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By Samuel Lasky

THE writer has been interested in determining the mineralogic dis-tribution of silver in the base-metal ore of the Ground Hog mine of the Asarco Mining Co. in the Central mining district of New Mexico.1 This ore consists of a varitextured mixture of sphalerite, chalcopyrite, galena and pyrite in a quartz gangue. The average ore contains 14 per, cent of zinc, 9.5 per cent of lead, 5 per cent of copper, and 10 oz. of silver per ton. Generally it is accepted that the silver in ores of this type, in which no definite silver minerals can be recognized, is contained in the base-metal minerals. Published assays of pure mineral specimens from many dis-tricts show that each of the base-metal minerals contributes in some degree to the total silver content of the ores, and to determine the pro-portionate amount contributed by each mineral in any specific ore it has been the practice to assay selected specimens of each mineral, the purity of which has been determined microscopically. There being no such assays available for the Ground Hog ore, and it being impract cable to have enough of them made to give average results, the writer resorted to a mathematical attack upon composite assays of large quantities of ore and concentrates. Surprising results were obtained, and it is the threefold purpose of this paper to present these results, to describe the mathe-matical method used, and to point out the value of using this method even when assays of pure specimens are available.

Jan 1, 1934

By Strathmore R. B. Cooke, Iwao Iwasaki, Hyung Sup Choi

Oleic acid is the chief ingredient of fatty acids used as collectors in nonsulfide flotation. With a few notable exceptions, the various quantities of saturated and other unsaturated acids comprising the remainder are usually unspecified. There have been occasional investigations to determine the collecting ability of these other acids and their effect on collection with oleic acid, but much remains to be done in this field. Hukki and Vartiainen, on the basis of tests using palmitic, oleic, and linoleic acids and an impure linolenic acid, concluded: "The collecting power of fatty acids used in flotation increases with increasing unsaturation of the hydrocarbon chain." 1 Their work was concerned mainly with the response of ilmenite to the foregoing collectors, although tests were also made with magnetite, pyrite, hematite, and rutile. Cooke and Nummela, employing an al- most identical technical procedure to evaluate flotation of hematite, magnetite, and goethite with various fatty acids, including oleic, linoleic, and linolenic acids of the highest purity obtainable, found: "The effectiveness of 18-carbon unsaturated fatty acids, as collectors for hematite, decreases with increase in the number of non-conjugated double bonds."' In the foregoing investigations, collector efficacy was measured on the basis of reagent addition in moles per liter.

Jan 9, 1959

By P. B. Liebermann

1. Haulage Tests on Coal-mine Cars THE haulage of coal from the face to the tipple is an important enough link in the production of coal to deserve its full share of study and care. In order to obtain a better understanding of mine haulage conditions, a series of tests and investigations has been made which promises to hasten the improvement of present conditions. For hauling coal through the mine and on the surface, locomotives are required, the size and power consumption of which depend on the resistance to motion offered by the mine cars. This resistance is principally caused by gravity and hearing friction. The effect of gravity can be reduced to a minimum by a suitable layout of the haulageways; that is, by arranging the grades in favor of the loaded trips, and by fixing the percentage of grade to that value which gives the lowest power consumption for loaded and empty trains. The bearing friction, which is considerably greater than is generally realized, can be easily reduced to a negligible quantity by the installation of a suitable anti-friction bearing that will stand the rough use and abuse of coal-mine service. The present investigation will deal with flexible roller bearings in comparison with ordinary plain bearings.

Jan 7, 1917

Joseph HartshoRnE, Pottstown, Pa.: I have read Professor Akerman's valuable paper with great interest. Few of the present generation of American steel metallurgists are aware of the very important part taken by Swedish engineers in the successful development of the Bessemer proeess, and I am afraid some of the older ones have forgotten it. Certainly, I think, most of us would have said that Terre Noire was the first to introduce the use of metal direct from the blast-furnace. It is very well, therefore, that honor should be given to whom honor is due. I can speak from personal experience upon one part only of Prof. Akerman's paper; namely, the effect of the temperature at which the molten metal is cast upon the quality of the finished steel. In a general way I have, of course, known for a long time that the

Jan 1, 1894

By C. C. RAE

The Texas Panhandle produced 18,677,000 bbl. of oil in 1932 as against 25,064,000 in 1931. The decline was caused by smaller market demand, since the Railroad Commission potential increased from 105,528 to 149,260 bbl. during the year. Well Completions, 1932 The development during 1932 compares with 1931' as follows: Year Wells Drilled Dry Holes Gas Wells Oil Wells Initial Pro- duction, Bbl. 1931 200 6 77 117 347 1932 136 18 28 90 603 Crude oil prices, small market demand, and lower allowable rate of production caused less drilling. Expiration of leases was one reason for a greater number of dry holes through forced drilling of questionable areas. The small number of gas wells reflected the influence of the business depression upon industrial and domestic gas demand, together with difficulties of franchise negotiations or pipe line extensions under present conditions. Probably much of the gas-well drilling was done on expiration leases, or to protect against drainage, and equalize withdrawals as between the various units held by each gas pipe line company. The increase in average initial daily production was due chiefly to excellent granite wash wells in the LeFors district developed by the Texas Co. and Skelly Oil Company. In the Panhandle district, comprising a major anticline with almost a million productive gas acres, the pools tend to merge in time, the development being confined to more productive areas. Hence separation into pools becomes a matter of time of development with some effort to keep dolomite, archosic and granite wash production separate. Many pools, like the Finley and Bowers, have mainly one type, but many leases and even individual wells produce from two zones. The oil production is usually closely associated with sea level, where proper porous formations

Jan 1, 1933

SHELBY M. HARRISON,* New York, N. Y. (written discussion ?).¬Your secretary requested a brief description of the Russell Sage Foundation, in order that members of the Institute, if they should desire to avail themselves of it, would know what type of service is offered to them through our institution. The foundation was established in 1907 by the gift of Mrs. Russell Sage of $10,000,000 as a capital fund, the income of which is to be spent for the improvement of social and living conditions in the United States. One of the lines of activity which the foundation has felt would lead toward this end is the development and promotion of community surveys; and because the scope and methods followed in these surveys are very similar to the scope and method of much of the institution's work in general, an idea of its main activities can perhaps be given best by describing one of our surveys. Incidentally, it may be pointed out that antecedent to the survey stand at least two important facts: first, the recognition. that communities are active, not static forces, that they develop, that changes in. material and human relationships occur continuously, and that with them come new social and civic problems which must, in many cases, be diagnosed and prescribed for anew; and second, the reality of scientific advances along lines which make possible at least some measure of solution of the problems. Evidences of these changes are abundant; many of them are found in the rapid growth of cities in the last few decades. Villages in agricultural districts, places where everybody knew everybody else, where the pulpit had been long the chief or only influence molding public opinion, where the air was unclouded by the smoke from factory stacks, where the water supply was not affected by pollution, where sunlight and building

Jan 5, 1918

By J. S. Ross

OIL-FIELD waters enter into many underground problems with which the petroleum engineer has to deal. Whether the problem is one of infiltration or natural encroachment, it is always desirable to determine the source of the water before commencing repair or remedial work. The usual mechanical tests for determining the source of extraneous water in wells are slow and expensive. An excellent means for the identification of oil-field waters may be afforded by their chemical characteristics when the chemical character of waters from the various sands has been established, by careful sampling and analysis cautiously interpreted. In the Salt Creek field, Wyoming, a fairly high degree of efficiency has been attained in the controlof field operations by utilizing the information afforded by the analysis. All of the operating companies appreciate this means of identifying waters, with the result that water-sampling has become general practice. Most of the chemical work dealing with Salt Creek waters has been done since the laboratories of the Midwest Refining Co. and the U. S. Geological Survey, were established in the field; the former in 1922, the latter in 1924. A spirit of cooperation has existed between the company and the government personnel by which many of the data for this paper were made available.

Jan 1, 1928

AT THE beginning of September, the French eased their pressure against Germany and allowed the latter to, be granted an arrangement for its reparation payments in kind according to the Lubersac-Stinnes agreement. The whole arrangement as to the German reparations is, however, but temporary. The Greeks suffered a disastrous defeat at the hands of the Turks in Anatolia, which rapidly resulted in the expulsion of the Greeks from Asia Minor, the Turks occupying Smyrna about Sept. 10. A few days after entering Smyrna the Turks sacked the city and finally set it afire, creating one of the most terrible destructions in history. At the same time their advance on Constantinople, together with their demands on the Allies, brought them directly in, con-flict with the latter and Great. Britain prepared for a new war, with doubt as to the support of France, whose political interests in the Near East are as different as their economic interests with respect to ;Germany. The Turkish situation became thus a threat against the peace of Europe. A revolution in Greece, followed by the abdication of King Constantine and the return of Venizelos to a function in the Government was one of the conse-quences of the defeat in Asia Minor. Civil war continued in Ireland, with more or less -bloodshed. Economically there has been no change for the better in Europe. In Great Britain there, are no signs of an -important trade revival. In Germany and Austria things are worse. French, Italian and Spanish affairs continue in a bad way. In the United States business is represented as "booming," but many people are inquiring where is the boom? About the middle of September Congress passed the tariff and the soldier bonus bills. The President signed the former and vetoed the latter, with a strong message that won praise among people who understand condi-tions. Congress tried to pass the bill over the veto, but failed. The President signed the tariff bill, which became effective Sept. 21. A severe handicap was thus imposed on American economics.

Jan 10, 1922

By Edgar Kendall

A KNOWLEDGE of the fundamental principles of locating, sampling, testing and evaluating materials is essential in prospecting for mineral aggregates. In this discussion, mineral aggregates will be considered sand, gravel, crushed stone and slag that are used as materials of con-struction. The quantity of mineral aggregates produced in the United States during the year 1935 for such purposes was roughly 165,000,000 tons, about 60 per cent of which was sand and gravel, 37 per cent crushed stone and 3 per cent crushed slag. The total value of this material was approximately $100,000,000. It is apparent therefore that the prospect-ing for suitable mineral aggregates is of considerable economic importance. In prospecting for mineral aggregates, the methods employed are the same whether the organization is large or small. In the large organiza-tion there may be available geologists for locating sources of supply, a land acquisition department to arrange for the necessary options or permits, engineers to do the sampling, a laboratory for testing, and a board of consulting materials engineers to make the final selection. Even small organizations must follow the same general procedure, though the respon-sibility for the selection of aggregates may rest with one man, who may or may not be an engineer, but who must depend entirely upon his own judgment.

Jan 1, 1939

By R. Laird Auchmuty

FOREWORD THE A. I. M. E. Subcommittee on Bituminous Mining has been trying for several years to secure the information that was collected by the Marquette Cement Manufacturing Co. on the subsidence of its property caused by mining coal beneath it. The Marquette company was willing to have these data used, but it was impossible to obtain them because the records had been filed away. About two years ago these records became available and the engineering data presented herewith were compiled from them by R. L. Auchmuty, assisted by L. E. Young, who was connected with the collection of the information. On account of the cost, it is impossible to reproduce all of the data here, although the original information is on file with the records of the Committee on Ground Movement and Subsidence. The accompanying charts show representative and average data and give only the engineering information with enough description to tell how it was obtained. It is hoped that all of those connected with the original case will participate in the discussion that this will bring forth. HOWARD N. EAVENSON, Chairman, Subcommittee on Bituminous Coal Mining.

Jan 1, 1931

By R. C. Stevens

INTRODUCTION Idarado Mining Company, a subsidiary of Newrnont Mining Corporation, is situated high in the San Juan Mountains in southwestern Colorado. Portals, offices and surface plants are located near the towns of Ouray and Telluride at elevations ranging from 9,000 to 12,000 feet. The Ouray portion of the development was initiated in 1943. Upon completion in 1945 of a 250-ton mill, processing of development ores containing copper, lead and zinc was undertaken; thus, serving as a pilot testing unit for larger scale milling operations. These facilities were subsequently enlarged and utilized until 1956. Meanwhile, in 1953 Idarado had acquired The Telluride Mines Company, 62 miles distant by highway; however, only six miles via a network of tunnels which eventually linked the two workings. Extensive underground development and increased ore production necessitated reconstruction and expansion of the milling plant. The facility was designed to accomodate processing of 1700 tons of ore daily. This goal was achieved and it represents the current daily output. MINERALOGY The veins are a compound fissure which have undergone several stages of mineralization. The first stage is represented by complex ores of copper, lead and zinc in a quartz gangue. Precious

Jan 1, 1970

By D. C. McLean

This report summarizes the work that has been done during the past several years in adapting resins for use as auxiliaries in mine roof support. The resins were applied in two ways: 1) by injection into the strata, and 2) as a bonding agent for roof bolts and reinforcing bar. The Explosives and Mining Chemicals Department of the American Cyanamid Co. has worked during this period in cooperation with the Roof Control Research Group of the U.S. Bureau of Mines, the Pattin Manufacturing Co., the J. H. Fletcher Co., the Homestake Mining Co., the U.S. Steel Corp., the National Mines Corp. and the Pocahontas Land Corp. in an effort to create resin formulations and methods for applying them as a practical and sate type of roof support for mining areas particularly where conventional support is inadequate, yet expensive. This, work has involved much pioneering in a field where theory, speculation, and pure mythology predominates, and little basic engineering data is available. It is strange butt true that, despite the importance of roof control both from an operational and safely standpoint, there is scarcely a mining' company in this country that has an engineer, or anyone, assigned to the study of roof support problem, except temporarily--after a bad roof fall. The responsibility for improving roof control methods seems to have been placed entirely upon the shoulder, of the USBM, various State departments of mines, and individual roof bolt manufacturing; companies. It was in cooperation with the USBM that Cyanamid first developed resins for mining use.

Jan 1, 1964

By George Ross Green

[In discussion of the paper of Mr. J. C. Bayles, read at the New York meeting of September, 1890, Trans., xix., p. 18.1 It is often so difficult to locate the causes of failures of machinery and apparatus which can be examined and studied at leisure, that it is not surprising that the causes of explosions should escape detection. Usually the explosion is the first evidence that anything is amiss, and the time for observing the conditions is necessarily brief. An incident in a welding-works near Essen, Germany, might be cited as exemplifying what trifling causes may lead to disaster, and how difficult, under the most favorable conditions, it may be to discover them. A blowing-engine was arranged with two suction-pipes at each end of the blowing-cylinder—one leading to the air, and the other to the gas-holder. Each pipe was provided with a valve, and all were so adjusted that the cylinder drew in gas and air in the proportions found most advantageous. The gases from the cylinder were carried directly to the furnace through suitable pipes, and while the cylinder was provided with relief-valves, every effort was made to prevent explosions, principally by compressing the gases to a point where the rate of efflux of the mixture was greater than the velocity of combustion, if the expression is here allowable. It was found that the apparatus would work satisfactorily for some time, and then the relative proportions of the mixture would change, and an explosion might have been the result. Experiments consuming days were made to discover a method of averting this danger, but they were unsuccessful, until it was observed that the change in the composition of the mixture of gas and air took place when the gasometer began to rise or fall—the back-pressure due to friction when the holder was rising or its absence when falling being sufficient to change the conditions. As soon as this was discovered,

Jan 1, 1892

E. W. King, Bozeman, Mont.: The form of measuring up ore in sight looks very plausible, as illustrated in the paper of Mr. Emmons, but from my experience of many years of mining in Montana and Nevada, I have found it is very hard to measure up anything nearer than a guess of what you have in sight, except in the case of a true vein, or a flat vein where the boundaries are well defined. I have been interested in several miues with Dr. A. R. Ledoux, and I know that my foreman and myself, going into the mines and using our best judgment, could seldom see more than 30 days' supply actually in sight, and yet we were running from 100 to 250 tons a day, and keeping it up year after year. Prof. John D. Irving, New Haven, Conn.: I understand from Mr. Emmons that this is a method which has been found applicable in the copper-mines in Tennessee, where the record could be made with a good deal of accuracy, and where the work in the mines allowed the necessary development to be done, so that the record could be kept up. I do not think there was any intention in his mind to imply that this was applicable to all cases, especially such as Mr. King has mentioned. President Charles Kirchhoff, New York, N. Y. : I think the point is that the paper impresses the necessity for doing it where the possibilities exist. There has been too little attention given to this very matter, particularly in the United States; but I think our English friends are following it very much more zealously, and the demand for it there is possibly greater than it is here, because English boards of directors handle mines that are often very much further away than our own are, and the English public and the English engineers generally are very much more insistent upon seeing how much longer current dividends are going to last, or current assessments are going to continue.

Jan 1, 1913

By B. B. Gottsberger

HAVE given considerable thought during the past year to the subject of licensing of engineers and par-ticularly to the position which the mining engineer should take on this question. I have found, however, that it is not a subject which yields much result for the thought expended on it. So far as any published record will show, mining engineers have been either ignorant of the extent to which the movement for the licensing of engineers has progressed or else indifferent to it. It is true that the Mining and Metallurgical Society of America, by a questionnaire sent out to its member-ship, did a great deal in calling this matter to the atten-tion of the mining profession, and so far as I know, the report of its committee, which analyzed the replies received, is the only published statement of the feelings and opinions of our branch of the engineering profes-sion. It is to be hoped that the conclusions shown by that report, namely, that mining engineers are almost unanimously opposed to the principle of licensing and consequently any legislation dealing with it, has received serious thought and that we are ready for an even more thorough consideration of the subject.

Jan 3, 1922

By A. T. Miesch

The purpose of this paper is to explore relations between the distribution and composition of uranium deposits on the Colorado Plateau and mineralogic, chemical, and lithologic aspects of their host rocks. The paper also appraises the host-rock sandstones as possible sources of elements in the uranium deposits. Other possible sources of elements are not discussed. Uranium deposits on the Colorado Plateau consist largely of sandstone and small amounts of mud-stone impregnated with uranium and vanadium miner- als and a suite of minor accessory minerals containing copper, lead, zinc, silver, iron, cobalt, nickel, yttrium, molybdenum, selenium, and arsenic, in addition to other elements locally. The deposits consist of clusters of closely spaced ore bodies which commonly aggregate several thousand tons, but range in size from less than one ton to several million tons. With only rare exception, the deposits show no close relation to fractures. The ore bodies are generally tabular in layers nearly parallel to the bedding in the host rocks, or they cross bedding at large angles to form roll structures. Absence of fracture control necessitates that the ore and associated elements were transported to the deposits by way of interstitial pore spaces in the sandstones. This points to the general process of lateral secretion as a possible mechanism of ore formation, and suggests the host-rock sandstones as a possible source of the metals. Roll structures in the ore

Jan 1, 1962

By M. D. Cooper

FOr the purpose of obtaining some first-hand data in regard to the shooting clown of coal in bituminous 'nines, it was the writer's good fortune to be employed as a shot-firer for almost one year. In all, 6,020 shots were fired by him during this period. All of the work was clone in what is known as the South Main section of the No. 2 Mine of the Ellsworth Collieries Co., Ellsworth, Pa., a subsidiary of the Lackawanna Steel Co. Position of Shot-firing in the Cycle of Operations The established practice of the Ellsworth Collieries Co. calls first for the undercutting of the coal by electric chain machines across the face of the entry or room. This is followed by replacing any posts removed by the machine-runners, or the setting of new posts or timber, as may be required. After this has been done the machine cuttings are loaded into cars. Then the coal is spragged, and a shot hole drilled to the depth of the undercut. Next in order, the shot-firer loads the hole and fires the charge. The working place is then cleaned up, timbered if necessary, the sides and face squared up, and loose material taken down. The face is again ready to be undercut.

Jan 1, 1917

By Sukune Takenouchi

Porphyry copper deposits in the southwestern Pacific region differ in some points of geologic features from those of the United States. The deposits distribute along old or active island arcs and are generally younger in age (1-16 m.y. B.P.). In Japan, however, no typical porphyry copper deposits are yet reported, though the geological situation of Japanese islands is similar to that of the southwestern Pacific. Fluid inclusions in some porphyry copper deposits In the southwestern Pacific region and those in igneous rocks genetically related to the ore deposits In Japan have been studied, and the genesis of ore-forming fluids from igneous rocks are discussed. From the results, the possibility of finding porphyry copper-type mineralization in Japan are considered.

Jan 1, 1976

By Robert O. Davis, Phillip A. Abbott

The response of geologic materials subject to nuclear weapon effects is of considerable interest in the design of buried protective construction. Recently, more consideration has been given to placing such structures in rock rather than in soil. Although rock has the obvious advantages of high strength and low deformability, discontinuities such as joints and fault planes severely complicate any response analysis. Nevertheless, some knowledge of the effects of these discontinuities must be developed, even if that knowledge remains largely qualitative in nature. In this paper, we present a constitutive description of cracked rock subject to uniaxial shock loading. The constitutive equations are based on certain average response characteristics of a particular cracked rock model. Rather than attempt to represent each material discontinuity individually, we have incorporated the discontinuity effects into constitutive relationships for a continuous medium. The resulting equations are suitable for use in hydrodynamic computer codes presently used for ground motion calculations. APPROACH The continuum description which will be presented below is based on a detailed analysis of a particular cracked rock model. This model can be visualized as a sequence of plates (representing the intact rock) separated by gaps (representing the discontinuities). This so-called "plate-gap" model was first used by Thouvenin (1) in an effort to explain the behavior of porous materials at high

Jan 1, 1971

By J. King Hoyt

IN both Sweden and England rapid progress is being made in metallurgical development, and the steel industry in both countries is distinctly on the mend. There has been some industrial trouble in Sweden in the iron mines and the wood pulp mills, but at the same time all the steel works have a sufficient stock of pig iron and ore to continue their operations for many months to come. Consequently the strike, unless long protracted, will not affect the output of steel in Sweden. Several of the steel manufacturers in Sweden, most notably Forsbacka and Sandviken, have been very suc-cessful recently in securing large orders, particularly from the continent, for ball-bearing steel, both hollow and solid. Whereas some years ago they ran into-se-rious competition with the German mills, the quality of the steel from these Swedish mills is such that they are now firmly established, and are selling some of the lead-ing manufacturers of bearings on the Continent, as well as automobile manufacturers. The secret of their success seems to lie in a better selection of ores, in more careful control of blast-fur-nace operations and better equipment. Rule of thumb in steel making is taboo, and strict reliance is placed on the laboratory. They are constantly experimenting, and metallurgists and chemists are sent to different countries for study and investigation. In their native ores they have, of course, a unique advantage in pos-sessing iron ores extraordinarily free from phosphorus. At Forsbacka, they are not content with the ordinary chemical analysis of the ingot; but also test the physical properties, as well as make metallographic investiga-tions for slag inclusions, segregations and oxides. In both England and Sweden they watch the nitrogen con-tent of the steel very carefully, a feature which does not appear in the ordinary analysis. In testing carbon, they do not use the color test, but employ an electric .induction device.

Jan 7, 1928