.548 254.469 65 204.204 33I8.3I 1 4 2.3562 .4418 19 59.690 283.529 66 207.345 3421. IQ H 2.5525 .5185 20 62.832 314.160 67 210.487 3522.66 i 2.7489 .6013 21 65.973 346.361 68 213.628 3631.68 if 2.9452 .6903 22 69.115 380.133 69 216.770 3739-28 I 3.1416 .7854 23 72.256 415.476 70 219.912 3848.45 iA 3-3379 .8866 24 75.398 452.390 7i 223-053 3969.19 1 1 3-5343 .9940 25 78.540 490.875 72 226.195 4071.50 iA 3.7306 1.1075 26 81.681 530.930 73 229.336 4185.39 il 3.9270 1.2271 27 84.823 572.556 74 232.478 4300.84 iA 4.1233 i.353o 28 87.964 615.753 75 235.620 4417.86 if 4.3197 1.4848 29 91.106 660.521 76 238.761 4536.46 'A 4.5160 1.6229 30 94.248 706.860 77 241.903 4656.63 1 5 4.7124 1.7671 31 97-389 754.769 78 245.044 4778.36 I I 5-1051 2.0739 32 100.531 804.249 79 248.186 4901.68 If 5-4978 2.4052 33 103.672 855.30 80 251.328 5026.55 II 5-8905 2.7611 34 106.814 907.92 81 254.469 5153-00 2 6.2832 3.1416 35 109.956 962.11 82 257.6ll 5281.02 2i 6.6759 3-5465 36 113.097 1017.88 83 260.752 54IO.6I 2f 7.0686 3.976o 37 116.239 1075.21 84 263.894 554L77 2 f 7.4613 4.4302 38 119.380 1134.11 85 267.035 5674.5I 2f 7.8540 4.9087 39 122.522 1194.59 86 270.177 5808.80 2! 8.6394 5.9395 40 125.664 1256.64 87 273.319 5944.68 3 9.4248 7.0686 4i 128.805 1320.25 88 276.460 6O82.I2 3 f IO.2IO 8-2957 42 I3L947 I385-44 89 279.602 6221.14 3 I 10.995 9.6211 43 135.088 1452.20 90 282.744 6361.73 3i II.78I 11.044 44 138.230 1520.53 9i 285.885 6503.88 4 12.566 12.566 45 141.372 1590.43 92 289.027 6647.61 4l I3.35I 14.186 46 144-513 1661.90 93 292.168 6792.91 4 1 14.137 15.904 57 I47.655 1734-94 94 295.310 6939.78 4l 14.922 17.720 48 150.796 1908.56 95 298.452 7088.22 5 15.708 19-635 49 153.938 1885.74 96 301.593 7238.23 S f 16.493 21.647 50 157.080 1963.50 97 304-734 7389.81 sl 17.278 23-758 5i 160.221 2042.82 98 307-876 7542.96 5f 18.064 25-967 52 163.363 2123.72 99 311.018 7697.69 6 18.849 28.274 53 166.504 2206.18 100 314.159 7853.98 7 21.991 28.484 54 169.646 2290.22 DIFFERENT STANDARDS FOR WIRE GAGES DIMENSIONS IN DECIMAL PARTS OF AN INCH Number of Gage American or Brown & Sharpe Birm- ingham or Stubs Iron Wire Wash- burn & Moen Mfg. Co Trenton Iron Co. Stubs' Steel Wire Impe- rial Wire Gage u. s. Standard for Plate oooooo .464 .46871; ooooo ACQ 432 '<+*"-'/ j 437C oooo .46 .ACA .30^8 .400 '^TO .400 TO/ j .40625 ooo .40964 TOT 1 .4.2C o yo^ .162% .360 272 37> pO*. Width of Belt, in Inches 2 3 4 5 I 6 8 IO 12 HTF 14 16 H.P 18 20 22 H.P. H.P. H.P. H.P. H.P H.P. H.P H.P H.P H.P. 6 44 65 76 .87 1.09 127 I-3I 8 5 1 fi-7 16 T A. C J *53 j 7 r 9 65 .98 3i 1.64 1.97 __ __ 10 73 1.09 45 1.81 2.18 1 1 8 I 2 5 2 2 A 87 2 l8 2 62 .07 ft C "3 -75 i 89 14 95 I. O2 1.52 2.02 2.53 3.05 _ __ T C T on I 64 2 IQ 2 7-2 7 2O 16 T 7 .16 1.74 i 8c 2.32 2.91 3.48 *7 18 4 i 06 2.47 2 62 3-9 327 3-7 39 2.07 2.76 2 1 3-45 4.14 _ _ 20 o T 8 2 OI 3f\A 476 2 1 C2 7 82 4r Q 22 6 2 4 7 2 6" 2 C I 37 C 4 18 5 O2 24 35 3-5 4-4 .02 5-2 7- 8-7 10.5 12.2 14. 16. 17- IQ. 25 3-6 4-5 5.5 7-3 9.1 10.9 12.7 14.5 26 3-8 4-7 5-7 7.6 9-5 11.3 13.2 I5-I 27 3-9 4-9 5.9 7-8 9.8 n.8 13-7 15-6 28 4.1 5.1 6.1 8.1 IO.2 12.2 14.3 16.3 29 4.2 5-3 6-3 8.4 iP-5 12.6 14.8 16.9 30 4.4 5-4 6.6 8-7 10.9 I3-I 15.3 17.4 IQ. 22. 24. 31 4-5 5-6 6.8 9- 11.3 13-5 15.8 18. 32 4-7 5-8 7- 9-3 n.6 14. I6..7 18.6 33 4-8 6. 7.2 9.6 12. 144 16.8 19.2 34 4.9 6.2 7-4 9-9 12.4 14.8 17.3 19.8 35 5- 1 6.4 7.6 10.2 12.7 15-3 17.9 20.4 3^ 5-2 6-5 7-8 10.5 I3.I 15-7 18.3 20.9 24. 26. 2Q. 37 5-4 6-7 8.1 10.8 13-5 16.2 i8.q 21. S 38 5-5 6.9 8-3 II.O 3-8 16.6 19-3 22.1 25- 28. 70. 39 5-7 7.1 8-5 11.3 14.2 17- IQ.Q 22.7 40 5-8 7-3 8-7 n.6 14.6 17.5 20.4 23-3 26. 2Q. 32. 42 6.1 7.6 9.2 12.2 15.3 18.2 21.4 24-3 28. 3L 34- 44 6-4 8. 9.6 12.8 16. 19.2 22.4 25-6 29. 32. 3S- 40 6-7 8-4 10. 13-4 16.8 20. i 234 26.8 48 7- 8.8 10.4 14. 17.4 21. 24.4 28. $1- 35- 78. 50 7-2 9. 10.9 14.6 18.2 21.8 25-4 29. 33- 36. 40. 54 7.8 9.8 n.8 15-6 19.6 23.6 26.4 71.2 35- 3Q. 43- 60 8.8 10.8 13-1 17.4 21.8 26.2 7.0.6 34-8 39- 44. 48. 66 9.6 12. 14.4 19.2 24. 28.8 33-6 78.4 43- 48. S3- 72 10.4 T 3- 15.6 21. 26.2 31.4 *6.6 41.8 47- C,2. S8. 78 11.4 14.2 17- 22.6 28.4 34. 3Q.8 45-4 S7- 62. 84 12.2 15.2 19-4 24.4 70.6 76.4 42.8 48.6 C.C. 61. 67. 74 CYANIDE DATA HORSE-POWER OF TURNED IRON SHAFTING As prime mover or head shaft carrying main driving pulley or gear, well supported by bearings Formula: H. P. = D 3 XR 125 Diam. Number of Revolutions per Minute of Shaft. 60 80 IOO 125 150 175 200 225 250 275 300 iH 2.6 3-4 4-3 5-4 6-4 7-5 8.6 9-7 10.7 n.8 12.9 l|-f 3-8 5.1 6.4 8. 9.6 II. 2 12.8 14.4 16. 17.6 19.2 2j\ 5-4 7-3 8.1 10. 12. 14. 16. 18. 20. 22. 24. 2 A 7-5 10. 12.5 15. 18. 22. 25- 28. 31. 34- 37- 2 H 10. 13. 16. 20. 24. 28. 32. 36. 40. 44- 48. 4} 13. 17. 20. 25- 30- 35- 40. 45- 50. 55- 60. 3T i.ooeoc > 0.99979 0.9992S 0.99847 0.9999* 0.9997C 0.99917 0.99831 I 0.9999( J 0.9996( ' 0.9990; 0.99815 5 0.9999: > 0.9995* > 0.9989i 0.9979^ J 0.9998S SI0.9994C \ 0.99876 > 0.9977e ) 0.9998 ) ,0.9993 0.99863 0.99756 89 88 87 86 4 5 6 0.99756 0.9961S 0.99452 0.99736 0.99594 0.99421 0.99714 0.99567 0.99390 0.99692 0.99540 0.99357 0.99668 0.99511 0.99324 \ 0.99644 0.99482 0.99290 0.99619 0.99452 0.99255 85 84 83 7 8 9 0.99255 0.99027 0.98769 0.99219 0.98986 0.98723 0.99182 0.98944 0.98676 0.99144 0.98902 0.98629 0.9910C 0.9885S 0.98580 0.99067 0.98814 0.98531 0.99027 0.98769 0.98481 82 81 80 10 11 12 13 0.98481 0.98163 0.97815 0.97437 0.98430 10.98107 0.97754 0.97371 0.98378 0.98050 0.97692 0.97304 0.98325 0.97992 10.97630 0.97237 0.98272 0.98218 0.98163 0.979340.978750.97815 10.97566 0.97502 0.97437 0.97169 0.97100 0.97030 79 78 77 76 14 15 16 0.97030 0.96593 0.96126 0.96959 0.96517 0.96046 0.96887 0.96440 0.95964 0.96815 0.96363 0.95882 0.96742 0.96285 0.95799 0.96667 10.96206 0.95715 0.96593 0.96126 0.95630 75 74 73 17 18 19 0.95630 0.95106 0.94552 0.95545 0.95015 0.94457 0.95459 0.94924 0.94361 0.95372 0.94832 0.94264 0.95284 0.94740 0.94167 0.95195 0.94646 0.94068 0.95106 0.94552 0.93969 72 71 70 20 21 22 23 0.93969 0.93358 0.92718 0.92050 0.93869 0.93253 0.92609 0.91936 0.93769 0.93148 0.92499 0.91822 0.93667 0.93042 0.92388 0.91706 0.93565 0.92935 0.92276 0.91590 0.93462 0.92827 0.92164 0.91472 0.93358 0.92718 0.92050 0.91355 69 68 67 66 24 25 26 0.91355 .90631 .89879 0.91236 0.90507 0.89752 0.91116 0.90383 0.89623 0.90996 0.90259 0.89493 0.90875 0.90133 0.89363 0.90753 0.90007 0.89232 0.90631 0.89879 0.89101 65 64 63 27 28 29 .89101 .88295 .87462 0.88968 0.88158 0.87321 0.88835 0.88020 0.87178 0.88701 0.87882 0.87036 0.88566 0.87743 0.86892 0.88431 0.87603 0.86748 0.88295 0.87462 0.86603 62 61 60 30 31 32 33 .86603 .85717 .84805 .83867 0.86457 0.85567 0.84650 0.83708 0.86310 0.85416 0.84495 0.83549 0.86163 0.85264 0.84339 0.83389 0.86015 0.85112 0.84182 0.83228 0.85866 0.84959 0.84025 0.83066 0.85717 0.84805 0.83867 0.82904 59 58 57 56 34 35 36 .82904 0.82741 .81915;0.81748 .80902 0.80730 0.82577 0.81580 0.80558 0.82413 0.81412 0.80386 0.82248 0.81242 0.80212 0.82082 0.81072 0.80038 0.81915 0.80902 0.79864 55 54 53 37 38 39 .79864 0.79688 .78801 0.78622 .77715 0.77531 0.79512 0.78442 0.77347 0.79335 0.78261 0.77162 0.79158 0.78079 0.76977 0.78980 0.77897 0.76791 0.78801 0.77715 0.76604 52 51 50 40 41 42 43 .76604 .75471 ! .74314 .73135 0.76417 0.75280 0.74120 0.72937 0.76229 0.76041 0.75088 0.74896 0.73924 ! 0.73728 0.72737 0.72537 0.75851 0.74703 0.73531 0.72337 0.75661 0.74509 0.73333 0.72136 0.75471 0.74314 0.73135 0.71934 49 48 47 46 44 .71934 0.71732 0.71529 0.71325 0.71121 0.70916 0.70711 45 60' 50' 40' 30' 20' 10' 0' Sine 9 o CYANIDE DATA 3. TANGENT AND COTANGENT FUNCTIONS. Tangent. Deg. 0' 10' 20 ' 30' 40' 50' 60' Deg. 2 3 0.00000 0.01746 0.03492 0.05241 0.00291 0.02036 0.03783 0.05533 0.00582 0.02328 0.04075 0.05824 0.00873 0.02619 0.04366 0.06116 0.01164 0.02910 0.04658 0.06408 0.01455 0.03201 0.04949 0.06700 0.01746 0.03492 0.05241 0.06993 89 88 87 86 4 5 6 0.06993 0.08749 0.10510 0.07285 0.09042 0.10805 0.07578 0.09335 0.11099 0.07870 0.09629 0.11394 0.08163 0.09923 0.11688 0.08456 0.10216 0.11983 0.08749 0.10510 0.12278 85 84 83 8 9 0.12278 0.14054 0.15838 0.12574 0.14351 0.16137 0.12869 0.14648 0.16435 0.13165 0.14945 0.16734 0.13461 0.15243 0.17033 0.13758 0.15540 0.17333 0.14054 0.15838 0.17633 82 81 80 10 11 12 13 0.17633 0.19438 0.21256 0.23087 0.17933 0.19740 0.21560 0.23393 0.18233 0.20042 0.21864 0.23700 0.18534 0.20345 0.22169 0.24008 0.18835 0.20648 0.22475 0.24316 0.19136 0.20952 0.22781 0.24624 0.19438 0.21256 0.23087 0.24933 79 78 77 76 14 15 16 0.24933 0.26795 0.28675 0.25242 0.27107 0.28990 0.25552 0.27419 0.29305 0.25862 0.27732 0.29621 0.26172 0.28046 0.29938 0.26483 0.28360 0.30255 0.26795 0.28675 0.30573 75 74 73 17 18 19 0.30573 0.32492 0.34433 0.30891 0.32814 0.34758 0.31210 0.33136 0.35085 0.31530 0.33460 0.35412 0.31850 0.33783 0.35740 0.32171 0.34108 0.36068 0.32492 0.34433 0.36397 72 71 70 20 21 22 23 0.36397 0.38386 0.40403 0.42447 0.36727 0.38721 0.40741 0.42791 0.37057 0.39055 0.41081 0.43136 0.37388 0.39391 0.41421 0.43481 0.37720 0.39727 0.41763 0.43828 0.38053 0.40065 0.42105 0.44175 0.38386 0.40403 0.42447 0.44523 69 68 67 66 24 25 26 0.44523 0.46631 0.48773 0.44872 0.46985 0.49134 0.45222 0.47341 0.49495 0.45573 0.47698 0.49858 0.45924 0.48055 0.50222 0.46277 0.48414 0.50587 0.46631 0.48773 0.50953 65 64 63 27 28 29 0.50953 0.53171 0.55431 0.51320 0.53545 0.55812 0.51688 0.53920 0.56194 0.52057 0.54296 0.56577 0.52427 0.54673 0.56962 0.52798 0.55051 0.57348 0.53171 0.55431 0.57735 62 61 60 30 31 32 33 0.57735 0.60086 0.62487 0.64941 0.58124 0.60483 0.62892 0.65355 0.58513 0.60881 0.63299 0.65771 0.58905 0.61280 0.63707 0.66189 0.59297 0.61681 0.64117 0.66608 0.59691 0.62083 0.64528 0.67028 0.60086 0.62487 0.64941 0.67451 59 58 57 56 34 35 36 0.67451 0.70021 0.72654 0.67875 0.70455 0.73100 0.68301 0.70891 0.73547 0.68728 0.71329 0.73996 0.69157 0.71769 0.74447 0.69588 0.72211 0.74900 0.70021 0.72654 0.75355 55 54 53 37 38 39 0.75355 0.78129 0.80978 0.75812 0.78598 0.81461 0.76272 0.79070 0.81946 0.76733 0.79544 0.82434 0.77196 0.80020 0.82923 0.77661 0.80498 0.83415 0.78129 0.80978 0.83910 52 51 50 40 41 42 43 0.83910 0.86929 0.90040 0.93252 0.84407 0.87441 0.90569 0.93797 0.84906 0.87955 0.91099 0.94345 0.85408 0.88473 0.91633 0.94896 0.85912 0.88992 0.92170 0.95451 0.86419 0.89515 0.92709 0.96008 0.86929 0.90040 0.93252 0.96569 49 48 47 46 44 0.96569 0.97133 0.97700 0.98270 0.98843 0.99420 1 .00000 45 60' 50' 40' 30' 20 ' 10' 0' Cotangent. TANGENTS AND COTANGENTS Cotangent. Deg 1 0' 10' 20' 30' 40' 50' 60' De 1 2 3 00 57.28996 28.63625 19.08114 343.77371 49.10388 26.43160 18.07498 171.88540 42.96408 24.54176 17.16934 114.58865 38.18846 22.90377 16.34986 85.93979 34.36777 21.47040 15.60478 68.75009 31.24158 20.20555 14.92442 57.28996 28.63625 19.08114 14.30067 S< 8* 87 86 4 5 6 14.30067 11.43005 9.51436 13.72074 11.05943 9.25530 13.19688 10.71191 9.00983 12.70621 10.38540 8.77689 12.25051 10.07803 8.55555 11.82617 9.78817 8.34496 11.43005 9.51436 8.14435 8c 84 82 7 8 9 8.14435 7.11537 6.31375 7.95302 6.96823 6.19703 7.77035 6.82694 6.08444 7.59575 6.69116 5.97576 7.42871 6.56055 5.87080 7.26873 6.43484 5.76937 7.11537 6.31375 5.67128 82 81 80 10 11 12 13 5.67128 5.14455 4.70463 4.33148 5.57638 5.06584 4.63825 4.27471 5.48451 4.98940 4.57363 4.21933 5.39552 4.91516 4.51071 4.16530 5.30928 4.84300 4.44942 4.11256 5.22566 4.77286 4.38969 4.06107 5.14455 4.70463 4.33148 4.01078 79 78 77 76 14 15 16 4.01078 3.73205 3.48741 3.96165 3.68909 3.44951 3.91364 3.64705 3.41236 3.86671 3.60588 3.37594 3.82083 3.56577 3.34023 3.77595 3.52609 3.30521 3.73205 3.48741 3.27085 75 74 73 17 18 19 3.27085 3.07768 2.90421 3.23714 3.04749 2.87700 3.20406 3.01783 2.85023 3.17159 2.98869 2.82391 3.13972 2.96004 2.79802 3.10842 2.93189 2.77254 3.07768 2.90421 2.74748 72 71 70 20 21 22 23 2.74748 2.60509 2.47509 2.35585 2.72281 2.58261 2.45451 2.33693 2.69853 2.56046 2.43422 2.31826 2.67462 2.53865 2.41421 2.29984 2.65109 2.51715 2.39449 2.28167 2.62791 2.49597 2.37504 2.26374 2.60509 2.47509 2.35585 2.24604 69 68 67 66 24 25 26 2.24604 2.14451 2.05030 2.22857 2.12832 2.03526 2.21132 2.11233 2.02039 2.19430 2.09654 2.00569 2.17749 2.08094 1.99116 2.16090 2.06553 1.97680 2.14451 2.05030 1.96261 65 64 63 27 28 29 1.96261 1.88073 1.80405 1.94858 1.86760 1.79174 1.93470 1.85462 1.77955 1.92098 1.84177 1.76749 1.90741 1.82906 1.75556 1.89400 1.81649 1.74375 1.88073 1.80405 1.73205 62 61 60 30 31 32 33 1.73205 1.66428 1.60033 1.53987 1.72047 1.65337 1.59002 1.53010 1.70901 1.64256 1.57981 1.52043 1.69766 1.63185 1.56969 1.50184 1.68643 1.62125 1.55966 1.50133 1.67530 1.61074 1.54972 1.49190 1.66428 1.60033 1.53987 1.48256 59 58 57 56 34 35 36 1.48256 1.42815 1.37638 1.47330 1.41934 1.36800 1.46411 1.41061 1.35968 1.45501 1.40195 1.35142 1.44598 1.39336 1.34323 1.43703 1.38484 1.33511 1.42815 1.37638 1.32704 55 54 53 37 38 39 1.32704 1.27994 1.23490 1.31904 1.27230 1.22758 1.31110 1.26471 1.22031 1.30323 1.25717 1.21310 1.29541 1.24969 1.20593 1.28764 1.24227 1.19882 1.27994 1.23490 1.19175 52 51 50 40 41 42 43 1.19175 1.15037 1.11061 1.07237 1.18474 1.14363 1.10414 1.06613 1.17777 1.13694 1.09770 1.05994 1.17085 1.13029 1.09131 1.05378 1.163Q8 1.12369 1.08496 1.04766 1.15715 1.11713 1.07864 1.04158 1.15037 1.11061 1.07237 1.03553 49 48 47 46 44 1.03553 1.02952 1.02355 1.01761 1.01170 1.00583 1.00000 45 60' 50' 40' 30' 20' 10' 0' Tangent. CYANIDE DATA 4. Common Logarithms. N 1 2 3 4 5 6 7 8 9 10 11 12 00,000 04,139 07,918 00,432 04,532 08,279 00860 04,922 08,636 01,284 05,308 08,991 01,703 05,690 09,342 02,119 06,070 09,691 02,531 06,446 10,037 02,938 06,819 10,380 03,342 07,188 10,721 03,743 07,555 11,059 13 14 15 11,394 14,613 17,609 11,727 14,922 17,897 12,057 15,229 18,184 12,385 15,534 18,469 12,710 15,836 18,752 13,033 16,137 19,033 13,354 16,435 19,312 13,672 16,732 19,590 13,988 17,026 19,866 14,301 17,319 20,140 16 17 18 20,412 23,045 25,527 20,683 23,300 25,768 20,952 23,553 26,007 21,219 23,805 26,245 21,484 24,055 26,482 21,748 24,304 26,717 22,011 24,551 26,951 22,272 24,797 27,184 22,521 25,042 27,416 22,789 25,285 27,646 19 20 21 27,875 30,103 32,222 28,103 30,320 32,428 28,330 30,535 32,634 28,556 30,750 32,838 28,780 30,963 33,041 29,003 31,175 33,244 29,226 31,387 33,445 29,447 31,597 33,646 29,667 31,806 33,846 29,885 32,015 34,044 22 23 24 34,242 36,173 38,021 34,439 36,361 38,202 34,635 36,549 38,382 34,830 36,736 38,561 35,025 36,922 38,739 35,218 37,107 38,917 35,411 37,291 39,094 35.603 37,475 39,270 35,793 37,658 39,445 35,984 37,840 39,620 25 26 27 39,794 41,497 43,136 39,967 41,664 43,297 40,140 41,830 43,457 40,312 41,996 43,616 40,483 42,160 43,775 40,654 42,325 43,933 40,824 42,488 44,091 40,993 42,651 44,248 41,162 42,813 44,404 41,330 42,975 44,560 28 29 30 44,716 46,240 47,712 44,871 46,389 47,857 45,025 46,538 48,001 45,179 46,687 48,144 45,332 46,835 48,287 45,484 46,982 48,430 45,637 47,129 48,572 45,788 47,276 48,714 45,939 47,422 48,855 46,090 47,567 48,996 31 32 33 49,136 50,515 51,851 49276 50,651 51,983 49,415 50,786 52,114 49,554 50,920 52,244 49,693 51,055 42,375 49,831 51,188 52,504 49,969 51,322 52,634 50,106 51,455 52,763 50,243 51,587 52,892 50,379 51,720 53,020 34 35 36 53,148 54,407 55,630 53,275 54,531 55,751 53,403 54,654 55,871 53,529 54,777 55,991 53656 54,900 56,110 53782 55,023 56,229 53,908 55,145 56,348 54,033 55,267 56,467 54,158 55,388 56,585 54,283 55,509 56,703 37 38 39 56,820 57,978 59,106 56,937 58,092 59,218 57,054 58,206 59,329 57,171 58,320 59,439 57,287 58,433 59,550 57,403 58,546 59,660 57,519 58,659 59,770 57,634 58,771 59,879 57,749 58,883 59,988 57,864 58,995 60,097 40 41 42 60,206 61,278 62325 60,314 61,384 62,428 60.423 61,490 62,531 60,531 61,595 62,634 60,638 61,700 62,737 60,746 61.805 62,839 60,853 61,909 62,941 60,959 62,014 63,043 61,066 62,118 63,144 81,172 62,221 63,246 43 44 45 63,347 64,345 65,321 63,448 64,444 65418 63,548 64,542 65,514 63,649 64,640 65,610 63,749 64,738 65,706 63,849 64,836 65,801 63,949 64,933 65,896 64,048 65,031 65,992 64,147 65,128 66,087 64,246 65,225 66,181 46 47 48 66,276 67210 68,124 66,370 67,302 68,215 66,464 67,394 68,305 66,558 67,486 68,395 66,652 67.578 68,485 66,745 67,669 68,574 66,839 67,761 68,664 66,932 67,852 68,753 67,025 67,943 68,842 67,117 68,034 68,931 49 50 51 69,020 69,897 70,757 69,108 69,984 70,842 69,197 70,070 70,927 69,285 70,157 71,012 69,373 70,243 71,096 69,461 70,329 71,181 69,548 70,415 71,265 69,636 70,501 71,349 69,723 70,586 71,433 69,810 70,672 71,517 52 53 54 71,600 72.428 73,239 71,684 72,509 73,320 71,767 72,591 73,400 71,850 72,673 73,480 71,933 72,754 73,560 72,016 72,835 73,640 72,099 72,916 73,719 72,181 72.997 73,799 72,263 73,078 73.878 72,346 73,159 73,957 COMMON LOGARITHMS 93 4. Common Logarithms. (Concluded). N 1 2 3 4 5 6 7 8 9 55 74036 74,115 74,194 74,273 74.351 74,429 74,507 74,586 74,663 74 : 741 56 74,819 74,89674,974175,051 75,128 75,205 75,282175,358 75,435 75,511 57 75,587 75,664 75,740 75,815 75,891 75,967 76,042 76,118 76,193 76,268 58 59 60 76,343 77,085 77,815 76,418 76,492 77,15977,232 77,887 77,960 76,567 77,305 78,032 76,641 77,379 78,104 76,716 77,452 78,176 76,790 77,525 78,247 76,864 77,597 78,319 76,938 77,670 78,390 77,012 77,743 78,462 61 78,533 78,604 78,675 78,746 78,817 78,888 78,958 79,029 79,099 79,169 62 79,239 79,309 79,379 79,449 79,518 79,588 79,657 79,727 79,796 79,865 63 79,934 80,003 80,072 80,140 80,209 80,277 80,346 80,414 80,482 80,550 64 80,618 80,686 80,754 80,821 80,889 80,956 81,023 81,090 81,158 81,224 65 81,291 81,35881,425 81,491 81,558 81,624181,69081,757 81,823 81,889 66 81,954 82,020 82,086 82,151 82,217 82,282 82,347 82,413 82,478 82,543 67 82,607 82,672 82,737 82802 82,866 82,930 82,995 83,059 83,123 83,187 68 83,251 83,31583,378 83,442 83,506 83,569 83,632 83,696 83,759 83,822 69 83,885 83,948 84,011 84,073 84,136 84,198 84,261 84,323 84,386 84,448 70 84,510 84.572 84,634 84,696 84,757 84,819 84,880 84,942 85,003 85,065 71 85,126 85,187 85,248 85,309 85,370 85,431 85,491 85,552 85.612 85,673 72 85,733 85,794 85,854 85,914 85,974 86,034 86,094 86,153 86,213 86,273 73 86,332 86,392 86,451 86,510 86,570 86,629 86,688 86,747 86,806 86,864 74 86,923 86,982 87,040 87,099 87,157 87,216 87,274 87,332 87,390 87,448 75 87,506 87,564 87,622 87,679 87,737 87,795 87,852 87,910 87,967 88,024 76 88,081 88,138 88,195 88,252 88,309 88,366 88,423 88,480 88,536 88,593 77 88,649 88,70588,762 88,818 88,874 88,930 88,986 89,042 89,098 89,154 78 89,209 89,265 89,321 89,376 89,432 89,487 89,542 89,597 89,653 89,708 79 89,763 89,818 89,873 89,927 89,982 90,037 90,091 90,146 90,200 90,255 80 90,309 90,363 90,417 90,472 90,526 90,580 90,634 90,687 90,741 90,795 81 90,849 90,902 90,956 91,009 91,062 91,116 91,169 91,222 91,275 91,328 82 91,381 91,434 91,487 91,540 91.593 91,645 91,698 91,751 91,803 91,855 83 91,90891,960:92,012 92,065 92,117 92,169 92,221 92,273 92,324 92,376 84 92,428 92,480 92,531 92,583 92,634 92,686 92,737 92,788 92,840 92,891 85 92,942 92,993 93,044 93,095 93,146 93,197 93,247 93,298 93,349 93,399 86 93,450 ^3,500 93,551 93,601 93,651 93,702 93.752 93,802 93,852 93,902 87 93,952 94,002 94,052 94,101 94,151 94,201 94,250 94,300 94,349 94,399 88 94,448 94,498 94,547 94,596 94,645 94,694 94,743 94,792 94,841 94,890 89 94,93994,988 95,036 95,085 95,134 95,182 95,231 95,279 95,328 95,376 90 95,424 95,472 95,521 95,569 95,617 95,665 95,713 95,761 95,809 95,856 91 95,904 95,952 95,999 96,047 96,095 96,142 96,190 96,237 96,284 96,332 92 96,379 96,426 96,473 96,520 96,567 96,614 96,661 96,708 96,775 96,802 93 96,848 96,895 96,942 96,988 97,035 97,081 97,128 97,174 97,220 97,267 94 97,313 97,356 97,405 97,451 97,497 97,543 97,589 97,635 97,681 97,727 95 97,772 97,818 97,864 97,909197,955 98,000 98.046 98,091 98,137 98,182 96 98,227 98,272 98,318 98,363 98,408 98,453 98,498 98,543 98,588 98,632 97 98 98,677 99,123 98.722 99,167 98,767 99,211 98,811 99,25 98,856 99,300 98,900 99,344 98,945 i 99,388 98,989 99,432 99,034 99,476 99,078 99,520 99 99 564 99.607 99,651 99,69 99,739 99,782 99,82690,870 99.913 99,957 f ~ or ~ HE ~ T II UNIVERSITY I) UNIVERSITY OF CALIFORNIA LIBRARY BERKELEY THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW Books not returned on time are subject to a fine of 50c per volume after the third day overdue, increasing to $1.00 per volume after the sixth day. 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