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By J. Douglas Causey

In 1984, at the request of the Bureau of Land Management, the Bureau of Mines studied 9,600 acres of the 12,350-acre Antelope Creek Wilderness Study Area (MT-065-266) in order to evaluate its mineral resources. Within this report, these 9,600 acres are referred to as the study area. The Antelope Creek Wilderness Study Area, Phillips County, MT, adjoins the north end of the Charles M. Russell Wildlife Refuge. Considered part of the Missouri River Breaks, the area straddles the edge of a thrust fault zone that has deformed the Mesozoic strata in the west half of the area. Shale, siltstone, and sandstone of Cretaceous Age are exposed in the area. Coal beds averaging 3.0 ft thick occur in the Judith River Formation. About 0.20 million short tons of coal were mined from the Judith River Formation adjacent to the west boundary of the area; no production is known in the study area.

Jan 1, 1986

By Jos. R. Guiteras

This paper describes the operations of the St. Joe Mining & Milling Co. in Boulder County, Colo., as of June 1936. Later a brief visit was made to the mine in September 1936; information obtained at that time has also been recorded. The company operates a gold mine, the Grand Republic, in the Sugar Loaf mining district; a 100-ton flotation mill in Lefthand Canyon near Gold Hill; and a custom sampling punt, the Boulder Ore Sampling Works, at Boulder, Colo.

Jan 1, 1937

By Edwin C. Reeder

This paper, describing milling methods and costs at the Hillside Fluorspar Mines at Rosiclare, Ill., is one of a series being prepared for and published by the United States Bureau of Mines on non-metallic milling methods. The milling practice described is that of one of the large mines in the Kentucky-Illinois fluorspar field in southern Illinois and western Kentucky, on the Ohio River. Milling methods throughout the district are similar in their general principles, although details vary considerably in different plants.

Jan 1, 1932

By R. A. Strehlow

This is the final report for U.S. Bureau of Mines contract HO-122122, which was in effect from June 30, 1972 through January 4, 1976. The work resulted in the design and construction of a large laboratory scale coal dust burner and the use of this burner to study gaseous and coal dust flammability. A new technique for determining gas phase flammability was developed and the effect of solid and gaseous suppressants on the propagation of coal dust flames was studied. In addition, a technique for measuring the C/H ratio in the flame was developed and the C/H ratio that was measured in a coal dust flame on this burner showed that the burning process was preceeded by pyroysis of the coal dust. Both experimental and theoretical studies showed that radiative trans-port is very important to the propagation of a coal dust flame.

Jan 1, 1977

By Lotfollah Nahai

India is one of the fortunate countries that has substantial reserves of many raw materials for producing steel; however, for historical and economic reasons these resources have not been aggressively developed until recently. Production of steel on an industrial scale started in 1912, but annual output was below 1 million tons3 in 1938 and about 1,500,000 tons in 1951. Expansion of the steel industry became one of the objectives of India's economic planning after independence in 1947. The Planning Com¬mission's 1951 report emphasized the importance of steel production, but financial obstacles, emphasis on river valley projects, and priority for increased food production in the First 5-Year Plan (1951-56) did not permit large-scale expansion of steel capacity. The 1956 planned target for crude steel, only 1,650,000 tons, was actually exceeded by production of 1,737,900 tons. In the Second 5-Year Plan (1956-61), however, construction of steel plants received a high priority. Currently three new steel plants, each with an annual capacity of approximately 1 million tons of steel, are nearing completion in Rourkela, Dorgapur, and Bhilai. Simultaneously, the two privately owned steel plants and the small State-owned plant in Mysore have been enlarged and modernized. As a result, India's crude steel capacity will be about 6 million tons in 1961, almost evenly divided between Government-owned and privately owned plants. Actual production in 1960 totaled 3,254,000 tons compared with 2,434,000 tons in 1959. Assuming that the population will be 430 million and that capacity production will be achieved, the 1961 per capita steel output will be only 31 pounds compared with 200 pounds for Japan in 1959. Some Indian experts feel that development of steel-consuming industries merits greater emphasis in the Third 5-Year Plan (1961-66) than expanding existing steel-producing facilities. Nonetheless, the Third 5-Year Plan calls for a 10 million ton annual capacity by 1966 to be achieved by expanding the Government-owned plants in Bhilai, Durgapur, and Mysore, and by establishing a new integrated Government plant in Bokaro, in the State of Bihar.

Jan 1, 1961

By MINE SAFETY BOARD

RECOMMENDATIONS OF THE UNITED STATES BUREAU OF MINES ON CERTAIN QUESTIONS OF SAFETY AS OF FEBRUARY 3 , 1933

Jul 1, 1933

By Jaffrey Y. Foley

Placer gold and platinum-group metals (PGM) In the Slate Creek area, northern Chistochina Mining District, are derived from silicified and carbonate-altered, Cretaceous-Tertiary (?) dikes and related mafic and ultramafic rocks. Gold In the placer deposits is also derived from Tertiary conglomerate and altered Jurassic-Cretaceous argilllte. The argilllte and Igneous bedrock sources show a unique Ag-Au-Cu-Hg-PGM association that Is attributed to a combination of magmatic, hydrothermal, and supergene processes. The bedrock and placer deposits contain a variety of gold silver-lead-copper and PGM alloys. The observed geochemical, mineralogic, and alteration features are consistent with current geological models for turbidite-hosted gold deposits. No economic gold or PGM lodes were Identified, but several areas warranting more detailed investigation were Identified. Conventional geochemical sampling and analysis of small sample splits weighing between 10 and 30 grams were shown to be unreliable as a consistent means of identifying gold- and PGM-bearing bedrock. Pan concentration of pulverized rock samples was shown to be a more effective, but still Imperfect means of Identifying gold and PGM source rocks. Geochemical data and mineralogic examination indicate that gold and PGM in potential lode sources are very finely and erratically disseminated, are chemically combined with other elements, and may not be entirely free-milling or amenable to simple gravity concentration.

Jan 1, 1990

By A. W. BELDEN

Among the investigations that the Bureau of Mines is conducting witha view to increasing efficiency in the utilization of fuels belonging to or for the use of the Government is an investigation of the processesthat take place in a foundry cupola during a melt. Some observations on the results of cupola tests of cokes at the Government fuel-testing plant in St. Louis, Mo., the coke being fromcoal from many coal fields of the United States, have been stated in a previous bulletin.s Especial attention was given to the meltinglosses that resulted from the use of different grades of coke, light and porous or heavy and dense. These losses amounted in one instance to 52.5 per cent of the iron charged and showed, in convincing manner, the need of exact information in regard to conditions in the fuelbed of the cupola.b Melting losses of iron have been fully appreciated but little under-- stood. The fact that these losses were possible with either light or heavy coke led to the belief that by using small charges 80 placed that. melting would take place in that zone of the cupola where the highest heat and the smallest percentage of oxygen prevailed and by confiningall melting to this zone these losses would be eliminated and the economical use of practically any coke produced for metallurgical purposes would become possible. This widening of the field from whichcoke might be drawn for foundry purposes would serve to place the foundryman in an independent position as regards his source of supply, and would tend to conserve the better grades of coking coals, which are being rapidly exhausted, by making the poorer grades available for mixing with them. In order to investigate conditions within a cupola, the Bureau of Mines as a first step decided to install a commercial cupola, to sample the gases during their travel from the tuy~res upward, and to determine the temperature of the fuel bed.

Jan 1, 1913

By A. Galaitsis

This report summarizes part of the work performed under the USBM Contract No. H0155113, "Noise Abatement of Continuous Mining Machines." It reviews, briefly, the aboveground tests performed on a Jeffrey 120M conveyor that were documented in Vol. I of the subject contract; and describes the performance of treatments implemented on underground equipment. The noise level at the operator's position in the aboveground-test facility was reduced from 101.5 to 91 dBA using treatments with satisfactory - aboveground - durability. Extensive underground evaluation has been performed only on the constrained layer damping, which has reduced the conveyor noise by 2 to 6 dBA depending on the operating conditions, and has been shown to be sufficiently durable. Other promising candidates for exploratory evaluation include resilient layers for the top/bottom decks, and smoother discontinuities between adjacent conveyor sections.

Jan 1, 1983

By M. E. Poad

Structural properties of steel-fiber-reinforced shotcrete and polymer-impregnated shotcrete, both plain and fiber-reinforced, were investigated by the Federal Bureau of Mines, Spokane Mining Research Center. The research center has found that flexural strengths can be increased by as much as 106 percent, and splitting-tensile strength by 50 percent, by introducing randomly oriented steel fibers. A slight decrease of compressive strength was found in the fiber-reinforced shotcrete. Polymer-impregnated shotcrete exhibited a threefold to fourfold increase in compressive and splitting-tensile strength. The techniques of preparing shotcrete with the dry process, using both fast-set agents and regulated-set cement, are described, along with the results of physical-property testing. Physical properties include compressive and splitting-tensile strengths, tangent and secant moduli, and stress-strain curves for plain shotcrete, fiber-reinforced shotcrete, and polymer-impregnated plain and fiber-reinforced shotcrete. Flexural strengths for plain and fiber-reinforced shotcrete are also reported. Steel-fiber shotcrete is the more promising of the new structural materials for ground support, and additional research is recommended.

Jan 1, 1975

By R. F. Abernethy

A small-scale method was developed for determining the free-swelling index of coal samples of limited quantity, especially the macerals. Results of a series of tests using a 0.3-gram sample correlated well with those by the standard method using a 1-gram sample. The standard and small-scale methods are modified to give unrestricted swelling for those coals having swelling index numbers above 7.

Jan 1, 1971

By Thomas M. Barczak

This U.S. Bureau of Mines (USBM) report evaluates the load supporting characteristics of grout columns used as point supports for mine subsidence abatement. The cone-shaped columns were constructed with sodium silicate and cementitious grout in both wet and dry environments. The scope of work included the testing of seven full-scale grout columns in the USBM's Mine Roof Simulator from which the load-deformation and failure characteristics were determined. The performances of grout columns are analyzed with respect to (1) the amount of roof contact established during column construction, (2) shape effects produced by the truncated cone geometry, (3) size effects in reference to grout strength and full-scale column capacity, (4) the effect of wet environments on grout strength, (5) the effect of the sodium silicate on the grout strength and full-scale column behavior, and (6) the stiffness of the grout column. Limited tests were also conducted on cylindrical columns constructed in fabric bags. Recommendations for point support construction using sodium silicate technology and the need for additional research to develop improved containment devices for column construction are addressed in the report.

Jan 1, 2010

"INTRODUCTION These inspection standards have been prepared for use as a guide for the Federal inspection of anthracite mines. They are a revision of ""Tentative Inspection Standards for Anthracite Mines,"" published as Bureau of Mines Information Circular 7231 in January 1943 and used as a guide for Federal inspections. Numerous changes in the original standards have been made, due in part to recognition of shortages of some types of safety equipment due to the war, in part to need of additional standards to cover certain mine conditions and practices, and in part to conditions not foreseen when the original standards were prepared.Throughout these standards reference is made to determining the methane content of the mine air by using a permissible flame safety lamp. The Bureau has approved various electrical devices for the detection of methane, but it is recognized that new devices for determining the percentage of combustible gases as well as the percentage of oxygen, might be perfected for general use in mines, and therefore it may be necessary to revise certain standards to include the use of such equipment if and when the device is accepted as being permissible.About one-fourth of these standards are marked with an asterisk (*) as being of particular importance in preventing accidents in many coal mines; however, failure to carry out the suggestions made in such of the other standards as are applicable may also lead to loss of life.With continuing change in mining methods, some of these standards may become inapplicable, and further revision will be advisable. Therefore, question regarding these standards and suggestions regarding new standards should be brought to the attention of the Bureau, so that changes may be made from time to time. Numerous changes proposed by mine operators and by State mining departments have been incorporated in these standards."

May 1, 1944

By J. H. Stears

Increasing use of Birmingham and other roof trusses prompted a Bureau of Mines study of support forces produced on a mine roof by these members. Equations, obtained from laboratory and field tests, are given for calculating the contact forces between the roof strata and a typical truss. Actual contact forces for a specific truss are difficult to estimate because of variable friction loss at the contact points. A finite-element analysis, using typical contact forces, indicated that trusses have a negligible effect on the stress field in massive, competent roof strata. The effectiveness of trusses in supporting broken rock strata was not analyzed. However, experience has shown that trusses are effective in supporting incompetent roof.

Jan 1, 1988

By Oliver Bowles

Accidental explosions in coal mines are due to various causes, but many of them can be directly attributed to coal dust; others that probably in no way depend on dust as a primary cause are propagated, greatly intensified, and made more disastrous by the presence of coal dust. The fact that coal dust in a bituminous mine will explode as a result of a fire-damp explosion has been generally accepted for many years, but the belief has also been held by many that coal dust is not in itself dangerous when unmixed with an explosive gas. Therefore, in past years little attention was given to dust in mines free from fire damp, and many disastrous explosions have resulted from lack of knowledge of the danger from coal dust. In the explosives gallery and experimental mine of the Bureau of Mines experiment station, Pittsburgh, Pa., it has been proved repeatedly and conclusively that coal dust will explode violently when no inflammable gas is present. PROPAGATION OF DUST EXPLOSIONS A coal-dust explosion is an extremely rapid burning or combustion of the coal particles. Their burning consists essentially of the combination of the hydrocarbons in the coal with the oxygen of the air, a process that generates heat and flame and produces hot gases and water vapor. These gases and vapors have a volume many times that of the original coal particles; thus they exert an outward motion and pressure which constitute the explosive wave. When fine particles of coal are suspended in the air, each particle is surrounded by the oxygen of the air, and thus is well placed to oxidize or burn rapidly whenever the temperature is high enough. If some particles are ignited from any cause they will fire others, and the combustion will extend from particle to particle with extreme rapidity wherever enough coal dust of sufficient purity is present.

Jan 1, 1925

Three complete connector assemblies and six separate contacts were submitted to a series of tests to establish the connectors permissibility and compliance with U. S. Bureau of Mines research Contract #H 0110423 D.C. portion. Test Procedure TPC-0118 was coordinated, and the test plan approved by the Bureau as fully complying with the intent of the contract for the direct current connectors. The components and connector assemblies have been demonstrated in testing that they meet or exceed all the requirements of the test procedure.

Jan 1, 1974

By Virgil A. Marple

The objective of this contract was to investigate time-integrated and real-time methods for determining the diesel exhaust particulate concentration in underground mines, in particular, coal mines. The microorifice uniform deposit impactor (MOUDI) is recommended for obtaining the time-integrated measurement of the size distribution. The mass concentration of diesel exhaust particles can be obtained from the particle size distribution of mine aerosols. On a mass basis, diesel exhaust particles are primarily in the submicrometer size range while coal dust particles are larger. Size distribution measurements made in the laboratory and in three underground coal mines exhibited two distinct modes with the diesel exhaust particles in the smaller particle mode and the coal particles in the larger particle mode. The point of separation between the two modes occurred in the 0.7 to 1.0 pm size range. The separation was found to be independent of mass fraction of the diesel exhaust particles, particle concentration and sampling site. Methods recommended for further consideration as real-time monitors of diesel exhaust aerosols in mines are photometers and filter pressure drop techniques. A preclassifier would be required in both cases to separate the larger dust particles from the sample. The Metrex Mineral/Diesel Photometer should also be investigated further once the electronics problems are eliminated.

Jan 1, 1986

By F. W. Wood

The Bureau of Mines has sought clarification of the Ti-TiN system by studying the phases formed by diffusion reactions between titanium and titanium nitride. Reaction couples were prepared by embedding pockets of TiN powder in arc-melted buttons of titanium. Specimens were vacuum annealed at nominal temperatures of 800°, 950°, 1,200°, and 1,500° C. Metallographically mounted cross sections from reacted specimens and from some that were not annealed were examined optically, with an electron microprobe, with an election microscope, and by X-ray diffraction. Each annealed specimen contained a segregated core primarily of d-phase material, an ?-phase diffusion layer, an a-phase diffusion layer, and host metal. On the basis of corresponding microprobe analyses, and considering results of certain other research, a new phase diagram is proposed. It contains no qualitative innovations, only quantitative adjustments. Results were also analyzed from the viewpoint of diffusion behavior. Diffusion coefficients calculated for the ? phase were sufficiently scattered that the parameters are very tentative. Nevertheless, the diffusion behavior reported is in reasonable agreement with one of two prior studies if it is assumed that the earlier investigators were mistaken in their identification of the nitride phase in which the diffusion occurred.

Jan 1, 1974

By M. M. Wong

The Bureau of Mines, under a cooperative research program with four lead companies, has investigated a nonsmelting process for the production of lead metal. The process, which would eliminate sulfur dioxide generation and minimize particulate lead emissions, involves ferric chloride leaching of galena concentrate to produce lead chloride, followed by molten-salt electrolysis of the lead chloride to yield lead metal and chlorine. This chlorine is used to regenerate ferric chloride in the leaching solution. The process was tested in an experimental unit with a capacity of 500 lb of lead metal per day. The tests were performed in three 10-day and six 5-day campaigns, during a period spanning 28 mo. The study was carried out using a southeastern Missouri lead concentrate. Typical lead recovery was about 98 pct. Process problems related to impurity buildup and control were studied. When copper and silver impurities were removed from the leaching solution, a lead metal purity of 99.999 pct was obtained. Lead-in-air levels and lead-in-blood levels of operating personnel were monitored. The process has potential for producing lead with minimum pollution, but is not ready for commercial utilization. Operation of a prototype commercial electrolytic cell and a full-scale pilot-plant investigation by industry are needed to evaluate the commercial viability of the process.

Jan 1, 1983

By D. O. Hamiltion

The ISMS program provided for the development and demonstration of equipment modifications in both conventional and continuous coal mining systems. This report describes activities during the demonstration of the conventional equipment and includes machine performance, results of data gathering, system evaluation, and recommendations for implementing improvements.

Jan 1, 1976