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By E. P. Dowding, J. Schlocker, C. H. Fuchsman, R. R. Lloyd, Mahan. W. M., O. C. Garst, W. T. Rawles

"INTRODUCTION The United States, although the leading consumer of chromite, depends almost entirely on imports for its supply. For instance, the consumption during. 1941 amounted to 714,645 long tons, whereas the domestic chromite production, although the highest since 1918, was 12,731 long tons or only 1.78 percent of the domestic consumption. 9/ Domestic production was tremendously, accelerated,after 1941 by war demands; however, only a small proportion of this domestic product was of sufficient quality to be substituted for the high-grade imported chromite demanded for metallurgical purpose. Chromite is used largely for making ferrochromium, an alloy containing 60 to 70 percent chromium which is used in making alloy steels. Peacetime specification for ferrochromium required that it should contain 68 to 69 percent chromium. These specification were lowered to between 60 and 63 percent, chromium in 1941 to permit the use of lower-grade ores. The specifications for metallurgical chromite, used for making ferrochromium, were established first by the Metals Reserve Company at 48 percent Cr203 and a Cr. Fe. ratio of 3 : 1 but later were lowered to 45 percent Cr203 and a Cr : Fe ratio of 2.5 : 1. The ratio of chromium to iron in chromite is important, because the contained iron enters the alloy in making ferrochromium and, although an ore may contain the required 45 percent Cr203, it may contain too much to be suitable for ferrochromium production. The principal sources of domestic chromite are California, Oregon, Montana, and Alaska minor, small, and widely scattered deposits in another dozen States. Without exception, these deposits are low-grade, require beneficiation to produce a commercial product, and are not competitive with imported high-grade ore in normal times. Nevertheless, these deposits form strategic reserve, which must be utilized in periods of national emergency. Recognizing this fact; the Bureau of Mines for many years has undertaken investigations to develop methods of utilizing domestic chromite ores. The problem has been approached from three angles: (1) Mechanical methods of concentration; (2) beneficiation by chemical or metal¬lurgical methods; and (3) production of metallic chromium by electrolysis of solutions prepared from ore or concentrate."

Feb 1, 1946

By N. Kumar Kittusamy

This report covers the work performed by the Advanced Products Division of FMC Corporation under Bureau of Hines Contract J0155166, Design Evaluation for Development of an Advanced Bolter Module. FMC has evaluated the existing ISMS bolter designs, and the corrections and improvements in progress, including the effect of the three-chain magazine presently being fabricated, and recommends that a complete bolter module featuring a new magazine, safety post and lower stabilizer or similar device be designed, fabricated, and tested, A 29 week program is proposed which includes a four week demonstration. This module would eliminate those reliability problems not presently being solved and would provide a reliable bolter module for a production oriented miner/ bolter.

Jan 1, 1975

By T. C. Wesson

The need for elemental-analysis information on coal mine dust for use in health and safety research prompted this study by the Bureau of Mines. Neutron-activation and X-ray fluorescent techniques were used to obtain five-element analysis (silicon, aluminum, iron, calcium, and magnesium) on 444 samples from 68 coal mines in 10 States. From these analyses, the average composition of the dust in coal mines was determined. The contribution of the primary dusting material (limestone dust) to the makeup of coal mines was shown. Regional differences in mine-dust composition were indicated.

Jan 1, 1974

By R. Y. Williams

The investigative work described in this report was undertaken by the Bureau of Mines under a cooperative agreement with the department of mining engineering of the University of Illinois and the Illinois State Geological Survey." The purpose of this agreement was to provide for a comprehensive investigation of coal-mining conditions in the State, with especial reference to the possibility of lessening waste in the mining and preparation of coal and of reducing the dangers to which miners are exposed. The Bureau of Mines paid particular attention to those phases of the investigation that were of general interest from their bearing on safety and efficiency in the coal-mining industry as a whole. Thus, it studied the occurrence of gas (methane) in the mines of the southern part of the State," tested the inflammability of the coal dust from many mines, examined the efficiency of the control of ventilating currents, and investigated the factors affecting the humidity of mine air with respect to their bearing on the occurrence of mine explosions. Following the establishment of the fact that under certain conditions dry bituminous coal dust is inflammable, there arose the problem of finding efficient methods of preventing or limiting coal-dust explosions. Experiments in the gas-and-dust gallery at the Pittsburgh testing station of the Bureau of Mines verified the fact that certain dusts that explode violently when dry are rendered inert by proper humidi- .fication of the atmosphere within the gallery, and the importance of humidity as a factor in limiting the inflammability of coal dust in a mine is demonstrated by the fact that there has never been in Illinois a dust explosion during the summer months, whereas the records show a number of dust explosions during cold weather. It is easy to see that the warm moisture-laden air that enters a mine in the summer must deposit moisture on cooling, whereas the cold and relatively dry air that enters in winter must take up moisture as it becomes heated in traveling through the mine.

Jan 1, 1914

By R. T. DeWoody, J. W. Chester, W. C. Miller

The work was done to develop a relatively efficient muffler for quieting the exhaust of a rock drill . The exhaust of a pneumatic rock drill is the source of the major part of the noise generated by the drill . The exhaust noise can be reduced in a number of different ways , but this study involved only reactive mufflers . The reactive muffler can be simulated by an electrical circuit . Information obtained from analogous electrical circuits was used to design an efficient exhaust muffler for pneumatic rock drills . Electrical analogies proved to be a valuable tool in the design of mufflers .

Jan 1, 1964

By Douglas F. Scott

In 1981 the U.S. Bureau of Mines and U.S. Geological Survey conducted a mineral survey of the Pyramid RARE II area (No. 5023) covering 23,500 acres (9,500 ha) of E1 Dorado National Forest and 7,900 acres (3,200 ha) of the Lake Tahoe Basin Management Unit (fig. 1). The Bureau of Mines investigation did not reveal mineral deposits in the area. Samples taken from silicified and limonite-stained metasedimentary rocks and aplite dikes were void of precious or base metals or uranium. Placer samples from stream gravels contained no gold values. Molybdenite occurs in quartz stringers within quartz monzonite near Grass Lake, adjacent to the area; no extension; were found in the area.

Jan 1, 1982

By George S. Rice

"INTRODUCTION During the past 4 or 5 years the frequent occurrence of bumps in coal mines of the Cumberland field, in Harlan County, Ky., and Wise County, Va., has caused much apprehension among miners and mining officials of that region.These bumps have caused many deaths and injuries, and have been increasing in frequency. Eight men were killed and a number injured by bumps in the first 4 months of 1934. Their unpredictable occurrence and the usual absence of any preliminary warning tremors or sounds, such as ordinarily precede a large fall of roof, cause fear of other bumps and impair the morale of mine workers.Acknowledgments This report on bumps in coal mines of the Cumberland coal field of Kentucky and Virginia is based on an investigation made at the urgent request of .the Harlan County Coal Operators Association, through James F. Bryson, director of safety of the association, to the Director of the United States Bureau of Mines, following a series of disastrous bumps in. Harlan County, Ky., and Wise County, Va. The request was granted and the writer detailed to undertake the investigation, which was made in June 1934.The officials of certain operating companies in the Cumberland field gave every facility for examining the conditions accompanying bumps in their mines. The writer is most grateful to them for the courtesies shown; to J. F. Bryson, to J. F. Davies, district engineer, Safety Division, U. S. Bureau of Mines, who accompanied the writer throughout his trip to the vari¬ous mines and gave him much assistance and detailed information regarding the occurrence of bumps; and to Dr. David White for reviewing the geological descriptions,Definition of Bumps ""Bumps"" are phenomena comparatively rare in the coal fields of the United States and, for that matter, in the coal fields of the world, because for their occurrence certain exceptional natural conditions are required strong, massive strata of sandstone or conglomerate above the coal and a fairly strong floor, as will be described in detail later."

Jan 1, 1935

By J. R. Thoenen, J. D. Warne

"INTRODUCTION Red-iron-ore deposits in northeast Alabama have been exploited at vari¬ous times for nearly 6o years. About 3-1/2 million tons of ore have been produced in the Gadsden district; but mining activity has been dormant since 1926, and furnaces within this section of the State now suffer a shortage of red ore.To alleviate these shortages, work by-the Bureau of Mines was recommended after preliminary investigations. 4/5/ Diamond drilling, to determine the lateral and vertical extent of ores of known deposits in Greasy Cove and on Shinbone Ridge, was done from August 1946 to May 1947, as Project 9-106, Alabama Red Iron Ore. Three holes were drilled in each area.ASKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of domestic mineral resources to the end that they- make the greatest possible contributions to the national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as possible after its conclusion. The Mining Division, Lowell B. Moon, conducts preliminary examinations, does the actual investigative work, and prepares the final report. The Metallurgical Division, Oliver C. Ralston, chief, analyzes samples and makes beneficiation tests."

Jun 1, 1948

By R. G. Knickerbocker, T. E. Evans, J. L. Morning, D. R. Torgeson, F. W. Wessel

"INTRODUCTION Pilot-plant studies on processes for converting low-grade domestic manganese ore to high-grade oxide or sulfide products by pyrometailurgical process was initiated at the Boulder City, Nev., Experiment Station in 1942. These investigations were given impetus by the possibility of a national shortage of ferro-grade manganese oxide for war needs.The manganese ore employed-in most of the pilot-plant smelting tests was from the manganosiderite-nodule deposits at Chamberlain, S. Dak. This deposit although low-grade, is extensive and represents, the largest reserve of manganese in continental United States. 6/ The Bureau of Mines has recently developed a Carryall mining-conical rolls treatment method that shows promise of making possible economic removal and subsequent beneficiation of the nodule-bearing shales. 7/ Smelting tests were made also on Artillery Peak, Ariz., mill concentrates in the productions of unrefined manganese matte for the steel The pilot-plant smelting program was based upon the fundamental fact that manganese, like copper, will sulfidize and become miscible with FeS. The matte this formed represents the initial smelting step in the pyrometallurgical treatment of the beneficiated ore. The concentrated nodules containing about. 18 percent manganese were smelted with varying amounts of pyrites and appropriate fluxes to produce Mns-FeS mattes containing 16 to 50 percent manganese. When the manganese and iron was completely sulfidized, the mattes contained 16 to 23 percent manganese. Reducing the pyrite resulted, of course, in the selective sulfidization of manganese and the production of a matte containing a correspondingly higher ratio of MnS to FeS. Complete sulfidization smelting produced slags of lower manganese content and hence resulted in higher manganese recoveries in the matte."

Sep 1, 1946

By By Staff

"Acid mine drainage can be controlled by water treatment, retardation of the pyrite oxidation reaction system, or enhanced prediction that allows preventive action to be taken. The Bureau of Mines is conducting research in each of these areas; the results of this research are summarized in the eight papers that comprise this volume. Field work to evaluate overburden analysis, alkaline injection, and bactericidal control of acid formation is described, along with two new inexpensive methods to treat acid mine water. These papers were prepared for an acid mine drainage technology transfer meeting held in Pittsburgh, PA, on April 3 and 4, 1985. INTRODUCTIONAcid drainage from coal mines is one of the most persistent industrial pollution problems in the United States. Over 5,000 miles of streams and rivers are adversely affected, primarily by underground mines that have been abandoned for decades. Meanwhile, at active mining operations and at sites where mining occurred after 1977, discharge water must be treated to meet fairly stringent regulatory limits--at a cost to the industry of over $1 million per day.The Bureau of Mines has a special responsibility to facilitate integration of mining and mineral processing with environmental safeguards. This responsibility is twofold: the development of techniques to reduce or eliminate environmental degradation, and the improvement of existing pollution control processes to make them more efficient and more cost effective. Research in acid mine drainage exemplifies the Bureau's concern for these environmental aspects of mining.This collection of papers summarizes much of the Bureau's recent research on acid mine drainage and will give the reader a sense of where the research is headed, in addition to providing details regarding new technology and recently acquired knowledge. The research papers address four basic objectives:"

Jan 1, 1985

By Suzann C. Ambrosio

Cameroon's mining industry continued to be dominated by crude petroleum. The value of petroleum output was estimated at $1 billion.2 The 1982 gross domestic product (GOP) was approximately $8.4 billion. During 1981, crude oil export revenues increased in value 30%, comprising approximately 56% of Cameroon's total export earnings. The 1982-87 5-year plan emphasized, hydrocarbon and agricultural development and targeted the exploitation of bauxite and clay deposits. New petroleum legislation was promulgated on November 26, 1982. Public Law No. 82-20 detailed hydrocarbon companies' obligations concerning oil and gas discoveries and exploitation. In general, the Cameroon Government has participated in joint ventures with private companies and has levied a 57.5% petroleum tax plus adjustable royalties. Exploration expenses were paid by concession holding companies, and the Government in the past has reimbursed 50% of expenses under certain conditions.

Jan 1, 1984

By S. D. Cramer

Corrosion research is being conducted by the Federal Bureau of Mines to determine suitable construction materials for geothermal resource recovery plants. As part of this research, the corrosion resistance of 31 iron-nickel-, aluminum-, copper-, titanium-, and molybdenum-base alloys was characterized and evaluated in laboratory corrosion studies in low-and high-salinity geobrines representative of those found in the Imperial Valley, Calif. General, crevice, pitting, weld, and stress corrosion were measured at 105° and 232° C in deaerated brines and brines containing dissolved 02, C02, and CH4 General corrosion rates in deaerated brines at 105° and 232° C were usually below 5 mpy for the alloys tested except carbon steel, the low-alloy steels, Monel 400, 70-30 cupronickel, and the aluminum-base alloys. Dissolving carbon dioxide and methane in the brines at 2320 did not markedly alter these results. However, the introduction of oxygen, which can enter the brine during process operations, seriously degraded the corrosion resistance of many alloys by increasing the incidence of stress corrosion cracking, crevice corrosion and, except for the titanium-base alloys, pitting. In deaerated brine at 2320 C, the general corrosion rates for carbon steel and the low-alloy steels were relatively unaffected by pH in the range of 6.1 to 3.0. However, general corrosion rates increased sharply below pH 3.0. In deaerated brine at 232° C, welds in several iron-, nickel-, and titanium-base alloys corroded at rates comparable to the general corrosion rates of the alloys, but the addition of oxygen to the brine increased corrosion rates for welds in Inconel 625 and E-Brite 26-1. Alloys exhibiting good corrosion resistance in the deaerated Salton Sea KGRA-type brine at 232° C were E-Brite 26-1, Inconel 625, Hastelloy S, Hastelloy G, Hastelloy C-276, TiCode-12, Ti-0.2Pd, Ti-2Ni, Ti-1.7W, and TZM. The alloys most resistant to corrosion in oxygenated Salton Sea KGRA-type brine at 232° C were the titanium-base alloys. These alloys appear the most suitable for use in the construction of geothermal resource recovery plants. Carbon steel and the low-alloy steels are unsatisfactory for high-temperature, high-salinity brines and alternative low-cost materials with improved corrosion resistance should be sought.

Jan 1, 1980

By James R. Dunn

Samples were taken of industrial mineral waste materials which are potentially capable of being used for filling underground coal mines for subsidence control in the Pittsburgh and the Scranton-Wilkes Barre areas of Pennsylvania. The samples were subjected to potentially relevant standard tests which are commonly used 1n the evaluation of soil materials and mineral "aggregate materials. Measurements of plasticity, liquid limit, and gradations, particularly in the -200 mesh size range, indicated a comparative lack of clay minerals. Cementitious reactions between sources of alkali, such as calcium hydroxide or portland cement stack dust, and of silica, such as clay or fly ash, were found to occur in various mixes of high-bulk materials. Strengths of up to about 400 psi at 84 days were observed. The possibility of emplacement of high-bulk material by both turbid flow (or density currents) below water and by mud flows above water were considered and both appear to be reasonable and possibly simpler than the current mechanisms of emplacement.

Jan 1, 1977

By J. R. Thoenen

In June 1929 the Bureau of Mines issued a 13-page Information Circular entitled "Mineral wool." This was one of the first publications to present to the public some technical aspects of the mineral-wool industry. Since that time several articles have appeared on the subject in the technical press as well as publications by State organizations. Inquiries for information on mineral wool have continued to be received by the Bureau of Mines in large numbers, and in 1935 it was decided, with the cooperation of the is industry, to make a field survey of the plants then producing and to collect therefrom technical data to be compiled in a paper for public distribution. As a first step, a brief questionnaire was mailed to the known producers asking if they would cooperate for publication. Favorable replies were received from of percent of the manufacturers, and the field work was started. As the study progressed and tie number of plants visited grew, it became more and more apparent that the industry had made rapid strides in technical operation and control of their product, as well as in increasing production during the mast decade.

Jan 1, 1938

By Steven J. Schatzel

Large-scale methane releases in dual salt mines have resulted in ignitions and mine fatalities as recently as 1979. Several past studies have implied that hazardous methane occurrences in U.S. salt domes are distributed neither uniformly nor randomly, but are geologically controlled and potentially predictable. A first step by the Bureau of Mines in addressing the problem of methane in deal salt mines required development of a new test to determine volumes of gases in solid salt samples. This report considers the results achieved when 80 deal salt samples were tested for gas content by dissolution in a controlled atmosphere chamber. Criteria were organized to delineate salt types based on geological occurrence. Outburst samples range from 0.014 to 7.4 cm3 CH4/100 g NaCl, anomalous salt samples from 0.0027 to 2.6 cm3 CH4/100 g NaCl, and normal salts from less than 0.0003 to 0.31 cm3 CH4/100 g NaCl. The presence of higher hydrocarbons was most common in samples containing larger quan¬tities of methane. The presence of higher hydrocarbons appears to be useful in detecting methane hazards where some methane may be lost before gas content testing. An exploratory rotary and/or core drilling program, dissolution testing for gas content, and up-to-date geologic mine napping could allow a mine operator to assess methane hazards in dual salt.

Jan 1, 1984

By Mandius C. Lundal

This report describes the work done to develop a coal mining machine to increase productivity and recovery from thin seams beyond the highwall, in addition to decreasing the miner's susceptibility to to highwall hazards First, radar transducers were adapted to measure coal thinkness and detect rock and coal interfaces; Then, the radar was incorporated into a cutterhead with steering controls. Next, visual displays were designed to show cutter position in the coal seam, and anticipated change in coal seam inclination, Finally, development of a telemetry system made remote control of the cutterhead possible. Simultaneously, a high-performance extended depth (HPxD) auger machine was designed with an automatic system to handle 600 ft of 36-in, diameter dual spiral flight conveyor sections. A two man crew controls all operations from a weather conditioned cab outside the VDZ, either at night or day time. As a primary mining tool, working 4000 hr/yr (2 shifts/day) recovering 60% of the coal 600 ft beyond the highwall, productlon to 500,000 ton/yr can be achieved. Volume I provides an overview of machine, systems and productivity.

Jan 1, 1977

By H. D. Raymond

This report contains a summary of designs, specifications, costs, and schedules developed for a prototype oil-shale demonstration mining program to be undertaken at the Horse Draw site in the Piceance Creek Basin, Rio Blanco County, Colorado. The objective of the demonstration program is to assess the feasibility of extracting oil shale and associated saline minerals from deep, rich oil shale zones which occur within the central portion of the Basin. Four mining systems were specified for demonstration. These include (1) chamber and pillar mining with backfill; (2) sublevel stoping with backfill; (3) sublevel stoping with full subsidence; and (4) block caving. Commercial-scale designs for each system were modified and scaled down as required to achieve program objectives. The demonstration mine layout and design includes specifications for ore handling, backfilling, ventilation, dewatering, maintenance, and supply systems. A feature of particular interest in the design is the combination of block caving and sublevel stoping methods into a single unit for demonstration of subsidence mining systems in deep oil shale deposits. The report also contains a detailed breakdown of projected capital and operating costs for the demonstration mining program.

Jan 1, 1979

By A. L. Engel

This report is a compilation of results of preliminary tests on scheelite (tungsten) ores and tailings. These investigations were made to assist in establishing satisfactory treatment methods for small-scale concentrator operations, or to indicate a. method for conserving previously lost mineral values in old tailings, if possible. A discussion of test procedures is included, as it was felt that this would add to understanding the results reported under the several projects. The treatment of scheelite ores has become more or less standardized. Important differences occur in textures of ores from various mining districts. However, and this must be considered when planning ore-dressing operations. In most of the present investigations, only a limited amount of work was done, usually just enough to answer a specific question in regard to a particular ore or concerning local conditions. Two methods of treatment included gravity concentration, magnetic separation, and flotation.

Jan 1, 1952

By Sidney Katell

This; report, covering the period January 1965 through December 1965, is a continuation of a series that began with the publication of Information Circular 7516 in October 1949. It is the seventh in a series of reports prepared in cooperation with the American Association of Cost Engineers. The abstracted articles are concerned with all phases of cost engineering in the field of chemical and petroleum plants and related subjects. They are from the following sources: 1. American Association of Cost Engineers Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress. 6. Chemical Week. 7. Coal Age. 8. Coal.3 9. Cost Engineering. 10. Hydrocarbon Processing and Petroleum Refiner. 11. Industrial and Engineering Chemistry. 12. Nucleonics. 13. Oil and Gas Journal. 14. Petroleum Management. 15. World Oil.

Jan 1, 1966