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By L. A. Haas

S02 reduction with CO was studied in an integral flow reactor at a nominal flow of 0.5 liter per minute. Reactant gas contained 3 percent SO2, 6 percent CO, and the balance He. SO2 conversion was determined for three different types of catalysts. The first consisted of 16 commercial catalysts used for various chemical syntheses. Only the commercial catalysts which contained transition metals in alumina removed more than 30 percent 80a at temperatures below 510° C. Two other types of catalysts were prepared in the laboratory either by pelletizing equal amounts of powdered alumina and transition metal oxides or by impregnating commercial alumina tablets with transition metal ions. Regardless of preparation techniques, Cr and Fe in alumina were the two best catalysts. The observed results suggest that an intermediate (SCO) is formed by the interaction of surface metal sulfides and carbonyls. Alumina then catalyzes the interaction of SCO with S02 to form the end products (sulfur and carbon dioxide). Over 80 percent S02 was removed at 460° C with 2 grams alumina impregnated with 2.5 percent iron.

Jan 1, 1972

By Russell G. Warncke

"This report is based primarily on a study of safety conditions and practices followed in the coal mines of Japan. Not all of the coal fields in Japan were studied, but typical mines in the largest producing areas and a fair cross section of coal-mine-safety conditions observed during February to April 1948 are described.Information was obtained through investigations conducted in the mines, discussions with mine-management officials and representatives of labor unions of the various mines visited, and examination of records and statistics from the various offices of the Coal Board of the Ministry of Commerce and Industry and from the Coal Association of Japan. Statistical data covering the same subject, obtained from different sources, varied in many respects and apparently were reported inaccurately, but such discrepancies can be attributed to different methods of reporting and compiling statistics.It is difficult to correlate the high fatal and nonfatal injury rates that prevail in Japanese coal mines with the conditions observed in the mines. Virtually all mines visited were attempting to prevent accidents and explosions, by apparently following known safety precautions for the prevention thereof. Some commendable safety innovations were observed at several mines; they indicated that mine officials are giving thought and consideration to hazardous conditions that affect their particular mines.Naturally, the operating officials and management were anxious to impress the writer with their interest in accident prevention and safety. Operating officials were found to be receptive to safety and wore interested in formulating definite safety programs. Some nines had well-planned and well-organized safety programs, which, if put into effect, would contribute greatly toward reduction of accidents.The approach to safety in Japan is quite different from that in the United States, especially the concept of personal responsibility for accidents and the extent to which the individual should be protected against hazards. Management is responsible for providing and maintaining safe working conditions. Collaboration between management and worker, as understood in the United States, does not exist in Japan.Increase in accidents since the cessation of hostilities is the result of unsettled economic conditions in the coal industry, influx of inexperience workers, and breakdown of discipline among the miners, who have been organized into unions. Those unions are greatly influenced by ""leftist"" tendencies.It was observed that the Japanese mine worker is fatalistic by nature and has little, if any, noticable safety consciousness. The most urgent major requirements to reduce accidents in the coal mines are to train the worker in accident prevention and instruct him regarding the inherent hazards of his occupation.Revision of the mining laws would help to reduce accidents if the companies would comply with such laws and provide safer working places and if the workers would cooperate with management and observe and comply with such laws as are enacted for their protection."

Dec 1, 1949

By George Watkin Evans

The United States Geological Survey has estimated 1 that the State of Washington contains 11,412,000,000 tons of bituminous coal and 52,442,000,000 tons of subbituminous coal, in beds more than 14 inches thick. As the present rate of production is about 4,000,000 tons a year, Washington apparently contains coal enough to supply Pacific coast markets for many years. The character of the coal beds of Washington renders the production of clean coal very difficult, and a considerable proportion of the output is washed before it is marketed. In 1915 Washington ranked fifth among the States in the amount of coal washed, though only twentieth in total output. In that year 37.9 per cent of the coal produced in the State was treated in surface cleaning plants.

Jan 1, 1924

By W. M. Mahan

This report describes work carried out by the Federal Bureau of Mines in cooperation with the General Services Administration (GSA). Tests on nickel oxide reduction were conducted at the Pyrometallurgical Laboratory at Pitts-burgh and Bruceton, Pa., and at a rented plant at Canonsburg, Pa. Nickel oxide was reduced to sponge nickel, which was then melted to produce specification-grade nickel ingots containing a minimum of 98.50 percent nickel plus cobalt and a maximum of 1.00 percent cobalt. One purpose of this study was to determine if specification-grade nickel could be made from nickel oxide produced at the United States-Government-owned plant at Nicaro, Cuba, in pilot-plant scale operations involving direct reduction and melting processes. A second and equally important purpose was to obtain cost data on the pilot-plant operation to estimate the cost of producing ingot nickel at an annual rate of 12 million pounds. Laboratory tests verified that nickel oxide, in saggers and in the presence of anthracite fines and dolomite in the ratio of approximately 20:5:1, could be converted to sponge nickel when heated to approximately 1,900° F. for about 2 to 4 hours, depending on the size and density of the oxide charge. The tests also determined the type of saggers suitable for pilot-plant operations.

Jan 1, 1959

By P. D. Laverty

This report describes a processing method developed by the U.S. Bureau of Mines to produce high-quality flake graphite from the steelmaking waste known as kish. The kish produced by current steelmaking practices is a mixture of graphite, desulfurization slag, and iron that is skimmed from the molten iron feed to the basic oxygen furnace. It is estimated that the graphite content of kish discarded by U.S. steel plants is more than sufficient to meet the total U.S. demand for flake graphite. That need is now filled by natural graphite from foreign sources. Kish was treated by a combination of screening and hydraulic classification to produce a concentrate containing greater than 70 pct graphite. Leaching of the concentrate with hydrochloric acid solution gave a graphite product with 95-pct purity. An optional secondary leaching operation with hydrofluoric acid produced graphite with a purity of 98 pet or greater. The flake size of graphite from kish ranged from 10 mesh down. Evaluation of test samples by industrial graphite users indicated that kish graphite is a suitable substitute for the natural material for most uses. A process flowsheet and material balance for pilot plant design are presented.

Jan 1, 2010

By Steven J. Page

Responding to the increasing concern for dust control in metal and nonmetal mining, the Bureau of Mines investigated typical dust reduction efficiencies of wet bar cutter machines as they are presently being used in salt mines. Wet bar techniques have previously been used in coal mines, achieving dust reduction efficiencies ranging from 11 to 60 pct. Two different wet bar techniques, namely, the front spray and the water trickle, have been studied as they are currently being used in two salt mines. Preliminary results show that the dust reduction efficiencies have a large variation (0 to 66 pct), as is the case for wet bars used in coal. However, whereas wet bars in coal required 3 to 4 gpm water consumption, wet bars in salt obtained similar efficiencies with only 0.1 to 0.4 gpm. The most reliable data obtained during this study show that the front spray system consistently performs at efficiencies between 41 and 66 pct, with an average of 54 pct. The results indicate that, although wet bar cutter techniques in salt mines are a relatively simple and inexpensive means of dust control with a minimum of water consumption, further investigation should be performed to fully evaluate and optimize wet bar cutter dust reduction efficiencies.

Jan 1, 1980

By Steven J. Page

Longwall double-drum shearers frequently have difficulty complying with the 2.0 mg/m3 dust standard and, therefore, require the use of effective dust controls. However, before dust controls can be implemented effectively, the major individual dust sources must be determined and their relative severity evaluated. The Bureau of Mines has recently developed a sampling strategy, based upon short-term gravimetric sampling, that can identify the major dust sources contributing to the shearer operator's exposure. This technique utilizes approved gravimetric sampling equipment already available to all mine operators and can be performed by two people in 2 days. Five examples, including data analysis, are discussed with respect to various cutting sequences. In addition, typical dust source contributions obtained from studies of double-drum shearer operations regularly in compliance are included. Mine operators can thereby compare their dust source evaluation results with those from these longwalls.

Jan 1, 1982

This manual provides instructions for installing, operating, and maintaining a protective canopy on the Joy Mfg. Co. loader. These instructions are based upon two actual install .at ions: one made in a mine on loader, model 14BU10-11AH, and one in the factory on model 14BU10- 11AH. The parts list and engineering drawings for the protective canopy are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other loaders with similar protective canopies. Skilled mechanics can determine if the instructions herein would be applicable to the other loaders and can determine any necessary modifications if they are not.

Jan 1, 1973

By Donald P. Schlick

Respirable dust provisions of the Federal Coal Mine Health and Safety Act of 1969 are designed to protect the most important resource of the coal mining industry--its workers. The Act imposes two respirable dust standards of 3.0 milligrams per cubic meter of air after June 30, 1970; and 2.0 milligrams per cubic meter of air after December 30, 1972. Under Federal regulations, each operator is required to carry out a dust sampling program established by the Secretary of the Interior and the Secretary of Health, Education, and Welfare, This program features the sampling of "high risk" face workers to establish that the exposure of each miner is below the dust standard, Mining sect ions, continuously in compliance with the regulations, may sample at less frequent intervals. In addition to requiring the mining company to take respirable dust samples, the Bureau of Mines will perform in-depth dust inspections twice a year, as well as frequent "spot inspections." The Bureau has established a semiautomatic computerized operation capable of processing over 1 million samples per year. This facility will be linked to various Bureau offices by a telecommunications system to provide automatic data printouts within hours after samples have been weighed.

Jan 1, 1970

By Terry J. Kreidler

In recent years, west-central Arizona and adjacent California have become the focus of geologic and exploration attention because of its excellent exposure of detachment-fault terrane. Detachment faults, normal faults with nearly horizontal fault planes, are the result of regional extension. Rocks on the lower plate consist of mylonitized intrusive, metasedimentary and crystalline rocks highly altered to chlorite; upper plate rocks comprise sedimentary, volcanic, metasedimentary, and metavolcanic rocks. The movement of the detachment fault causes the rocks on the upper plate to be severely fractured and brecciated thus making them Ideal conduits for mineralizing fluids. Mineralization favored the more reactive sedimentary and volcanic rocks of the upper plate. Three gold deposits, located in upper plate rocks, are currently being mined along the Colorado River corridor: the Picacho Mine near Yuma, Arizona, 70 mi south of the study area; the American Girl Mine In southeastern California, 60 mi southwest; and the Copperstone Mine near the southern end of this study area. Samples from the above three mines were used to create a geochemical model of detachment-related gold deposits. Antimony, arsenic, barium, copper, mercury, molybdenum, manganese, tungsten, and zinc all occur In the mine samples in concentrations at least three times greater than found elsewhere in similar rock types. Samples taken by the Bureau from the wilderness study areas contain similar anomalous concentrations of the same elements as well as elevated concentrations of several other elements Including: lead, fluorine, cerium, uranium, and samarium.

Jan 1, 1992

By William W. Adams

A new record in accident prevention was made by the metal-mining a industry of the United States in 1938, as signalized by a lower fatality rate than in any previous year. The rate was less than half as high as in 1911, the earliest year for which figures are available. A good safety record was also established in the prevention of nonfatal injuries, as the injury rate was lower than in any other years except 1931 to 1935, a 5-year period notable for its unusually low injury rates. Employment was more limited in 1938 than in 1937, both in number of men employed and total number of man-hours worked. The number of workdays per man also was smaller than in 1937. Operating companies reported that 7,233 mines were active in 1938 or some part of the year and that the total number of men employed was 103,027. This figure represents the summation of the average number of men employed as reported by the companies, the average for each mine being that for the period during which the mine was active. The number of employees at all mines in 1938 was 15,402 less than in 1937. Reports covering all mines indicated a total of 188 million man-hours worked during the year, or 21 percent less than the nearly 240 million man-hours worked in 1937. In the performance of this work accidents occurred that resulted in the death of 156 employees and the injury of 1.2,722, each injured employee being disabled for more than the remainder of the clay on which he was hurt.. The fatality rate for 1938 was 0.83 per million man-hours worked, which was 9 percent more favorable than the rate of 0.91 for 1937. Nonfatal injuries occurred at the rate of 67.61 per million man-hours worked, an improvement of 10 percent compared with the injury rate of 75.37 for 1937.

Jan 1, 1941

By L. Garner McDonald

The U.S. Bureau of Mines tangentially impacted potential coal-cutter bit shank materials against sandstone to investigate the potential of the materials to ignite natural gas by a friction-generated hot streak. The shank material samples were mounted in a 24-in, 550-lb flywheel, which was rotated at surface speeds of 400 to 900 sfpm. The sandstone was advanced toward the rotating flywheel at feed rates of 1 mil per impact. The atmosphere mixture was 7 vol pct natural gas in air. Three grades of polycarbonate resin, an ultra-high-molecular weight polyethylene, and a zinc alloy (ZA27) were among the potential materials. None of these materials caused ignition of the methane at any of the three test speeds (400, 600, and 900 sfpm), but the above materials do not have sufficient strength to hold a carbide tip during coal cutting. Of the materials having sufficient strength to hold a carbide tip, three nickel-based alloys proved less likely to cause a natural gas ignition than did iron-based alloys such as 4340 (a commonly used shank material for coal cutters).

Jan 1, 2010

By A. O. Ipsen

As part of the Bureau's intensive investigation of domestic manganese deposits, lots of ore for testing were collected by Bureau engineers during examinations of several properties in Juab County, Utah. One low-grade and two intermediate-grade samples (13.5, 25.3 and 27.5 percent manganese) were procured by engineers of the Bureau of Mines from the 900--and 1,100-foot levels of' the Tintic Standard mine, situated 2 miles southeast of Eureka, Utah. The ore bodies were described as blocks of ore approximately 60 feet long, 40 feet wide, and 20 to 100 feet deep. The manganese-iron association in the Tintic Standard ores was intimate, and no significant concentration of the low-grade sample was made by ore dressing, However, both of' the higher-grade samples were readily beneficiated to marketable manganese products. Ore from the Oxen No. 5974 claim, 2 miles northeast of Eureka, Utah was low in grade (19.4 percent manganese) and was not amenable to the production of high-grade concentrates owing to the intimacy of association of the manganese minerals with silica. However, a fair manganese recovery was obtained in a product that, when sintered, assayed plus 40 percent manganese. The ore body is reported to be a replacement in limestone and is composed of manganese oxides intermixed with silica, decomposed rhyolite, and limestone. The Fields property consists of five mineral claims situated 3 miles north of Eureka, Utah. The deposit is a replacement in a contact between limestone and a quartz dike. Tests were made on representative samples of a 50-ton lot stored on the property. Although the mineral association in the ore (22.2 percent manganese) is not particularly complex, the physical properties of the manganese minerals render the ore refractory to ore-dressing beneficiation. As the ores varied widely in physical and chemical characteristics, samples from each property were considered as separate ore-dressing problems.

Jan 1, 1949

By M. E. Tyrrell, C. W. Houck

Mixtures of zirconium diboride and refractory metals of group VI were resistance sintered to high - density compacts using modified electric welding equipment . To evaluate the use of chromium , molybdenum , or tungsten as binders for zirconium diboride the sintered compacts were examined in polished sections and tested for crushing strength , hardness , microhardness , oxidation rate , and resistance to mechanical shock . Chromium yielded the highest compressive strength , the greatest resistance to mechanical shock and oxidation , and a satisfactory Rockwell hardness . Molybdenum did not yield a satisfactory cermet . Tungsten yielded compacts having high microhardness but very low mechanical strength .

Jan 1, 1964

By Gary P. Sames

The Bureau of Mines recently initiated a study of geologic features that contribute to roof instability in western U.S. underground coal mines. The purpose of the study is to provide information for use in ground control planning and safety hazard reduction in that region, where mining activity has been increasing. Hazardous geologic conditions were surveyed in selected underground coal mines in Utah and Colorado, and both depositional and structural features were identified as potential ground hazards. Although the conditions found do not differ in kind from hazardous geologic conditions in the Eastern United States, they do differ in intensity of occurrence and relative importance. Three depositional features dominate where unstable roof occurs in western underground coal mines: paleochannel deposits, crevasse splay deposits, and flood basin deposits. Three structural features identified as hazardous, but not so widespread or common as the depositional hazards, are faulting, jointing, and igneous intrusions. This survey establishes a foundation for future studies aimed at reducing and preventing ground control accidents in western coal mines.

Jan 1, 1988

By C. M. Palencia

The Bureau of Mines evaluated the potential availability of molybdenum resources from 88 mines and deposits that account for more than 90 pct of the demonstrated resource base in market economy countries (MEC's). For each property, tonnage-cost relationships were developed that indicate the molybdenum potentially available at different average production costs, including a 15-pct rate of return on invested capital. From the 23 MEC primary deposits, 2.5 billion 1b Mo was determined to be potentially available at a price of $411b, rising to 4.7 billion 1b Mo at $8/lb. Copper price-molybdenum tonnage relationships were developed for those mines and deposits from which molybdenum can be recovered as a byproduct of copper production. This analysis showed that another 3.4 billion lb Mo is potentially available based on a copper price of $0.7511b, rising to 4.3 billion lb Mo at $l.00/lb. The United States has been the world's largest molybdenum supplier since 1924. Its remaining resources are sufficient to meet the domestic demand of 57 million lb/yr Mo (averaged for a 10-yr period) through the end of the century. Production from primary domestic mines was suspended during most of 1983 because of oversupply of materials. A major concern is the cheap molybdenum byproducts from foreign copper operations in which employment and the need for hard currency override economics in meeting production goals.

Jan 1, 1985

By T. C. Shelton

The Bureau of Mines Contract No. H0101706 with Virginia Polytechnic Institute and State University was a part of a broad-scale investigation directed toward applied problems in mine safety and particularly toward preventing accidents and fatalities resulting from falls of roof and ribs in coal mines. Under the auspices of the Chemical Stabilization Program, Bureau of Mines, Spokane Mining Research Center, Spokane, Washington, the broad objective of the Contract was to conduct research for the purpose of studying the behavior of large engineering structures. Contract No. H0101706 consisted of two related but distinct tasks. TASK I was to make "Barodynamic Analysis of Large Mine Models," and TASK II was "Preparation of Undisturbed Rock Specimens.?

Jan 1, 1974

By W. H. Oppelt

The Federal Bureau of Mines investigated combustion of lignite in domes-tic heating equipment to obtain information on equipment performance and to evaluate testing procedures. Three types of domestic heating equipment were tested, ranging from a hand-tilled, magazine-type space heater to a ram-type overfeed stoker. Lignite was readily burned in each of the three units under various test conditions. Burnoff rates determined by adding weighed charges to the magazine were found to be in error because of shrinkage of the lignite when only a portion of the magazine capacity was consumed during a test. More reliable burnoff rates could be determined by carbon-nitrogen balances. A hand-fired magazine-type space heater (Booker heater) was operated without the furnace attachment at efficiencies to 75 pct. One test series was run with minimum supervision under conditions encountered in actual household operation. No mechanical trouble was encountered.

Jan 1, 1960

By E. Chin

Although Japan is a major producer of crude steel, it is poor in industrial raw materials. This Bureau of fines report describes Japan's raw material needs for chromium, cobalt, manganese, nickel, and tungsten to produce ferroalloys and alloy steels. Japanese imports of these ores or metals by quantity and source are given for 1972-81, inclusive, to indicate (1) the changes in the consumption and supply pattern, and (2) the degree of Japan's dependence on foreign sources. This report also describes measures implemented by Japan to reduce the risk- of supply interruption, and discusses the possible implications of supply shortages.

Jan 1, 1983

By W. D. Striffler

Land disturbed by surface mining in Colorado and other western states has increased substantially over the past several years and is likely to increase even more in the future. This study was initiated to provide basic information on hydrologic and erosional characteristics of regraded coal spoils in Colorado as an aid for planning future reclamation activities. Eleven of twenty-one surface mines licensed in Colorado were sampled during the summer of 1980 and 1981. Mines not sampled included mines which had not progressed to the point that reclamation had begun, and mines where operators denied permission to sample. All coal regions were sampled with the exception of the San Juan Coal Field. Physical and hydrologic characteristics of regraded coal spoils in Colorado were determined using standard field and laboratory procedures. Field sampling included characterization of sites (slope, vegetation density, proportion of surface rock, bare soil, etc.) and infiltration measurements using a l-meter square drop former raining on a 1/2 square meter rectangular plot frame. Core samples collected in the field were analyzed for saturated hydraulic conductivity, bulk density, organic matter, moisture retention and texture. The erosion potential of each site was determined using the Universal Soil Loss Equation (USLE). Results of the sampling indicate that infiltration rates vary widely both within and between sites. However, definite trends with respect to coal fields are apparent. For example, the Green River (Yampa) coal region had a wide range of sampled infiltration rates (1.2 to 5.1 cm/hr). However, most of the sites clustered towards the low end of the range. The North Park (Marr Strip) also was rated at the low end of the infiltration range (2.0 to 3.0 cm/hr). Average infiltration rates for the Canon City and Uinta Coal Regions were at the high end of the range (4.9 to 5.5 cm/hr). Multiple correlation analysis of infiltration rates vs. site characteristics showed that infiltration rates were most closely correlated with the depth of wetting, the amount of mulch cover, and site slope. The depth of wetting was highly correlated with the depth of the topsoil and the bulk density of the spoil. In general, the topsoil at all sites appeared to be highly permeable to water intake but once saturated, subsequent infiltration depended upon characteristics of the underlying spoil. Vegetation cover affected infiltration on individual mine sites but was not as pronounced as topsoil characteristics or mulch. Erodibility of topsoil and spoils, as determined by Wischmeier's "K" factor, ranged from 1.34 to 0.56 tonnes/ha. (topsoil) and 1.25 to 0.66 tonnes/ha. (spoils). Definite trends in erodibility are evident. The Green River (Yampa) Coal Region displayed consistently higher erodibilities (1.34 to 0.75 tonnes/ha.) than other coal fields (0.72 to 0.56 tonnes/ha). Lowest erodibilities were observed in the Uinta, North Park, and Raton Mesa Coal Regions (0.56 to 0.62 tonnes/ha). Erodibilities of underlying spoils showed similar trends as the topsoils. Erosion potential (the product of soil erodibility and rainfall erosivity) was detennined using calculated ?K? factors and rainfall erosivities (R) taken from Clyde (1976). Results show that the Delagua coal field, Raton Mesa Coal Region had the greatest erosion potential due to the high rainfall energies in the region, while the North Park and Uinta Coal Regions had the lowest potential erosion.

Jan 1, 1981