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By John T. Popp, Jodi A. Rulli, Anthony T. Iannacchione

Anomalous geological features in the coal and surrounding strata of a mine in northern West Virginia have fractured and deformed an inherently weak roof rock prior to mining. Horizontal stresses, as much as six times greater than overburden related horizontal stresses, have induced cutter roof failure. This failure was distinguishable from rock deformation associated with geological anomalies because it was induced by mining. The characterization of these features has allowed for the prediction of zones of unstable roof rock and the determination of failure trends on gateroad stability. Geological anomalies included clastic dikes and a narrow zone of sandstone roof. Clastic dikes, representing intrusions of shale and claystone, were invariably accompanied by local roof rock instability, and often formed the boundaries of roof falls. Shale was the dominant roof lithology except where a small sandstone occurred in the northwest portion of the longwall mining area. The sandstone occurs in two phases: a sandstone-filled channel, 5-m- thick and 60-m-wide, which eroded and replaced the shale roof and the upper part of the coalbed; and a sheet sandstone unit which was crossbedded to interbedded with the underlying shale. Horizontal stresses are naturally relieved through the initiation of cutter roof failure. This failure may extend from a few meters to several tens of meters horizontally, and from a few centimeters to several meters vertically. Orientations of entries and crosscuts has a greater influence on the direction and total length of cutter roof failure at the rib-roof intersection than does the principal directions of the in situ horizontal stresses. Seventy-four percent of the cutter roof failures occurred along the rib-roof intersection. Orientations of cutter roof failure away from the rib- roof intersection were clustered in the north-south direction and may have been influenced by the horizontal stress field.

Jan 1, 1984

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Jan 1, 1938

By H. M. Katz, J. L. Speirs, F. B. Hill

Jan 1, 1961

By Lloyal O. Bacon

In the spring of 1952 Calumet and Hecla Inc. began a geophysical program near Shullsburg, Wis., in the Wisconsin-Illinois lead-zinc district, to assist the geological and drilling exploration programs. Sphalerite, the ore mineral in this area, occurs with a considerable amount of marcasite. In general the higher the percentage of sphalerite in the ore, the higher the percentage of marcasite; however, there may be mineralized zones high in marcasite but low in sphalerite. Orebodies in general are relatively narrow and elongated.

Feb 1, 1956

By K. A. Natarajan, I. Iwasaki

The influence of dissolved oxygen and the Pt - Pt-O reaction on the measurement of redox potentials in solutions containing ferrous-ferric couple was examined. Current-potential curves were used to illustrate the shift in measured potentials toward the oxygen potential in oxygenated and deoxygenated systems at low concentrations of ferrous and ferric ions. The ranges of concentrations of the ferrous-ferric couple, in which the interference from oxygen and the platinum-oxygen reactions becomes significant, are illustrated through the mixed potential mechanism.

Jan 1, 1975

By S. J. Shale

Recent changes at Cornwall are highlighted by development of a panel caving method, with slushing drifts, for underground practice as open pit operation nears close. Metallurgy keeps the pace with high recovery from increasing amounts of harder to liberate, higher sulphide content, underground ore.

Jan 7, 1953

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Jan 1, 1938

Jan 3, 1951

A week-long educational program and two-day symposium on applying the fluidizing reactor to the minerals industry drew more than 100 engineers to the University of Arizona at Tucson several weeks ago. The educational program, intended for engineers who will work closely with the reactor, attracted registrants from all sections of the U. S. and Canada. Meeting at the College of Mines on February 23 for a full week of intensive classwork, the engineers ploughed in with enthusiasm. Eight hours daily of lectures and laboratory work were followed by a generous helping of homework supplied by Professor Sigmund L. Smith, who directed the course. The study program was completed on Friday and the following Monday marked the start of a symposium of technical papers covering a wide variety of operations and new ideas.

Jan 4, 1959

By L. W. Kempf

THE thermal expansion characteristics of aluminum alloys have been examined by several investigators, among whom may be mentioned Shakespear,1 Schulz,2 Hidnert,3 Hidnert and Sweeney4 and McCullough.5 Shakespear compared the expansion of a series of aluminum alloys containing 14 per cent copper, with separate additions of about 1 per cent each of manganese, tin and zinc with that of pure copper. Schulz examined the expansion of aluminum and zinc and some aluminum-zinc alloys. Hidnert determined with a high degree of precision the expansion characteristics of pure aluminum, some aluminum-copper, aluminum-zinc, aluminum-silicon and some commercial alloys. Hidnert and Sweeney examined the expansion characteristics of aluminum-beryllium alloys. McCullough, by an interferometer method, determined the expansivity of some aluminum-copper, aluminum-magnesium, aluminum-iron, aluminum-nickel, aluminum-silicon and aluminum-manganese alloys. Incidental to an investigation carried out during the past six years and leading to the development and exploitation of an aluminum piston alloy of relatively low thermal expansivity, the expansion characteristics of a wide variety of alloys were examined. Some of the data which might be of general interest are gathered in this paper.

Jan 1, 1933

Jan 1, 1953

By R. W. Raymond

The death of Professor Blake removes the oldest of American economic geologists and mining engineers, and deprives this Institute of one of its earliest and most illustrious members. To many of us it brings a personal loss also, the loss of a friend. William Phipps Blake was born June 21, 1826, in New York City. His father, Elihu Blake, was a surgeon-dentist of eminence, a direct descendant of William -Blake, who settled in the Massachusetts Bay Colony about 1630. He was prs pared for college at private schools in New York, and entered the Sheffield School of Yale, where he was graduated as Ph.B. in the chemical course, class of 1852, the first graduating-class of the institution. In the same year he became chemist and mineralogist of the New Jersey Zinc Co., and chemist of chemical works at Baltimore, Md. In 1853, he started the Department of Mineralogy of the World's Fair at New York City. In 1854, 1855 and 1856, he was mineralogist and geologist of the United States Pacific Railroad Surveys of Willianlson, Pope, and Whipple, and for the War Department at

Jan 1, 1911

By W. J. Keep

Those who have observed the influence of various elements upon cast-iron will be interested in the methods used by us to form the several series of test-bars, which form the basis of the conclusions presented in this paper. We found that we could not, by adding ordinary white stickphosphorus to molten iron, produce bars which would exhibit to the eye the peculiar influence of phosphorus. By melting wrought-iron drillings with red phosphorus, Mr. H. S. Fleming produced in his laboratory 10 pounds of phosphide of iron, containing 10.22 per cent. of phosphorus. With this we made two series of test-bars, the first with our white-base iron, and the second with our FLM gray-base iron. Before the time of making these bars we had been unable to procure regularly made pig-iron which contained enough phosphorus to permit of the production of

Jan 1, 1890

By F. L. Holderreed

A choosy in what they would smelt. The furnace charge had to be coarse, and it had to be rich. They discarded fines in excess of about 1/10 the total weight. They wanted 10% copper content and fussed about anything with as low as 5%. They concentrated the copper content of the charge as much as they could by prior selection. They roasted off enough sulfur to further enrich the copper content of the succeeding fall of matte (a melt of cuprous and ferrous sulfides or Cu2S.FeS). Then they desulfurized the iron and fluxed it by carefully adding silica (quartz, not silicates) for a slag of lower density than the cuprous sulfide (Cu2S or white metal). After skimming off the slag, they further desulfurized the white metal by blowing the molten bath with compressed air. The result was blister copper. Yesterday Their techniques and furnaces? Some experimented with mechanically rabbled roasters, but their standard roasting practice was burning coarse sulfide ore in 250-ton heaps. These heaps, approximately 24 x 24 x 6 ft, were burned for about 75 days down to 6-10% sulfur. The turnaround time for a given roasting position was 100 days. Assuming the base was a hearth, the calculated rate of treatment was on the order of 0.004 tpd per sq ft.

Jan 1, 1971

By Ernest Lilley

THE tin deposits of Cornwall appear to have been worked for at least 3000 years. Prior to the sixteenth century, the tin came exclusively from alluvial deposits. At that time, shallow pits or mines were started in the hill sections. Mining of copper seems to have begun at the same time, but does not appear to have been especially important until about 1700. From that time until the close of the nineteenth century, copper was of major importance. Lead, and to a lesser extent, other metals, such as antimony, iron and manganese, were produced in commercial quantities during the same period. With the opening of the eighteenth century carne increasing difficulties with water because of the increasing depth of the mines. Among the efforts made to overcome this difficulty was the construction of the "Great County Adit," begun in 1748, taking 20 years to complete, and with its branches having a length of 20 miles. Adits proved capable of handling-only a few of the water problems, and led to rapid adoption of the steam pumping engine in the latter part of the eighteenth century and the early part of the nineteenth. It was in this period that the Cornish pumping engine, still considered by Cornishmen to be the most satis-factory unit for handling large quantities of water, carne into existence. The development of a means of controlling the water made possible the opening up of a number of rich deposits where profitable work-ing was further assisted by numerous improvements in mining and milling machinery. During the middle of the past century, Cornwall, with an average yearly production of 10,000 tons of tin metal and an even slightly larger tonnage of copper, enjoyed a period of unprecedented prosperity. How-ever, the relatively high prices of both copper and tin served not only to encourage prospecting (and much speculation) in Cornwall, but also in other countries. The rapid development of copper mines in the United States, together with sudden impoverishment of the lodes with increasing depth in the greatest of the Cornish copper mines, brought the copper boom to an abrupt end, the production of copper at the close of the cen-tury being negligible in importance and being secured in large measure

Jan 1, 1932

NEW MEMBERS The following list comprises the names of those persons who became members during the period Jan. 1, 1917 to Feb. 10, 1917. ALLEN, ROBERT SEXTON, Chief Chemist at Concentrator, Inspiration Cons. Copper Co. Globe, Ariz. ALTIO, KARL FREDRIK, Min. Engr., The Sissert Mining District Co., Ltd., Polefskoy Zavod, Perm Government, Russia. ARGALL, PHILIP HENRY, Mgr., Ozark Smelt. & Min. Co., Magdalena, New Mexico. BAILEY, MARC Supt., Wolverine & Arizona Min. Co., Bisbee, Ariz. BAKER, DAVID FRANKLIN, Asst. Supt. of Blast Furnaces, Alan Wood, Iron and Steel Co., Swedeland, Pa. BATES, BENNETT R, Min. Engr 1025 Peoples Gas Bldg., Chicago, Ill. BECK, HOWARD A Shift Foreman, Aurora Cons. Mines Co. Aurora, Nev. BELL, LEO RICHARD Casilla 270, La Paz, Bolivia, South America. BENJAMIN, FLOYD SHAW, District Mgr., Aetna Explosives Co., Inc., 800 Torrey Bldg., Duluth, Minn.

Jan 3, 1917

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Jan 1, 1938

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Jan 1, 1938

By N. T. Burdine

AIME 1953 DIRECTORY SUPPLEMENT COMMITTEES NOMINATING E. H. Rose, Chairman R. E. Byler J. F. Myers Grover Molt S. W. Engelmann S. J. Swainson EDUCATION A. C. Dorenfeld, Chairman G. P. Lutjen A. E. McHugh H. Rush Spedden T. G. Chapman T. M. Morris T. Barker S. R. B. Cooke W. O. McClintock

Jan 1, 1953