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By A. L. Slaughter

The Homestake mine, located in western South Dakota, was discovered in 1876. The first reported production was in I 878. Total production through 1965 is 6,554,249 troy ounces of silver and 27,961,276 troy ounces of gold, worth $987,000,000 at present prices. Precambrian sedimentary formations at Lead total 20,000 feet. The Poorman Formation, the oldest, is chiefly ankerite carbonate. The Homestake Formation is iron-magnesium carbonate. The younger formations are argillaceous with some quartzites. The Cambrian Deadwood Formation unconformably overlies the Precambrian. All are cut by Tertiary intrusives. Sideroplesite schist of the Homestake Formation was converted to cummingtonite schist in the zones of higher-grade metamorphism. The Precambrian rocks show the effects of extreme isoclinal folding. A second stage of folding ( cross folds) may have been caused by the Tertiary intrusives. All folds plunge to the southeast. The Homestake ore bodies are pipe-like replacements of the Homestake Formation in zones of cross folding. It is believed that dilatation of the schists has increased permeability in these zones. Chloritization of the schists is the most widespread effect of the mineralization which is divided into four stages. Principal minerals of the first stage are quartz, chlorite, and arsenopyrite; in the second stage, quartz, ankerite, and pyrrhotite. In the third stage only pyrrhotite was deposited. The fourth stage followed the intrusions of Tertiary dikes and deposited mostly pyrite and calcite. Gold accompanies all stages and is always the last mineral to be deposited. It is most closely associated with arsenopyrite of the first stage but can be interpreted as having been deposited during the fourth stage and superimposed on the products of the earlier stages.

Jan 1, 1968

By Leo J. Vogel, E. D. Hummer, David J. Akers

INTRODUCTION An efficient refuse-disposal system is a necessary part of the modem cleaning plant. The large-scale refuse system and disposal area, engineered for the lifetime of the plant, has become more important due to the greater tonnages of refuse produced from increased quantities of mechanically mined and prepared coal. Laws and increased government regulations have affected the design and operation of disposal systems. THE EFFECT OF MINE AND PLANT OPERATION Refuse disposal starts at the mining face. The mining system, the type of roof support, the machinery used, and the degree of discipline at the face contribute to the amount and type of refuse that must be removed through the disposal system. Economies gained through modification of the mining system or mining machinery may be partially offset by increased dilution of the mined coal with impurities from associated rock formations. In some cases the change in the mining system and equipment has reduced the dilution. In all cases the ratio of impurities that must be removed from the raw-coal feed to the plant not only affects the maintenance and

Jan 1, 1979

A small group of members of the Institute headed by W. H. Shockley, has insistently demanded that the Institute submit to the members for letter ballot the question of our using in our publications and corre-spondence certain so-called "simplified spellings." The principal argu-ment in favor of this proposal is written by Mr. Shockley and will be submitted in full to the membership for ballot. It rests chiefly on the desirability of saving the time of school children in the learning of the spelling of the English language. A sample of correspondence had with one of the gentlemen on this subject is given herewith in order that members may see what the correspondence and publications of the Institute would look like if we adopted the proposals. This sample was chosen at random: "Onse I condemd the report ov a president of the Institute. He did not pruve his case even on paper-"a hot air profet," I sed. Time has pruved he was." "I rote yu about the muvement to better the spelling in the Institute Bulletin, etc., neglecting to say some things that I mite hav said and things hav happened since which no member ov a democratically governed society shoud stand without protest."

Jan 12, 1919

By John V. Beall

Many months ago, the ME staff began thinking about what to put on the February cover of the Centennial Commemorative issue. We have considered photographs of mines, equipment, symbolic artwork and various collages. Our theme is "the next 100 years in mining" and the cover ideally should convey a related message or idea. All of us are convinced that there are many exciting technical changes that will be coming. But even so, we decided that, in our opinion, the engineer is the most vital factor. For this reason we chose to put a man on the cover of this issue. At first it was going to be the face of a man with whom each member could conceivably identify himself. It was one of the Bobs on our staff (we have four) who came up with the thought that since it's the future we are talking about, we should have a young man's or a student's face. Of course we firmed up our idea at the ninth hour, and it was too late to canvass the mining schools. However, by a stroke of luck, we were rapping with a group of University of Arizona students on the terrace of the Pioneer Hotel on December 7, 1970, and met Dave Bolles.

Jan 1, 1971

The School of Mineral Industries is dedicated to education in mineral conservation and research by which the means may be found to make conservation effective. This includes diligent search for mineral truths and the energetic discovery, complete recovery, and maximum utilization of irreplaceable mineral resources. Standards of living depend upon two factors: human resources-intelligence, imagination, initiative, know-how, work; and natural resources-plants, animals, and minerals, including water, air, soil, heat and light from the sun, and all other such resources that are useful to man. Human relationships have not kept pace with scientific achievement; as a result man, in desperation, wittingly, premeditatively sacrifices freedom for security. Many natural resources, through overproduction, mismanagement, and greed, have definitely moved over into the exhausted or exhaustible category. The United States cannot maintain present standards of living on an agricultural economy alone, and serious harm can ensue if there are marked disproportions in numbers and relationships between city and rural populations. The most materialistic New Yorker must see virtue in bucolic loveliness. The United States is rated wasteful and inconsistent most of the time. It does not make sense to dole out through the keyhole what a wage earner can bring through the open door; to raise wages to lower the cost

Jan 1, 1950

INTO their great Pacific Northwest counting house went the members of the Industrial Minerals Division recently, to count their blessings amidst the scenic grandeur and mineral wealth of the State of Washington. From their vantage point in Seattle, those who attended the IMD's fourth Pacific Northwest meeting turned their sights to the South and Southeast, scanned Montana, Idaho, Oregon and Utah, and predicted a very healthy economic future for their region. The praises of Idaho's booming phosphate industry were sung by Earl W. Murphy, secretary of that State's Chamber of Commerce. He said the establishment of Fort Hall, on the banks of the Snake River near Pocatello, first turned the eyes of the world toward what is now the center of the greatest known deposits of phosphate rock-the section adjacent to the common corners of Idaho, Wyoming and Utah. With the founding of Fort Hall, Mr. Murphy said, historians will also rank the construction of the first electric furnaces for the production of elemental phosphorous as equally significant in the commercial history of the West. Those furnaces were installed only last year by the Westvaco Chemical Div. of the Food Machinery & Chemical Corp. at Pocatello, at a cost of $8 million.

Jan 7, 1950

J. E. JOHNSON, JR., New York.-It seems to me that it ought to be somebody's job to tie these notch tests with the reversed-stress tests, because the thing that causes failures in structures, in a great majority of cases, is where the material is stressed repeatedly up somewhere near the elastic limit, and the repetition of that stress seems to bring about what I suppose you may call a growth of crystals and that eventually develops into a break. It seems to me that it would be of the greatest value if there could be a coordination of the results of a shock test of some kind with the reversed-stress test, so that we could be sure that a material that had shock-test resistance would have reversed-stress resistance. H. F. MOORE,* Urbana, Ill.-The question raised by the speaker concerning the correlation of results from impact tests of notched bars with the results of repeated-stress tests is a very complicated one. Impact on a specimen sends energy into the specimen, and if the specimen absorbs this energy without fracturing there must be developed both stress and elongation. A notch in the specimen allows but little elongation to take place before rupture, and develops the ductility of the

Jan 5, 1919

By M. C. Fuerstenau

Each year during the AIME Annual Meeting, the MBD Division has its Business Meeting. Because many members cannot attend, it has be- come policy for the secretary of the Division to present highlights of the business conducted at the Meeting in Fine Grind. This year the Meeting was held on March 1 in the Americana Hotel. Five major items of business were brought up for discussion. These were: (1) the proposed name change for the Division, (2) institution of the Taggart Award, (3) a name change for a Unit Committee, (4) MBD funding of scholarships, and (5) authorship of Fine Grind articles. The Matter of What We Should Call Ourselves A lively discussion was held on the issue of a name change for the Division. Two names have been proposed: (1) Mineral Processing Division, and (2) Mineral Engineering Division. A number of strong reasons for changing the name from Minerals Beneficiation Division have been pointed out. Perhaps the most important of these is that the term "beneficiation" does not describe all of the functions that engineers in our Division perform. Further, there are inherent problems associated in the term, in that beneficiation is a long word which has the twofold disadvantage of being both difficult to pronounce and difficult to spell.

Jan 1, 1971

By J. R. Finlay

THE other day, I fell into conversation with two gentlemen who desired to improve the condition of the people; so that the talk was semi-political. They seemed to agree that I was inclined to be "con-servative," "reactionary," perhaps an "evolutionist," looking upon "reform" with suspicion. Finally I rejoined somewhat in this manner: "You attach to me phrases that I have heard all my life but which convey no meaning to me. It is quite true that I do not make a fetish of terms like reform, liberty, democracy and so forth; neither do I worship the idea that `things are good enough as they are,' `leave well enough. alone' and so forth. There is more satisfaction in building something up than in tearing something down, or in just maintaining something that is already built. Progress is a popular word; but what is progress? In my opinion it is comprised, so far as public welfare is concerned, of two elements: Improvements in production of goods and knowledge; improvements in keeping order." This substitute for politics, economics, reform, pro-gress, conservatism, radicalism, democracy, socialism, monarchism and all the phrases of public welfare may seem over-simple; perhaps it is, but at least it defines something. It seems to me to be at least worth attention.

Jan 4, 1922

By John V. Beall

The "free form life," The Wall Street Jourlzal called it. That is what the young people are practicing who have dropped out after successfully completing a college education. The ones described were first-rate students who did not embark on careers but instead selected such nonintellectual jobs as delivering mail, short- order cooking and the like. We couldn't help thinking that it wasn't so long ago, that we had the ideal setup in mining for folks of this persuasion when most college grads were started out as muckers. Actually there isn't much new in this business of doing your own thing. Being a type that takes westerns seriously, we jumped at the chance to catch the rerun of the wide-screen flick "How the West Was Won." There was Jimmie Stewart playing the part of the mountain man, with a canoe full of furs going east down river. Coming west up river, is a settler with his daughters. This mountain man had on his fringed buckskins, his two-year growth of long hair and a tremendous thirst. He had been doing his thing and planned to keep right on doing it. However, one of the pretty settler girls had other ideas. The same fate probably awaits today's individualistic youths.

Jan 1, 1970

By H. B. Fuqua, B. E. Thompson

The area discussed herein, commonly known as the North Texas district, embraces the following 10 counties: Archer, Baylor, Clay, Cooke, Foard, Hardeman, Knox, Montague, Wichita and Wilbarger. It is underlain by two major structural features. The northernmost portion of the district, including Cooke, Montague, northern Clay, Wichita, Wilbarger, Foard and Hardeman counties, is underlain by the system of buried mountains known as the Red River uplift, which is parallel to and closely related to the Wichita-Amarillo uplift of Oklahoma and the Texas Panhandle. While the presence of a great majority of the numerous oil fields of the area is traceable to this feature, the production in Archer, southwestern Clay and southeastern Baylor counties is due to the influence of what is known as the Cisco Arch (so called because of its influence on Cisco deposition), the axis of which extends in a northwest-southeast direction across Archer County. It has been impossible for the authors to isolate the statistics for production for each of the many small pools of this district, as such statistics are not kept by the operators except for the district as a whole, therefore Tables 1 and 2 are comparatively short. The number of wells

Jan 1, 1935

By the courtesy of Sir Robert Hadfield, we have received the fol¬lowing communication relating to the development and encouragement of science and research in Germany at present. These statements have been translated by Sir Robert from various German sources, and are presented here as an indication of what Germany is doing not only to further her military power, but also to prepare for the period of trade rehabilitation to which she is looking forward after the close of, the war. KAISER WILHELM TRUST FOR PROMOTION OF WAR SCIENCE The Kaiser has approved the foundation of a Trust with the name given above. The aim of the Trust is to further the development of scientific and technical aids to warfare, by uniting the scientific and the military forces of the country for work together. The scientific Work is to be carried on by the following technical committees (or commissions) (1) Committee for the chemical raw materials, for the production of munitions-manufacturing materials. (2) Committee for chemical war materials (powder, explosives, gas, and the like). (3) Committee for physics, including ballistics, telephony, telegraphy, determination of targets and distances, measurements, and the like. (4) Committee for engineering and communication. (5) Committee for aeronautics. (6) Committee for obtaining and preparation of metals.

Jan 8, 1918

By E. A. Anderson

In 1918 the American Society for Testing Materials held a symposium2 on what was then known as season cracking. The sessions included six papers, all on brass. During the ensuing 26 yr., many new workers have come into the field and several other metals have been found subject to failure by stress-corrosion cracking when the right combination of stress and environment is achieved. It is not surprising, therefore, that the present symposium has brought forth 29 papers covering alloys of seven important metals. The phenomenon of stress-corrosion cracking is not necessarily confined to these seven metals. Dix3 has stated, "Indeed, it is probable that ingenious investigators can find solutions which will stress-corrosion crack any known metal or alloy." Mears, Brown, and Dix4 have indicated that stress- corrosion cracking failures are not necessarily limited to metals but may include the plastics. It is to be expected that the increase in the number of metals known to crack in service and the general emphasis on such failures at a symposium such as this will alarm many to whom the subject is un- familiar. Such alarm is not justified by the record. It is true that stress-corrosion

Jan 1, 1945

By W. R. Ingalls

MANY years ago, I expressed the opinion, in writings and otherwise, that it was possible to desulfurize zinc blende autogenously, i.e., without the use of extraneous fuel, and that at some time this would be accomplished. This opinion was based on thermal calculations and also on observations of the behavior of blende during roasting in different ways, all of which observations tended to confirm the theoretical calculations. Among such observations were things like the following: Once in carrying out the stall roast of cupriferous pyrites as a regular metal-lurgical operation, I was minded to charge a stall with lump blende, ranging from walnut to egg size, as I recollect, following the same procedure as with pyrites, and setting fire to the kindling wood, observe what would happen. The blende charge ignited well enough and bravely began to burn, quite actively the first day, at a diminished rate the second day, while on the third day burning ceased and the charge quickly became cold. It was just like trying to set a grate full of anthracite afire with insufficient kindling wood. The volume of air drawn through the stall was too great, quickly cooling the entire contents below the ignition temperature, which means, of course, that burning ceased.

Jan 12, 1922

Discussion of the paper of WALTER 0. SNELLING, presented at the New York meeting, February, 1915, and printed in Bulletin No. 100, April, 1915, pp. 695 to 704. A. F. LUCAS, Washington, D. C.-Are the results of the experiments in practical operation? WALTER 0. SNELLING.-There have been no large-scale operations up to the present. The necessary conditions of temperature are easily arranged for, but the required condition of pressure, 800 lb., is not so simple a matter. The company has been working on this problem, and at the refinery in Oklahoma work of this kind is now being carried on. The way in which an ordinary still will leak at 50 lb., and more at 100 lb., leaves some doubt in the mind of many as to what can be clone at a continuous working pressure of 800 lb. On the other hand, the fact that they are making ammonia abroad by a method which employs higher pressures and temperatures than anything involved in this method, leads me to believe that the difficulties, which will undoubtedly arise when this is attempted on a commercial scale, can be overcome. WILLIAM N. BEST, New York, N. Y.-Is there any change in the calorific value of these oils?

Jan 5, 1915

By Earle E. Schumacher, W. C. Ellis

For the purpose of developing combinations of higher strength and conductivity than are obtainable by heat treatment alone in the age-hardening copper alloys, an investigation has been made of the effects of combinations of heat treatment and strain hardening on the properties in question. The investigation was limited to a study of the alloys containing nickel and silicon; nickel, silicon and cadmium; and cobalt and silicon. The experiments made in the course of the study arc described in this paper in three groups: 1. The effect of hard drawing subsequent to heat trcatment on the mechanical and electrical properties of the alloys. 2. The effect of low-temperature aging on the properties of heat-treat,ed and hard-drawn alloys. 3. The effect of strain on the rate of aging of quenched nickel-silicon-copper alloys. Preparation and Compositions or the Alloys The alloys were prepared by melting cathode copper in an electric resistance furnace and adding sufficient of the hardening elements to bring the compositions to the desired values. The purities of the hardening elements were as high as could be obtained in commercial practice. The metals were what are designated in the trade as electrolytic nickel, cobalt rondelles, commercial stick cadmium and fused silicon. The alloys

Jan 1, 1931

By Samuel S. Wyer

The following description of methods for conducting gas-producer tests is probably the first attempt to give the subject an analytical, thorough and comprehensive treatment. In some cases where tests have been made, the methods have been so unsystematic and ambiguous that it has been impossible to secure comparable results. To eliminate this difficulty, the following provisional code of gas-producer tests— which has some resemblance to the code of boiler-trials of the American Society of MechanicalEngineers—has been developed. The primary object in testing a gas-producer is to determine whether the producer is working satisfactorily or, what is the same thing, to see if the efficiency is as high as it should be with the type of producer in question; and also to find out if the composition of the resulting gas is adapted to the work it has to do. In order that the test shall be of any value, it must be thorough and comprehensive, and must be conducted with skill and care. When so conducted, the test will reveal the economy of the'producer; and, by making suitable changes, the efficiency will often be increased very much. As a result of the tests made by Jenkins,' the efficiency was raised from 56.2

Jan 1, 1906

By P. N. Ivanov

The world experience shows that the tremendous potentialities of the computers and other technical means in improving management efficiency are not fully utilized. One of the causes is the tendency to solve the problems of management automation divorced from the management methods and schemes which demand continuous improvement in view of the steady progress of the social production. It may be safely affirmed that making decisions on management improvement divorced from management schemes or on both divorced from management automation problems cannot lead to success. The grave and sometimes unsuperable difficulties encountered in management automation arise from copying traditional management methods and schemes without solving the problems which exist both in management and automation fields. The system solution of management problems has unquestionable advantages and is not proposed for discussion. What is proposed to discuss is the difficulties emerging in developing a methodology of the system approach to management improvement and automation. Though aware of the fact that the questions proposed for discussion are not new, we think it advisable to briefly review them, first because they fall in the "chronically unsolvable" category, and, secondly, as it will enable us to illustrate the method of solving them in the framework of the proposed system approach.

Jan 1, 1977

By Edward H. Robie

IN many ways, the Annual Meeting of the Institute in February was the most successful yet held. Attendance surpassed even that of the 75th Anniversary Meeting in 1947 with its international flavor. The number of technical sessions and the number and quality of papers presented almost certainly set a new record. The banquet was the best attended of any yet held even though the price reached a new high. Despite the demand for almost 1700 tickets to the banquet, some felt that the price-$13.50-was higher than they could afford. There are two points of view: One is that this is the big social event of the year for members and that it is worth from three to five dollars more to have it at the Waldorf and to have a luxury menu, as we did this year, with turtle soup, a fish course, guinea hen for the entree, and wild rice (which we understand is $3.50 per lb) for a vegetable. The other point of view is that a seven or eight dollar banquet of more simple food at the Commodore Hotel would more than make up in appeal, especially to the younger and less well-heeled members, what it would lack in glamour.

Jan 1, 1952

By Lee W. Abramson

INTRODUCTION The design of rock support for underground nuclear waste repositories requires consideration of special construction and operation requirements, and of the adverse environmental conditions in which some of the support is placed. While repository layouts resemble mines, design, construction and operation are subject to quality assurance and public scrutiny similar to what is experienced for nuclear power plants. Exploration, design, construction and operation go through phases of review and licensing by government agencies as repositories evolve. This paper discusses (1) the various stages of repository development; (2) the environment that supports must be de signed for; (3) the environmental effects on support materials; and (4) alternative types of repository rock support. Much of the information presented in this paper was derived from work conducted for Basalt Waste Isolation Project. Most of the information, however, would apply to other hard rock repositories. REPOSITORY DEVELOPMENT AND THE NEED FOR ROCK SUPPORT Repository development can be characterized by five general stages: exploration and design, excavation, waste emplacement, re trievability period, and backfilling. It is helpful to understand these phases of development to see where and when rock supports are required and how the design is verified. The description that follows is simplified. Details have been omitted, and future plans may not conform to this scenario.

Jan 1, 1984