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By Daniel R. Babich, Jeffrey R. Vipperman, Eric R. Bauer

Prolonged exposure to loud noise can cause permanent damage to the auditory nerve and/or its sensory components. Despite regulations and efforts by government and industry to reduce noise-induced hearing loss (NIHL), it is still a problem in the U.S. coal mining industry. The Mine Safety and Health Administration noise standard (30 CFR3 62), which was enacted in September 2000, is aimed at reducing NIHL in the mining industry. To address NIHL in various aspects of coal mining and provide the necessary information to effectively implement control technologies, the National Institute for Occupational Safety and Health conducted a cross-sectional survey of noise sources and worker noise exposures. Noise surveys consisting of full-shift worker noise exposure (dose) determination, time-motion studies (task observations), and equipment and/or area noise profiling were completed in 8 underground coal mines, 10 surface coal mines, and 8 coal preparation plants. The studies revealed that more than 40% of all workers monitored were subject to noise exposures above 90 dBA TWA8. A summary of these studies is presented, their application to administrative and engineering controls is discussed, and exposure reduction methods are reviewed.

Jan 12, 2006

By Ralph H. Espach

The value of careful fractionation in the manufacture of petroleum products is recognized more and more by petroleum refiners. Recent studies have shown that the quality of the products depends largely on the type of fractionating equipment and on the care used in operating the equipment. For example Rue3 has shown that careful fractionation of pressure distillate will greatly reduce the amount of chemical treatment necessary to produce finished gasoline. The advantages of the combination of pipe still and bubble tower in obtaining good fractionation are well recognized in the petroleum industry. However, the equipment designed in the past has in general been much too large for convenient laboratory use. The present paper describes a continuous-distillation apparatus for the laboratory study of fractionation. This apparatus has given very satisfactory results in the study of different crude oils and petroleum products. A discussion of the theory and action of bubble towers has not been given, as this subject has been discussed previously by Cooke and Rue4. It is believed that the distillation curves of the products obtained from this apparatus show clearly its capabilities.

Jan 1, 1928

By R. P. Vinson

The Bureau of Mines examined the effects of high humidity and water droplets on the GCA Corp. real-time aerosol monitor (RAM--l). which uses a lO4mm cyclone preseparator. Tests were conducted both in a laboratory and in a full-scale model mine entry. The laboratory tests were conducted in a test chamber saturated with moisture and water droplets. Under these extreme conditions. the RAM-I responded by indicating dust concentrations of 1-1/2 to 2 mg/m3? although the air was dust free. Within the first 2 h of each test. water accumulated in the cyclone and affected the cyclone particle separation characteristics. resulting in readings of 3 to 4 mg/m3. In addition. condensation formed inside the RAM-I case and affected the liquid crystal display (LCD). However. the full-scale mine entry tests revealed that the RAM-I can function ac-ceptably in an atmosphere of water vapor and water droplets similar to the most severe conditions found in an underground mine.

Jan 1, 1984

By J. R. Hauger, P. A. Romans, W. J. Niebuhr

With suitable instrumentation and techniques it is possible to determine the presence of tantalum in columbium to 20 ppm . This paper discusses the selection of X- ray spectrographic instrumentation and describes a technique for accomplishing the low level determination of tantalum . An ion- exchange method of separating tantalum from columbium is also described .

Jan 1, 1964

By George L. Gates

The Bureau of Mines developed a rapid instrumental method of analyzing oil well scales containing primarily barium sulfate. After removal of oil and water by carbon disulfide) the scale was dissolved in strong hydrochloric acid. The cations, barium, calcium, strontium, magnesium, and iron, were determined with the flame photometer using the method of additions. Sulfate was deter-mined colorimetrically after separation by selective adsorption on an alumina column. Phosphate was determined colorimetrically and carbonate titrimetrically. The method was reasonably accurate, although iron and magnesium were found to have mutual interference.

Jan 1, 1965

By E. S. Leaver

The mineral value in the ores from the Mother Lode mining districts of California is almost entirely gold, Although many mines have produced extremely high-grade ore the usual mill grade averages approximately $7.00 gold per ton. Fully 80 per cent of the gold has been and is now being recovered by amalgamation. Various methods have been introduced to recover the gold that was not obtained by the amalgamation processes. They include vari¬ous kinds of gravity concentration which in some cases were followed by chlorination or cyanidation. The usual practice includes only stamp battery, plate-amalgamation, and vanner concentration. In the very early practice the tails were run to waste through the main drainage streams of the different mining districts. During later years very large storage dumps have been impounded. These old tails, together with those being saved from present mills, furnish the problem discussed in this article. The clean sand portion of these mill tails is amenable to the usual cyanidation. The slime portion contains the major amount of the gold lost, but it also contains 1-1/2 to 3 per cent carbon, which precludes direct cyanidation of this part of these low-grade waste tails. The black carbonaceous slime portion is the particular problem considered in this report.

Jan 1, 1930

By Vernon F. Swanson

Several laboratory flotation tests were conducted by the Bureau of Mines on a sample of unweathered diorite from the B. F. Camden property, Amherst County, Va. Results showed that an ilmenite concentrate analyzing 45.5 percent Ti02 (titania), 0.07 percent P205 (phosphorus pentoxide), and 2.21 percent Si02 (silicon dioxide) could be produced from a feed containing 7.72 percent Ti02 and 3.94 percent P205. Ti02 recovery in the concentrate was 47.6 percent in a batch test. The weathered saprolite material overlying the diorite required scrubbing and desliming to remove argillaceous material and preliminary flotation of apatite followed by flotation of ilmenite. The resulting concentrate analyzed 47.3 percent Ti02, 0.19 percent P205, and 0.99 percent Si02 from a starting feed of 8.99 percent Ti02 and 3.37 percent P205; TiO2 recovery was 54.5 percent.

Jan 1, 1963

By J. P. Hansen

The Bureau of Mines has investigated the S02 leaching of MgO from high-MgO-bearing Florida phosphate concentrates. The S02 was effective in leaching some of the MgO from three phosphate concentrates; flow rate of the S02 and leach time were major factors in determining the amount of MgO leached. Calcining the samples, then grinding to minus 200 mesh, and elevating the leach temperature gave only small increases in the amount of MgO leached. The research also showed that some of the MgO was so intimately associated with the phosphate mineral that it could not be removed by S02 leaching. This amounted to about 0.6, 0.7, and 1.0 pct MgO in three leached residues. The calculated heads for the three concentrate samples averaged 1.4, 1.1, and 1.5 pct MgO, respectively, before leaching.

Jan 1, 1985

By James S. Browning

Domestic production of lithium minerals, source of the lightest metallic element, has increased from an average of 1,327 short tons of concentrate in the 1935-39 period to approximately 37,830 short tons in 1954. This rather phenomenal growth in production and use reflects growing industrial interest in the metal and its salts. This information circular has been prepared to summarize for the casual technical reader the reserve, mining, processing, and consumption situation pertaining to the mineral spodumene - the principal source of lithium. A relatively complete bibliography is included for those who may need more detailed information.

Jan 1, 1958

By D. J. Judy, D. J. Rabovsky, W. H. Pailes, V. Castranova, K. Van Dyke, J. Rabovsky, N. A. Sapola, M. McPeek

"Platelet activating factor (PAF) can be released from pneumocytes following exposure to occupational dust (Am. Rev. Respir. Dis. 135:83, 1987). In addition, PAF has been shown to induce pulmonary inflammation, edema, and bronchoconstriction (Hosp. Prac. 19, 67, 1983). This investigation reports the effects of PAF on the properties of three types of cells found in the lung. PAF (1-100, K1/2 = 2.5 pH) caused depolarization of neutrophils as well as generation of chemiluminescence and secretion of hydrogen peroxide. These responses were dependent on the presence of extracellular sodium. However, PAF did not alter oxygen consumption of neutrophils. Although PAF (10 uM) caused depolarization of alveolar macrophages, no stimulation of chemiluminestence, superoxide secretion, or oxygen consumption was observed. However, PAF (10 uM). did potentiate chemiluminescence and superoxide secretion in response to zymosan (2 mg/ml) by 55% and 36%, respectively. In addition, PAF (10-90 uM) caused aggregation of alveolar macrophages. PAF (2-10 uM) also caused depolarization of type II cells, but did not affect membrane integrity or oxygen consumption. However, PAF (10-18 PM) enhanced the activities of two distinct forms of cytochrome P-450 in type II cells and caused aggregation of type II cells at PAF doses above 18 uM. These data indicate that PAF can affect the secretory activity of pulmonary phagocytes and the ability• of type II cells to detoxify foreign compounds (Bureau of Mines Grant - G1175142).INTRODUCTIONPlatelet activating factor (PAF) is a glycerophospholipid (1-0-alkyl-2-acetylsn-glycerol-3-phosphoryl choline) which has been shown to Mediate a broad range of biological activities (1-3). Its pulmonary actions include contraction of pulmonary tissue (4), secretion of leukotrienes from leukocytes (5), airway constriction (6), pulmonary edema (7), and enhanced migration of neutrophils into the airspaces of the lungs (8,9).PAF can be released from several different cell types, such as, basophils, neutrophils and alveolar macrophages, in response to a variety of particulates or membrane stimulants which include zymosan, calcium ionophore, phorbol esters, chemotactic agents, and endotoxin (10-13). Therefore, PAP may play an important role in the development of pneumoconioses by mediating pulmonary responses of lung cells to a variety of occupational dusts. To investigate this possibility, we determined the effects of PAF on several physiological parameters of neutrophils, alveolar macrophages, and alveolar type II epithelial cells."

Jan 1, 1988

By R. V. Ramani, R. Bhaskar

"While the National Academy of Sciences has stated that gravimetric sampling technology for compliance purposes is adequate, research into various aspects of respirable dust control require data on many other parameters of airborne dust. These, in turn, have created the need to use many instruments, other than personal gravimetric samplers, in mi ne environments for dust measurement. There is a need to evaluate the performance of these instruments under conditions of potential use.As part of research in the Generic Technology Center for Respirable Dust, cascade impactors, gravimetric personal samplers and gravimetric samplers collecting dust using isokinetic sampling principles were employed for dust measurements under identical conditions in a mine airway. During the course of the experiments, 8-stage cascade impactors and gravimetric samplers drawing air isokinetically were located in the center of a mine airway at various stations. Two types of data were examined - concentration of dust and size distribution of the dust collected in the samplers. The data show that the amount of dust collected by an impactor is less than half the amount collected isokinetically. The size distributions of the dusts collected from the two instruments, though comparable, show a consistent difference in median diameters. The cause for this bias is examined.The paper presents and discusses the results of the tests, including the concentrations and size distributions obtained from the two instruments for different experimental conditions. There is a need to document the performance of various dust measuring devices in mine airflow conditions.INTRODUCTIONThe sampling of airborne dust in mines can be done for several purposes. Traditionally, dust sampling has been restricted to the gravimetric measurement of airborne respirable dust to comply with the regulations governing the mining industry. Instruments such as the MRE gravimetric sampler, and personal gravimetric samplers that have collection characteristics similar to the human respiratory system have been in use for the last two decades. Presently available instrumentation for the purpose of regulation have been considered adequate by the Committee on the Measurement and Control of Respirable Dust in Mines (National Academy of Sciences, 1980),"

Jan 1, 1989

By Helen W. Lang

This report describes a monitoring system applied by the Bureau of Mines to provide rapid, continuous determination of the main constituents of exhaust gas during the Bureau's approval schedule testing of diesel engines for under-ground use. Commercially available continuous analyzers with strip chart readout are employed for nitric oxide (mass spectrometric), carbon dioxide (nondispersive infrared), methane (NDIR), carbon monoxide (NDIR), and oxygen (polarographic). Good correlation is obtained between the continuous instrumental results and those obtained by batch chemical and gas chromatographic methods.

Jan 1, 1969

By Lucia Kuizon

The Antimony RARE II area is underlain principally by Mesozoic igneous rocks associated with the Sierra Nevada batholith. The San Andreas fault zone is near the southern boundary. Metallic mineral deposits are associated with the fault zone. These deposits were formed from magmatic solutions, and tend to be along shears and fractures within the country rock. Marble and dolomitic marble deposits occur in Paleozoic roof pendants or inclusions in the Mesozoic intrusive rocks in the area (Troxel and Morton, 1962, p. 52).

Jan 1, 1982

By R. G. Sandberg

Many gold-bearing ores throughout the Western United States contain small quantities of mercury. The presence of mercury not only decreases the gold-loading capacity of the activated carbon, but complicates the fire refining of cathodes and creates a potential health hazard. The Bureau of Mines investigated methods to limit mercury extraction during gold ore leaching and to remove mercury from cyanide leach solu-tions. Mercury dissolution was reduced from 40 to 10 pct by decreasing NaCN concentration from 20 lb to 0.34 lb per ton of solution at a pH of <11. When 0.1 lb CaS per ton of ore was added to a leach slurry, mer-cury extraction was reduced from 27 to 0.4 pct. Less than 0.5 pct of the mercury was solubilized when <0.1 lb CaS per ton of are, along with lime and NaCN, was added to a simulated grinding circuit.

Jan 1, 1984

By H. R. Babitzke, H. Kato, R. E. Siemens

An investigation was made to provide further information for evaluating columbium- hafnium alloys for use as high - temperature structural materials . The columbium- hafnium system was investigated between 700 ° and 2,400 ° C by melting point , thermal analysis , X - ray diffraction , electrical resistivity , and metallographic techniques . The equilibrium diagram is the beta isomorphous type , with columbium tending to stabilize the beta phase . Addition of 60 atomic percent columbium stabilizes the beta phase at 700 ° C. The allotropic transformation temperature of hafnium is 1,750 ° ± 20 ° C. A minimum melting point occurs near 75 atomic percent hafnium .

Jan 1, 1964

By William W. Elmer

This paper, describing the mining method at the Black Butte quicksilver mine, is one of a series of papers being prepared by the U. S. Bureau of Mines on mining practices, methods, and costs in the various districts of the United States. It is presented to show the mining practice and costs in the successful treatment of low-grade quicksilver deposits. The operation discussed is an excellent example of w1-pat can be done in working a limited tonnage of low-grade ore under sound management. The Black Butte mine is situated at Black Butte, Lane County, in the southern part of the State of Oregon, 17-1/2 miles from Cottage Grove -- a station on the Siskiyou branch of the Southern Pacific Co. The Black Butte mining district lies in the foothills of the Calapooia Mountain Range, which connects with the Cascade Range on the east and with the Coast Range on the west. The elevation at &apos;.lie reduction plant is 1,000 feet above sea level. The apex of Black Butte Mountain, or which the mine is situated, has an elevation of 2,700 feet. The district possesses exceptional natural facilities infrequently met with elsewhere for the mining and reduction of cinnabar ores. Several factors which contribute to the unusually low mining costs are:

Jan 1, 1930

By D. A. Reynolds

The Bureau of Mines-American Gas Association survey of the carbonizing properties of American coals was begun in 1929, and has been continued almost without interruption since that time. Upwards of 100 coals have been carbonized at low, medium, and high temperatures in this survey, and about 200 additional coals have been carbonized at high temperatures only. All survey coals were blended with coal of different rank for carbonization at one high temperature (900° C,). During the past few years, 12-high-volatile A coals were blended with Pocahontas No 3 coal from Kimball, McDowell County, W. Va., and in this report the physical properties of the cokes from these high-volatile coals and their blends are compared.

Jan 1, 1949

By John Nagy

Results of initial research by the Bureau of Mines are given on the dust explosion hazard of float coal and on the related factors of occurrence, rate of production, sampling techniques, transport, and deposition of float coal. Tentatively, it is suggested that where float coal deposits prevail, a mini-mum of 80 percent incombustible be maintained in the top 1/8-inch layer to neutralize the explosion hazard of the surficial coal deposit.

Jan 1, 1965

By T. R. Strombotne

The purpose of this report k to document a contract undertaken by TSA Systems, Incorporated for the United States Bureau of Mines to develop a commercially available source of a continuous, working,, level detector for the measurement of radon daughter products in various working environments. The basic radon measuring technique was devised by Robert Droullard and Robert Holub and has been applied here. For further details or purchasing information contact: TSA Systems, Incorporated 4919 North Broadway Boulder, Colorado 80302

Jan 1, 1982

By Eugene Frey

The Romur is one of several properties in the Copper Mountain mining district, Fremont County, Wyo., that contain scheelite deposits. The district lies on the southern slope of the Bridger Mountains, 18 miles northeast of Shoshoni and 15 miles from the rail point at Bonneville on the Chicago, Burlington & Quincy Railroad (figs. 1 and 2). The tungsten deposits occur in a zone of pre-Cambrian schists and gneisses that have been cut by numerous basic dikes and granite pegmatite dikes. Scheelite occurs in lenses and pods that lie parallel to the foliation and bedding in the metamorphic rocks. The more important deposits are found in a lime-silicate rock consisting primarily of zoisite but with small quantities of quartz and carbonate. Scheelite was found in December 1941, and the area was mapped by the U. S. Geological Survey early in 1942. In November 1942 the Bureau of Mines commenced work on the Stardust-Comet group for the purpose of developing reserves for war requirements. The initial work consisted of driving an alit in the ore zone a distance of 109 feet. This zone was sampled during the progress of the work, and subsequently surface and underground exposures on adjoining properties also were sampled (figs: 5, 6, 7, and 8). One hundred twenty-four samples were obtained. Sample and assay data are shown in tables 2, 3, and 4.

Jan 1, 1950