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By J. J. Cummins

The Bureau of Mines heated at 150° to 350° C for 0.5 to 360. days Green River oil shale that had been previously extracted by benzene to provide information on in situ processing conditions, to determine the effect of low-temperature heating on the unconverted kerogen, and to determine the composition of benzene-soluble thermal products. The methods used in determining the composition of the soluble thermal products consisted of fractionation of the soluble material, elemental analysis of the soluble products, fractionation of the polar resins by ion-exchange chromatography, gas chromatographic analysis of [n]-alkanes3 and mass spectral analysis of the branched plus cyclic alkanes and aromatic oils. The methods used to determine the effect of low-temperature heating on the unconverted kerogen remaining in the oil shale heated residues consisted of carbon-hydrogen analysis, volatile material determination, carbon residue determination, and oxidation rate determination. In general, it was concluded that significant increases in the degradation of kerogen to oil occurred between the temperature range of 250° to 350° C; that the composition of the soluble products depends upon the temperature at which they are formed; and that the [n]-alkanes are pyrolytically degraded from the kerogen structure. In particular, the 250° C heating temperature is beneficial to the formation of branched plus cyclic alkanes. Also, the heated and unconverted oil shale kerogen and the soluble thermal products become more aromatic as the temperature increases from 150° to 350° C.

Jan 1, 1974

By Robert C. Hickman

"INTRODUCTION Two holes were drilled on the G. S. Stiner zinc prospect, in the Lead Mine Bend area of Union County, Tenn. The holes were drilled in the vicinity of an area of gossan float and were bottomed in the Maynardville formation of the Nolichucky shale. Drilling was started January 24 and completed February 16, 1947. The total footage drilled was 421.2 feet.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, does the actual investigative Work, and prepares the final report. The Metallurgical Branch, Cliver C. Ralston, chief, analyzes samples and makes beneficiation tests.The project was under the general supervision of Mitchell H. Kline, chief, Raleigh Division, Mining Branch, Raleigh, N. C.LOCATION AND ACCESSIBILITYThe prospect is located approximately 20.5 miles southwest of Tazewell, Tenn. It is reached from Tazewell by driving 13.8 miles southwest on State route 33, thence 6.8 miles over graveled roads in a northwesterly direction to Stiner's general store. The drill holes are located in the bottom land northeast of the store (fig. 1 and 2)."

Feb 1, 1948

By C. Travis Anderson

 The general conclusion of earlier investigators was that the action of sulfur dioxide on manganese oxides of Cuyuna ores was not sufficiently pre- ferential to be attractive as the basis for a commercial process. Bradley4/ and his coworkers discarded it for leaching with boiling ammonium sulfate solution, and Sweet5/ used a baking operation to render the iron insoluble. These results were confirmed by the early tests in the present investigation, which were made on brown ores (Sagamore), using acid additions, because at that time the Technologic Committee on Manganese held the opinion that these ores constituted the major available reserve in the Cuyuna district. However, when it appeared that the black ores, or the formation in which they occur, were a possible source of a large tonnage of manganese, the use of sulfur dioxide and sulfuric acid leaching was again reviewed, and a satis- factorily preferential action on the manganese was found. It was originally thought that the use of sulfuric acid ahead of, or at least with, the sulfur dioxide simplified the process, particularly by preventing formation of dithionates. Removal of the phosphorus from the solution by neutralization with lime or fresh ore was suggested. The tests recorded in this report indicate that it is not practicable to use enough acid to prevent formation of dithionate and that the value of excess sulfuric acid is doubtful, particularly in regard to satisfactory manganese:phosphorus and manganese:iron ratios.

Jul 1, 1942

By G. R. Hopkins

[Apparent progress in fuel economy at petroleum refineries, as measured by the average amount of .seat units required to refine a barrel of crude oil, received a set-back in 1935, when the average rose to 562,00 B. t. u., compared with 562,000 B.t.u. in 1937 (see fig. l). The primary factor in the rise in average heat requirement's per barrel of crude oil refined in 1938 wan the decline in total runs to Invariably the average requirement increases when crude ins to stills decline, and vice versa. In other words, annual gains in fuel efficiency at refineries arc masked by the degree to which the capacity is utilized. Additional crude runs give lower average e heat requirements in two ways - first, because they are mane with the c expenditure of comparatively small amounts of auxiliary heat, and, second, because the additional runs generally represent simple topping operations. In 1938 crude runs, to stills declined 1.6 percent (from 1,183,440,000 barrels in 1937 to 1,165,015,000 barrels in 1938), but the total heat consumption declined only 0.4 percent, or from 663,866 billion B. t. u. in 1777 to 660, 56 billion in 1938 .]

Jan 1, 1939

By G. R. Hopkins

[Apparent progress in economy at petroleum refineries, as measured by the average amount of hest units required to refine a barrel or crude oil, received a set-back in 1938, when the average rose to 567,000 B. t. u., compared with 562,000 B. t. u. in 1937 (see fig. 1). The primary factor in the rise in average heat requirement's per barrel of crude oil refined in 1938 was the decline in total runs to Invariably the average requirement increases when crude inn to stills decline, and vice versa. In other words, annual gains in fuel efficiency at refineries are masked by the degree to which the capacity is utilized. Additional crude runs give lower average heat requirements in two grays first, because they are mane with the expenditure of cc-comparatively small amounts s of auxiliary heat, and, second, because additional runs generally represent simple topping operations. In 1938 crude runs to stills declined 1.6 percent (from 1,183,440,000 barrels in 1937 to 1,165,015,000 barrels in 1938), but the total heat consumption declined only 0.4 percent, or from. 663,866 billion B. t. u. in 1777 to 660, 56 billion in 1938.]

Jan 1, 1939

By L. B. Pankratz

The heat contents of the sesquioxides of erbium, holmium, thulium, and ytterbium (Er203, Ho203, Tm203, and Yb203) in the cubic crystalline form were measured over the temperature range from 298° to 1,800° K. The erbium and holmium sesquioxides gave regular heat content-temperature curves. Thulium sesquioxide had a minor thermal anomaly near 1,680° K, with a heat absorption of 310 cal/mole; similarly, ytterbium sesquioxide had a minor anomaly near 1,365° K, with a heat absorption of 150 cal/mole. The heat content results are presented in both tabular form (at 100° intervals) and in algebraic form. Entropy increments, corresponding to the tabulated heat content results, also are listed.

Jan 1, 1963

By M. J. Dailey

This paper is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The property of the Silver King Coalition Mines Co. is situated in the western past of the Park City mining district, Utah, about 1 ½ miles southwest of the town of Park City, The elevation at the collar of the main shaft is 8,137 feet above sea-level.

Jan 1, 1930

By D. Harrington

Ventilation of underground workings consists of establishment of such control of air currents that the underground workers may work in safety, with maximum comfort and efficiency, mad without impairment of health; and that the mine openings may be made subject to such control of air flow as to remove from the workings at ordinary times harmful gases and dusts, and at time of emergency, such as fire or explosion, there may be maintained as much or as little air flow as may be desired covering portions of the mine or the mine in its entirety. Control of air flow is the keystone of any ventilating structure, and this very essential feature is obtainable only by the installation of mechanically operated fans, to ether with other ventilating devices such as doors, overcasts, regulators, etc. Every mine, large or shall, coal or metal, should from the outset be equipped with a fan. While much has been written about natural ventilation and many claims have been made that in specific mines there is sufficient natural al" flow, there are few if any mines, coal or metal, where natural ventilation supplies anything like adequately safe or healthful conditions for underground workers even at ordinary times; and at a time of mine fire or explosion the mines depending upon natural ventilation are practically helpless, and certainly are decidedly dangerous to those unfortunates forced to be in them.

Jan 1, 1933

By X. Shi, V. Vallyathan, N. S. Dalai

"Using. ESR spin trapping methodology, evidence was obtained that fresh quartz dust in a cell-free aqueous medium generated hydroxyl - and possibly superoxide radicals. The hydroxyl radical generation potential decreases on storing of fresh quartz dust in ambient air and on the addition of either catalase, superoxide dismutase, desferoxamine, or DMSO. The role of quartz related radicals in the biochemical mechanism of acute silicosis is suggested from these findings.IntroductionThis report summarizes our electron spin resonance (ESR) detection of oxygenated radical formation by freshly crushed quartz particles in a cell-free aqueous medium, and its inihibition by radical scavengers. This study was undertaken with to elucidate the primary biochemical mechanism involved in the development of silicosis (Farber, 1983; Reiser and Last, 1979; Silicosis and Silicate Disease Committee, 1988). In particular the mechanism by which the quartz particles exert their toxic action on cells and the process(es) by which these actions progress to fibrogenesis are still not well understood (Farber. 1983; Reiser and Last, 1979;). It is generally believed that the action of quartz particles on the cell membrane is the starting point of the silicotic process (Farber, 1983; Parazzi et al., 1968). Thus the surface characteristics of the quartz particles have been the subject of several recent studies (Bolls et al.. 1983; Dalai et al., 1986; Fubini et al., 1987). Recently, We reported that mechanical crushing of quartz under normal atmosphere generates free radicals which decay with time, and that these free radicals are associated with a higher cytotoxicity of fresh quartz dust as compared to aged dust from the same stock (Dalai et al., 1986; Vallyathan et al.. 1988). The formation of Si• and. SiO--type of radicals from quartz particles crushed under atmospheric conditions has also been reported by Fubini et al. (1987). In addition, Gulumian and van Wyk (1987) have reported that quartz particles react with hydrogen peroxide (H202) to generates hydroxyl radicals (•OH) and suggested that this process might contribute to quartz's pathogenicity. However, these authors did not report the effects of metal chelators, so it was not clear as to whether the detected -OH radicals simply resulted from the Fenton reaction involving exogenous metal ion contaminants. Earlier, Marasas and Harington (1960) reported that quartz particles could function as an oxidant in a number of in vitro oxidations, including the hydroxylation of proline and lysine. They postulated that silica dusts, on reacting with water, could release H2O2 which might have the potential to react with various biological constituents and thus cause tissue damage. In fact, Gabor and coworkers (Gabor and Anca, 1974; Gabor et al., 1975) suggested that the cytotoxicity of quartz particles might be associated with the generation of some 'factor or factors possessing the properties of a free radicals capable of promoting the peroxidative chain cleavage of polyunsaturated fatty acid moieties of the phospholipids in the cell membrane. More recently Weitzman and Graceffa (1984) reported that asbestos is able to catalyze the generation of • OH radicals from H2O2. Their later work indicated that lipid peroxidation may be one of the mechanism by which asbestos produces tissue injury (Weitzman and Weitberg, 1985). This is significant because • OH radicals are capable of causing peroxidation by abstracting hydrogen atoms from cell-membrane lipids and initiating lipid peroxidation in lysosomal membrane (Fong et al., 1973). In fact, the formation of oxygenated species in reactions involving quartz was suspected since Kolbanev et al. (1980) reported the detection of H2O2 in the reaction of fresh quartz particle with aqueous medium. The present work was thus undertaken to detect the anticipated formation of some oxygenated, radical species by reactions of quartz in a cell-free media and its inhibition by radical"

Jan 1, 1988

By S. J. Schatzel, P. W. Jeran, W. P. Diamond, F. E. McCall, F. Garcia, J. C. LaScola, T. P. Mucho

The National Institute for Occupational Safety and Health, Office for Mine Safety and Health Research, is investigating the geologic and mining factors influencing the migration of longwall gob gas. One goal of these studies is to optimize methane drainage strategies to reduce the volume of gob gas that reaches the underground workplace. As part of this research effort, longwall gob gas flow paths in a mine operating in the Pittsburgh Coalbed, PA, were investigated using SF6 tracer gas. Tracer gas released into the ventilation airflow underground generally stayed in the bleeder system and was vented at the associated bleeder fan shafts. Tracer gas injected into an inactive (intaking) gob gas venthole migrated to the two inby producing ventholes on the study panel, indicating that all three ventholes were in communication. The tracer gas that was injected into the gob generally stayed in the gob and only migrated to the ventilation system in response to the venthole on the study panel closest to the injection hole going off production. Tracer gas flow velocities in the longwall gob reservoir and factors influencing the production performance of gob gas ventholes in the study area are also discussed.

By J. E. Miller

This paper reports experimental determinations by the Bureau of Mines of compressibility factors to 4,000 pounds per square inch absolute (p.s.i.a.) for helium at temperatures from -10° to 130° F. and for 16 helium-nitrogen mixtures at 70° F. This information is needed for computing accurate discharge volumes and is necessary for determining an average-density value for use in orifice-meter formulas. In thermodynamic calculations, several functions of the compressibility factor with pressure and temperature are required. The data in the original publications (6, 8)5 of this study have been reexamined and have been given a more comprehensive treatment. The recalculated compressibility factors are higher by approximately 0.2 percent because in the earlier work a linear relationship between the compressibility factor of helium and pressure was assumed.

Jan 1, 1961

By K. K. Kelley, L. B. Pankratz, W. W. Weller

Mullite is a substance of prime importance in ceramic technology . Despite this fact , its thermodynamic properties have received little attention . A Bureau of Mines literature survey disclosed the absence of lowtemperature heat capacity data , the absence of an experimental entropy value for 298.15 ° K , and the lack of heat content data beyond the temperature range from 298° to 576 ° K. Data supplied in this Bureau report fill these gaps in the thermodynamic knowledge of mullite . According to equilibrium phase studies of Aramaki and Roy ,3 the mullite phase melts congruently at 2,123 ± 15 ° K , and the equilibrium crystallinephase composition extends from Al Si2013 to Al6.8 Si₂ Q4.2 . The results in this report are for the stoichiometric composition , Al Si¿Qз . • Heat capacity measurements were made over the temperature range from 50 ° to 298 ° K , and the entropy at 298.15 ° K was evaluated . Heat content measurements covered the temperature range from 298 ° to 1,800 ° K. Heat content

Jan 1, 1963

By P. W. Jeran, M. C. Irani, D. H. Lawhead

The methane emissions from an advancing coal mine section were continuously monitored for 120 days. During this time, the section advanced 2,000 feet into virgin Pittsburgh coalbed producing 54,565 tons of coal with a total methane emission of 91 million ft3. Analysis of the data gathered showed that daily methane emissions did not correlate with overburden thickness and daily coal production. A good correlation was found between the daily methane emission and the average length of rib exposed to virgin coal.

Jan 1, 1976

By R. L. King, J. Cervik, A. A. Campoli

The Bureau of Mines performed laboratory experiments to evaluate the triboelectric effect of particulate-laden gas streams on polyethylene pipe at various velocity, humidity, dust-size, and dust-load conditions. Charges in excess of 10 kV were produced on the outside and inside surfaces of laboratory pipe samples, when exposed to 40 pct relative humidity (RH) gas stream containing coal dust. However, no charges were produced in laboratory tests that duplicated the over 75 pct RH and dust-free gas streams found in working underground pipelines. Bare cop- per wire, which is wound around the polyethylene pipe in a 1-ft (31-cm) spacing and grounded, eliminated the charge on the outside surface of the pipe, but not on the inside of the pipe surface,

Jan 1, 1986

By Jon I. Voltz

The U.S. Bureau of Mines has conducted fundamental coal fragmentation studies to evaluate the effects of impact energy and direction of bedding planes on dust generation, size distribution, and impact-output energy relationships. Product size distributions were obtained for the fragmented samples by screening to minus 150 mesh. The minus lS0-mesh fines were analyzed with a light scattering photometer with a measurement range of 176 to 1.9 /.tm. Increased input energy produced a significant increase in the weight of plus 3/8-in material for impact perpendicular to the bedding planes. No significant trend was observed for parallel impact. Impact direction had little influence on dust size distribution, and input versus output energy relationships. As expected, total airborne dust measured at time of impact and percent particulates below 11 /.tm in size generally increased with increased input energy for both directions of impact. Energy used for sample fragmentation increased with increased energy input.

Jan 1, 1989

This U.S. Bureau of Mines (USBM) report conveys the results of an economic analysis of minerals in the West Mojave Management Area (WMMA), including the Desert Tortoise Priority Habitat (DTPH), a proposed special land management area. Undiscovered mineral resources were estimated for the entire WMMA, which totals 8.7 million acres. Known mineral resources were studied for the DTPH, which is an area of 1.2 million acres contained within the WMMA. Federal lands within the WMMA are managed by the Bureau of Land Management (BLM). The WMMA includes Federal, State, and private lands in the western portion of San Bernardino County and the eastern portion of Kern County. The center of the study area is 20 miles northwest of Barstow, California (Figures 1 and 2).

Jan 1, 1993

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Uruguay has been prepared from the best available information in Washington, but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State .

Sep 1, 1930

By R. Barany

The heats of formation of anhydrous ferric sulfate and anhydrous indium sulfate were determined by solution calorimetry. At 298.15° K the heats of formation from the metal, rhombic sulfur, and oxygen were -615.6 ±O.7 kcal/mole for ferric sulfate and -649.6 ±O.6 kcal/mole for indium sulfate. Heats of decomposition at 298.15° K are given for the reaction that forms metal oxide, sulfur dioxide, and oxygen) and for the reaction that forms the metal oxide and sulfur trioxide.

Jan 1, 1965

Develop a safe, efficient filter for removing diesel particulate matter (soot) from the exhaust of underground mining machines equipped with water scrubbers. Approach The Bureau of Mines and the Donaldson Company, Inc., jointly developed a low-cost, disposable, pleated-media filter (PMF) system. The system is intended for use on Part 36 permissible equipment or other machines equipped with water scrubbers. The PMF is installed downstream of the water scrubber to take advantage of the cool exhaust produced by the water bath. This demonstration system was tested on three Jeffrey 4114 Ramcars and a Wagner LST-5 scoop at Utah Fuel Company's Skyline mine near Scofield, Utah. Figure 1 illustrates a clean filter element being inserted into the canister on the Ramcar. How It Works The PMF system consists of a water trap, an optional over-pressure relief valve, filter canister, and PMF Under normal operations exhaust from a vehicle equipped with a water scrubber is heavily laden with water, especially on immediate startup of the engine. The water trap is designed to remove most of the water droplets from the exhaust before they enter the PMF, thus improving PMF performance. The over-pressure valve is designed to limit the exhaust backpressure by venting off some exhaust gas before the: filter. It is attached to the water trap upstream of the PMF. Figure 2 illustrates and shows a break out sectional view of the location of the PMF on the Ramcar.

Jan 1, 1991

By Kenneth M. Earl

In its investigation of deposits of strategic minerals, the Bureau of Mines did some development drilling at the New Galena Deposit in an endeavor to find an additional source of supply of lead. In Bucks County, lead and zinc minerals have been found in shales over a largo area west and northwest of Doylestown. Considerable mining has been done in the vicinity of New Galena on the North Branch of Noshaminy Creek, 3 miles northwest of Doylestown. It has not been possible to obtain a satisfactory history of the New Galena mine, as there is much disagreement in statements. Most of the mining was done in open pits. Two shafts were sunk to shallow depth; one of these became part of the main pit' which is 256 foot long, 50 to 75 feet wide, and 20 to 44 feet deep. Small pits 8 to 10 foot square wore sunk on the ore zone, which extends some 1450 feet to the southwest. The rock containing the minerals is either black or gray shale. The gray material closely resembles limestone. The following minerals have been reported from the mine: quartz, ankerite, calcite, galena, sphalerite, pyrite, chalcopyrite, and bornite. Some of the galena has yielded 10 to 15 ounces of silver and 10 cents in gold per ton. The average grade of the ore as mined is not known. To investigate the downward extension of the ore shoot, the Bureau drilled two holes aggregating 373.9 feet, No additional ore was developed by this work.

Jan 1, 1950