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By William H. Pomroy, Shail J. Butani

"This Bureau of Mines publication presents a statistical analysis of official U.S. Mine Safety and Health Administration (MSHA) metal and nonmetal mine fire reports from 1950 through 1984, plus accounts of selected nonreportable fires (less than 30 min and no injury) and opinion data on fire hazards from mine safety directors. Fires were analyzed by time trends, ore type, ignition source, burning substance, location in mine, equipment involved, means of detection, duration, number of injuries and fatalities, mining method, and successful extinguishing agent. The leading ignition sources were electricity in underground fires and engine heat in reported surface fires. The most frequent burning substance was combustible liquids for all nonreportable fires, reported surface fires, and reported underground fires from 1978 to 1984. For underground fires reported prior to 1978, timber was the leading burning substance. Mobile equipment was the type most frequently involved in both underground and surface fires. Underground fires occurred most often in haulageway or drift areas, and reported surface fires occurred most often in plant and mill buildings, while most nonreportable surface fires occurred in other areas. The most common methods of extinguishment were water hose lines for reported fires and dry chemical handportable extinguishers for nonreportable fires. INTRODUCTIONIn support of the Bureau of Mines research on mine fire protection, two separate baseline studies on mine fire incidents have been prepared. The first study addressed coal mine fires. The results of that study are summarized in the Bureau's Information Circular 8830, ""A Statistical Analysis of Coal Mine Fire Incidents in the United States From 1950 to 1977."" This second report, addressing metal and nonmetal mine fires, is the companion to IC 8830. Together, these two reports provide a comprehensive, factual summary of the mining industry's fire experience.This report, like IC 8830, covers (1) MSHA fire incident reports, (2) records of nonreportable fires (less than 30 min and no injury), and (3) mine safety directors' opinions on fire hazards. The MSHA fire reports provide the most reliable, objective, and accurate historcial record of the major noncoal mine fires that occurred during the study period (1950 through 1984). However, MSHA fire reports alone understate the true magnitude of the fire problem because metal and nonmetal mines have been legally required to report fires to MSHA only since 1968. Although some fires were reported prior to 1968, doubtless a great many were not. Also, the reporting regulations that took effect in 1968 specify that only fires lasting 30 min or longer or involving an injury need to be reported. MSHA fire reports are thus limited in scope by MSHA's legal authority. In order to provide a more comprehensive data base, it was also necessary to gather and analyze mine company records of nonreportable fires."

Jan 1, 1986

By C. I. Pierce

Knowledge of the water content of oil-bearing formations is important in petroleum-reservoir evaluation work. Electric logging provides a means for making reliable estimates of water content if resistivity-saturation relationships representative of the formations are available. Relationships can be determined in the laboratory by a number of methods. This report describes and presents results of a laboratory investigation conducted at the Bureau of Mines Appalachian Experiment Station, Morgantown, W. Va. (1) to evaluate an evaporation method of attaining water saturations in sandstone samples when determining resistivity-saturation relationships and (2) to compare saturation exponents derived from data obtained, using different methods of achieving water saturations. A series of tests was conducted to determine the effect of evaporation on salinity distribution within the core specimen. Results of these tests show that a zone of high salinity was set up at the surface of a sample during evaporation and that long periods were required for the sample to reach resistance equilibrium after evaporation had ceased. Equilibrium time ranged from several minutes to several days, depending on the sample size and the technique used. The high-salinity zone was removed from the sample by using auxiliary porous material in capillary contact with the sample surface during evaporation. Salinity determinations and resistance measurements indicate that, at saturations greater than the minimum interstitial values, the mechanism of flow during evaporation was one of moisture migration mainly as a liquid from the interior of the test specimens to their exterior surfaces. The concentration of the contained brine remained essentially unchanged, except for a narrow zone near the evaporating surfaces.

Jan 1, 1958

By Samuel P. Harteis, Eric S. Weiss

The National Mining Association and the Mine Safety and Health Administration requested that the National Institute for Occupational Safety and Health (NIOSH) conduct full-scale evaluations of a recently developed carbon fiber-reinforced polymer (CFRP) reinforcement technique for upgrading existing mine ventilation seals to withstand an explosion pressure of 50 psi or greater. The evaluation was conducted in the NIOSH Pittsburgh Research Laboratory’s Lake Lynn Experimental Mine (LLEM) near Fairchance, PA. The purpose of the evaluation was to determine the blast resistance of the CFRP reinforcement technique, designed to increase the strength of two types of existing 20-psi-rated in situ mine ventilation seals. Two candidate ventilation seals were selected to represent the 20-psi alternative seal designs typical of those used in mines prior to July 2006. Installed within the LLEM were (1) a 4-ft-thick pumpable cementitious foam seal using material with a designed 150- to 200-psi average compressive strength at 28 days and (2) a 24-in-thick, low-density cementitious block seal with a center pilaster and keyed to the floor and ribs. The materials necessary for the CFRP reinforcement technique were then installed on the outby (active) side of each seal, and the seals were subjected to explosion overpressures. Both seals with the CFRP reinforcement retrofit successfully withstood explosion pressures of 60 psi or greater during the full-scale evaluations in the LLEM.

Jan 1, 2008

By Jerry W. Stengel

The Bureau of Mines subjected two manufacturers' chemical oxygen (K02) self-rescue breathing apparatus to a series of laboratory environmental treatments designed to simulate various conditions in underground coal mines. The environmental treatments consisted of extremes of temperature, shock, and vibration. The tests were designed to be used as predictors of the ability of the self-rescuers to survive those environmental insults with no degradation in their protection to the wearer. Based on the severity of the treatments, simulating conditions more severe than offered by the mining environment, the two apparatus tested should be able to withstand the abuse offered by the mining environment and still function as intended in an emergency. Correlation of these tests with results of long-term field evaluations is needed to provide confidence in the laboratory tests as predictors.

Jan 1, 1982

Utilize innovative processing technology to prepare high-purity, ultrafine advanced ceramic powders with little or no contamination occurring during the milling process. Advanced ceramic materials made from these powders could substitute for high-temperature alloys containing critical materials such as chromium, cobalt, and nickel. Approach Modify and evaluate the Bureau's turbomill, developed earlier to grind a variety of ceramic raw materials (clay, mica, and talc), as a milling or size-reduction technique for hard and abrasive advanced ceramic powders, such as silicon carbide. Background Powders for producing ceramic materials, such as silicon carbide. silicon nitride, alumina, and zirconia, which arc being considered for use in severe applications requiring high-temperature and/or corrosion resistance, are very difficult to reduce to fine sizes for processing into finished parts. Traditional techniques of particle size reduction, such as ball milling and jet milling, are very energy intensive and/or slow. These traditional techniques often produce materials that have a nonuniform particle size distribution and are contaminated by the milling media or container.

Jan 1, 1989

By D. E. Hirsch

A systematic procedure for separation, characterization, and semiquantitative analysis of high-boiling petroleum distillates was developed by the Bureau of Mines and applied to a 370° to 535° C distillate of Wilmington, Calif., crude oil. Separation procedures employed were isothermal and molecular distillation, chemical treatment, silica-alumina adsorption, and gel permeation chromatography. Characterization and analysis were accomplished by gel permeation chromatography correlations and mass and nuclear magnetic resonance spectrometry. These data should be useful in improving petroleum processing and utilization and in achieving the energy conservation inherent therein.

Jan 1, 1974

By F. S. Crawford

The average visitor to a large electric-shovel operation may wonder how electric power can be treated as carelessly as apparently it is in open-pit mining, and how the mining company can string it carelessly along the ground in great, black, hoselike cables, whereas the power company, which has learned to respect his deadly agency, keeps power lines far out of reach. This is explained by the fact that this particular kind of application of power to moving machinery requires the use of trailing cable instead of the more permanent type of construction that permits a moving contact, such as a trolley. The cables are designed to insulate fully the enclosed power lines against damage and loss of current; and employees are taught to handle them carefully, although engineers are not satisfied that the trailing cable is foolproof and are seeking constantly to improve methods and equipment to insure greater safety. In some sections they rely mainly on the construction of the cable and perfection of equipment, while in others additional precautions are taken, such as handling the cable with rubber gloves, slings, tongs, or loops. In some sections no temporary repairs are made to cables, while in others such repairs are made and later are vulcanized in the shop. At some operations the cycle of shovel duties is arranged so that cables are very seldom exposed to flying rock fragments while at others this exposure appears to be unavoidable. Methods of fastening the cable to the shovel frame and transporting the loose cable vary. Inspection and care of the cable are important in insuring its safety and durability. A limited amount of information was obtained by field engineers of the United States Bureau of lines from operators in various parts of the United States, as methods of handling electric-shovel operations differ with the districts; practices followed and equipment used in these districts are described in this circular.

Jan 1, 1936

By R. A. Beall

Homogeneous zirconium-alloy ingots have been cast on a production basis by the consumable-electrode arc-melting process at the Northwest Electrodevelopment Experiment Station, Bureau of Mines, Albany, Oreg. This paper describes the various methods used to introduce alloying materials into the ingot and evaluates 1 each method by the degree of homogeneity of resulting ingots, as determined in tests on sections cut from the ingots. As many as 30 or more ingots, each 6 to 10 inches in diameter and weighing 300 to 500 pounds, were melted, using each method; and, as most of them subsequently were fabricated to strip 0.1 inch thick, the test results are considered to be representative of production practice. Ingot homogeneity has been considered more difficult to achieve in arc-melting practice than by methods where the molten metal is poured into molds and the addition can be stirred into the total mass of metal before casting. Owing to the unique requirements of consumable-electrode arc melting the addition can be made only to that part of the total mass of the ingot that is molten at one time. Observation of the flowlines in 500-pound ingots produced at Albany indicates that the molten pool has a maximum depth about equal to the ingot diameter. The weight of metal molten at one time is, therefore, not over 100 pounds. Characteristically, the arc-melting process is conducive to segregation, which can be overcome, at least partly, by adding the alloy constituents almost continuously during casting.

Jan 1, 1956

By C. J. Walker

The Bureau of Mines undertook a theoretical and laboratory study to determine the feasibility of using ethylene as a tracer for natural gas in underground gas-storage reservoirs. The study indicated that ethylene was a useful gas tracer in underground gas storages. Tracer losses were not excessive. Laboratory tests were conducted at pressures as high as 500 psia in both wet and dry consolidated-sandstone cores, evaluating tracer loss with gas blends containing natural gas with different concentrations of ethylene tracer. Under certain conditions losses were less than 17 percent.

Jan 1, 1966

By L. G. Marshall

The geology, mining, beneficiating, types of products, and costs in terms of percent of total costs and of labor, power, and supplies of two crushed-limestone operations in Madison County, Iowa, are described in this paper. The operations are basically similar, differing in refinements in mining, product types, and markets. The operations are comparable as to personnel and as to weighted costs in terms of percent of total costs and in terms of man-hours, power, and sup-plies. The waste-to-stone stripping ratio is 1 to 0.8 at both operations, the powder factor is 0.29 pound of explosives per ton of stone, and daily production is 95 tons per man-shift. Both companies use crawler-mounted diesel shovels for loading, truck transportation, wagon drills, and dry screening.

Jan 1, 1963

By Charles D. Martens

Raw non fuel minerals produced in the United States during 1981 had an estimated value of $25 billion, about the same as that of 1980. In terms of 1980 dollars. the value of minerals produced during 1981 was $23 billion.2 This chapter includes tables for 1980 that were not available for publication in the 1980 Minerals Yearbook, but does not include the corresponding tables for 1981. The underlying causes of the overall decline in U.S. nonfuel mine production during 1981 were varied, but the common factor was the worldwide recession. In some cases the decline was traced to foreign competition. For example, iron ore production was lower in part because of increased imports of steel products such as coiled steel sheet. Another problem experienced by the domestic mining industry was the continuing difficulty in attracting capital. This was due in part to the attractiveness of investments outside the mining industry, such as short-term, high-interest securities. Another reason was the importation of commodities from countries where overall costs were lower because of such factors as high ore grade, lower taxes, lower wages, government subsidies, and less stringent safety and environmental regulations.

Jan 1, 1982

By R. V. Ramani, K. Bode

"IntroductionThe theory of particle dispersion and deposition in turbulent flow is important to many fields of science and engineering. Dispersion has been studied in some detail since the early fifties (Taylor, 1954; Fischer, 1967; Osipov and Grekov, 1968; Skobunov, 1970 and 1973; Klebanov and Martynyuk, 1974). A broad research effort has also been underway in studying the mechanics of dry particle deposition. Friedlander and Johnstone (1957) proposed a theory, according to which particle deposition from vertical pipe flow could be described by an eddy diffusion transport followed by a final flight to the surface. There have been numerous revisions and additions to this original theory (Owen, 1960; Liu and Agarwal, 1974; Liu and llori, 1974; El-Shobokshy and Ismael, 1980) The mining process essentially consists of breaking in situ materials and transporting them out of the mine. An inherent characteristic of this process is the generation of fine particles. Fine airborne particulates are associated with a number of threats to the health of the miners; fine coal dust can also result in mine-wide catastrophic incidents such as dust explosions. For these and other reasons, it is important to understand the behaviour of airborne dust particulates, particularly their generation, entrainment, transport, dispersion, and deposition in the mine environment for their control.Mine related studies on dispersion and deposition have been few. Yet, several studies of gas and dust dispersion, diesel exhaust contamination, and methane ingress into mine workings have recognized the need for developing reliable parameter values for fundamental understanding of the phenomena (Da""Yes and Slack, 1954; Hodkinson, 1957; Hodkinson and leach, 1958; Mass and Wildschut, 1966; Airey, 1969; Courtney et al., 1986; Stefanko, Ramani, and Thakur, 1974; Stefanko, Ramani and Kenzy, 1977; Bhaskar, 1987, Bhaskar and Ramani 1990; Qin and Ramani, 1989; Shankar and Ramani, 1990)."

Dec 1, 1995

By Neil B. Young

Analytical results for nahcolite, dawsonite, total extractable alumina, and oil yield are presented for samples representing Green River Formation oil shales in the saline section of two cores from Colorado's Piceance Creek basin. Analyses are also reported for samples extending the analyzed section of Colorado corehole No. 3 beyond that reported previously. These data permit evaluation of the deposit for possible production of three coproducts--shale oil, alumina, and sodium carbonates--from the saline section of the formation at these sampled points.

Jan 1, 1970

By Arnulf P. Hagen

This project was designed to explore the suitability of using fluorinated inorganic materials as solvents for the in situ mining of thin seamed, heavily overburdened coal; to build a data base for the selection of an inorganic solvent for use for coal cleaning; to determine if fluorinated solvents will reduce the organic and inorganic sulfur contents of the coal, as well as to lower the ash content. The coal samples have been combined with pure solvent, as well as with aqueous solutions at atmospheric pressure and at increased pressure. The increased pressure experiments are important since they duplicate the conditions anticipated for an in situ cleaning and mining operation. Trifluoroacetic, difluorphosphoric (phosphorodifluoroidic), and trifluoromethanesulfonic acids have been found to be effective for the cleaning of high sulfur, high ash coal at 300°C and at atmospheric pressure. At pressures up to 20,000 psi the effectiveness of these reagents is not decreased.

Jan 1, 1983

Control the release of ground-water into active underground coal workings by short-term pumping from dewatering wells sited on fractures. Approach The sudden release of fracture-stored groundwater into underground coal workings often occurs when mine workings are developed beneath fracture valleys, Pumping from fracture trace-sited dewatering wells, prior to development of the underlying workings, can be an efficient means of intercepting fracture-stored groundwater before it is released into the mine. Dewatering operations are discontinued once the underlying mine workings have been fully developed, and the maximum possible reduction in fracture storage has been achieved through pumping. How It Works An aerial photographic technique known as fracture trace analysis is used to site dewatering wells on rock fractures in a valley bottom. Downhole caliper and temperature logs are used to assess the fracture flow potential of each dewatering well drilled.

Jan 1, 1987

To reduce accidents associated with transporting, installing or maintaining mine conveyor belts by providing easy-to-use tools for use in specific tasks. Approach The Bureau of Mines, through a re-search contract, developed three devices for use on conveyor belt systems 1) for use in moving and positioning conveyor components. 2) to reduce spillage and clean-up around conveyors, and 3) to lessen the maintenance of the belt system. The Saucer Skid Moving conveyor components using runner nose 1-beam skids is a simple task when the direction of travel parallels the beams. However, when the unit is moved sideways or around corners for final positioning, the web of the beam scrapes the floor with a bulldozing effect. Many strain and sprain injuries hap-pen when mine workers drag the skids into position at this paint. To minimize such injuries, the Bureau of Mines developed a saucer skid five feet in diameter with rounded sides and a flat bottom. Its design incorporates eight reinforced ribs with holes so the component may be secured to the skid, and eight exterior eyelets to which towing chains may be attached. The skid can be easily moved in any direction because its rounded sides slide over the mine floor rather than drag across it.

Jan 1, 1984

Large quantities of combustible materials are often found in underground metal and nonmetal mines, with support timber predominating. Wood lagging and timber, wires and cables, brattice cloth, hose, paper products, cardboard cartons, and wooden containers are additional combustible materials commonly found in underground storage areas. Shorted or overloaded electrical cables, worn sockets and plugs, spontaneous combustion, careless smoking, and welding and cutting are common fire ignition sources. Inexpensive, reliable fire detection and suppression systems are available to provide early warning and to extinguish fires that originate in underground storage areas.

Jan 1, 2011

By Joseph A. DeCarlo

This publication presents a tabulation of oven-and beehive-coke plants in the United States as well as pertinent statistical data on the number, capacity, kind, and condition of the ovens. Coke is an essential raw material in pig-iron production and the coal-chemical materials produced during the coking process are used to manufacture fertilizers, paints, plastics, synthetic rubber, explosives, detergents, nylon, pharmaceuticals; dyes, and many other products necessary to the high standard of living in this country. In table 1 the oven-coke plants in the United States on December 31, 1959, are listed. This shows the name and address of the company, location of the plant, classification or type of ownership, number and type of ovens, annual coke capacity, and the coal-chemical materials produced. The "furnace" plants I are those owned by iron and steel companies and most of them are integrated with blast furnaces to facilitate transportation of raw materials for steel making. Furnace plants represented 87 percent of the total coking capacity and their average annual capacity was 1. 3 million tons. The "merchant" plants are those associated with chemical companies, gas utilities, as well as those that produce metallurgical, industrial, and residential-heating grades of coke and coal-chemical materials for sale on the open market. These coke plants are smaller than furnace plants and in 1959 their average coke capacity was only 520 thousand tons annually. On December 3l, 1959, there were 54 furnace and 20 merchant oven-coke plants in existence in the United States.

Jan 1, 1960

By F. L. Klinger

CRUDE OIL refining continued to be the foremost industry of Bahrain in 1963. This island, the largest of a group 30 kilometers off the Saudi Arabian coast, is the site of the first petroleum discovery in the Persian Gulf and in the Arabian peninsular region. The island's only oilfield was discovered in 1932; exports of crude began in 1934 and the refinery was built in 1936. Although its crude oil has been less than 1 percent of annual Middle East output in recent years, Bahrain has been an important refining center for many years, processing a substantial portion of Saudi Arabian petroleum as well as all local production. The Bahrain refinery annually accounts for 17 percent 0 the petroleum products produced in the Middle East and 25 percent of the exports. Bahrain's mineral resources consist of oil, gas, and basic construction materials. Petroleum production and refining are the important mineral industries and contribute most of the national income by payments for taxes, wages, and local services including construction and material supply. The petroleum industry has supported a large share of local business and extensive indirect employment, and its early establishment also helped Bahrain to strengthen its position as a trading center in the Persian Gulf. The country's entrepôt trade produces about 20 percent of Government revenue, and Bahrain is somewhat less dependent on the petroleum industry than are the neighboring States to the west.

Jan 1, 1964

By Robert S. Sanford

"INTRODUCTION AND SUMMARYThis paper is one of a series recently undertaken by the Mining Branch, Bureau of Mines, College Park, Md., to describe current practice in hauling ore and waste by truck at various mines.Heavy-duty ore trucks are replacing railroads at many large open-cut mines and even at a few underground mines. Recently a few mines have been equipped with trucks for transporting ore to a central point, from which conveyor belts move the ore out of the mine. This paper deals only with truck haulage methods and costs.The requirements for efficient low-cost truck haulage are good trucks designed for heavy loads, adequate truck maintenance, smooth roads, and well-trained truck drivers.A correct balance must be maintained between the primary crusher capacity, the number of shovels loading ore, and the number of trucks hauling ore.The cost of tires is important. Tire companies are manufacturing better tires. Mining companies are prolonging the life of tires by building better roads and maintaining correct tire pressure.The trend is toward heavier equipment. In 1949 it cost $0.0925 a long ton to haul ore and waste with a 15-ton truck and $0.0743 a long ton with a 22-ton truck.When trucks are properly maintained, hauling costs do not increase with the age of the trucks. During 1948 it cost $0.1118 per long ton to haul with the four oldest 15-ton trucks and $0.1130 per long ton to haul with the four newest 15-ton trucks, two of which were purchased in 1945 and two in 1947.The weighted ayerage cost of hauling a long ton of ore to the crusher and waste to the dump has been reduced from $0.1159 in 1948 to $0.087 in 1949."

Oct 1, 1950