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By Arcy, D&apos Banister

Drilling practices at the Silver Summit mine in Shoshone County, Idaho, and the steps taken to increase drilling efficiency are described for the 1952 to 1958 operating period. Mining and development methods are outlined, and drilling equipment and practice are discussed, Cost and performance data include drilling time, bit duty, steel failure, drill repair, and compressed-air consumption. Steps taken to increase drilling efficiency and decrease costs are described, including modifications of bit design, new procedures for drill-rod fabrication and new processes for completing certain drill-machine repairs.

Jan 1, 1963

By D. A. Reynolds, R. G. Travis, James J. Dowd, R. F. Abernethy

"1. Reserve estimates have been made for eight coal beds in Monongalia County, W.Va., but only the Pittsburgh, Sewickley, and Upper Freeport beds are important at this time. The Pittsburgh, Sewickley, Waynesburg, and Upper Freeport beds contain the largest recoverable reserves.2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 3,526 million tons as of January 1, 1954. Of this total, 3,294 mil¬lion tons is in beds 28 inches and more thick. Areas in each bed except the Pittsburgh were omitted from the estimate because available data relative to the bed characteristics are too meager for 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.3. Recoverable reserves of coal have been estimated in beds 28 inches and more thick. This thickness is about the minimum now being mined by hand loading onto conveyors in the Appalachian region. The weighted average recovery for all beds in Monongalia County, as determined by this investigation, is 47.9 percent. This percentage is based on the total thickness of coal (less partings three-eighths inch thick or more) in the bed rather than on the thickness of the coal mined. Based on the weighted average percentage of recovery for all beds in Monongalia County, the recoverable reserves are estimated at 1,577 million tons as of January 1, 1954.4. Monongalia County coals of the major producing beds are of high-volatile a bituminous rank.5. The Pittsburgh and Lower Freeport beds in this county yield coal that can be used as metallurgical coal, especially when blended with low-volatile coals. The Lower Freeport coal is coked singly and in beehive ovens, and makes good metallurgical coke.INTRODUCTIONThe investigation to evaluate the reserves of coking coal was planned to cover three phases: (1) Estimation of known measured and indicated recoverable reserves of all coking coal; (2) study of methods of upgrading marginal coals through effective preparation; and (3) study of carbonizing properties of coals and coal blends not now widely used for metallurgical coke making."

Jun 1, 1956

By F. E. Walker, S. J. Aresco, J. B. Janus

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 instructions 4/ 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 . The Government purchased approximately 5 million tons of coal in fiscal year 1962. In connection with these purchases , the Bureau analyzed 7,114 samples . These are published ( table 1 ) for the use of Government officials and the public . A series of publications has been completed on coal analyses by States or , where production is small in any one State , by groups of adjacent States . In addition to analytical data showing composition and quality of coals of the States , the publications contain brief descriptions

Jan 1, 1963

By O. C. Blade

A comparison of certain properties of the commercial aviation gasolines produced in the United States during October 1949, 1950, and 1951 is presented in table 1, the 1951 data being average values from tables 3 through 6 of the present report. Trends in the average values of certain characteristics of these fuels may be seen in figures 1 through 4 which also indicate the minimum and maximum values. As may be observed, with the exception of changes in kinematic viscosities, the properties of commercial aviation gasolines have not varied greatly during recent years. A list of aviation-gasoline survey reports published by the Bureau of Mines is given on page 6. A summary of the average values of the properties on jet fuels is shown in table 2.

Jan 1, 1952

By Robert E. Barieau

In the design of plants to separate helium from natural gas, it is necessary to estimate the enthalpies of the various streams at various positions in the process. This Bureau of Mines report surveys the various methods that have been used to determine enthalpies and gives information on the organizations with such capabilities. The minimum information required for developing an enthalpy diagram is presented, and the relative merits of the various methods are discussed. It is concluded that methods that require no mass flow rate or energy measurements are to be preferred.

Jan 1, 1965

By Robert E. Barieau

In the design of plants to separate helium from natural gas, it is necessary to estimate the enthalpies of the various streams at various positions in the process. This Bureau of Mines report surveys the various methods that have been used to determine enthalpies and gives information on the organizations with such capabilities. The minimum information required for developing an enthalpy diagram is presented, and the relative merits of the various methods are discussed. It is concluded that methods that require no mass flow rate or energy measurements are to be preferred.

Jan 1, 1965

By Ludwig Schmidt

The economic value of reducing the evaporation losses of crude oil and of gasoline is so well founded that the petroleum industry is constantly seeking new and improved storage tanks and methods of handling its products to further reduce these losses. A comparison of the methods and apparatus used in handling and storing crude oil and its products today with those in general use 10 years ago would show that an oil tank is no longer simply a container for holding liquid, but is now considered an important piece of equipment which if, subjected to constant inspection and care. In fact, the modern vapor-tight tank often requires as much care as a boiler or pump when one considers Its various component parts such as vapor-tight gage hatches and thief-hole covers, vacuum and pressure relief valves, swing line apparatus, vapor-recovery systems, insulation, cooling devices, and often automatic gaging devices. As an auxiliary to the physical equipment of the tank itself the subject of paints and paint colors is now given considerable attention. In addition to vapor-tight tanks and auxiliary equipment, other types of tanks for reducing, evaporation which are new to the industry have also been developed and placed on the market within the past few years. The development of the floating roof type was an innovation in tank construction, directed toward the reducing of evaporation losses. This type of roof rides on the surface of the oil and thus eliminates all vapor space. It is especially valuable for working tanks.3 A recent development in tank construction is a new type of tank roof known as the diaphragm or "breather roof," Which practically eliminates the movement of air-vapor mixture from a storage tank filled with oil. It is of especial value for use on tanks in which oil is stored over long periods.

Jan 1, 1930

By Robert L. Marovelli

The thermal conductivities of six rocks were measured by the transient line source method over the temperature range of -850 to 1,500° F. Close-fitting ceramic probes were used in 0.065-inch-diameter holes drilled through 5-to 6-inch-thick rock specimens. Taconite, granite, quartzite, and basalt were used in the tests. The method yields absolute data and is applicable to both laboratory and in situ measurements.

Jan 1, 1965

By J. M. Stuve

Calorimetric determinations of the low-temperature heat capacities, standard enthalpy of formation, and high-temperature enthalpies were made of (Na20)4 ?Fe20,(c). The resulting values of entropy (S°), enthalpy of formation (?Hf°), and free energy of formation (?Gf°) at 298.15° K are 104.676 cal/deg mole, -656.2 ±.kcal/mole, and -603.4 A kcal/mole, respectively. Tabulations of Cp°, S°, - (G°-H°298)/T, H°-H°298, ?Hf°, ?Gf°, and log Kf are given to 1,200° K.

Jan 1, 1971

By L. E. Schultze

[The Bureau of Mines conducted bench-scale studies to develop techniques for stripping tetravalent cerium from tri-n-butyl phosphate solutions. Experiments were conducted in a constant-temperature bath using beakers and mechanical stirring. Ninety-five pct of the cerium was stripped from a 50-pct tri-n-butyl phosphate 50-pct kerosene solution containing 0.18 M cerium in 15 minutes at 50° C using 0.11 M aqueous formaldehyde.]

Jan 1, 1974

By A. E. Kehew

Earth resistivity surveys using the Wenner electrode configuration were made in unmined areas and reclaimed spoils at three surface lignite mines in western North Dakota. The study sites were the Center, Indian Head, and Falkirk Mines. Automatic interpretation of the curves was accomplished with the method of Zohdy and Bisdorf (1975). Overburden materials become more homogeneous with respect to resistivity during the mining and reclamation process. The spoils curves show localized hetero-geneities probably related to discontinuous moisture content variations in the spoils. Consistent resistivity differences in spoils occur between mines with over-burdens of different mineralogic compositions. Groundwater chemical composition in terms of total-dissolved-solids (TDS) is inversely correlated (r=-0.61) with apparent resistivity at the 80-foot spacing from a survey centered at a piezometer screened near the base of the spoils. Better inverse correlation is probably pre-vented by high variability in TDS within the spoils groundwater. A useful predictive relationship may be the plot of mean apparent resistivity at the 80-foot spacing for ar. entire mine against mean TDS for all wells in spoils at that mine. Data from more mines are needed to test the hypothesis.

Jan 1, 1982

By K. C. Dean

Horizontal and vertical air classification systems were tested individually and in simulated tandem use for the recovery of ferrous and nonferrous metals and of other noncombustible and combustible products from shredded urban refuse. The horizontal air system with a larger tonnage throughput was used to obtain preliminary separations, and a smaller capacity vertical system was used as a cleaning device. Air elutriation, magnetic separation, and screening of shredded minus 6-inch municipal refuse recovered 92 percent of the metal in a relatively clean iron product contaminated only by adhering coatings or entrapped materials, recovered 97 percent of the combustibles in a 97-percent combustible product, and rejected 88 percent of the nonmetal noncombustibles. Cleaning of the preliminary combustible fraction produced a 98-percent paper product while rejecting other combustibles (plastics, rubber, textiles, etc.) into a 94-percent combustible product. Retreatment of the preliminary noncombustible fraction produced a relatively clean glass product.

Jan 1, 1971

By M. S. Fleming

The objective was to evaluate central lubrication systems for potential use on underground mining equipment. Previous use on continuous mining equipment resulted in poor system performance because of improper selection of lubricants, component failures, and an inconsistent delivery of lubricant to the bearings. The principles and operational characteristics of systems are reviewed and evaluated, and it was concluded that systems are available which can provide reliable central lubrication if properly applied, installed, and maintained. The procedures for applying a system to a continuous miner are discussed. Investigation revealed the lack of significant information on lubrication-related equipment failures and injuries related to maintenance and repair operations, the lack of significant failure rate data for central lubrication system components, and the lack of performance standards for central lubrication systems and components. To continue the development of systems for underground mining equipment it is recommended that a data bank on failures and reliability for equipment with and without central lubrication systems be created, and standardized specifications and performance criteria be developed for central lubrication systems and components which will be used on underground mining equipment.

Jan 1, 1979

By K. K. Kelley

Synthetic fluorphlogopite mica (KMg3AlSi3010F2) is a relatively new product developed at the Norris (Tenn.) Station of the Bureau of Mines, Thermodynamic data have applications both in the production and use of this product, and the work described in this paper was undertaken to fill the need for such data. Measurements were made of the heat of formation at 298° K., the heat capacity between 50° and 298° K., the entropy at 298° K., and the heat-content and entropy increments between 298° K. and a maximum of 1,804° K. These basic data are combined to obtain heats and free energies of formation of the mica from the elements and from molecular constituents at temperatures ranging from 298° to 1,800° K. Minimum heat requirements to form melted mica from commonly used ingredients were calculated.

Jan 1, 1959

By W. M. Bangert, F. S. Boericke

"INTRODUCTION Previous investigations of the Boulder City station of the Bureau of Mines have demonstrated that low-grade domestic chromite concentrates can be roasted with carbon to obtain selective reduction of the contained iron, and that the reduced iron can be removed by acid leaching of the roasted products to produce residues with higher chromium iron ratios. Thus, some chromite ores or concentrates that originally contain too much iron to be acceptable for the production of ferrochrome can, by this treatment, be rendered marketable as ""high-grade"" chromite. 3/The present report supplements the earlier work of the Bureau and re¬cords the results of small-scale laboratory tests investigating the effects of:1. Temperature and time of the reducing roast.2. Chromite and carbon particle size.3. Ratio of carbon to chromite in the initial roast mixture.4. Variations in the alumina and silica content of the ore.5. Back-oxidation of the roast product.6. Temperature and time of leaching .of roast product.This work differs from that done previously in that particular emphasis was placed on roast mixtures containing just enough carbon for the reduction of the iron in the chromite, whereas some two and one-half times this amount of carbon was used in the earlier work.In addition to these tests, the mechanism of the production reactions was examined for the purpose of explaining the precance of acid-soluble chromium, which occurs under certain conditions of chromite reduction."

Jul 1, 1945

The following are abstracts from papers presented at the 4th Symposium on Respirable Dust in the Mineral Industries and· were produced through research funding under the Generic Mineral Technology Center for Respirable Dust. Full articles appear in the proceedings published in July 1996 in Applied Occupational and Environmental Hygiene. (Volume 11, Number 7). The two addresses included in the proceedings point to the progress, prospects, problems, and perspectives on control of respirable dust and dust-related disease in the mineral industries. The symposium papers deal with respirable dust issues that are longstanding such as characterization, health effects, control of airborne coal dust, new and emerging issues such as iron toxicity, diesel particulates, and sampling. The papers were grouped into the following topics: continuous dust monitoring, encompassing the development of a fixed-site monitor that will provide continuous information on instantaneous and time-weighted respirable dust concentrations; mechanisms involved in the generation of dusts in mine environments, important for dust control at the source; characterization and control of diesel emissions (particularly diesel particulates) in mine atmospheres; mining systems effects and models; dust control in mine working faces and in milling environments; characterization of the physical, chemical mineralogical, and biological properties of the dust and their relevance to health effects and sampling; dust-lung interactions, encompassing results from several biomedical studies dealing with acute and chronic inhalation of airborne dusts and associated lung responses; the role of iron in causing lung injury; and therapeutic strategies for ·the control of pulmonary disease. All papers submitted to the organizers were peer-reviewed. In the proceedings, we have not differentiated among the platform and poster papers; rather, they have been grouped into the above topical areas. Taken together, these papers reveal significant progress in the control of dust generation, characterization of dust, understanding of dust-lung interaction, and mining and milling practices to reduce dust exposure - all essential for reducing dust-related occupational hazards at the workplace.

Jan 1, 1998

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 Joseph M. Singer

Ignition of hybrid coal dust - methane - air mixtures by hot- turbulent - pulsedgas jets was investigated . The turbulent jets were generated by explosions in a primary chamber of stoichiometric mixtures of methane , oxygen , and nitrogen . The hot - gas ignition apparatus provided an adjunct means of testing , on a small scale , the type of ignition that exists in large - scale galleries or in coal mines . = coal particle The temperature Ignition variables were channel diameter , channel length , size , fuel concentration , and temperature of the hot - gas jet . of the hot jet was varied by changing the oxygen indices ( OI ) of the primary explosion mixtures . Coal dust having approximately 37 percent volatile matter was used . 02 O2ટ + N₂ The hybrid coal dust - methane - air mixtures required higher jet temperatures ( higher oxygen indices ) for ignition than the single fuel component methane - air mixtures . Methane in air concentrations less than the lower flammable limit of methane could be ignited in the presence of coal dust if the jet temperatures were increased . A specific explosion transmission ( ignitability ) curve existed for each coal dust concentration . The total fuel concentrations at the lower limit of each ignition curve was always close to or greater than stoichiometric , indicating that not all the coal dust was involved in the ignition .

Jan 1, 1964

By H. M. Thorne

The oil-shale deposits of the Puertollano basin in the Spanish province of Ciudad Real appear to have been give little consideration in discussions of oil-shale resources throughout the world. A small, integrated oil-shale operation has been conducted at Puertollano since about 1922 by a French company, Sociedad Mimora y Metalurgica de Penarroya, hereinafter referred to as "Penarroya", but only within recent years have the potentialities of the Spanish oil-shale deposits been recognized. Empresa Nacional "Calvo Sotelo" do Combustibles y Lubricantes, hereinafter designated as "Calvo Sotelo," which was created in 1942 by the National Industrial Institute of Spain to produce liquid fuels from oil shales, has made marked progress in the design and construction of a complete oil-shale plant at Puertollano. Penarroya is mainly a coal-mining company, and the oil-shale operations were on a small scale of approximately 220 tons a day in October 1947. It is an integrated operation comprising oil-shale mining and retorting and shale-oil refining. Motor gasoline, Diesel fuel oil, light burner fuel oil, lubricants, paraffin wax, cresols, and ammonium sulfate are manufactured.

Jan 1, 1950

By Franklin H. Persse

Domestic bismuth supply was projected from production figures for the ores in which it occurs--copper, lead, zinc, and tungsten. Published and unpublished data concerning host ores were examined to determine bismuth reserves and resources, and mine production. Potential recoverable bismuth occurring with reserves and resources of copper, lead, and zinc was estimated to be 36.3 million pounds. A bismuth availability diagram was developed from quantity estimates and ratios of production cost to value for these host ores. Additional recoverable bismuth occurring with domestic tungsten reserves was estimated to be 1.5 million pounds. Domestic byproduct production of bismuth will approximate 1.3 million pounds annually by 1980. This quantity will provide about 37 percent of the 3.5-million-pound estimated requirement for that year. Known world supply of bismuth appears to be sufficient for world demand to the end of this century. The study indicates that bismuth reserves and potential resources in the rest of the world have not been adequately reported.

Jan 1, 1970