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By R. P. Vinson, Abdurrahman Cetinbas, Joseph Cervik, M. G. Zabetakis

The effect of water infusion on the flow of methane and on the production of dust was investigated at an active face in the Pittsburgh coalbed. The average total flow of methane at the face decreased by approximately 79 percent, whereas the flow from the ribs increased about 24 percent after infusion. On the day after infusion, dust concentrations appear to have been reduced; however, the presence of large quantities of rock dust obscured the results on the following days.

Jan 1, 1972

By Charlie Wyche

In 1980, gold, silver, and pit and quarry construction materials were the principal minerals produced in the Dominion of Fiji. The combined value of these minerals totaled some $7.2 million,2 over 85% of all mineral production, Production of cement, sand and gravel, and quarry products continued to increase, but gold and silver production from Fiji's only operating mine declined slightly from the previous year's level. Mineral exploration has been carried out by U.S., Australian, British, Canadian, West German, and South African companies since the early 1960's, and a high level of activity was maintained throughout 1980. At the end of 1980, some 40 mineral prospecting licenses covering over 4,300 square kilometers were in force, and 19 applications were under consideration by the Mineral Resources Department. Total expenditures by mining companies on land base projects exceeded $6 million in 1980.

Jan 1, 1982

By K. O. Bennington

Thermodynamic properties were determined by the Federal Bureau of Mines for lithium metasilicate (Li2Si03) and lithium disilicate (Li2Si205). Their enthalpies of formation were investigated by hydrofluoric acid solution calorimetry. The standard values are ?Hf°298 -393.8 ± 0.8 kcal/mole for Li2Si03, and ?Hf°298 -611.8 ± 1.0 kcal/mole for LiSi205. Enthalpy increments above 298 K were measured by copper-block drop calorimetry from 298 to 1,404 K for Li2Si03, and from 298 to 1,281 K for Li2Si205. Low-temperature heat capacities were determined adiabatically from 6 to 305 K for Li2Si205 only. The derived standard entropy is S°298 = 29.20 ± 0.10 cal/deg-mole. The various experimental data were combined with other data from the literature, and resulting properties of ?Hf°, ?Gf°, and log Kf were tabulated as a function of temperature.

Jan 1, 1976

By F. R. Lee

[THE Bureau of Mines was established in July 1910 to conduct research and to Establish standards for mining equipment and practices which would conserve human life, natural resources, and property in the mineral industries. Several lists of equipment approved by the Bureau as permissible for use in gassy coal mines have a been issued since then. The lists covering all approved equipment except breathing apparatus and explosive have been consolidated info two publications: Bulletin 543, Permissible Equipment Approved to January 1, 1953, and Information Circular 5220, Permissible Mine Equipment Approved By The Bureau of Mines During 1953-62. The purpose of this publication is to supplement Bulletin 543 kind Information Circular 8220 with a listing of permissible equipment approved during 1963 and 1964. The schedules (standards) under which equipment listed herein have born approved are as follows (titles and dates of approval and revision are given in footnotes): Schedule 2F,3 schedule 6D,4 schedule 7C,5 schedule 8C,6 schedule 9B,7 schedule 10C,8 schedule 12D,9 schedule 22,10 schedule 24,11 schedule 25B,12 schedule 28,13 schedule 29A,14 schedule 30,15 and schedule 31.16]

Jan 1, 1966

By W. J. Fene

A comprehensive study of all bituminous coal-mine fatalities occurring in Pennsyl¬ vania during the 5-year period, 1926-1930, was made to try to determine the factors that in¬ fluence accidents which cause these fatalities. During this study some two thousand reports of fatalities were reviewed, and pertinent information as to causes and influencing factors were tabulated therefrom. These tabulations are discussed in detail, and in some instances recommendations are made with a view to reducing the hazards in certain classes of these accidents.

Sep 1, 1931

By H. S. Chiang, Y. Luo, S. S. Peng

"IntroductionThe way in which the particle sizes distribute in the airborne coal dust plays an important role in the transportation of the dust in the mine air and human respiratory systems. Though the particles of a size less than 10 microns could be inhaled, the real distractive portion of the dust is that the sizes range from 1 to 5 microns since only they can reach the lungs and be retained there. Those with an equivalent diameter larger than 5 microns will settle on the membranes of the branchial tubes(1) while those with diameter less than 1 micron can either be exhaled out of the lungs or the settled quantity is so insignificant that does very little harm to the lungs. In the transportation process, the finer dust will fly farther away from the sources than the coarser ones. Thus once the fine dust is generated and becomes airborne, it will spread out to a larger area.In this paper, the coal samples collected from two longwall faces were analyzed statistically for size distribu¬tion. A mathematical model is proposed and the effects of different conditions on the dust size distribution were analyzed using the mathematical model.Sampling and Statistical AnalysesSampling Instrument and ProcedureThe instrument used in the sampling were Mine Safety Appliance (MSA) personal sampling units equipped with 10-mm nylon cyclones, pre-weighed MSA PVC filters and constant-flow pumps.Two longwall operating faces were selected for the dust sampling. The two faces were located in two coal mines ex-tracting Pittsburgh seam. The double-ended ranging-drum shearer applying the unidirectional cutting sequence was employed. The two-leg shield supports were used for face support. The width of the two faces was about 215 meters.In each of the two faces, four sampling stations were set up. The stations were located at the cross-cut immediately outby the headentry side, the 15th support (25 m), 65th support (107 m) and 111th support (182 m) from headentry T-junction, and numbered as #1, #2, #3, and #4 station, respectively (Figure 1). At each sampling station, a group of three sampling units was hung at proper position. At cross¬cut (#1) station, the units were hung about one foot under the roofline in the center of the cut (Figure 2a), and at the stations in the face, the units were position near the hydraulic legs and one foot below the support canopy (Figure 2b).One complete set of 12 samples was collected for each day. The sampling were performed for five consecutive days. All the samplings were conducted in the morning shifts. The time duration of the sampling for each day was about five hours. During that time, the shearer might complete 5 to 7 mining cycles."

Mar 1, 1989

By Michael G. Zabetakis

Investigation of gas explosions usually reveals that the combustible gases have come from transmission and storage facilities or from natural gas or oil wells. However, combustible gases such as methane and hydrogen can derive from biological processes. Hazardous situations have been created in the past by the use of abandoned mines for the disposal of sewage and rainwater, by the interconnection of storm and sanitary sewers, by sealing the openings in manhole covers when repaving the roadway over a sanitary sewer, and by the construction of buildings over or near garbage fill areas without adequately providing for the release of combustible gases.

Jan 1, 1962

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions4/ issued by the Bureau of Mines, the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1957

By H. Kim, R. W. Plummer, T. J. Stobbe, W. G. Jones

"Exposure to airborne dust in coal mines has caused respiratory disease in coal miners. The causal agent in these diseases remains unknown, although the minerals found in and around the coal seam have been implicated. Toxicological studies designed to establish the effect of different mineral combinations and concentrations are lacking because the mineral content of coal mine dust has not been defined. This paper reports the initial results of a study done to characterize the mineral content of the coal mine dust found in a mine in the Upper Freepott seam in Northern West Virginia. Coal mine dust samples were collected using 4- stage cassette impactors at nine locations in the mine. The samples were analyzed by an x-ray microdiffraction film technique supplemented by energy dispersive scanning electron microscopy. Primary size modes of about 17 to 20 micrometers from the samples collected at the haulageway and the returnside of the continuous miner were found. From the returnside of the roof bolter samples, a primary size mode of 12to15 micrometers was measured. The minerals found in high percentages were illite, kaolinite, quartz, and calcite. The distribution of minerals in inter· and intra- location samples showed wide variations. Trends in these variations are presented. Stobbe, T. J.; Plummer, R. W.; Kim, H.; Jones. W.: Characterization of coal mine dust. Appl. Ind. Hyg. 2:95· 100; 1986. IntroductionDisease-associated dusts in coal mine environments continue to afflict miners in today's modern mines. The relationship between exposure to coal mine dust and the development of various respiratory diseases has been well recognized; however, the reasons for variation in occurrence of these diseases among miners in different geographic areas,(1) rank of coal seams,(2-3) and jobs (4) remain uncertain. Several papers have reported on the causal agent in the development of these diseases. Davis (5) found that the percentage of the non-coal minerals present in the lungs of deceased miners increased as the level oi pneumoconiosis became more severe. Reisner (6) reported that cell damage caused by coal mine dust increases with the mineral and quartz content of the dust and with the geo· logical age and rank of the coals. Two studies, investigating the in vitro effects of mineral dusts. reported by Seemayer and Manojlovic (7) also obtained positive correlation between cytotoxicity and the mineral content of coal mine dust. Gormly (8) postulated that destruction of macrophages by certain mineral dusts is the first step in the development of pneumoconiosis. In 1980, Adamis and Timar (9) reported that quartz. sandstone, slate. respirable colliery dust. bentonite, illite, and some kaolins had cytotoxic effects on rat peritoneal macrophages""in vitro."" Walton,(10) however, reported that the presence of high clay, illite, and kaolin mineral exposures reversed the hazards associated with increasing quartz exposures. This finding was supported by Le Bouffant and coworkers.(11) They reported that illite present in coal mine dust strongly inhibited the pathogenic effects of quartz while kaolin had a weaker inhibitory effect."

Mar 1, 1989

In this U.S. Bureau of Mines report, proposed narrow-vein and longwall mining concepts using drill-split technology (described in part 1 of this series) and in situ liner concepts (described in part 2 of the series) are combined and applied conceptually to environmental problems. Proposed applications deal with (1) acid mine drainage (AMD), (2) solid waste disposal, (3) site remediation, and (4) pollution prevention through innovative industrial design. For control of AMD from abandoned hillside mine workings, it is proposed that source veins be re-mined, processed for residual values, then backfilled using an impermeable compound backfill mix. For solid waste disposal, "vertical landfills" are proposed, consisting of trash-backfilled underground rock quarries. Vertical landfill activities take place in in situ lined containments that geohydrologically isolate the mining-backfilling activities. Site remediation through the creation of in situ underliners, for the capture of toxic leachates, and pollution prevention through the underground storage of toxic, flammable, and explosive materials in in situ containments, are proposed.

Jan 1, 1995

By H. D. Baylor

This paper, describing the operations of the Louisville Cement Co. in quarrying limestone for the manufacture of quicklime, is one of a series being prepared for and published by the United States Bureau of Mines on stone quarries throughout the United States. Those papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating only and not total costs. It is recognized that publication of total costs might in many instances cause embarrassment to individual operators as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. ACKNOWLEDGMENTS The author acknowledges the assistance of J. H. Lemmon, plant superintendent, Charles Taylor, plant engineer, and F. H. Compton, chief engineer, of the Louisville Cement Co. in the compilation and preparation of this paper.

Jan 1, 1932

By Kristine M. Krajnak

Occupational exposure to hand-arm vibration through the use of powered hand tools can result in reductions in tactile sensitivity, grip strength and manual dexterity. In fact, even acute exposures to vibration cause shifts in vibrotactile thresholds in exposed fingers (2,4,5). Although reductions in tactile sensitivity after acute vibration exposures are transient, cellular changes associated with this shift in sensitivity could lead to the more permanent reductions in tactile sensitivity that are a common symptom of hand-arm vibration syndrome (HAVS). Methods Animals. Male Sprague Dawley rats (6 weeks of age) were used for all experiments. Animals were housed in AAALAC accredited facilities, and all procedures were approved by the NIOSH Animal Care and Use Committee and were in compliance with the CDC guideline for care and use of laboratory animals. Vibration exposures were performed by restraining rats in a Broome-style restrainer, and securing their tails to the vibration platform using 6 mm wide straps that were placed over the tail every 3 cm. Restraint control animals were treated in an identical manner except that the tail platform was set on isolation blocks instead of a shaker. Tail temperature and current perception thresholds (CPTs). Rats were exposed to 4 h of tail vibration (125 Hz, 49 m/s2), or restraint. Tail temperature was collected prior to and immediately following the exposure using an infra-red camera. Sensory neuron function was assessed by measuring CPTs with a Neurometer (Neurotron, Baltimore, MD). Transcutaneous nerve stimulation was applied to the C10 region of the tail. Three frequencies were used to test specific fiber types (5 Hz – C, 250 Hz - Ad, and 2000 Hz – Aß). The intensity of the stimulus was automatically increased in small increments until the rat flicked its tail. Tests at each frequency were repeated until the animals displayed 2 responses that were within 2 CPT (or 0.02 mA) of each other (2-4 tests/animal). CPT tests were performed prior to the exposure, immediately following the exposure, and 24 h after the exposure. Data Analyses. Temperatures were analyzed using a one-way ANOVA with animal as a random variable. ANCOVAS were used to analyze the CPTs at each frequency. Temperature at the time of the CPT test was used as a covariate, and animal was used as a random variable Results Tail temperatures declined between pre and post exposure (F(1,25) = 62.85, p < 0.001; mean ± sem pre 25.96°C ± 0.42, post 20.71°C ± 0.77), but were back to baseline levels by 24 h after the exposure in both groups of rats. The ANCOVAs demonstrated that exposure to a single bout of vibration did not alter sensitivity of C (5Hz) or Ad (250 Hz) fibers to stimulation.

Jan 6, 2006

By George A. Morgan

The successful expansion of crude oil production begun in late 1977, led to promising development of the nonfuel minerals sector. Although actual production of nonfuel minerals was limited both in variety and in percentage of output on a world scale, the potential for expansion with a rapidly developing infrastructure was significant. The energy base was expanding with construction of two new hydroelectric powerplants in addition to the existing plant near Edea. The Song Loulou plant will have a 240-megawatt capacity, and a hydroelectric plant under construction in the northern part of the country by mainland China will have 72 megawatts of installed capacity. Inflation of between 15% and 20% resulted in a real gross domestic product (GDP) of $2.8 billion2 in fiscal year 1980 (July 31 to June 1), up 6% from that of the previous fiscal year. Petroleum became the leading export item in terms of value, surpassing coffee and cocoa exports. Mineral exports as a whole increased eightfold in value, mainly because of oil sales. Oil exports also caused a reduction in the trade deficit by nearly one-third, and the Government expected its 1980-81 budget to be balanced at $1.17 billion. The Port of Douala accounted for about 8 million tons of cargo, or 93% of total maritime traffic for Cameroon. Expansion plans for the port call for an initial increase to 5 million tons, and a cargo handling capacity of 7.5 million tons in 1985 and 10 million tons by 1990. The Port of Victoria will gain importance with the startup of an oil refinery. The country&apos;s third seaport at Kribi was used solely for timber shipments, and capacity at the Port was to triple by 1981. The Government operated its own shipping line with six oceangoing freighters. France was the dominant trading partner, accounting for 25%

Jan 1, 1982

By James R. Boyle

The value of Alabama&apos;s nonfuel mineral production in 1984 was $409.8 million, and established a new record high for value of nonfuel minerals in the State, at 13.4:% over the previous high of 1983. Output of nearly all nonfuel minerals increased; phosphate rock was one of the exceptions, with no recorded output in 1984. Cement, crushed stone, lime, sand and gravel, and clays were the major commodities produced in Alabama. Alabama led the Nation in the production of crushed marble; was second in bauxite; third in fire clay and kaolin; fourth in bentonite, ferroalloys, and dimension marble; fifth in masonry cement, lime, and recovered sulfur; and sixth in portland cement. Alabama ranked 22d in the Nation in value of nonfuel minerals produced.

Jan 1, 1986

Quickly and cheaply consolidate underground slimes to facilitate their use as backfill and permit their easy handling for other reasons. Approach: The slurry containing slimes is pumped into active stopes and electrokinetically dewatered to provide consolidated back fill. How It Works: To densify slimes electro-kinetically two electrodes are placed in the material to be dewatered and densified. Typically, the electrodes are pieces of wire mesh fencing. One is placed on the bottom, and the other is suspended in the slurry near the surface. Figure 1 is a simplified section of a test. A d-c voltage of 100 to 400 volts is applied across the slurry. This causes the solid particles which are in suspension in the water (usually these are negatively charged) to migrate toward the anode; simultaneously, the water moves toward the cathode. Water immediately adjacent to the negatively charged solid particle surfaces contains an excess of dissolved positive ions. When these ions are attracted to the electrode and move towards it, they also exert

Jan 1, 1976

By Larry A. Lass

The U.S. Bureau of Mines, in cooperation with the Iron Range Resources and Rehabilitation Board, investigated the potential of using northeastern Minnesota papermill waste sludges as a binder for Mesabi Range iron ore (taconite) concentrate. Sludges from five different commercial papermill waste treatment operations were evaluated in laboratory tests. Except for the coarsest sludge, all were fairly easy to blend with the taconite concentrate using conventional mixing methods. The coarsest sludge had to be reslurried at 2 pct solids before adding it to the concentrate in order to obtain pellets without visible sludge clumps. Drying and grinding the sludges made them less effective as binders because of a lower degree of rehydration. On a dry weight equivalent basis, twice as much raw sludge binder was required to obtain similar pellet physical properties as with bentonite; however, the pellets made with raw sludge had superior metallurgical properties. Over 30 pct higher reduction rates and over 1500 C higher softening temperatures were obtained with sludge binder than with bentonite. Sludge D, which had the lowest fiber and the highest alkali metal content, resulted in the lowest reducibility enhancement. Even though more raw sludge was required than bentonite, the sludges have virtually no value, and therefore may provide a cost-effective additive binder for producing improved metallurgical-quality pellets. Large-scale testing has not been done to confirm these laboratory results.

Jan 1, 1989

By E. D. Regad, W. E. Wallace, P. S. Mike, C. A. Hill, V. Vallyathan, M. J. Keane

"Respirable-sized quartz, a well-established fibrogenic mineral dust, is compared with kaolin in erythrocyte hemolysis assays aher treatment with saline dispersion of dipalmitoyl phosphatidylcholine, a primary phospholipid component of pulmonary surfactant. Both dusts are rendered inactive after treatment, but the membranolytic activity is partly to fully restored aher treatment with phospholipase Ai. an enzyme normally associated with cellular plasma membranes and lysosomes. Phospholipid-coated dusts were incubated for periods of 2-72 h at a series of applied enzyme concentrations, and the adsorbed lipid species and hemolytic activity were quantitated at each time for both dusts. Surfactant was lost more readily from quartz than from kaolin, with consequent more rapid restoration of mineral surface hemolytic activity for quartz. Interactions of surfactant and mineral surface functional groups responsible for the mineral-specific rate differences, and implications for determining the mineral surface bioavailability of silica and silicate dusts, are discussed. INTRODUCTIONMineral particles depositing in the lung acinus will contact an aqueous coating containing surfactant molecules spread on the air-liquid interface and dispersed within this hypophase; the primary components of that surfactant are diacyl lecithin phospholipids (King and Clements, 1972; King, 1982). Adsorption of this surfactant can suppress the cytotoxicity of mineral dusts (Marks, 1957). Suppression of hemolytic activity, a measure of membranolytic potential and an indicator of bioavailability of the mineral surface, of respirable-sized quartz and kaolin clay dusts with the adsorption of dipalmitoyl glycerophosphorylcholine or dipalmitoyl lecithin (DPL) has been measured (Wallace et al., 1985). Such contact and adsorption of pulmonary surfactant in vivo may provide a first defense system of the lung against respired dusts."

Mar 1, 1992

By R. B. McElwaine

From November 1943 to April 1944, the Bureau of Mines put down 18 churn-drill holes aggregating 2,571 feet of bore in an investigation of the virtually abandoned zinc deposits of the north-central Arkansas district, principally in Marion, Boone, Searcy, and Newton Counties. The ore of this area occurs in flat-lying sedimentaries of the Mississippian and Ordovician ages. Much of the zinc is in the form of carbonate and silicate, although some sulfide has been produced. Preliminary studies resulted in selection for investigation of the Big Hurricane mine in northwest Searcy County, the Spies mine in northeast Newton County, and the Coon Hollow mine in eastern Boone County The comparatively large production of th.ese properties in the past was a factor in the selection. This report describes the work accomplished in the investigation and presents the data obtained.

Jan 1, 1948

By Forrest T. Moyer

Frequency rates of injuries per million man-hours of exposure were improved during 1965 slightly to moderately over those of 1964 at metal mines, nonferrous reduction and refining plants, nonmetal mills, stone quarries and mills, sand and gravel operations, and slag operations. However, at metal mills and nonmetal mines the rates of occurrence of work injuries were less favorable. The severity rates of injuries during 1965 were better than in 1964 at metal mines and mills, stone quarries and mills, and slag operations. Conversely, severity rates were worse at nonferrous reduction and refining plants, nonmetal mines and mills, and sand and gravel operations.

Jan 1, 1966

By M. R. Geer, H. F. Yancey

Fuel requirements of the Pacific Northwest have been increased greatly by the war . To the normal peacetime demands for fuel have been added the requirements of new industrial and metallurgical plants engaged in war production , the increased demand arising from expansion of existing industrial establishments , increased amounts of railroad fuel required to handle wartime traffic , and increased quantities of domestic fuel required by the influx of war workers . In the face of these augmented demands for fuel shipments of fuel oil have been curtailed , wood fuel which normally is an important factor in both industrial and domestic markets of the area is less abundant , and the production of coal in Washington has decreased sharply . The fuel requirements of the region have been met so far by shipping large tonnages of coal into the Pacific Northwest from Utah , Wyoming , Montana , and Colorado ; the quantity received from these States and Canada in 1943 amounted to 2,688,9124/ tons , 175 percent of the Washington production . or The proximity of the Washington coal mines to large centers of war production has resulted in widespread migration of miners to employment in shipyards and aircraft plants ; the ensuing shortage of miners largely accounts for the decreased production of coal in the State . Hence , strip mining , which requires relatively few workers and a shorter time for development , offers an attractive means of alleviating the local coal shortage and obviating the necessity of shipping coal from the producing areas of the Rocky Mountain States to the Pacific.coast . So urgent has been the necessity for augmenting local coal production that any coal property that promises to be amenable to strip mining , even though the coal may be inferior in quality , has warranted examination . Even low- grade coals that cannot compete in the normal market can be used locally , thus releasing better coals for shipment to critical centers. of consumption ... One such deposit of low- rank fuel examined by the Bureau of Mines is in western Lewis County , about 9 miles east of Toledo , Wash . The coal is lignitic and on the as - received basis has a heating value of 6,000 to 6,500 B.t.u. per pound . The property is of interest primarily because the physical conditions favor operation by stripping and offer opportunities for low- cost production with very low manpower requirement .

Jan 1, 1945