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By R. W. Raymond

(Pittsburg Meeting, March,1910.) THE Giroux Consolidated Mines Co. is equipping a five-compartment shaft at Kimberly, Nev., which will serve the Alpha mice. The depth of this shaft, January, 1910, is 963 ft., and of this depth 948 ft. was opened by raising, 15 ft. of sinking was done so that the bearers, collar-set, and three shaft-sets might be installed and concreted, and with this done it was possible to erect the necessary surface-equipment for resuming shaft-timbering on the completion of the raise. The arrangement of the shaft-timbering is shown in Fig. 1. At the 1,000-ft. level of the Alpha, and 750 ft. SW. from the Alpha shaft, a 14- by 18-ft. station was cut, and a 25-h-p. air-hoist *as installed. From here the raising commenced on July 5, 1909. The raise was cut approximately 13 by 21. ft. in area, and supported by timbering with square sets, illustrated in Fig. 2, which shows the division into four compartments. The end compartments, which were used as chutes, had the center girts heavier than in the others on account of the wear from falling rock. The chute-lining was braced by inserting 8- by 8-in. stiffeners parallel to and half way between successive caps. Similarly, the lagging on the wall sides of the cage-way and the compartment for pipes and ladder was stiffened with 4- by 6-in. timbers. In the pipe-and-ladder compartment the chute-stiffeners were reinforced with 8- by 8-in, struts, and as the cage-way was partitioned off by braced lining, there was practically no chance of rock entering the ladder-way in case a chute burst into the cage-way. Over the two center compartments the last two, sets were always bulkheaded with 8- by 12-in. timbers, shown in Fig. 3, and from the lower bulkhead the cage sheave-wheel was suspended. After a round of holes had been blasted and the loose

Jun 1, 1910

By D. B. RUSHhIORE

I. INTRODUCTION. OF primary importance in mine-installations is the hoist, which has a very direct bearing on the successful operation of a mine. Conditions vary greatly with different mines, and especially in different localities. Such factors as depth, incline, the number of levels, permissible or desirable speeds, conditions of ore, etc., are always more or less special in each case. Veins of ore are never exactly duplicated, and the nature of the ground through which shafts are sunk may considerably modify permissible values. As mining-laws are made by the different States, they necessarily vary somewhat, and, even when not fully observed, they introduce factors which qualify the conditions of hoisting men and ore. The amount of timbering required is often of importance as relating to hoisting-conditions. Methods of loading ore affect the time required, as also does the question of the use of cars or skips. Safety-precautions must be very carefully considered, and the number of men in each mine, the number of compartments, and often the method of removing water from the mine, must. have careful consideration. While a general discussion of the subject. of hoisting is possible, most cases are entirely special, and can be considered only in connection with the peculiar conditions pertaining to that particular installation. The cost of installation of the hoisting-plant may be an appreciable amount, while the cost of raising the ore may be but a small part of the total operating-charge. In many cases, however, the output of the mine is limited by the capacity of the hoist, and the latter thus becomes of the first importance. * Presented also, by mutual agreement, at the meeting of the American Institute of Electrical Engineers, New York, N. Y., Mar. 11, 1910.

May 1, 1910

By Joseph A. Holmes

(Pittsburg Meeting, March, 1910.) AT the Mining Experiment Station of the U. S. Geological Survey, in Pittsburg, an investigation of the process of combustion is being carried on in a specially-designed furnace having an unusually long combustion-chamber. This work is conducted by a committee consisting of H. Kreisinger, mechanical engineer; Dr. J. C. W. Frazer, chemist; and Dr. J. K. Clement, physicist. The problem, essentially one of physical chemistry, is extremely interesting to all who are concerned in the burning of coal or the construction of furnaces. The main object of these experiments is to ascertain the relation between the amount of the volatile combustible driven from the coal and the combustion-spaces necessary to burn it completely. Our best steam-coals vary from 15 to 45 per cent. of fixed combustible. The greater part of the latter is burned on the grate; but the volatile combustible leaves the freshly-charged coal and must be burned in the combustion-space. If this space is not large enough, the volatile combustible will leave the furnace only partly burned, and the result will be a considerable heat-loss and a smoky stack. Strictly speaking, the factor which determines the completeness of combustion of the volatile matter, after it has been mixed with a certain amount of air, is the length of time the mixture is allowed to remain in the combustion-space; but this length of time depends on the extent of the space itself. Let us suppose, for instance, that, when a given coal is burned at a certain standard rate, the volume of the volatile combustible driven off per second is 10 cu. ft. Adding, say, 10 cu. ft. of air, the volume of the resulting burning mixture is increased to 20 cu. ft. If the combustion-space is 20 cu. ft., the burning mixture will stay in it,

May 1, 1910

By E. Gybbon Spilsbury

(Pittsburg meeting, March, 1910.) THE recovery of gold and silver from their ores by means of the cyanide process has been so successful in the last few years that any radical improvement would seem impossible; yet the appliance to which I wish to call attention in this paper is really a radical departure from the methods now in general use. The most modern and approved of these, known as the all-sliming method, depends for its success on the grinding of the. ore so fine that practically 90 per cent. of it will pass through a 200-mesh screen. The slimes thus produced are then agitated and aerated in tanks of various types. The main object of this treatment is to insure such a thorough admixture of the pulp and solution that every particle of the ore is surrounded by a volume of solution sufficient to insure the dissolving of the whole of the gold- and silver-content. In addition, in order to expedite the action of the cyanide, and to oxidize such elements as would, if left in their active state, become cyanicides, air is blown in under pressure. In the Pachuca tank, this air is the active and sole means of agitation. The chief objections to all the methods off agitation used heretofore are the expense of operating and maintaining the mechanical devices for keeping the pulp in suspension, and the length of time required to obtain a fairly complete extraction. of the values. These objections are inherent to any method of agitation effecting a circulation of the pulp and the solution together, by giving the whole mass a circular movement, as in the low-tank system, or a vertical circulation, as in the Pachuca-tank system. In both methods, the particles of ore are kept traveling in the same direction as the solution, and with very little difference of speed; so that, while the whole mass is in

May 1, 1910

By N. M. Langdon

Spokane Meeting, September, 1909.) THE following corrections to the paper of Mr. Langdon (Bulletin No. 34, October, 1909, pp. 919 to 940), received after the publication of the paper in the Bulletin, will be incorporated in the paper as finally published in the forthcoming Vol. XL. of the Transactions, but are here presented for the information of members:' Page. 921. Table I., furnace M2, item 11. For " 8801 " read "0.8801." 922. Table II., furnace C, item 2, under gas. For " 0.011 C " read " 0.011 0." Furnace G, item 13, under gas. For " 5.074 air " read " 3.074 air." Item 15, 114.269 " should be " 4.289." Furnace H, item 2, under iron. For " 0.04 " read ".0.01." 923. Table II., furnace J, item 1, under iron. For " 0.95 " read " 0.93." Furnace N2, item 6, under gas. For " 0.66 CO," read 0.066 C02." 924. Table III., furnace C, item 17. For " 379 " read " 397." 927. Table IV., furnace C, item 4. For " 0.0124 " read 0.0424." Furnace G, item 15.. For " 4,060 " read " 4,066." 928. Line 2. Items 19 and 20 of heat-supply, should be items 20 and 21. 930. Line 3. Expunge remainder of paragraph after the word " supplied," and substitute the following : "As compared with the fusion-zone, the loss by radiation n C was 25.5 per cent. of the total (2,278 units) supplied to that zone, while in D it was 22.5 per cent. of the total heat (1,824 units) supplied to that zone. Finally, as compared with the reduction-zone, C lost by radiation 36.8. per cent. of the 1,580 units supplied to that zone,

May 1, 1910

By Ednlund D. North

Discussion of the paper of Edmund D. North, presented at the Spokane meeting, September, 1909, and published in Bulletin No. 37, January, 1910, pp. 21 to 25. A. SCOTT REID, London, Eng. (communication to the Secretary*) :-As a constructor of several glass mine-models, I have read with much interest the description of the model of the Montana-Tonopah mine-workings by Edmund D. North. As an interchange of ideas and experience is always an advantage, and in view of the fact that such models are coming more and more into vogue, perhaps the following remarks on this subject may prove of interest to mining engineers generally and to Mr. North particularly. In the model of the Waihi gold-mine, New Zealand, which I constructed, a dust-proof case is used. The top, bottom, front, and two ends are of glass; the back only is of wood, painted a dull white, against which the mine-workings show very distinctly. Each mine-level is represented by a horizontal sheet of glass, supported on metal runners fixed to the uprights at each end of the case, in a manner similar to that described by Mr. North. The corner uprights are strengthened by having a metal band screwed to the inside face of each, to which the metal runners or supports for the sheets of glass are screwed in turn. The reason for having this additional strength is that as the mine is developed in depth, and fresh levels are opened, the increasing weight of the glass sheets, added to the model, caused the unsupported wooden uprights to bend slightly, so that the glass sheets-did not fit in with the desired nicety, and co-ordination was, to a considerable extent, lost. Strengthening the uprights in this manner is not important in models of mines in which only a few levels have been opened, or when the sheets of glass are small, but in the Waihi model there are 15 sheets of glass to be supported, and more to be added as development proceeds, and the weight is considerable.

May 1, 1910

By AIME AIME

. COUNCIL.* PRESIDENT OF THE COUNCIL. D. W. BRUNTON DENVER, COLO. (Term expires February, 1911.) VICE-PRESIDENTS OF THE COUNCIL. W. C. RALSTON SAN FRANCISCO, CAL. W. L. SAUNDERS : NEW YORK, N. Y. H. V. WINCHELL ST. PAUL, MINN. (Term expires February, 1911.) BENJAMIN B. LAWRENCE NEW YORK, N. Y. JOSEPH W. RICHARDS SOUTH BETHLEHEM, PA. ALBERT SAUVEUR CAMBRIDGE, MASS. (Term expires February, 1912.)

Apr 1, 1910

By Charles R. Keyes

Continued discussion of the paper of Charles R. Keyes, Trans., xxxix., pp. 139 to 169, 850 to 856, and Bulletin Ho. 34, October, 1909, pp. 945 to 947. CHARLES R. KEYES, Des Moines, Iowa (communication to the Secretary*):-It is with pleasure that I acknowledge the value and interest of the historical notes on early mining at Lake Valley, contributed by Messrs. MacDonald and Courtis. In my own paper there was no attempt to enter into this phase of the subject; partly for reason that the intention was to take up this in detail in another connection, partly because there was not space enough to. devote to it in a brief geologic paper, and partly on account of the fact that the strictly mining features are quite distinct from the purely geologic characteristics. As may be inferred from its perusal, the brief historical paragraph prefacing my paper was in reality geologic in its bearing. The events referred to therein relate to the published information concerning the geologic structure. The personages principally mentioned were noted merely to show how the names of several of our most distinguished scientists came to be closely associated with that of Lake Valley. Far from my intentions was it to slight the memory of any , of that brave band who, with lives in their hands, took so active a part in the early development of the mines. The value of their records is perhaps much greater than that of any published notes. The narratives of Messrs. MacDonald and Courtis are as thrilling as many other experiences related of that time and place. Few of us at the present time can appreciate the dangers of that early day, when the fierce Apache all but swept the. white man from that part of the country, when renegades from Texas overran the land, and when the outlaws of the nations took their last stand before advancing civilization. In marked contrast do we to-day reach Lake Valley by means of the 11 iron horse"; and out of a luxurious Pullman

Apr 1, 1910

By AIME AIME

COMMITTEES. LOCAL COMMITTEE.-R. C. Crawford, Chairman; Harrison W. Craver, Secretary; Julian Kennedy, Taylor Allderdice, E. W. Pargny, Charles L. Miller, W. H. Rea, S. A. Taylor, M. E. Wadsworth, W. A1. Henderon, A. C. Dinkey, W. L, Jones, E. L. Messier, George Mesta, J. H. Jones, G. H. Riley, S. L. Goodale, D. W. McNaugher. LADIES' COMMITTEE.-Mrs. Taylor Allderdice, Chairman; Mrs. Julian Kennedy, Mr. R. C. Crawford, Mrs. E. M. Herr, Airs. J. W. Marsh, Mrs. T. A. Mellon, Mrs. G. P. Bassett, Jr., Airs. D. M. Clemson, Mr. Charles L. Miller, Mrs. V. L. P. Shriver, Mrs. W. A. Bostwick, Mrs. A. C.. Dinkey, Mrs. A. P. Childs, Jr., Mrs. F. R. Dravo, Mrs. Hermon Griffin, Mrs. W. H. Nimmick, Mrs. F. H. Lloyd, Mrs. S. G. Cooper, Mrs. S. H. Church, Mrs. E. N. Ohl. The Institute Headquarters was established at the Hotel Schenley, where a bureau of information was maintained for the benefit of the visiting members and guests of the party during the time of the meeting. TECHNICAL SESSIONS. The first session, held Tuesday evening, Mar. 1, 1910, in the large lecture hall of the Carnegie Institute, was called to order by Harrison W. Craver, Secretary of the Local Committee. Mr. Craver introduced Dr. John A. Brashear, who extended to the members and guests a hearty welcome to the city of Pittsburg, to which David W. Brunton, President of the Institute, responded. The following papers were presented in oral abstract by the authors: Biographical Notice of Dr. Charles B. Dudley, by Dr. R. W. Raymond, New York, N. Y. Biographical Notice of William Metcalf, by Col. II. P. Bope, Pittsburg, Pa. Development of Hindered Settling Apparatus, by Robert H. Richards, Boston, Mass. (Illustrated by lantern-slides.) A Few Mining Districts in the Argentine Republic, South America, by Z. S. Beyl. (Illustrated by lantern. slides.)

Apr 1, 1910

By Warden A. Moller

(Pittsburg Meeting, March, 1910.) THE Fushun coal-field, now being opened up by the South Manchurian Railway Co., is connected with the main line by a branch, 30 miles long, from Sui Chia Tun, 10 miles south of Mukden, the capital of Manchuria. The coal-field, which lies on the southern bank of the Hun river, 25 miles east of Mukden, consists of a long narrow valley,. running east and west between hills composed of granitic and volcanic rocks. At the foot of the northern hills, the Hun river flows westward towards the Liao river, which drains the greater part of South Manchuria. At the foot of the southern hills, resting immediately upon volcanic rocks, and overlain by 20 ft. of alluvial, is a thick layer of Tertiary shales, carrying near the base two coal-seams. In many places the lower of these two seams is in immediate contact with volcanic lauds and basalts, the flows of which were evidently both prior and subsequent to the formation of the coal-seams. This contact has practically destroyed the lower seam for commercial purposes. The value of the field lies in the upper seam, which, for a length of nearly 8 miles, varies from 100 to 130 ft. thick. Of this seam, 85 per cent is good coal. The seam dips to the north conformably with the shales, at angles of from 25° to 30°, and appears to have an uninterrupted dip for about 1.5 miles before being possibly cut o$' by the northern hills. The coal-bearing shales extend east and west for a length of about 20 miles, but towards the east the continuity of the seams is broken by intrusive rocks. The coal is of the sub-bituminous variety, low in ash, bright in appearance, and breaks with a conchoidal fracture. It has the usual qualities of Tertiary coal-quick steam-raising and poor stacking-qualities. Pieces of resin, varying in size from

Apr 1, 1910

By David H. Browne

(Pittsburg Meeting, March, 1910.) NICKEL has always been a fruitful mother of problems. Previous to the year 1906 nickel was regarded as an element replacing iron in copper-mattes, and it was believed that the same laws which governed the elimination of iron could be applied-to nickel. This conception has lately undergone a complete change, and nickel in all its stages is now regarded as an element replacing copper; in other words, copper-nickel is considered now as two elements, but as one metal. When we commenced our investigations on Monel metal we made a great many experiments on the conversion of mattes, both high copper and high nickel. We studied closely the composition of the mattes and the changes produced by the blow. We found in all cases certain agreements which we believe are due to some law. Briefly stated, our conclusions are as follows 1. Nickel is not an element replacing iron in matte. 2. Nickel-copper alloys act in the matte-blow like one metal. 3. Nickel-copper alloys follow, during the matte-blow, exactly the same laws as govern. the behavior of copper alone. This brings up the question : What are the laws governing the production of metallic copper, and what are the relations copper to sulphur and iron during the Bessemer blow ?

Apr 1, 1910

By James Douglas

Discussion of the paper of James Douglas, presented at the New Haven meeting, February, 1909, and published in Bulletin No. 29, May, 1909, pp. 439 to 451. JAMES DOUGLAS, New York, N. Y. (communication to the Secretary*) :-In my paper on the Conservation of Natural Resources, I referred to the slow replacement of bee-hive ovens by the by-product ovens as a most notable instance of waste. And I quoted from Mr. Parker's report for .1906 an explanation given by him in accounting for the small production of by-product coke. It was that the markets for the by-products of the coke-ovens was so limited that some of the ovens constructed were out of operation. His report on the manufacture of coke in 1908 1 does not record an improvement, and attributes the strange fact that we alone, of all the industrial peoples, delay the adoption of this cardinal improvement from the continuance of the same almost inexplicable cause. To quote again from his report, lie says (p. 241): "The year 1908 was not marked by any notable gain in the construction of by-product coking plants, though some new work was done. There was a net increase of 115 in the number of completed ovens in 1908 over 1907, the totals for the two years being, respectively, 3,892 and 4,007. The additional equipment consisted of 140 Koppers regenerative ovens built at Joliet, I11., by the United States Steel Corporation, but this increase was partly offset by the dismantling of Y5 Semet Solvay ovens at Sharon, Pa., the net gain being 115 ovens. Included in the total of 4,007 completed ovens in 1908 are 152 Newton-Chambers ovens at Vintondale, Pa., but as no recovery of by-products was made at this plant in 190S, the production of coke is included with that from beehive ovens. The 56 ovens of the same type at Pocahontas, Va., have not been in practical operation since they were first. installed. In addition to these there was one other by-product plant of 120 ovens. Oat. was not operated during the year. The number of retort ovens producing coke in 1908 was 3,679, as compared with 3,811 active ovens in 1907." In describing the anomaly he says (p. 249): It has been contended that the development of the by-product coking industry would have shown more rapid progress if markets for the by-products were * Received Feb. 2, 1910. Mineral Resources of the United States for 1908, Part I1., U. S. Geological Survey (1909).

Apr 1, 1910

By Sydney H. Ball

I. INTRODUCTION. DURING the past 50 years the attention of mining-men has been turned to Africa, and within the past decade prospecting-expeditions sent into Central Africa have resulted in the opening-up of several mines. Having recently spent two years in the Belgian Congo for the Société Internationale Forestiere et Miniere du Congo, it is our purpose to outline briefly the mining-conditions in that part of Central Africa. Before it became, in 1908, a Belgian colony, this region was known as the Congo Free State. II. LOCATION AND AREA. The Belgian Congo lies in southwestern Central Africa, west of the continental divide, is illustrated in Fig. 1. It has a coastline of but 20 miles on the Atlantic, but widens rapidly eastward to points 5° north and 14° south of the equator. Its area is 908,000 sq. miles, which is almost one-quarter that of the United States and Alaska, or more than one and one-half times that of Alaska. Stated in other terms, its area is nearly one-third that of the United States, exclusive of Alaska and the insular possessions, or more than that of all the United States east of the Mississippi river. III. TOPOGRAPHY AND DRAINAGE. From north to south, Africa is made up of three topographic elements: 1, the Atlas mountains, a highly-accentuated region

Apr 1, 1910

By AIME AIME

COUNCIL PRESIDENT OF THE COUNCIL. D. W. BRUNTON DENVER, COLO. (Term expires February, 1911.) VICE-PRESIDENTS OF THE COUNCIL. W. C. RALSTON SAN FRANCISCO, CAL. W. L. SAUNDERS NEW YORK, N. Y. H. V. WINCHELL ST. PAUL, MINN. (Term expires February, 1911.) BENJAMIN B. LAWRENCE NEW YORK, N. Y. JOSEPH W. RICHARDS SOUTH BETHLEHEM, PA. ALBERT SAUVEUR CAMBRIDGE, MASS. (Term expires February, 1912.)

Mar 1, 1910

By W. H. Blauvelt

THE subject of fuel-briquetting has attracted much attention on the part of engineers and investors for the past 15 or 20 years, and especially in recent years, during which a number of plants have been built, with more or less commercial and technical success. Our technical literature contains numerous descriptions of certain processes, and discussions of the industry in general. For a history of the development of the art in the United States, and for descriptions of many of the processes which have been tried, reference may be made to the files of our Transactions, and, for more recent information, to a paper by C. T. Malcolmson, read before the First Annual Convention of the International Railway Fuel Association in June, 1909. The purpose of the present paper is to describe the briquette-plant of the Solvay Process Co. and the Semet-Solvay Co. at Detroit, Mich., which, after a period of long and costly evolution, is now operating satisfactorily on a commercial basis. I believe that it will be of interest to some of our members to have the details of operation, lower-consumption, labor, etc., as worked out on a practical and commercial scale in a going operation. The briquette industry has had a somewhat checkered career in the United States, and much the larger portion of the failures has been due entirely to commercial causes. It seems axiomatic to say that before undertaking the installation of a plant for manufacturing briquettes it is necessary that the local situation should be carefully examined : First, to determine the kind of briquettes, if any, the local market will consume; that is-to say, whether the available fuel-supply is such that briquettes would be a welcome addition, and whether the most promising field is the industrial or the domestic market. Second, if there is an available supply of raw material, as coal,

Mar 1, 1910

By Lewis T. Wright

(Pittsburg Meeting, March, 1910.) I HAVE long been aware that ferruginous copper furnace slags if fused in the electric arc will yield metallic iron containing copper, and in order to confirm this knowledge, and to obtain further information of the behavior of such slags in the high temperature and reducing conditions of the electric furnace, a number of samples of slag were fused in an experimental electric furnace. The results obtained, given in Table I., show that a very large amount of metallic iron was produced, and that this iron carried with it practically all the copper, gold, and silver, and more than 50 per cent. of the sulphur, of the original slag. The metallic buttons formed in the electric furnace were clean, hard, but not brittle.

Mar 1, 1910

By Clarence P. Linville

(Pittsburg Meeting, March, 1910.) IT is recognized that, in all metallurgical operations, the greatest possible uniformity in all conditions is essential to the best results. It is the constant aim of metallurgists to secure this uniformity, and their success in this respect has been in many cases the cause of great advances in the metallurgical processes themselves. Of all such processes, the production of pig-iron in the modern blast-furnace is perhaps the most complex and the most difficult of control. Notwithstanding the great progress of recent years, there is still great difficulty in obtaining anything like uniform conditions and results in the manufacture of pig-iron. The reason is not far to seek. The ores vary in composition and physical properties, often carrying a varying amount of gangue material, unevenly distributed The coke may vary in composition, cell-structure, moisture, hardness, and other properties. The blast, the weight of which far exceeds that of any other constituent, varies in its moisture-content and consequently in its chemical composition ; and its temperature, by reason of the method of heating, is not uniform, but, besides varying from time to time with atmospheric and other outside conditions, has a maximum and minimum for every changing of stoves. Now, with regard to these variations, the modern demand for uniformity has been greatly aided. Chemical analysis has made it possible to select ores so that the composition of the charge can be kept fairly constant; coal may be obtained from a given field, and coked in the same kind of ovens under conditions which . make the fuel practically uniform ; the Gayley

Mar 1, 1910

By George W. Riter

Discussion of the paper of H. 0. Hofman and C. R. Hayward, presented at the New Haven Meeting, February, 1909, and printed in Bulletin No. 30, June, 1909, pp. 513 to 529. GEORGE W. RITER, Salt Lake City, Utah (communication to the Secretary*).-In their paper, Messrs. Hofman and Hayward deal with a branch of silver metallurgy that is on very uncertain ground, both as a commercial process and as a metallurgical science; moreover, its field is limited to few localities and to peculiar conditions. The literature on the subject is incomplete and full of conflicts. The paper under discussion clears u p no disputed points; on the contrary, because of hasty generalization, its tendency is towards further confusion. In Table I., the authors assume that each test-lot of 1,800 g. of ore contained exactly 5.499 g. of silver, that any variation in the quantity of silver recovered, however slight, should be ascribed to variation in the time of grinding. It is barely possible that the ore was mixed so uniformly as to justify this assumption; but those of us who know how difficult it is to get uniform samples of any ore in which silver mineral is present in rich particles will have a doubt on this point. The unlikelihood of getting absolutely uniform test-lots of ore also reflects on the data in Table II., on the effect of varying the amount of salt in a pan-charge. The authors say " The salt series was the last one that was investigated." This again raises a question as to whether the ore was split into test-lots at the time of sampling, or whether it was kept in bulk in such a way as to permit mechanical concentration of values before the end of the experiments. The conclusion following Table II.: " There is no reason, therefore, for going beyond six per cent. of salt," is hardly to the point. If we assume that salt is of benefit only when in solution, it follows that the relation between the quantity of salt

Mar 1, 1910

By William Wraith

1. INTRODUCTION. AT the Washoe smelter,. Anaconda, Mont., the blister-copper from the converters is transferred, by means of a crane, to a refining-furnace,, in which it is brought to proper pitch by means of air and poles. From this furnace the refined copper, containing gold and silver, is poured into cast-iron molds placed on a platform-conveyor, giving an anode 36.75 in. long, 28 in. wide, and 21 in. thick. By reason of a disagreement between the smelter and the refinery, in reference to the silver-content of the anodes, it became necessary to investigate the methods of sampling used. II. SMELTER METHOD OF SAMPLING. At the smelter the sampling is done by " spotting " into water a small portion of the molten stream of copper as it flows from the furnace, by batting" the stream with a wooden paddle. The first sample is taken 30, min. after the pouring is started, three. other samples being taken at 1-hr. intervals, each sample weighing from 4 to 6 oz. The samples are dried, examined for particle's of burnt wood, screened on a 10-mesh screen of No. 8 wire to remove the fines, the oversize then screened on a 4-mesh screen of No. 20 wire to remove the coarse, the undersize of this screen being taken as the sample. Teh four portions thus obtained are thoroughly mixed and spli in half by passing over a 16-slot splitting-device, slots being 0.5 in. wide. One-half of the sample is sent to the laboratory for analysis and one-half kept as a duplicate. III. REFINERY METHOD OF SAMPLING. The method used at the refinery and also used in this investigation is the one developed by Dr. Edward Seller, of

Mar 1, 1910

By Joseph W. Roe

MANY questions arising in the work of the mining engineer may be solved quickly and with sufficient accuracy by the methods of descriptive geometry; but, unfortunately, this subject is more often considered from a mathematical view-point than as an effective tool. for solving practical problems. Some of the principles involved are merged into the ordinary operations of mechanical drawing, and are used unconsciously by the engineer in his every-day work. The rest are stowed away on the book-shelf with his forgotten or rarely-used college text-books. One reason for this condition of "innocuous desuetude " may lie in the unfortunate and often cumbersome notation which it has been found necessary to introduce. If some of these principles can be recalled to the engineer's attention in terms of every-day use they may prove of practical bearing. Recently, in talking with several mining engineers, I used some of the drawing-room methods of a machine-designer, to the evident surprise of those around me. These men were perfectly familiar with the methods, but their application to mining-work had not occurred to them. At their suggestion the present paper is offered, not in any way as a treatise, but merely to suggest a certain point of view, in hope that it may lead others far more familiar with mining-problems to pursue the subject further. I. To FIND THE STRIKE. As the simplest and most fundamental problem, let it be required to find the strike of a vein when the location and elevation of three points on the outcrop are known. It will be assumed for the present that the vein is a plane.

Mar 1, 1910