Search Documents

By H. H. Fields, Stephen Krickovic, M. G. Zabetakis, Albert Sainato

The Bureau of Mines is in the process of degasifying a virgin area in northern West Virginia from the base of an 839-foot -deep vertical borehole. An in situ gas pressure hole 199 feet long, and seven degasification holes ranging in depth from 500 to 850 feet (average 618 feet) were drilled in an 8-foot-thick virgin Pittsburgh coalbed from the enlarged (14-foot-diameter) bottom of this borehole. The in situ pressure at the back end of the hole and the range of gas and water flows from degasification holes as they were completed and closed off were 203 psi, 79,000 to 257,000 cfd (average 160,000 cfd), and 5 to 8 gpm per hole (average 6.8 gpm), respectively. Twenty-four hours after the seven holes were connected through individual water traps to a common collector for natural venting of the gas through pipes to the atmosphere, the total gas and water flows and the in situ pressure dropped, respectively, to 971,000 cfd, 1.3 gpm, and 18 psi. Eighty days later the corresponding values dropped to 529,000 cfd, 0.50 gpm, and 13 psi. After 180 days of degasification, 91 million cubic feet of gas had been removed from the affected virgin area. This represents 60 to 70 percent of the gas calculated to be contained in the area of coal affected by the holes.

Jan 1, 1973

By d&apos, Kathleen J. Amico

THIS SUMMARY appears in Minerals Yearbook volumes I and III, which cover mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, as well as the principal minerals imported into and exported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U .S. mineral production also is included. Mineral production may be measured at any of several stages of extraction and processing. The stage of measurement used in the chapter is normally what is termed ?mine output." It usually refers to minerals in the form in which they are first extracted from the ground, but customarily includes for some minerals the product of auxiliary processing operations at or near mines.

Jan 1, 1965

By S. J. Schatzel

In an effort to increase productivity, many longwall mining operations in the U.S. have continually increased face lengths. Unfortunately, the mining of larger panels may increase methane emissions. The National Institute for Occupational Safety and Health (NIOSH) conducted a mine safety research study to characterize and quantify the methane emissions resulting from increasing face lengths in the Pittsburgh Coal-bed. The goal of this research effort was to provide the mine operator with a method to predict the increase in methane emissions from the longer faces for incorporation of additional methane control capacity into the mine planning process, if necessary. Based on measured methane emission rates of 0.066 m3/s (140 cfm) for a 315 m (1032 ft) face, projected longwall face methane emission rates were 0.090 m3/s (191 cfm) for a 366 m (1200 ft) face, 0.106 m3/s (225 cfm) for a 426 m (1400 ft) face, and 0.124 m3/s (263 cfm) 488 m (1600 ft) face.

Jan 1, 2006

By Donald R. Irving

ALTHOUGH the quantity of material handled at metal and nonmetal mines in the United States in 1962 was 2.7 billion tons, the same as in 1961, a larger proportion was waste. At metal mines, crude ore production declined 1 million tons and waste output rose more than 18 million tons; at nonmetal mines crude ore production declined 6 million tons and waste output rose 36 million tons. Copper and iron ore producers increased their share of crude ore and material handled from about three-fourths to four-fifths of the national metals total, and sand and gravel and stone producers in-creased their share of the nonmetals total, also from three-fourths to four-fifths. Six States-Arizona, California, Florida, Michigan, Minnesota, and Utah-each handled more than 100 million tons of ore and waste, and together they accounted for 43 percent of the U.S. total. When the large-volume construction materials (sand and gravel and stone) were excluded from the totals, four States-Arizona, Florida, Minnesota, and Utah-supplied over half of the material handled.

Jan 1, 1963

By d&apos, Kathleen J. Amico

THIS SUMMARY appears in Minerals Yearbook volumes I and III, which cover mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, as well as the principal minerals imported into and exported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U.S. mineral production also is included. Mineral production may be measured at any of several stages of extraction and processing. The stage of measurement used in the chapter is normally what is termed "mine output." It usually refers to minerals in the form in which they are first extracted from the ground, but customarily includes for some minerals the product of auxiliary processing operatons at or near mines.

Jan 1, 1963

By E. D. Gardner

"Introduction Ore from stopes in metal mines is generally dumped or drawn into chutes or raises through which it passes by gravity to the haulage levels. Occasionally, and under some conditions quite frequently, the ore in a chute will wedge or hang and refuse to run. This hanging of the ore may be due to the packing of damp or clayey material, to boulders forming an arch, or to loose lagging or other timber becoming lodged in the chute.In drawing material from a loading chute it is drawn out a car at a time, and the intermittent flow of the material .increases its tendency to hang. When the obstruction in the chute is near or at the loading gate, the chute pullers start the ore by punching it with iron bars inserted through openings in the chute gate. When the obstruction is beyond reach of the bars, other means of starting the ore must be used.In some systems of mining, chutes or ore raises are built with timber as the stope extends upward. Generally, a manway is left alongside of the chutes, and when the ore hangs in a chute usually it can be started by a miner from the manway ladder by pounding on the timbers of the chute or by punching the ore with a bar inserted through small holes in the chute lining. Special methods of starting clogged ore, such as shaking a chain left hanging in the chute, are used at some places.In other systems of mining, ore passes or chutes are run through solid rock and when the ore hangs in one of these passes, either it must be blasted or else started from the top. Sometimes the ore can be started by running water into the top of the chute, but if the water does not start the ore moving, it must be blasted from underneath. This is done by detonating a bundle of cartridges under the obstruction in the chute or raise."

Jan 1, 1927

By Edward J. Kansa

In a Bureau of Mines study, unsteady, spherically symmetric, one-dimensional, compressible-flow (finite sound speed) equations were solved numerically for a spherical deflagration propagating concentrically in a spherical vessel with Mach numbers ranging from 0.2 to 0.7; trajectory histories agree with the infinite-sound-speed theory developed by Perlee, Fuller, and Saul (PFS). A preliminary result of this study shows that flames propagating with speeds greater than 20 pct the speed of sound in the unburned gas mixture generate a complex history of aerodynamic waves distributed throughout the spherical vessel. Although the average pressure and flame radius agree with those predicted by the PFS models, the aerodynamic waves have a pronounced effect on the flame velocity, differing appreciably from that predicted by the PFS model.

Jan 1, 1976

Provide a coalbed methane data source for industry use in mine planning. Approach Coalbed methane data have keen collected and formatted into a computer implemented data base with software developed for storage, retrieval, and generating files of selected data in response to information requests and for statistical analysis of relationships among various coal parameters. How It Works Coalbed methane data is obtained by the Bureau's direct method test on exploration coal cores. The test involves sealing fresh coal cores in desorption canisters and periodically bleeding the gas into a water-filled, graduated cylinder to measure the volume of gas released. Coalbed methane data collected over the past 9 years have been entered into a computer-implemented data base for efficient retrieval and statistical analysis. Data base processing is accomplished with a commercially available storage, sorting, retrieval, and report writing software package (Datatrieve 11). Information requests from the coal industry are processed with the system, and the data in the desired output format am printed and forwarded to the requestor. Information such as coalbed name, location (state and county), depth of sample, gas content, and coal rank are available from the system. The data can be used for

Jan 1, 1982

By Howard E. Parkinson, John N. Murphy

Abstract-Underground mines are typically extensive labyrinths that employ many people working over an area of many square miles; exten¬sive analysis of mine-communications systems has identified specific problem areas, in particular the excessive times required to locate key personnel underground, the inadequacy of existing phone systems in terms of capacity and privacy, and the inability to communicate with men on the move with wireless communications, as is taken for granted on the surface. A review is presented of the existing systems, the prob¬lem definition, and the various approaches that have been or are being investigated to solve these problems. Manuscript received June 8, 1977; revised August 28, 1977. The authors are with the Industrial Hazards and Communications group, Pittsburgh Mining and Safety Research Center, Bureau of Mines, U.S. Department of the Interior, Pittsburgh, PA 15213.

Aug 28, 1977

By W. E. Miller, Kennedy. R. E., G. W. Jones

"INTRODUCTION Ethyl mercaptan (CH3,CH2SH), a combustible organic liquid of the thioalcohol type, is employed at an odorant in many types of fuel gases and dangerous atmospheres, which in themselves are devoid of characteristic odors, to give warring against leakage of such gases or atmospheres into places where they might constitute health or explosion hazards.Ethyl mercaptan has a penetrating disagreeable odor resembling that of onions, garlic, hydrogen sulfide, or rotting cabbage, that exceedingly low concentrations of it can be detected. The of odorants as a beans of detecting leakage of gases and atmospheres has been investigated extensively by chemists and engineers of the Bureau of Mines, and numerous reports as to its value have been published."

Jun 1, 1942

By Charles L. Kimbell

Annual global steel industry investment is partly mirrored in the data for selected market economy countries that appear in table 13 for 1988-90. No reasonably comprehensive 1991 data were available for inclusion in this study, and the partial reporting available was so incomplete that it was impossible to demonstrate whether the level advanced or declined from the 1990 level of nearly $15.5 billion. Moreover, with the radical changes that are now being effected in the steel industries of the states that were the U.S.S.R. and its CMEA partners, it is most regrettable that comprehensive and comparable data, both current and historic, on investment in this area are not available. Updated information on market economy country petroleum industry capital and exploration expenditures by geographic area has been included in table 14, and it is evident that there was a substantial upturn in investment in 1991. The level of almost $74.5 billion was 14.5 % above the 1990 level and included gains in every topical category and geographic area. The source of information for this table has been changed to the Oil and Gas Journal Database from the previously used Chase-Manhattan Bank study of Capital Investments of the World Petroleum Industry, which has been discontinued. Because of this source change, it has been necessary to modify the structure of the table somewhat, but its total scope of coverage is regarded as basically unchanged. It should be noted that the grand total, as well as some of the detail appearing for 1987, corresponds precisely with those in the previous source.

Jan 1, 1993

By B. J. Scheiner

As part of its mission to reduce pollution associated with mineral production, the Bureau of Mines is developing a dewatering technique for phosphatic clay waste that uses a flocculant, polyethylene oxide (PEO). This flocculant forms strong, stable flocs, which can be partially dewatered on a static screen and dewatered further on a rotary screen. Using this technique, a field test unit (FTU) was operated at a nominal 100 gal/min. Consolidated phosphatic clay material containing 20 percent solids was produced when feed slurries of 3 percent solids were treated with 0.69 pound of PEO per ton of feed solids. Pit and column tests indicated that the PEO-treated material continued to dewater; compacted products containing 40 percent solids were obtained after 45 days.

Jan 1, 1981

By Gary W. Kramer

The Bureau of Mines has developed a rapid analytical method for the determination of anions by ion chromatography (IC) in phosphate rock mining materials and cement kiln dust (CKD). The procedure employs an Na2C03 fusion of the sample, followed by a water extraction that allows direct injection of the sample into an ion chromatograph without separator column poisoning by the transition metal ions. Fluoride (F-) and phosphate (P043-) were determined in 24 phosphate rock processing and waste material samples by the IC method. The results were compared with a pyrohydrolytic distillation-titration method for F-and a colorimetric procedure for P043-. Excellent analytical agreement was obtained for F-and p043-values determined by IC and the comparable wet chemical methods. Fluoride values ranged from 0.3 wt-pct in the filter cake to 3.6 wt-pct in phosphate rock concentrate. Phosphate values ranged from 1.2 wt-pct in the filter cake to 33.8 wt-pct in the rock concentrate. Fluoride, chloride, phosphate, nitrate, and sulfate in several CKD samples were determined by the IC method and standard wet chemical techniques. Excellent agreement was obtained between the two methods for all anions. A total of 113 CKD samples from all areas of the United States was analyzed by the IC method. Fluoride values ranged from <0.01 to 0.36 wt-pct. Chloride values ranged from <0.01 to 12.5 wt-pct. Sulfate values ranged from 0.41 to 31.6 wt-pct. Phosphate and nitrate were detected in only about 25 pct of the samples at >0.02 wt-pct. Maximum phosphate and nitrate values were 1.0 and 1.6 wt-pct, respectively.

Jan 1, 1982

By M. Viswanathan, M. J. Jorgensen, N. K. Kittusamy

Operating heavy construction equipment is often associated with elevated rates of low back discomfort (LBD). However, there have been few formal studies that dealt with evaluating controls that can reduce the LBD among these workers. The objective of this study was to determine the effectiveness of using a continuous passive lumbar motion system (CPLMS) in reducing low back discomfort among operators of heavy earthmoving equipment. The CPLMS is an additional seat support that has a lumbar support bladder and a pump to provide cyclic inflation and deflation. Two groups of operators were identified as potential subjects for this intervention study, the intervention group with a mean age of 41.2 years and experience of 9.7 years used the CPLMS, and the control group with a mean age of 37.5 years and experience of 7.6 years did not use the CPLMS. Body part discomfort surveys were collected from both groups. In addition, the intervention group completed a CPLMS preference survey. The body part discomfort survey was collected up to eight days at three different times of the day. Results from the body part discomfort survey showed a decreasing trend the longer the CPLMS was used, for both the upper and low back region. A decreasing trend for the low back was also found comparing morning to evening discomfort scores across the days when using the CPLMS. When compared to their regular seat, 54% of the operators felt very comfortable in using the CPLMS, 36% of them wanted one for their equipment, and 54% showed interest in experimenting with the CPLMS for a longer time period. Results from this study indicate that the use of a CPLMS can effectively reduce the low back discomfort experienced by operators of heavy construction equipment.

To provide for continuous remote sensing of carbon monoxide (CO) in underground mines. The Approach A transducer module has been developed as a wall-mounted, continuously operating instrument that will measure ambient levels of CO, and produce a signal that is proportional to the concentration.

Jan 1, 1982

By H. C. George

This report presents a comprehensive tabulation of lifting cost data collected from oil companies in many different fields. These data were collected during the writer&apos;s studies of surface equipment and methods of pumping oil wells, in practically all of the important oil fields in the United States and are based on average operating conditions at 57 groups of properties with a total of 4,497 producing wells. Although lifting cost is only a part of the total cost of producing oil, it nevertheless gives a representative cost figure for purposes of comparison.

Jan 1, 1923

By Oliver W. Keener

The operation described herein differs from the usual practice in the Tri-State district in two important respects: (1) the ore is loaded into cars which are tramped to the shaft and hoisted on self-dumping cages, and (2) about 30 per cent of the ore is loaded by power shovels. The four-month period covered by the cost data appended at the end of the paper immediately followed a period of about one year during which the mine was shut down, and the expense incident to the resumption of operations is reflected in the costs. The author acknowledges the assistance of C. F. Jackson, mining engineer, U. S. Bureau of Mines, in the preparation of this paper and the compilation of the data.

Jan 1, 1929

By G. S. Rice

The recommendations of the Bureau of Mines on rock dusting practices are embodied, except in a few details, in the Recommended American Practice for Rock-Dusting Coal Mines to Prevent Coal-Dust Explosions, approved by the American Engineering Standards Committee. December 30, 1925. It is specified that the dust to be used is of a elm that all will pass through a sieve having 20 meshes per linear inch and that 50 per cent or more will pass through a sieve having 200 meshes per linear inch. Thus the coarsest size of dust and the minimum proportion of fine dust are specified, but the specification does not indicate whether a larger proportion of fine dust would be desirable. There have been advocates of the use of that size of rock dust of which the particles would all approach 200-mesh in fineness. Explosion tests were made in the Experimental mine in the earlier period of testing which indicated that the finer rock dust is somewhat more effective under test conditions, but not sufficiently so to Justify the cost of finer grinding of the dust; also there are some disadvantages of finer dust described hereafter.

Jan 1, 1930

By G. E. Rennick, F. E. Armstrong, J. Pasini, J. R. Abrams

An oil well penetrating the Pittsburgh bituminous coalbed in northern West Virginia was plugged and safely mined through 3 months later. A sensitive chemical tracer, introduced into the oil reservoir before the test, was not detected in the mine air following the plugging and during mining of the pillar and penetration of the well. Effectiveness of the plugging in preventing reservoir gas from entering the mine through the well hole was verified by continuous monitoring of the mine air for indications of sulfur hexafluoride, an inert gas detectable in amounts as minute as 112 part per billion. Expand- able cement and fly ash-gel-water slurry were utilized to seal the well above and below the coal seam. Three other wells were also plugged using various techniques.

Jul 1, 1972

By E. C. Lane

This report on properties of commercial motor fuels is the twelfth in a series made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the United States Department of the Interior. The first report contained data on motor gasolines sold during the winter of 1935-36.V The -present report, covering the summer of 1941, presents analytical data for 1,857 samples, representing the products of approximately 135 companies. As in previous surveys, these companies include both large and small suppliers. In addition, the Pacific coast is represented by data averaged by the Pacific Coast Technical Group before being submitted, and these data are published exactly as they were received. Conforming to previous surveys, the data cover three groups of samples -- regular-price, premium-price, and third-grade gasolines -- and each group has been aver aged separately. The number of samples, items, and brands comprising each group, exclusive of those of the Pacific coast, are as follows: Regular price, 1,010 samples, 291 items, and 86 brands; premium price, 577 samples, 263 items, and 78 brands; third-grade gasoline, 270 samples 159 items, and 74 brands. The meanings of these terms as used in the surveys are as follows: Sample: The individual supply of gasoline obtained at the filling station and analyzed in the laboratory.

Jan 1, 1942