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In 2006, data obtained from the Mine Safety and Health Administration (MSHA) indicated a total of 935 underground (6.3%) and 13,950 surface (93.7%) mining operations.1

Jan 1, 2008

By Sidney Katell

This study estimates capital investment, operating costs, and selling prices for four underground bituminous mines producing coal with annual production ranging from 1.06 to 4.99 million tons. It is assumed that the mines have a 20-year life. Wages and union welfare payments are considered as of November 12, 1973, under the Bituminous Wage Agreement of 1971, and costs for material and equipment are based on 1973 indexes. Initial capital investment ranges from $12,540,700 for the 1.06-million-ton-per-year (MM tpy) mine to $44,720,500 for the 4.99 MM tpy mine. Total capital investment ranges from $21,850,700 to $75,693,500 for the same mines. Corresponding selling prices for the coal range from $8.76 to $7.53 per ton, assuming a 12-percent discounted cash flow rate of return after Federal income taxes.

Jan 1, 1974

By K. E. Tame

The Bureau of Mines is studying possible modifications in conventional uranium ore-processing steps to confine and permit controlled disposal of radioactive wastes. Surveys of Ra226 contamination of liquid wastes from uranium mills indicated that the Vanadium Corporation of America plant at Durango, Colo., had one of the more urgent problems. A possible procedure for minimizing the waste disposal problem was to reuse the waste solution in the mill--in effect, erasing the need for disposal of liquid waste. In examining this possibility, interlocked bench-scale leaching and solvent extraction tests simulating the Durango flowsheet were made. The simulated reuse of barren raffinate for leaching and washing was carried through three separate campaigns of 9, 12, and 35 cycles each.

Jan 1, 1961

By Charles N. Speltz

Coal resource data from public and private sources, in conjunction with previously published data, were used by the Bureau of Mines to determine the location and extent of strippable coal resources in Colorado. Total strippable resources of approximately 18 billion tons were estimated in 12 separate coal regions, fields, or deposits. Coal recoverable by contour mining techniques was not included. Criteria used in defining strippable resources were a minimum coalbed thickness of 2 feet and a maximum overburden thickness of 150 feet, except where the coalbeds are of exceptional thickness. Ail Colorado coal is either Cretaceous or Tertiary in age. Cretaceous coals occui In the Dakota Sandstone, the Mesaverde Group, and equivalent formations while Tertiary coals occur in the Dawson Arkose, the Fort Union and the Wasatch Formations, and equivalent formations. The strippable coal ranges in rank from bituminous in the Yampa region to ligniferous in the Denver basin. Ali this coal is low in sulfur content (less than 1 percent); ash content is low to high; heating value ranges from 3,000 to 12,000 Btu's per pound. Ash from the lignite of the Denver basin was found to contain an abnormally high percentage of kaolinite which conceivably could be recoverable as alumina.

Jan 1, 1976

By D. L. Hollis

An arc plasma reactor, constructed and used for studying extractive metallurgical processing, was adapted by the U.S. Bureau of Mines to separate gases of different masses by using the high rate of plasma rotation. With argon and helium as input gases, peripheral reactor outlet ports had a measured average increase of about 10 pet in argon concentration relative to helium with the plasma on compared with plasma off for the same gas inlet concentrations in both cases. Approximately the same average increase in argon concentration occurred from the peripheral outlet port compared with a central outlet probe with the plasma on. There was no difference with the plasma off.

Jan 1, 2010

By J. F. Barkley

At the request of several Federal agencies, tests were conducted on a relatively recent type of anthracite -burning equipment named the Anthratube. This device, rated at 130,000 B.t .u. per hour, was designed to burn Pea-size anthracite automatically for steam or hot-water house heating and for domes-tic hot -water supply. ACKNOWLEDGMENTS The helpful cooperation of the Anthracite Institute and the manufacturers of the equipment, Axeman-Anderson Co., Williamsport, Pa., is gratefully acknowledged.

Jan 1, 1953

By Thomas A. Jones

An impure variety of barite, which lends itself well to the manufacture of heavy drilling mud for oil wells, is widely distributed throughout the Ouachita Mountains in Arkansas. The ore mined in the area and used for drilling muds usually contains an average of 67 percent barium sulfate, although ores as low as 50 percent BaSO4 are occasionally used. Due to the increased demand for barite for drilling caused by the intense search for hew oil occurrences during the years 1945 and 1946, the Federal Bureau of Mines began an investigation of barite deposits in the Ouachita? Mountains in October 1946. In all, 10 barite deposits were examined, trenched, sampled, and studied during the investigation, which was terminated in May 1947.

Jan 1, 1948

By Richard A. Winters

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 49,875 acres of the 54,833-acre Big Jacks Creek Wilderness Study Area (ID-111-7C) in order to evaluate the mineral resources. The study area is located in Owyhee County, ID, about 15 miles southwest from Bruneau, ID. No mining districts are in the study area, but part of one placer claim, located in 1924, extended into it. The northern portion of the area was covered by oil and gas lease applications; all were cancelled prior to 1985. No economic concentrations of minerals were found in the study area. INTRODUCTION This report describes the USBM (U.S. Bureau of Mines) portion of a cooperative study with the USGS (U.S. Geological Survey) to evaluate mineral resources and potential of the Big Jacks Creek study area at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will be used to help determine the suitability of the study area for inclusion into the National Wilderness Preservation System. Although the immediate goal of this and other USBM mineral surveys is to provide data for the President, Congress, government agencies, and the public for land-use decisions, the long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at a reasonable cost.

Jan 1, 1986

By Rudy J. Matetic

The National Institute for Occupational Safety and Health (NIOSH) at the Pittsburgh Research Laboratory (PRL) is conducting research to reduce the noise exposures of roof bolting machine operators and to prevent additional cases of Noise Induced Hearing Loss (NIHL) thru the development of engineering noise controls. This paper describes and evaluates an engineering noise control for the roof bolting machine, namely the collapsible drill steel enclosure. The results of the evaluation demonstrated that using the collapsible drill steel enclosure provided a 7 dB(A) reduction in sound pressure level at the operator?s position of a roof bolting machine.

Jan 1, 2008

By Seth C. Schaefer

The Federal Bureau of Mines studied the Gibbs free energies of formation of chromous fluoride (CrF2), chromic fluoride (CrF3), and chromium (II,III) fluorides (CrF2.40 and CrF2.45) with high-temperature galvanic cells employing calcium fluoride doped with 1 mole-pct yttrium fluoride as the electrolyte. Free-energy changes were obtained from open-circuit potential measurements for the following cells: Cr, CrF2 // CaF2 // NiF2, Ni (a) NiO, NiF2 // CaF2 // CrF3 , Cr203 (b) CrF2 , CrF2.40 // CaF2 // NiF2, Ni (c) and CrF2 ?45 , CrF3 // CaF2 // NiF2, Ni (d) with the following overall reactions Cr(s) + NiF2 (s) = Ni(s) + CrF2 (s) (1) 3NiO(s) + 2CrF3 (s) = 3NiF2 (s) + Cr203 (s) (2) 5CrF2 (s) + NiF2 (s) = 5CrF2.4O (s) + Ni(s) (3) and 3.64CrF2.45 + NiF2 (s) = 3.64CrF3 (s) + Ni (s) . (4) These results were combined with the best available literature values of ?Gf° of NiF2, NiO, and Cr203 to deduce Gibbs free energies of formation for the chromium fluorides expressed as follows: ?Gf°(CrF2) = -179.31 + 24.33 X 10-3T ± 0.43 kcal-mole. (5) (858.1 - 964.9 K) ?Gf° (CrF3) _ -226.16 + 1.82 X 10-3T ± 0.79 kcal/mole (6) (880.8 - 957.8 K) ?Gf°(CrF2.40) _ -213.65 + 32.14 X 10-3T ± 0.44 kcal/mole (7) (0053.9 - 936.8 K) and ?Gf°(CrF2.45) _ -176.17 - 12.67 X 10-3T ± 0.80 kcal/mole (8) (875.1 - 937.6 K). Free energies and equilibrium fluorine pressures for three univariant and one bivariant equilibria are illustrated.

Jan 1, 1976

This chapter presents proportionate mortality ratios (PMRs) derived from death certificate data in the National Occupational Mortality Surveillance (NOMS) database for the years 1986 through 1993. At the time this report was prepared, 1993 was the latest year for which data were available. Industry is classified under the 1980 U.S. Bureau of the Census classification system [Bureau of the Census 1982]; cause of death, under the International Classification of Diseases, Ninth Revision (ICD-9) [World Health Organization 1977]. A PMR of 100 indicates a mortality risk for a particular industry group that is similar to that for all industry groups combined. A PMR over 100 suggests a higher risk; a PMR under 100 suggests a lower risk. PMRs are subject to many factors that affect their reliability and validity and may not be comparable across populations with very different causes of death. An elevated PMR for a specified cause of death among an occupational or industry group may indicate a relationship between a work exposure and the cause of death specified. However, there are many limitations of PMRs as a measure of risk; they are most useful for generating hypotheses about exposure-disease relationships, which can then be tested in other studies. Selected PMRs are presented separately for males and females for coal mining, metal mining, nonmetallic mineral mining and quarrying (which includes nonmetal, stone, and sand and gravel), and for oil and gas extraction. All PMRs have been adjusted for age and race. In general, PMRs are presented only if the lower 95% confidence limit exceeded 100. If a PMR in an ICD-9 subcategory was above 100, however, the PMR for the larger category into which the subcategory falls is always presented and may be less than 100. PMRs can be expected to be elevated for conditions that have a high prevalence in particular occupational groups. PMRs showed elevated values for conditions known to affect miners, such as coal workers' pneumoconiosis, pneumoconiosis due to silica, tuberculosis, chronic pulmonary heart disease, and injuries. Additional findings of interest were- • An elevated PMR for myocardial infarction among male coal miners (table 2-1); • Elevated PMRs for neurologic disease in general and anterior horn cell disease, in particular among male metal miners (table 2-3); • An elevated PMR for rheumatic heart disease in male metal miners (table 2-3); • Elevated PMRs for malignant neoplasms of the digestive organs and peritoneum and for malignant neoplasms of the colon and rectum in female nonmetal miners (table 2-6); and • Elevated PMRs for non-A, non-B hepatitis and arteriosclerotic heart disease among male oil and gas workers (table 2-7).

Jan 5, 2000

By Gary A. Kingston

Domestic nickel resources are costed to develop a contingency supply curve of U.S. nickel availability at various costs. It is estimated that 4.3 billion pounds of nickel is potentially recoverable from 698 million tons of ore at prices ranging up to $6.36 per pound of nickel. Over 95 percent of the total is estimated to be available at a price of less than $4.00 per pound.

Jan 1, 1970

By E. P. Hayes

This report supplements the date contained in Bureau of Mines Information Circular 6156, "Special features of core drilling in the salt beds of Western Texas and New Mexico," by J. S. Wroth. That circular dealt with the drilling of the first 12 of the 24 potash tests made by the U. S. Bureau of Mines in cooperation with the U. S. Geological Survey; this report is concerned with the drilling of the last 12 tests. ACKNOWLEDGMENTS The writer is indebted to R. E. Heithecker, the Bureau of Mines engineer who had charge of the drilling of tests 13 to 17, for his well-prepared records on the drilling of these tests.

Jan 1, 1933

By A. R. T. Dennues

"INTRODUCTION There are presented in this report the results of limited studies by the Bureau of Mines of the firedamp safety of some powder-powered tools proposed for use underground in coal mines. This study was made to obtain general information and specific technical data for a cable splicer and some rail punches now commercially available, the aim being to keep abreast of developments and to anticipate hazards.ACKNOWLEDGMENTSAcknowledgments are made to the Mine Safety Appliances Co., Pittsburgh, Pa., for supplying equipment for these tests, and to the Pittsburgh Coal Co. for making possible observations of the use of these tools in coal mines.The assistance of other members of the Explosives Division is acknowledged: J. E. Crawshaw, for examination of ammunition and, propellant powders; H. L. Wilson, for analyses of the natural gas used in the gallery and Jerome C. P. Weinheimer and Martin Bashel, for conducting the gallery tests.GENERALDescriptions of the DevicesPowder-powered tools of the type tested utilize the energy of charge of,propellant powder accomplish tasks. They are essentially small guns adapted to special work. Of the family of such tools now commercially available from one manufacturer, two have been proposed for use underground in coal mines, namely a cable splicer known as model TI and two models of rail punch known as R40 and R60. These tools employ blank-cartridge ammunition and special projectiles to accomplish the work indicated by these descriptive names."

Jul 1, 1947

By Robert Lundquist

REAM is a unique method of rock breaking using high energy projectile impact. This report-describes the most recent in a series of tests demonstrating mining applications for the REAM method. In an underground limestone mine at Greer, West Virginia, REAM was used to drive a short tunnel and drill a large diameter borehole. Along with breakage data from these tests the goal of the program was to examine environmental problems which might result from the use of cannons under-ground. A total of 103 shots was used to advance a 14-l/2-feet high by 10-feet-wide face a distance of 5-1/2 feet. It is estimated that the 9.3-pound-concrete projectiles launched at 5000 feet per second will break an average of 0.78 tons of limestone or 67 percent of the 1.125 tons of granodiorite broken in previous tests. The 9-inch-diameter borehole was drilled horizontally by repeated axial impact for 7 feet, 2-1/2 inches by 21 shots giving an average of 4.12 inches per shot. Scaling this result to compressible impact energy yields an estimated 5.8 inches per shot for a 12.8-inch-diameter hole compared to 8 inches per ~hot for a 16-inch-diameter hole in granodiorite. Noise measurements indicate that a silenced cannon can be used within a few hundred feet of mine personnel in a room and pillar mine within the legal limit of 140 dB impulse without additional protection. Some fume measurements were made with satisfactory results, even though the military propellants used produce much greater quantities of toxic fumes than the liquid propellant proposed for the future.

Jan 1, 1976

By Arthur J. Hudson, Lawrence W. Scott

The performance of RETIMET metal foam as a flame arrester on explosion-proof enclosures was investigated by the U.S. Bureau of Mines both in laboratory tests and at the U.S. Mine Safety and Health Administration's (MSHA's) Approval and Certification Center, Triadelphia, WV. The objective of this research was to develop a permissible pressure vent for use on lightweight, vented, explosion- proof enclosures. In laboratory tests, four grades of RETIMET, a stainless steel foam material, were evaluated: (1) 45 NC-7, (2) 45 NC-13, (3) 80 NC-7, and (4) 80 NC-13. Explosive gas mixtures were prepared by a dynamic flow system. Ignition was by a low-voltage arc. Each grade of RETIMET metal foam successfully arrested the flame front in all methane-air tests. To evaluate RETIMET metal foam on large, commercial size enclosures, a multicompartmented enclosure was designed and tested in MSHA's explosion gallery in Triadelphia, WV. Extensive explosion testing revealed that a minimum vent-area-to-enclosure-volume ratio of 11.33 in2/ft3 is required to keep internal pressure rises below 3 psig. The RETIMET metal foam functioned satisfactorily in all tests as evidenced by the absence of external ignitions.

Jan 1, 1992

In 2005, a total of 2,063 coal mining operations reported employment to the Mine Safety and Health Administration (MSHA). Coal mines comprised 14.1% of all mining operations. ? Bituminous mines comprised 92.6% (n=1,911) and anthracite mines 7.4% (n=152) of coal mining operations. ? Approximately 70% of all coal mines were located in three states: Kentucky (28.0%), West Virginia (21.8%), and Pennsylvania (20.6%).

Jan 1, 2008

By E. C. Perkins

The purpose of the research described in this report was to develop techniques for using ilmenite from domestic deposits for the production of titanium tetrachloride. The research was done by the Federal Bureau of Mines in cooperation with the General Services Administration under contract DMP-116, Utilization of Domestic Ilmenite. Bench-scale continuous chlorination of an Idaho ilmenite containing 27.9 percent titanium and 35.6 percent iron yielded a crude titanium tetrachloride suitable for purification and for the production of titanium metal and pigment. A summary of the results of 380 hours of operation showed that 82.4 percent of the titanium was chlorinated, with 92.5 percent utilization of chlorine. The construction- of a. quartz tube chlorinator 4-inches in diameter and 24 inches long is described with the necessary details of operation.

Jan 1, 1961

By C. F. McCarroll

[Laboratory research and, control in the u?odnction an; utilization of petroleum and its product s have eqLmde& greatly during the past decade, rind much of the routine control and experimental equipment noirr requires the con-stant daily use of liquid nercury. In spite of this greater use, very little consideration has becn given to the hazard that might be occasioned by the toxic vapors of mercury unavoicl.a~l.p spilled or otherwise exposed to the atmosphere during the normcl 2rgced1u.e of ln30r~tor;~r operations. A sfmple visual exami~stion gf' sone of the laborztories reveals the prescnce of a considerable quantity of mercury in the craclcs of floors, on work tebles, ad on and mo7md eql~ipmeilt st.ads. Usually this yercurj ie contaminated with oily and dirt BO th~t it remint; in R finely divided state and a srnarl amount presents a relativell- lag? surface for evaporation. Since mercury shows meas~rable vo!-atility st a tempero.turc as lor^ 2s 8.5O F., mercury vapor will bo present in the atnosphere of anjr laboratory wbr.e mercury is exposed. promiscuously]

Jan 1, 1939

By J. B. Littlefield

The Greenburg-Smith impinger was developed at the Bureau of Mines in cooperation with the United States Public Health Service in 1922 in the course of an investigation of dust-sampling instruments available at that time. Although it is not used extensively outside of the United States, it is now soused in this country to collect samples for the determination of any dustiness, and most of the information correlating degree of dustiness with physiological effect has been obtained by the impinger method. The chief disadvantages in the use of the regular impinger, especially in mines and other places accessible with difficulty, are its bulk, weight, and power requirements. It requires a source either of electricity or of compressed air, which necessitates connections and extension of existing supply lines to each sampling point; the only alternative is the use of a relatively large pump hand-operated with considerable effort.

Jan 1, 1937