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By Orville R. Lyons

THE Russellton preparation plant of Republic Steel Corp., located north of Pittsburgh, Pa., prepares 395x0-in. Thick-Freeport coal by means of a 13-ft 6-in. diam Chance cone and 16 No. 7 Deister tables. The plant feed ranges between 370 and 410 tons per hr, of which approximately 31 pct is 1/4xO-in. size, and the plant reject ranges between 14 and 16 pct of the feed.

Jan 6, 1953

By W. B. Mather

Literature dealing with rock drilling presents a mass of conflicting data. The principal cause of the confusion is attributed to varying definitions of the hardness factor of rock and cutting media. The future development of more efficient drilling methods demands that this problem be solved. The first step in the solution is the compilation of complete data on the physical properties of rocks.

Jan 2, 1951

By J. Gordon Parr, M. J. Bibby

In addition to the (bcc) - (cph) transformation at 882°C a second distinct change of slope has been observed on a titanium cooling curve between 905" and 960°C.1,4 Duwez,1 commenting on work by McQuillan,2-4 attributed this arrest to contamination of the specimen with oxygen—a possibility that existed even at the reduced pressure of 10-5 mm Hg at which the experiments were conducted.

Jan 1, 1963

By William E. Ford, Edward Salisbury Dana

This section includes the common calcium titano-silicate, Tiianite; also a number of silicates which contain titanium, but whose relations are not altogether clear; further the titanate, Perovskite, and niobo-titanate, Dysanalyte, which is intermediate between Perovskite and the species Pyrochlore, Micro- lite, Koppite of the following section. In general the part played by titanium in the many silicates in which it enters is more or less uncertain. It is probably in most cases, as shown in the preceding ages, to be taken as replacing the silicon; in others however, it seems to play the part of agaaic element; in schorlomite (p. 510) it may enter) in both relations.

Jan 1, 1922

By A. J. W. Schwandt

Magmont is a venture jointly owned by Cominco American Incorporated of Spokane, Washington and Dresser Minerals, Division of Dresser Industries, Houston, Texas. Cominco American assumed direction of the operation in 1961 and completed exploration, preproduction planning and development, and is now the operating partner managing the operations. The plant has a rated capacity of 4200 tpd and produces in excess of 60,000 tons of lead per year. [ ]

Jan 1, 1970

By Harry A. Perry

The Highlad underground uranium mine is located in the southern Powder River Basin, Converse County, Wyoming. Development by Exxon Minerals Company began in 1973 and average production from the complex roll- front deposit ranges from 500 to 600 stpd. A staff of six eight grade control technicians work within the Geology Department to guide and monitor production, to minimize waste and to account production to reserve estimates. A thorough knowledge of the complex roll- front deposit aids in accounting production to reserve estimates. Grade control technicians assist the mine geologist in making geologic cross sections, in estimating reserves, and in predicting monthly and quarterly production grades.

Jan 1, 1980

By Jack A. Caldwell

Jan 1, 1985

By Agustin S. Segura, Luis G. Gutierrez

Foreign investment in Mexico, particularly of American capital, has increased steadily since 1940. At present, however, these investments are less important to the Mexican economy than in earlier periods. In the last few years, local or Mexican capital has participated in most American investments in Mexico with the encouragement of the Mexican Government. Foreign investment in a wide variety of industrial activities has gone up in the last decade, placing mining investments in second place. This growth is the result of the Mexican Government's favorable attitude toward industrial expansion. The process has been encouraged through tax exemption on infant industry, through customs protection, and through other incentives.

Jan 11, 1959

By Erwin S. Sperry

It is a tradition in the brass industry that bismuth is ail injurious element in brass, even more deleterious than antimony; but such a belief has lacked verification. The occasional presence of bismuth in commercial copper (although less frequent than was formerly supposed) led the author to investigate this tradition. The f'ollowing experiments mere conducted in the same man-

Jan 1, 1899

The regular activities of the Institute are financed mainly by income derived from members' dues, from advertising in MINING ENGINEERING, JOURNAL OF METALS, and JOURNAL OF PETROLEUM TECHNOLOGY, and from the sale of publications to the public In addition, collateral activities and special projects are financed each year by means of income - from endowed funds controlled and administered by the Institute. An active effort is being made to increase the endowment funds of the Institute through a standing committee, of which Wilfred Sykes is Chairman, and of which the other members are N G

Jan 1, 1952

Eckley B. Coxe, Drifton, Pa.: Anthracite coal differs from other fuels in its greater solidity. It does not burn like coke or wood, or like bituminous and coking coals, which become more or less spongy when heated, so that combustion can take place to some

Jan 1, 1892

ARIZONA Tucson University of AriZona, Mining Engineering Society. B CALIFORNIA Berkeley University of California, Mining Asso. B University of California, Library. B & T Los Angeles Chamber of Mines and Oil. B Southern California Local Section. T Public Library. B & T Oakland Oakland Free Library. T San Francisco California State Mining Bureau. T Mechanic's Merchantile Library. B Mining and Scientific Press. B Stanford University Stanford University Geological and Mining Society. B San Diego Public Library. B COLORADO Boulder University of Colorado, Library. T Denver Bureau of Mines. B Colorado Scientific Society. B Mining American. B Denver Public Library. B & T Golden Colorado School of Mines Magazine. B Colorado School of Mines Library. T Colorado School of Mines Scientific Society. B

Jan 1, 1923

By D. Hartley

United States Steel Corp's. Minntac mine is located at Mt. Iron, Minn. on the Mesabi Iron range. The taconite pit is two miles wide, with a maximum depth of 170 ft. Millions of tons of crude ore, waste rock, and surface overburden are handled annually at the mine. All crude ore plus some of the lower-grade rock are rail-hauled; other materials are trucked. Length of rail haul averages 3.5 mi, with a lift of 140 ft. The maximum grade against the load is 1 ½ %. Nine 1200 hp diesel-electric locomotives handle trains of 40-and 50-cu yd side dump cars in crude ore and lower-grade rock service. In addition to this continuous operation, locomotives handle coarse tailings disposal and switching duties on an intermittent basis. All railroad equipment operates under the supervision of a mine control foreman through voice radio communication. The pit foreman also has this frequency available, quickly accommodating any changes in operation that may be required.

Jan 1, 1970

By S. C. Sun, D. R. Mitchell

Experiments show that ores such as tungsten and tin, which slime excessively, can be deslimed and upgraded by ultrasonics. The method proposed depends primarily upon the stratifying and peptizing action caused when high frequency sound waves are propagated upward through ore pulp in a cylinder tube. Stratifying and peptizing are somewhat hindered by the accumulating action, which embodies additional effects of reflection and refraction.

Jun 1, 1956

By Ta M. Li

A record 340 senior students with majors in mining and mineral engineering from 21 shcools in the US may be expected to enter a manpower-hungry mineral industry in 1975. While starting salaries may have been the deciding factor in job selection in the past, 1975 graduates will find salaries almost the same in most mining sectors. Meanwhile, the survival prospects of various mineral engineering schools had the usual ups and downs in 1974, but tightening state budgets could still take a toll in reducing the number of schools offering mineral engineering degrees. Two such schools on the endangered list include Montana College of Mineral Science in Butte, Mont., and the College of Mines, University of Idaho, in Moscow, Idaho.

Jan 3, 1975

By W. C. Hagel

In 1952, Hauffe and pfeiffer1,2 reported that parabolic rates of nickel oxidation are decreased by factors of two and four at 1100° and 1000°C, respectively, when Li2O vapor is present. Hauffe 's3 explanation was that monovalent lithium enters the crystal lattice of p-type NiO to decrease cation-vacancy concentration and, hence, diffusion of Ni2+ ions across the growing oxide. After first succeeding in adding lithium directly to molten nickel, the purpose of this investigation was to determine whether alloyed lithium is a more effective oxidation inhibitor than the external vapor. Seven 650-g heats were prepared by melting carbonyl nickel inductively under 1 atm of argon. Various amounts of lithium were added by dropping small chunks into the melt. Only about 10-pct recovery was achieved with the remainder lost by spattering and volatilization. Nominal and actual

Jan 1, 1965

By Frank L. Bazzanella, Paul A. Weyler

A brief introduction to gravity concentration is presented, including some discussion on the more common minerals currently recovered. The important considerations in basic design of a gravity plant are mentioned and four currently operating flowsheets are presented. The plants discussed in detail include the Climax Molybdenum Co. By-Product Plant and the Canada Tungsten Ltd. Plant. Plants briefly highlighted include the Palabora Mining Co. Uranium Recovery Facility and the Bridge Hill Ridge Heavy Mineral Recovery Plant of Mineral Deposits Ltd.

Jan 1, 1978

By Norman Weiss

There was a time in the early history of man's use of metals when ore could be directly reduced to usable form by the use of fire. In those days the term "milling," or its many synonyms signifying the concentration of an ore's metallic con- tents before smelting, was little known. Centuries later, even before Agricola, or even before the Greek and Roman civilizations, simple means were found to concentrate metallic minerals that possessed special characteristics such as high specific gravity, hardness, magnetic response, or simple appearance. In this way, the art of milling became valuable to civilization because it eliminated most of the cost and labor of transporting and melting the worthless nonmetallic part of an ore. As civilization became more dependent upon metals and solid fuels, the art of ore dressing (one of our synonyms) increased in importance and complexity, until today it has become a gigantic industry firmly based upon a mature but rapidly advancing technology. Technically trained people are needed in growing numbers to serve this industry.

Jan 1, 1970

By Robert Mehl

IT has been shown that quenched iron of high purity exhibits a Widmanstätten figure much resembling martensite in appearance.1 This figure exhibits a maximum of four directions of the surface traces that characterize it, suggesting that a Fe forms from y Fe in plates parallel to the {111}, octahedral, planes in the y lattice. Because of this, and also because of the general similarity to the structural appearance of martensite and to the Widmanstätten figure obtaining in slowly cooled hypoeutectoid steels it has been suggested2 that the orientation relation-ships obtaining between the y and a phases in pure iron are identical with those demonstrated in martensite3 and in slowly cooled hypoeutectoid steels,4 and indeed that the crystallographic mechanism of formation of a Fe from y Fe is the basic mechanism determining the orientation relation-ships found in both martensite and in slowly cooled hypoeutectoid steels. This paper will present experimental evidence in support of this view.

Jan 1, 1934

By Graham MacFarlane

The eastern coal-field of Kentucky covers about 11,000 square miles of territory. On the east and south it extends to the State lines of West Virginia, Virginia and Tennessee. Its western boundary may be roughly described as an irregular line beginning at the Ohio river, in Greenup county, thence through the counties of Carter, Menifee, Wolfe, Estill, Jackson, Rockcastle, Pulaski and Wayne, to the Tennessee line. The changes in the rock-intervals and in the coal-seams from the northeastern end of the field to the south and southeastern end are so great that no satisfactory identification of the coals has yet been made, and the correlation of the Kentucky coals

Jan 1, 1896