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Australia is tightening its rules governing mineral processing and the purchase of rural land by foreign investors" Rural land purchasers in the future will have to demonstrate to the Foreign Investment Review Board, the applicable governing body, that they will introduce new techniques or developments that will benefit Australia. In mineral processing, the criterion will be the availability of maximum opportunities for Australian equity capital. The changes are designed to discourage absentee landlords and speculators from abroad. A diamond field discovered several years ago in the northern section of Western Australia, known as the Kimberley region, is now thought to be one of the largest in the world, according to Conzinc Riotinto of Australia Ltd. (CRA). Figures released late in 1981 by CRA indicate that the main orebody of at least 100 million metric tons contains possibly 500 million carats of diamonds with a conservative market value of $8 billion. The diamond stones in the 100-acre deposit are about 10% gem-quality, 30% near gem, and 60% industrial. Initial production is expected to be about 17 million carats annually, which could be expanded to 25 million carats annually. World production of natural diamonds has been about 40 million carats per year from a reserve base of about 700 million carats.

Jan 1, 1982

By S. M. Shelton

Preliminary work in the investigation of electrolytic manganese, as reported4/, showed promise for a practical procedure of continuous production. Laboratory work was continued in the direction of process simpliication to determine an economically feasible procedure that would require a minimum of expensive equipment for plant erection and a minimum of reagent consumption for operation. Results furnished enough evidence to indicate that modifications of the process could be made leading to simplified procedure and with no sacrifice in operating efficiency. A supply of at least 200 pounds of the metal was desired for alloy research, and it was believed worth while to utilize available facilities in a search for difficulties that were not encountered in the laboratory and that might arise in larger-scale operation. Consequently, an experimental pilot plant was erected. The plant was designed for a capacity of 15 pounds per day of metal and operated under simulated plant practice.

Jan 1, 1938

By S. M. Shelton

Preliminary work in the investigation of electrolytic manganese, as reported J, showed promise for a practical procedure of continuous production. Laboratory work was continued in the direction of process simplification to determine an economically feasible procedure that mould require a minimum of expensive equipment for plant erection and a minimum of regent consumption for operation. Results furnished enough evidence to indicate that modifications of the process could be made leading to simplified procedure and with no sacrifice in operating efficiency. A supply of at least 200 pounds of the metal was desired for alloy research, and it was believed worth Mile to utilize available facilities in a search for difficulties, that were not encountered in the laboratory and that might arise in larger-scale operation. Consequently, an experimental pilot plant was erected. The plant was designed for a capacity of 15 rounds per day of metal and operated under simulated -plant practice.

Jan 1, 1938

By R. Duncan Gardner

This paper describing the milling practice at the concentrator of the Harmony Mines Co. is one of a series being; prepared by the Bureau of Mines on milling methods and costs in the United States. For the period February 15, 1929, to June 1, 1929, the concentrator treated 200 tons of copper ore per day containing 3.84 per cent copper and recovered 99.2 per cent of the total copper in concentrates averaging 26.61 per cent copper. Milling practice at the Harmony Mines is in most respects similar to the usual practice at the average flotation concentrator producing bulk flotation concentrates. The exceptionally high recovery is due to a number of minor conditions. These minor details will be stressed throughout this paper.

Jan 1, 1930

By Louis C. Brichta

The rapid depletion of known deposits of high-grade ore and the need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores in the Tri-State District, led the Bureau of Mines to examine likely mining sites. Underground operations failed to remove all of the ore in a number of areas, and it appeared possible that some of them might be reworked successfully by low-cost open-pit methods. The South Carthage or Hull tract in Jasper County, Mo., was selected by Bureau engineers as favorable for the development of an open-pit mine.

Jan 1, 1949

By Bertrand L. Johnson

As potash is more necessary to the agricultural economy of the United States now than ever before it is gratifying to find that the virtual stoppage of imports from Germany in late 1939 caused none of the anxious foreboding that gripped American farmers in 1914. For long decades this country, in common with tie rest of the world, depended upon German potash, but today our expanded needs can be mot from domestic sources. The present armed conflict in Europe, like that of 1914, disrupted a world monopoly, but the cartel that in recent years controlled 90 percent of the world output (see fig, 1) was an international syndicate comprising French, Polish, and Spanish as well as German producers and having reported sales agreements covering production in the U. S. S. R. and Palestine. The break-up of these commercial agreements has necessitated readjustments but generates no such alarm as the closing of a single source of supply. In striking contrast to the critical shortage that developed a quarter century ago, no increase in prices has occurred or is anticipated in the domestic market.

Jan 1, 1940

By A. C. Johnson

The T. L. shaft of the Eureka Corp., Ltd., near Adams Hill, Eureka, Nev., was sunk in 1954 and 1955 to permit exploration and development of the lead-zinc-silver ore that had been indicated by drilling. This paper describes the sinking of the 4-compartment, vertical shaft to a depth of 1,127 feet and includes pertinent details of equipment, methods, and costs. A shaft crew of 10 men, supplemented by 13 hoistmen, topmen, carpenter, and shop crewmen, sank and timbered the 1,127 feet of shaft in 630 workdays. Total labor per foot of shaft was 107.95 man-hours. Supplies per foot of shaft included 20 pounds of explosives, 1.61 pounds of drill steel, and 200 board-feet of timber. Power consumption, including that required for pumping, averaged 3,726 kw.-hr. per foot.

Jan 1, 1958

By W. W. Odell

Engineers interested in the manufactured-gas industry have witnessed p pronounced improvements in gas-generating equipment and marked changes in operating procedure during the past decade. In spite of these changes, however, the trend of development in the near future seems to be doubtful. Uncertainty exists mainly because no one can yet accurately calculate the number of years which will elapse before petroleum products become too expensive for, general use in making gas. Research in this field has been active, and the ultimate results are awaited with interest. Some engineers predict that in the future coking coal will be carbonized on such a large scale that coal gas will be used (straight or modified) for city distribution; others maintain that gas oil will be used in large quantities in the production of base gas; they believe that it will be economical to use oil even at appreciably higher prices. The question involves, among other; factors, consideration of initial and relative costs of equipment, flexibility of operation, salability of coke, cost of distributing different gases, and the relative value of by-products, It is common belief that for many years large quantities of oil will be used in gas-making, particularly in the generation of peak gas or that water gas will be used for the synthetic production of hydrocarbons to enrich additional water gas. In this paper interest centers in a discussion of the practicability of employing synthetic processes in view of reported investigations of the chemistry of the synthetic reactions. For many years it has been known that the chief components of water gas would react chemically under proper conditions to form methane. As long ago as 1903 a patent3 was issued in this country for a gas-making process which included the synthetic production of methane. More recently the studies of numerous investigators here and abroad have shown that besides methane it is possible to produce other paraffins, olefins, and additional, materials adaptable for enriching water gas or for other uses. The question arises: In what manner, if at all, can such processes be incorporated, as a part of the gas-making scheme in a city-gas plant?

Jan 1, 1928

By D. Harrington

Correct ventilation of underground workings whether in coal or in metal mines consists in establishing such control of air currents that the miners may work in safety, with maximum comfort and efficiency, and without impairment of health; also in controlling the air flow so that the mine workings may at ordinary times be kept reasonably free of harmful gases or dusts, and so that in time of emergency, as when a fire or an explosion occurs, there may with minimum delay be maintained as much or as little air flow as is desired throughout the mine in its entirety or in certain parts of the mine. Control of air flow is the essential point of any mine ventilating system, and is obtained only by the installation of mechanically operated fans, and other ventilating devices such as doors; overcasts, regulators, etc. Every mine, large or small, coal or metal, should from the outset be equipped with a fan. Much has been written about natural ventilation, and many claims have been made that in specific mines or parts of mines there is sufficient natural air flow. As a matter of fact, there are actually very few if any mines, coal or metal, where natural ventilation creates atmospheres anything like adequately safe or healthful for underground workers even at ordinary times or under ordinary. conditions; and at the time of a fire or an explosion mines depending upon natural ventilation are practically helpless, and are decidedly dangerous for the unfortunates forced to be in them either at the time of the disaster or afterwards when trying to handle conditions arising from the emergency.

Jan 1, 1929

By Wilton Johnson

Native asphalt was produced in 1981 by five companies in three States, Alabama, Texas, and Utah. Texas was the leading State in production of native asphalt. Total production increased in 1981 to 1.26 million tons, while value increased 10.5% to $27.7 million. Bituminous limestone, used primarily for street and road repair, was produced by Whites Uvalde Mines and Uvalde Rock Asphalt Co., both in Uvalde County, Tex., and Southern Stone Co., Colbert County, Ala. Gilsonite was produced by American Gilsonite Co., Uinta County, Utah, and Ziegler Chemical and Mineral Corp., Weber County, Utah. This material was used for purposes other than road repair.

Jan 1, 1982

By C. Özgen Karacan

The methane emission rate into an underground mine environment from overburden strata during longwall mining is impacted by reservoir and geomechanical characteristics of the coal measure rocks in the overlying strata, as well as the presence of any coal seam. The reservoir characteristics and how they change during mining potentially affect the performance of gob gas ventholes, which consequently impacts the efficiency of methane control in the mining environment. This study presents reservoir and elastic properties of coal measure rocks in the Lower Monongahela Group in Greene County, southwestern Pennsylvania, of the Northern Appalachian Basin. Since the source of methane in this region from underground mining is located between the Sewickley coal and the Pittsburgh coal, a specific emphasis was given to this interval. Core analyses were performed in the laboratory to determine rock porosity and permeability. Geophysical logging data (gamma, density, sonic) obtained from two exploration boreholes were used for evaluating formation boundaries, shale contents, log porosities, and geomechanical properties of formations. Permeability was also calculated using density-log data and empirical equations and compared with laboratory measurements and slug tests performed in isolated intervals of boreholes. The results presented in this study can be used as data sources for reservoir studies related to the production and control of methane.

Jan 1, 2009

By D. H. Platt

Gypsum and gypsite, used in the manufacture of plaster and plaster products, have been mined from deposits near Acme, Hardeman County, Tex., for more than 30 years. The Certain-toed Products Corp., 120 East Lancaster St., Ardmore, Pa., operates the Acme, Tex., mine. Underground hauling was done with storage-battery and Diesel-electric-powered shuttle cars. Many mining companies and individuals have manifested interest in all types of equipment powered by Diesel or Diesel-electric units, as attested by the recent increase in use of Diesel-powered equipment in underground metal and nonmetal mines. The purpose of this paper is to describe the manner in which a storage battery-powered Joy Model 60D2 shuttle car was converted to Diesel-electric power. The conversion was made, at the instance of the operating company, by Stewart & Stevens on Services, 4801 Lemon Ave., Dallas, Tex. This is believed to be the only such converted shuttle car in use.

Jan 1, 1950

By A. C. Richardson

During the past two and a half years the U. S. Bureau of Mines and the University of Alabama, with the cooperation of the different coal operators, have been making an extensive study of coal preparation in the State of Alabama. Considerable time has been devoted to the study of the washing characteristics of the Mary Lee bed and the various methods used in preparing from it a low-ash coal suitable for the manufacture of metallurgical coke. One of the phases of this problem is the utilization of middlings products from the washing plants. This paper gives the results of treating jig middlings on a coal-washing table at the Bureau of Mines laboratory at Tuscaloosa, Ala. The sample used was secured from the Sayreton washery Of the Republic Steel Corporation, Sayreton, Ala.

Jan 1, 1931

By F. A. Rutledge

The Bureau of Mines Investigated the Copper Bullion claims at Rua Cove on the east coast of knight Island in Prince William Sound, Alaska, during November-December 1948 and March-April 1949. This project was part of the Bureau of Mines program for developing critical and strategic minerals in Alaska, Mineralization at the copper deposit on the Copper Bullion group of claims is mainly pyrrhotate and chalcopyrite, confined to a northeast-trending shear zone in the greenstone 2,000 feet northwest of Rua Cove. The property has been partly developed by two adits, by a number of crosscuts from the upper adit, and by several diamond-drill holes.

Jan 1, 1953

By S. P. Kinney

The efficient operation of a blast furnace is primarily dependent upon efficient contact between the descending stream of solid materials and the ascending stream of gas. The United States Bureau of dines is conducting a program of research dealing with the interior of the present-day furnace. The work is being carried oat by.(1) observations on commercial furnaces end (2) experiments in the laboratory. Through the courtesy of the officials of the Illinois Steel Co. it was possible to make a detailed investigation of the interior of the shaft of Number.4 furnace at the company's South Works, South Chicago, Ill. The experimental work is to be reported in a U. S. Bureau of Mines bulletin which will include the results of several thousand observations on the interior of the shaft of this furnace. Such of the data as are presented later in this paper constitute only a brief summary.

Jan 1, 1929

Under the Bureau of Mines Research Contract Number H0252071, Foundation Sciences, Inc. has compared the relative effectiveness of roof bolts installed at an angle over the rib with that of bolts installed vertically at the rib side, The information gathered during this investigation was sufficient to supply supplementary information on the mechanics of roof support systems and the general acceptability of field instrumentation methods. During the 140 days of field investigation, 235 bolts were installed, 45 inclined and 190 vertical, in two adjacent intersections. Of these 235 bolts, 30 were in-stalled with load cells and 38 were tested for anchor capabilities. In addition to this instrumentation, the deformation of the opening was measured by convergence meter on 9 lines throughout the two testing areas, and a borescope and photo-elastic gauges were utilized to obtain information on the roof action beyond the surface.

Jan 1, 1977

By Lloyd A. Morley

This eight-chapter document is the second volume of a two-volume report that presents a comprehensive outline of coal-mine electrical power systems from theory to practice. Together, the two volumes contain the vital aspects that go into planning and designing a mine power system. Building upon Volume I, the subject of protective equipment and relaying starts Volume II, first as an introduction in Chapter 8, then by a treatment of device selection in Chapter 9. Chapter 10 continues system protection in terms of transients and overvoltages. Chapter 11 describes the design of major power equipment, including power centers, switchhouses, and substations. Solid-state applications in mining are given in Chapter 12, and batteries and battery charging are discussed in Chapter 13. Chapter 14 covers electrical-equipment in hazardous locations of mining operations. The report concludes with Chapter 15, a discussion of electrical maintenance as well as some specific mine electrical problems. Information on surface and underground use is included in all these chapters. An index finishes the documentation and is cross-referenced to both report volumes.

Jan 1, 1982

By C. H. Riggs

This petroleum-engineering report of the Atlanta oil field in BO them Arkansas reviews reservoir conditions and pressure-production history of one of the important Smackover limestone fields in southern Arkansas. The study of the field was made and the report prepared to aid operators in this and similar fields to increase the efficiency of recovery through the application of better engineering practices. A similar study of the Magnolia field in Arkansas by Carpenter and Schroeder was the first of these reports prepared under a joint agreement between the Arkansas Oil and Can Commission and the Bureau of Mines. The increasing demands for petroleum and its products and the steadily increasing cost of discovering and developing oil field; emphasize the importance of conserving known reserves of oil and gas. In recent years vast improvements have been made in the technique of oil recovery, both by better utilization of the natural energy stored in the reservoir and by improved methods of applying external energy to the reservoir system. This report may aid in oil conservation by careful evaluation of the several factors that did or did not contribute the greater recovery in the Atlanta field and by suggesting improvements in production methods and applications.

Jan 1, 1949

By A. C. Richardson

[During the past two and a half sears the U. S. Bureau of Mines and the University of Alabama, with the cooperation of the different coal operators, have been making an extensive studs of coal preparation in the State of Alabama. Considerable time has been devoted to the studs of the washing characteristics of the Mars Lee bed and the various methods used In preparing from it a low-ash coal suitable for the manufacture of metallurgical coke. One of the phases of this problem is the utilization of middlings products from the washing plants. This paper gives the results of treating jig middlings on a coal-washing table at the Bureau of Mines laboratory at Tuscaloosa, Ala. The sample used was secured from the Sayreton washery of the Republic Steel Corporation, Sayreton, Ala. WASHERY PRACTICE The Mary Lee bed is very bony, and operators find it difficult to produce from this bed a washed coal much under 10 per cent ash. Experience has shown that in the preparation of a coking coal from the Mary Lee bed it is best to use a process which permits the recovery of a middlings product. Middlings are desirable because separation according to specific gravity is never perfect, and a middlings product makes possible a low ash in the primary warned coal without excessive losses of combustible in the refuse. The general washery practice on the Mary Lee bed is to crush the run-of-mine coal through some maximum screen size and wash it upon some one type of jig without re-treatment of any of the products made. The maximum size treated varies from 3 inch to J inch. The middlings product from multiple-cell jigs is usually termed "boiler fuel" and when possible is utilized as such. At present the production of boiler fuel is often in excess of power requirements, and the surplus, due to its high ash content, becomes waste.]

Jan 1, 1931

By John B. Knaebel

This paper, describing the milling operations of the St. Joseph Lead Co. at Balmat, N. Y., is one of a series of similar papers being prepared by the United States Bureau of Mines on practice at various mills in the United States, Canada, and Mexico. The company also operates a mine end mill at Edwards, 12 miles northeast of Balmat. Mining practice in the district, as exemplified at the Edwards mine, is described in another information circular of the Bureau of Mines.3 The writer gratefully acknowledges the generous cooperation of the company officials which made this investigation possible, and wishes to thank R. J. Mechin, manager, P. W. Wolf, mill superintendent, and F. G. Kuehl, assistant mill superintendent, for their helpful assistance. Especial thanks are due J. S. Brown, geologist, for supplying information on the characteristics of the ore, and to C. F. Jackson, principal mining engineer, U. S. Bureau of Mines, for helpful suggestions.

Jan 1, 1932