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By James C. Cawley

This paper updates an earlier report by the authors that studied electrical injuries from 1992 to 1998. The previous information is expanded and supplemented with fatal and nonfatal injury rates and trends through 2002. Injury numbers and rates were used to compare and trend electrical injury experience for various groups and categories. This information allowed identification of at-risk groups that could most benefit from effective electrical safety interventions. The data presented in this paper are derived from the U.S. Labor Department?s Bureau of Labor Statistics? Census of Fatal Occupational Injuries, Survey of Occupational Illnesses and Injuries, and Current Population Survey. Between 1992 and 2002, 3378 workers died from on-the-job electrical injuries. Electricity remained the sixth leading cause of injury-related occupational death. From 1999 to 2002, 4.7% of all occupational deaths were caused by electricity, down from 5.2% in the 1992?1998 time period. The cause of death was listed as electrocution in 99.1% of fatal cases. Contact with overhead power lines was involved in 42% of all on-the-job electrical deaths. The construction industry accounted for 47% of all electrical deaths between 1992 and 2002 but showed overall improvement from 1995 to 2002 by reducing its electrical fatality rate from 2.2 to 1.5 per 100 000 workers. In addition, 46 598 workers were nonfatally injured by electricity. Contact with electric current of machine, tool, appliance, or light fixture and contact with wiring, transformers, or other electrical components accounted for 36% and 34% of nonfatal electrical injuries, respectively. Contact with underground buried power lines was involved with 1% of fatal injuries and 2% of nonfatal injuries. The research of the National Institute for Occupational Safety and Health aimed at evaluating commercially available overhead power line proximity warning alarms is described. This paper is expected to be the initial step for eventual development of a performance standard for such systems.

Jan 1, 2008

By E. J. Gleim

The importance of "good voltage,? especially for direct-current systems in coal mines, is not always fully appreciated. From the practical 4 aspect there are three viewpoints from which low voltage may be considered, namely: (a) its effect upon operation of electrical equipment, (b) its effect upon cost of maintenance and power, and (c) its effect upon safety in the mine. The design of electrical motor-driven equipment usually is based upon a given or assumed constant value for the voltage of the system; consequently, when there is an appreciable drop below this value, unsatisfactory operation is likely to follow. In the case of shaker conveyors, for example, one manufacturer has pointed out that these conveyors must be operated at a certain definite speed if maximum output is to be secured. As shunt motors are used in the conveyor drives, either a rise or fall in voltage will produce corresponding changes in speed and thus seriously affect the efficiency of the conveyor. The introduction of automatic control for mine equipment has been greatly retarded because the relays, contactors, and other special devices required have failed to function properly when attempt was made to operate them on systems subject to variable and low-voltage conditions.

Jan 1, 1937

By A. Landsberg

Kaolinitic clays are potentially a vast domestic resource for aluminum. Utilization of this resource could decrease or eliminate the nearly complete dependence of the United States on foreign raw materials for this important metal. Furthermore, processing of clay to aluminum through anhydrous chloride metallurgy could reduce the high electrical energy requirements of the conventional Hall-Heroult aluminum reduction process. Several anhydrous chloride processes have been proposed; however, unresolved technical problems have prevented their commercialization. In particular, an acceptable chemical means has not been found to extract aluminum from clay as a highly pure anhydrous aluminum chloride. This Bureau of Mines report identifies and discusses the important chemical problems involved in achieving an acceptably rapid, self-heating, selective chlorination reaction and the subsequent separation of iron chloride byproduct from the anhydrous aluminum chloride.

Jan 1, 1983

By CHARLES L. WRIGHT

Previous work.-The general plan of work outlined for the Government fuel-testing plant erected at the Louisiana Purchase Exposition, at St. Louis, Mo., in 1904, included investigations relative to the briquetting of coals found in the United States. These investigations embraced the possibility of making satisfactory commercial fuels from lignite or low-grade coals which do not stand shipment well; of benefiting culm or slack coals that are wasted or sold at unremunerative prices; and of improving the furnace efficiency or ability to withstand transportation of good coals. This work was begun in 1904 and was continued in 1905, 1906, and 1907 as an essential part of investigations looking to the determination of methods for reducing waste and increasing efficiency in the utilization of the fuel resources in the United States. The initial briquetting tests at St. Louis, which included examination into the behavior of different coals or mixtures of coals in the briquetting press, experimental study of the merits of various substances used as binders, and consideration of the physical properties and resistance to weather and abrasion of the briquets, have been described.a They demonstrated that satisfactory briquets could be made from most coals, and that by briquetting the commercial value of many low-grade coals and lignites could be raised enough to more than cover the cost of manufacture. Norfolk plant.-The briquetting plant of the Geological Survey was moved from St. Louis, Mo., to Norfolk, Va., in 1907, along with the steam boiler and producer-gas equipment of the fuel-testing plant, as the closing out of the affairs of the Louisiana Purchase Exposition and the consequent removal of the buildings from Forest Park made a change of location necessary. Norfolk was selected largely with a view to the testing of coals for naval purposes, and because of facilities in the way of buildings and materials offered by the Jamestown Exposition Company. The work at Norfolk was chiefly devoted to making steaming and briquet tests of coals which reach the Atlantic seaboard at Norfolk and Newport News and are used by the navy and merchant marine. Two briquet machines were installed at the Norfolk plant, one being the English machine used in briquetting tests by the Geological Survey at St. Louis in 1905 and 1906, and the other an American machine. The briquets made at this plant were tested on locomotives of several railroads entering Norfolk and on the United States torpedo boat Buldle in comparison with the run-of-mine coal used in making them. Some of the tests were conducted by the railroads on their own locomotives, but those on the Biddle and on the locomotive of the Seaboard Air Line Railway were carried on by W. T. Ray and Henry Kreisinger, of the United States Geological Survey. Personnel.-Charles T. Malcolmson continued in general charge of the briquetting section after the removal to Norfolk until January 1, 1908. Walter J. Chapman continued in charge of operation of the briquet machines and of the observations reported under the heading "Details of manufacture." Charles L. Wright supervised the installation of the English briquet machine and later in the year continued the physical tests of briquets and the analyses in the chemical laboratory of the section until January 1, 1908, on which date he was placed in general charge of the work of the section. G. E. Ryder and Ralph Galt also continued with the staff, but the former was obliged to resign soon after the plant was in operation on account of ill health; the latter continued with the section as computer until the close of work on December 1, 1908.

Jan 1, 1911

By Robert E. Hershey

1. This investigation shows that the most important beds in Claiborne County, from the standpoint of present production and reserves, are the Coal Creek and Jellico. Together, they contain 69 percent of the known recoverable reserves in the county. Reserves in five other beds are tabulated in this report; in order of quantity of reserves, they are: Blue Gem, Lower Pioneer, Pewee, Big Mary, and Rex. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and on 1,800 short tons per acre-foot of coal in place, are estimated to be 60 million tons, as of January 1, 1953. Of this total, 55 million tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager to permit making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956

By W. I. Nissen

This Bureau of Mines report presents the design for a commercial-sized flue gas desulfurization (FGD) demonstration plant that uses the citrate process. The goal of the Bureau's citrate process is to minimize the undesirable environmental impacts of industrial plants emitting SO2-bearing gas. The FGD plant is located at the George F. Weaton powerplant, Monaca, Pa. Construction was completed in April 1979 and will be followed by preliminary testing and a 1-year testing and evaluation program. Design capacity of the FGD plant is 156,000 scfm of 0.2-volume-percent-SO2 flue gas yielding about 16 tons of sulfur per day. The plant is intended to (1) clean fly ash, SO2, and Cl- from the gas while cooling the gas in a venturi scrubber, (2) absorb SO2 from the gas using 1,200 gpm of a countercurrent-flowing citric acid-sodium citrate-sodium thiosulfate solution, (3) react the absorbed SO2 in two 13,000-gal stirred closed vessels with added H2S, thus precipitating elemental sulfur and regenerating the citrate solution for recycle, and (4) recover the sulfur from the slurry by air flotation, followed by melting in a heat exchanger and separation from the occluded citrate solution in a sulfur decanter at 35 psi and 135° C.

Jan 1, 1979

By Shail J. Butani

In 1986 the Bureau of Mines conducted a probability sample survey, Mining Industry Population Survey, to measure such employee characteristics as occupation; principal equipment operated; work location at the mine; present job, present company, and total mining experience; job-related training during the last 2 years; age; sex; race; and education. The population estimates are necessary to properly analyze the Mine Safety and Health Administration (MSWA) injury (includes illness and fatality data) statistics; that is, to compare and contrast injury rates for various subpopulations in order to identify those groups that are exhibiting higher than average injury rates. This report uses the survey's results to characterize the U.S. metallic mining workforce from March through September 1986. Similar reports have been published for the stone, sand and gravel, and nonmetallic mining industries, as well as for the entire metal and nonmetal mining (includes metallic, stone, sand and gravel, and nonmetallic industries) sector and the coal mining sector.

Jan 1, 1988

By J. Dean Warner

From 1984 through 1987, the Bureau of Mines investigated numerous prospects and new discoveries of columbium, rare-earth elements (REE), uranium, zirconium, and other metals associated with the multi-phased peralkaline granite at Bokan Mountain, southeastern Alaska. This report summarizes the mineral evaluations and estimates indicated and inferred resources for those prospects containing significant tonnage and grade. A total of approximately 96.2 MM lb Cb205 (43 pct of the tonnage at a grade exceeding 0.125 pct Cb205), and 11.8 MM lb U308, 27.9 MM lb Th02, 133.0 MM lb Y203, 637.6 MM lb ZrO2, and 241 MM lb REO are estimated to be contained within nine deposits totalling 37.8 million tons (at least 80 pct of resource tonnage also exceeds 0.5 pct Y203 + REO). Generally, half of the REO content is composed of the heavy yttrium subgroup. Several deposits also contain beryllium and tantalum; 2.1 MM lb of Ta205 and 8.9 MM lbs of BeO were estimated. These estimates would likely be substantially increased with additional exploration. Four deposit types were investigated; shear zones and fracture-related deposits, pegmatites, mineralized dikes, and placers. Mineralized dikes contain most of the beryllium, columbium, tantalum, yttrium, zirconium, and REE resources, whereas shear zones and fracture-related deposits (Ross-Adams mine) contain the principal of the uranium resource. Pegmatites are similarly mineralized as are dike deposits, and contain low levels of gold. Placer potential is suggested, but no deposits were found.

Jan 1, 2011

"The mission of the Respirable Dust Center is to enhance the health, safety and productivity of the miners 'through advancing the fundamental .understanding of all aspects of respirable dust associated with mining and milling and the interaction of dus.t and lungs for reducing the incidence and severity of respirable dust disease. All Dust Center activities are focussed to be responsive to this mission which is shared by several federal agencies closely associated with the Generic Mineral Technology Center for Respirable Dust such as USBM, M,SHA, and NIOSH, and the mining industry. While significant progress has been achieved in making mine atmospheres cleaner and healthier, respirable dust disease remains the nations worst industrial hazard. GOALSThe goals of the Respirable Dust Center have been formulated to recognize the diverse scientific, engineering and medical aspects of respirable dust as well as the need to enhance the interaction, education and technology transfer in the respirable dust area.The Center goals are to:1. Enhance the understanding of the scientific, engineering and biological characteristics of fine and respirable mineral particles, fibers, organic aerosols, and complex particles found in the mining and milling atmospheres.2. Advance the understanding of the physical behavior of airborne respirable dust particles in flowing streams under different. stimuli during mining and milling.3. Advance fundamental understanding of the causative mechanisms for the occupationally related lung impairments and the airway diseases of mine and mill workers.4. Establish the relationship between natural and cultural factors (mine geology, mineralogy, mining and milling methods, equipment and control measures) in the generation, exposures, and pathogenic properties of fine particles.5. Contribute to the development of control mechanisms for reducing ambient respirable dust concentrations, worker exposure, the incidence and severity of dust related lung disorders and disease prevention in mining and milling atmospheres.6. Enhance functional integration among the various research personnel in the Center, as well as, with other groups, such as MSHA, NIOSH and USBM involved in respirable dust research and control.7. Develop technically trained personnel for employment in the mineral industry for respirable dust research and control.8. Enhance the availability of respirable dust-related information utilizing several technology transfer avenues."

Jan 1, 1990

By James H. Prout

Roof warning signals were studied in 18 mines covering 5 coal seams. The results of this study confirmed that roof talk must be interpreted for each individual mine after all other conditions are present that indicate danger of roof fall. Characteristics of roof talk pulses were studied to ascertain features used in interpretation. Roof talk pulse decay time was found to be typically 0.1 to 0.5 seconds depending on the dimensions of the entires. Time between roof talk pulses was found to correlate inversely with the degree of danger under certain conditions. Roof talk and machinery noise recordings obtained during this study were used for subjective tests of ear protectors in a simulated coal mine noise environment. These tests required a detailed interpretation of roof talk and yielded results with high statistical power. Results of these tests showed that the use of personal ear protectors in high noise levels does not degrade a miner's ability to discriminate speech and roof talk. A training course was developed to encourage coal miners to pro-tect their hearing by proper use of personal hearing protectors.

Jan 1, 1973

By E. L. Rawlins

The development of commercial natural-gas reserves in the Michigan stray sandstone horizon of central Michigan during the past few years has resulted in expansion of the natural-gas industry in that State. The location of the natural-gas reserves of Michigan in the general vicinity of domestic and industrial markets is of economic importance, and in supplying these markets with natural gas a reasonable knowledge of, the extent and availability of the reserves is needed in formulating regulations for drilling gas wells and producing natural gas in analyzing the feasibility of projects to construct natural-gas transmission lines, in promoting and developing markets for the domestic and industrial consumption of natural gas, and in solving many engineering and economic problems common to the natural-gas industry. The development of the natural-gas industry in Michigan has been related closely to the development of oil production. The potential oil production of Michigan is comparable with that in most of the eastern oil-producing States. The development of oil production probably will continue, especially in the central Michigan Basin area; and as wells are drilled to deep horizons in the search for oil, more knowledge will be obtained of the gas reserves in formations above the oil-bearing horizons.

Jan 1, 1936

By F. E. Spencer

Calculated equilibrium data are presented for three phases in the flue gas stream from a hypothetical open cycle MHD generator. A typical coal is "burned" with 1.0 gram-mole K2O seed per kilogram coal and with 101 percent of stoichiometric air. Tables of composition and the overt thermodynamic properties, enthalpy and entropy, are given for the temperatures 2200 (-100) 1100 kelvins, pressures 1.0 and 1.5 atmospheres, and slag rejection figures of 90 and 75 percent.

Jan 1, 1973

By Ronald W. Stingelin

This study undertook the development and implementation of a methodology for estimating the impact of coal seam interaction on the eastern bituminous underground reserve base as published in USBM Information Circular 8655. The effects of previous mining in multiple coal seam areas on currently mined and reserve seams are predicted as a percentage coal loss by an engineering assessment model called the Coal Loss Calculation Model. The model utilizes twelve input variables easily derivable from mine maps or other existing data sources and calculates the effects of subsidence and high-stress due to remnant pillars in the previously mined seam. Extensive literature review resulted in the identification, definition, and quantification of the critical variables of seam interaction. Export opinion surveys were made of mining experts, MESA mine inspectors, and coal mine operators. Statistical analysis was used to establish the redundancy of the critical variables and to develop a total coal loss prediction algorithm. A regional analysis resulted in the production of a series of thematic maps on coal characteristics and distribution. A derivative map showing the areas of commonality within the eastern bituminous coal region served as the basis for implementation of the coal loss calculation model. The model was developed and tested using data from four coal mines in western Pennsylvania and southern West Virginia.

Jan 1, 1976

By J. A. Woolf, A. P. Towne

"INTRODUCTION A considerable part of the metallurgical work of the Precious Metals Section comprises ore-testing experiments on ores selected as representative of various mining districts on areas. Projects authorized by the Bureau and assigned to the Precious Metals Section generally include only those ores or tailings in which the precious metals are the main valuable constituents; however, there are also included ores that contain strategic or critical metals in addition to the precious metals. The recovery of strategic and critical minerals is the most important phase of the treatment of this latter class of ores. However, if a considerable percentage of the precious-metal content of such ores can be recovered without complicating the flow sheet too much, it may be possible to treat an ore for the recovery of strategic or critical metals that could not otherwise be treated at a profit.Standard testing procedure involving cyanidation, amalgamation, gravity concentration, and flotation, or a combination of these methods, is employed in the greater part of this work. However, as the complexity of the ores furnished for this work has increased, it has been necessary to include special applications of standard procedures in many instances, Standard methods of conducting tests and the purposes of the work as a whole have been discussed in previous reports 4/ of ore-testing studies. In the present report, whenever it has been necessary to apply some special phase of standard treatment, this has boon explained in detail in that particular section of the report."

Aug 1, 1944

By Steven R. Munts

The U.S. Bureau of Mines investigated mines, prospects, and mineralized areas in the South Providence Wilderness Study Area (WSA) in 1982. No mines are currently operating in the WSA, however, the Golden Gift Mine in the southeastern part of the WSA produced $6,800 1/ worth of gold and silver and five mines adjacent to the east boundary of the WSA had a total production of about $3,500,000 1/ in gold, silver, lead, and copper. There is no recorded placer gold production. Over 350 lode and placer mining claims are in and immediately adjacent to the WSA. Of these, 74 were actively held (1982) and at least one area, which is partly within the northeast portion of the WSA, was being actively explored by private industry in 1982. Adjacent to the southeastern border of the WSA the Big Horn Mine contains an estimated 200,000 tons of indicated and inferred marginal reserves averaging 0.25 oz/ton gold; and the Hidden Hill Mine has 550 tons of subeconomic resources averaging 0.60 oz/ton gold. An additional 11,000 tons of marginally economic gold-bearing dump reserves average 0.17 oz/ton gold at the Bighorn, Hidden Hill, and the Buena Vista Mines and the Midas Touch Prospect. Sample analyses indicate eight mines and prospects in, and five adjacent to the WSA may have additional gold-silver-lead-copper vein-type resources. Five of these prospect areas may have a disseminated gold resource and one may have gold resources in a skarn. One prospect may have a porphyry-type copper-molybdenum resource. Although gold placer claims were filed sporadically throughout the WSA, none appears to have placer gold resources. Likelihood for mining is greatest at the Big Horn Mine; if a mill is built there, it could process Big Horn Mine ore, ore from the Hidden Hill Mine, and gold-bearing dumps at the Big Horn, Hidden Hill, and Buena Vista Mines and the Midas Touch Prospect. All of these resources are adjacent to the WSA; however, their development would increase likelihood for development of resources in the WSA. Two major fault zones (the Hidden Hill, and the Big Horn) appear to have controlled the mineralization at many of the prospects and mines. All of the prospects or mines with vein-type occurrences and resources are on or adjacent to one of these fault zones. Veins throughout the eastern half of the WSA contain various amounts of gold, silver, and copper; only veins near the Big Horn Mine and in the northeastern corner of the WSA contain lead. Some veins are as thick as 6 ft, are traceable intermittently for over 2 mi along strike, are sporadically mineralized, are encased in prophylitic, argillic, and phyllic altered host rock, contain pyrite, chalcopyrite, galena, specularite, barite, or fluorite, and display multiple stages of quartz veining and (or) brecciation. Sample analyses at five prospects (map nos. 3, 18, 23, 24, and 31) indicate they may have disseminated gold resources. To date no oil or gas has been discovered within the WSA. However, some oil and gas leases are currently (August 1982) held within this study area.

Jan 1, 1984

By O. C. Blade

In its general study of crude petroleum, the Bureau of Mines has published several reports that include analyses of samples of crude petroleum from Oklahoma fields3/. This report discusses briefly the properties of crude oil samples collects in come of the major producing Yields in the State. ACKNOWLEDGMENTS This investigation was conducted by the Bureau of Mines in cooperation with the State of Oklahoma. The study was via e under the general supervision of R. A Cattell, chief engineer, petroleum and Natural-Gas Division, Bureau of Mines, Whishington, D. C., and N. A. C. Pith, supervising engineer, Petroleum Experiment Station, Bureau of Mines, Bartlesville, Okla., and. Under the direct supervision of Ludwig Schmidt, senior petroleum engineer, Bureau of Mines, Bartlesville, Okla.

Jan 1, 1939

By O. C. Blade

[In its general study of crude petroleum, tic Bureau of Mines has published several reports that include analyses of samples of crude petroleum from Oklahoma fields3/. This report discusses briefly the properties of crude oil samples collects in come of the producing fields in the State ACKNOWLEDGMENTS This investigation was conducted by the Bureau of Mines in cooperation with the State of Oklahoma. No study was made under the general supervision of R. A Cattell, chief engineer, petroleum and Natural-Gas Division, Bureau of Mines Washington, D. C., and N. A. C. Smith, supervising engineer, Experiment Station, Bureau of Mines, Bartlesville, Okla., and under the direct supervision of Ludwig Schmidt senior petroleum engineer Bureau of Mines, Bartlesville, Okla.]

Jan 1, 1939

The following pages discuss the objectives, the background, and scope of work of an industrial engineering analysis of far-,n haulage systems in underground retreat coal mining. This study ran concurrently with an existing industrial engineering study of methods of improving safety and production efficiency in underground pillar extraction. 1. OBJECTIVES The objective of this project was to provide basic data inputs that will inpart knowledge as to the major constraint to pillar extraction sections. Furthermore, the industrial engineering study will suggest ways to optimize haulage systems and to develop more efficient work practices and operational techniques that will maximize equipment utilization.

Jan 1, 1975

By R. H. Hiltz

One of the major hazards in underground coal mining is fire. The inherent hazard of fire is exaggerated by the nature of coal mining restricted areas, the highly combustible nature of coal itself, and a potential for explosive concentrations or dust and gas in the air it becomes imperative therefore to make every effort to eliminate the causes of fires, while providing the most effective means possible to control and extinguish those fires which may occur it has been demonstrated by prior work that the problem of control increases in proportion to the time necessary to institute control procedures. There are several areas of underground coal mining with obvious fire potential. Some of these, like belt heads, have reliantly undergone improvements in standby fire control devices Others, although having fire suppression systems available to them, have not received as complete a systematic study of their problems. Face machinery, particularly those without a water supply, falls in this latter category.

Jan 1, 1973

By C. Froger

Since its creation in 1950, the Centre d'Etudes et Recherches des Charbonnages de France at Verneuil-en-Halatte (Oise) has been conducting many investigations concerned with airborne dust measurements, particularly in underground mines. The work has resulted in the development, a few years ago, of a new process of dust sampling, whereby the airborne dust particles are collected by a rotary filter of polyurethane foam rotating at high speed within 8 housing.

Jan 1, 1973