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By Richard L. Sayrs

The Eve Mills deposit is in Monroe County, Tenn., near the southeastern corner of the State. The deposit was examined in February 1943 by a Bureau of Mines engineer, and drilling the property was recommended to increase the on: reserves enough to justify mining should war needs require it. The deposits were explored, by 32 diamond-drill holes totaling 11,649 feet during the periods from July 1943 to November 7, 1945, and from April 1944 to August 17, 1944. The drilling campaign disclosed a large area of mineralization. The ore, however, is apparently confined to long, narrow sheets. The indicated grade of the ore bodies blocked cut by the Bureau of Mines is 4.o8 percent zinc and 2.10 percent iron.

Jan 1, 1949

By M. K. Quinn, A. W. Khair

"This paper presents an analysis of respiraple dust generation due to the action of a continuous miner. Underground coal cutting by a drum-type continuous miner was simulated in the laboratory using a specially designed unique automated rotary coal cutting simulator (ARCCS). An analysis of -400 mesh particles was done on gravity collected material. Samples of entrained dust were collected through the use of cascade impactors. Both samples were analyzed for size distribution and particle shape. Using the simulated coal cutter permitted variation of operating and in-situ parameters to provide information on the effects on generation of -400 mesh particles. In these tests coal blocks with an approximate dimension of 18 in. x 15 in. x 6 in. (45.7 cm x 38.1 cm x 15.2 cm) were first subjected to confining pressures, equivalent to in-situ conditions. Such blocks were then cut by the cutting head of the ARCCS, thus simulating the action of the continuous miner in underground coal mining. During the tests under a particular set of in-situ and operating parameters a number of other parameters such as 1) penetration of bit into coal, 2) penetration resistance (thrust and cutting pressures), 3) rotating velocity of cutting head, and 4) acoustic emission activity in the coal block were monitored. After each cutting cycle the fractured surfaces were photo¬graphed and a velocity survey was conducted by using a sonic technique. At the end of each experiment the cutting paths of the bits in coal were photographed using an optical microscope with an attached camera.IntroductionThe continuous-mining machines introduced in the 1950's now account for more than half the production of coal from underground mines. Unfortunately, these continuous miners, designed for increased productivity, have also increased the concentration of respirable dust in mines. As a result, the Federal Coal sine Health and Safety Act of 1969 was enacted to enforce on the coal operators that the airborne respirable dust not exceed 2 mg/m3, and was intended to reduce the incidence of coal workers pneumo-coniosis. This plus the other aspects of the legislation and the subsequent monitoring and enforcement by MSHA made it very imperative that the coal operators provide a relatively healthier and safer working environment for the coal miners. Since 1970, the Federal government has paid over 11.7 billion dollars to more than 470,000 miners with coal workers pneumoconiosis and their survivors (Newmeyer, 1981). These regulations, coupled with the assessment of the continuing burden on miners, the mining industry and taxpayers appear to have provided an impetus for the mining community towards comprehending the different parameters that influence dust generation and entrainment."

Jun 1, 1988

By Foster Fraas

The objective of this research was separation of one highly conductive mineral from a second conductive mineral , a procedure which is impractical in commercial electrostatic separators using metal rolls . Such separators permit separation of nonconductive from conductive minerals . A new technique involved use of carrier electrode rolls specially prepared by anodizing and / or oxidizing at high temperatures to form suitable oxide surfaces . Specific oxides included aluminum , copper , and nickel . The significant result provided by the new surfaces was the extension of the separation range to higher conductivities , an extension in relative mineral conductivity from 10-14 mhos . The results are in accordance with the blocking- layer theory .

Jan 1, 1964

By A. M. Dale, J. Standeven, B. Evanoff

We encountered several areas of methodologic uncertainty during development of a data collection method for use with vibrating hand tools in metal assembly. A local manufacturer sought our assistance designing a data collection method for evaluating and predicting risks of upper extremity disorders associated with use of vibrating hand tools. Current methods of vibration measurement are described in ISO 5349 [2]. However, the complexity of measuring vibration along with other exposures such as force and posture has limited the number of workplace-based studies of upper extremity disorders that have included direct measurements of vibration. Data from this preliminary study was used to look at two issues: a comparison of vibration values between production and non-production workers when performing the same task, and a comparison of worker ratings of vibration comfort to direct measurement of tool vibration. Methods Eight experienced production workers used each of six metal fastening tools to install fasteners. Vibration was collected by 3 tri-axial accelerometers, one attached to the tool handle following ISO 5349 recommended locations, one attached to the hand dorsum on the 3rd knuckle and one to the thumb side of the wrist. Data sampling rate was 10,000 samples/second. Hand grip and feed forces were obtained using a Novel pressure sensing mat on the palm. Each trial consisted of installing 10 fasteners per tool for each of the 6 tools. The test set-up placed the wrist in the position typically used by the operator during production. Each worker documented subjective comfort and effort ratings on a seven point scale following each series of fastener installations. One series of testing was completed by three non-production workers inexperienced in fastener installation to simulate use of alternative employees for data gathering. Vibration data for each trial were acquired, digitized, and stored using Lab View. The X, Y, & Z axes were used to calculate the vector sum response for each tri-axial accelerometer. The tool data were digitally filtered following ISO recommendations. Calculated data consisted of the mean RMS over the tool’s on- time, the starting and breaking peak impulses, and the peak of the frequency response. Results Production workers (n=8) were right hand dominant males with a mean age of 55 years and normal hand strength (mean right grip = 106 lbs). Non-production workers (n=3) had similar characteristics. We found large and statistically meaningful differences in hand force during tool use between production and non-production workers (mean production workers = 9.77 lbs, mean non-production workers = 43.30 lbs, p = 0.0001). Vibration values obtained from the hand also showed a statistically meaningful difference (mean in production workers = 0.67 Gs, mean in non-production workers = 1.48Gs, p = 0.0014, figure 1). Experienced worker ratings of comfort during tool use demonstrated a moderate correlation with measured vibration (r=0.63). Worker ratings trended with direct recordings from the tool handle as shown in figure 2.

Jan 6, 2006

By M. P. Board

The U.S. Bureau of Mines, under a cooperative agreement with Hecla Mining Co., conducted a rock mechanics study at four widely spaced horizons in a deep mine shaft in northern Idaho. The objective of the project was to measure and analyze rock deformation and lining behavior during construction of a deep shaft in a high in situ stress field within an isotropic rock mass. Rock mass displacements were monitored with multiple-position borehole extensometers. Liner stress and strain were measured with concrete pressure cells and embedment strain gauges. This report discusses the general trends and magnitudes of data from the four test sites, and relates the data to a proposed anisotropic constitutive model for the rock mass. A design procedure is then outlined for specifications of liner thickness and support installation sequences for future shaft sinking.

Jan 1, 1989

By R. S. Conti

This U.S. Bureau of Mines (USBM) report discusses the results of research conducted in the USBM experimental mine at its Lake Lynn Laboratory to determine the alarm times of smoke and carbon monoxide (CO) sensors, and a point type heat sensor (PTIIS) to slowly developing coal-conveyor belt fires. The tests were conducted at air velocities of 0.44 and 0.97 m/s, The data clearly indicate that smoke sensors provide earlier warning of fire than 10 ppm CO sensors, and that 10 ppm CO sensors provide earlier warning than PTHS, A success rate of 1.0 (indicating detection of every test fire) was obtained for both smoke and C8 sensors. For the PTHS, the success rate was 0.57 at the lower air velocity, decreasing to 0 at the higher air velocity, Data are also presented showing the sequence of fire events and detection events at the two air velocities as a function of time. Results show that early detection and warning of underground mine fires will improve the probability of miners' escape.

Jan 1, 2010

By N. S. Dalal, B. Jafari, F. H. Y. Green, M. Petersen, V. Vallyathan

"Stable coal radicals (SCRs) were detected by electron spin resonance (ESR) spectroscopy in the lung tissue of autopsied coal miners. The SCR concentrations were measured in the lung tissues from 98 coal miners with and without (a) coal workers' pneumoconiosis (CWP), (b) cancer, and (c) a history of cigarette smoking. Concentrations of SCRs were also determined in the lungs of nonminer controls. The SCR concentration was related to longer mining tenure, CWP disease severity, lung cancer, and cigarette smoking. The mean concentration of SCRs in the lung tissues of miners with 30 ± 1.4 y of coal mining exposure was 5.3 ± 1.3 x 10"" spins/g versus controls who had a nondetec¬table level (< 10 15 spins/g). An increase in disease severity was accompanied by a progressive increase in SCR concentration. A SCR concentration of 4.8 ± 0.7 x 10"" spins/g was found for simple CWP (with moderate coal macules) versus 7.8 ± 4.6 spins/g lung tissue for complicated CWP (with progressive massive fibrosis). Significantly higher (i.e., 10 x 10"") concentrations of SCR in the coal miners' lung tissues were associated with an exposure history in the anthracite regions of northeastern Pennsylvania. These results in¬dicate a possible role for SCRs in the disease process. Furthermore, ESR appears to be an adequate methodology for the quantitation of coal dust retained in the lung and for distinguishing exposures to anthracite and/or bituminous coal.THE PREVALENCE AND SEVERITY of coal workers' pneumoconiosis (CWP) differ markedly between geographic locations, mines, and coal fields irrespective of comparable levels of exposure to coal mine dust These differences cannot be fully explained by the presence of silica and other minerals in the coal mine dust.' Rank of coal is also an important factor in the pathogenesis of CWP. Equally important is that the prevalence of CWP decreases from east to west in the United States,' and South Wales miners develop more severe CWP than miners in Scotland.' However, there are conflicting reports that cast uncertainty on the influence of rank of coal in the development of CWP."" These problems are complicated but will be solved as new technology emerges and as more is learned about the disease process."

Mar 1, 1992

By Seth C. Schaefer

The Bureau of Mines investigated the standard Gibbs energies of forma-tion AGfo, for NiCr204 (nickel chromite) and CoCr204 (cobalt chromite). High temperature galvanic cells employing stabilized ZrOz (zirconia) as the solid electrolyte were used to measure the open-circuit potentials for the cell reactions ?

Jan 1, 1986

By E. B. Kester

Of the many angles from which coal can be studied it is evident that some have a direct and others have only an indirect bearing on its physical or chemical nature . The more drastic the treatment employed in an investigation , the more inferential become the conclusions permissible from the experimental evidence obtained . Thus , ultimate and proximate analyses tell something concerning age , behavior on carbonization , and possible industrial usefulness , but nothing regarding structure or composition in the larger sense . Strong oxidation reveals the fact that benzenoid , pyrrol , and furane rings are prevalent in the chemical substances present , and milder oxidation indicates that the mass of coal , as in the case of the peats and lignites , is humic in character . But beyond such points of information , very little additional can be gained by the use of these more or less vigorous measures . To gain wider knowledge of the actual constituents of coal substance as found investigators have worked out systems of separation by means of solvents , of which a large number have been employed at various times both singly and in combination . The list of solvents includes petroleum ether , benzene , toluene , xylene , ethyl ether , alcohol , acetone , carbon bisulphide , pyridine , quinoline , aniline , phenol , tetralin , glycol ethyl ether glycol ethylether acetate , glycol methyl ether , glycol diethyl ether , pine oil , mesityl oxide furfural , benzaldehyde , ethylene oxide , rosin , caustic potash in solvents , amyl alcohol plus pyridine , chloroform , carbon tetrachloride , acetylene tetrachloride , naphthalene , and others . Once a coal has been extracted it has become common practice to subdivide the extract by means of partial solution in other and weaker solvents . Thus , we find the oily and solid bitumens of Fischer ( 1 ) , 3 Bone ( 2 ) and others ; the alpha , beta and gamma constituents of Wheeler ( 3 ) ; the classification of Novak and Hubacek ( 4 ) embracing oils , resins A , resins B , bitumens An , bitumens Bn , and bitumens Cn ; Crussard's ( 5 ) malthenes , asphaltenes , and carbenes , borrowed from asphalt terminology; and the 40 or more subdivisions of the phenol extract of coal worked out by Frazer and Hoffman ( 6 ) . Perhaps the primary object of interest in these many researches has been to find the coking principle of coal , and to study it and to learn why certain coals form hard , wellfused cokes , and others merely fall to pieces during carbonization . The origin of the various constituents of the gas and tar , the temperature at which each forms , and something of the mechanism of their synthesis have also been sought , as well as new bases for adjudging rank .

May 1, 1931

By Travis Q. Lyday

Australia was one of the world&apos;s principal producers of minerals and metals, and its minerals industry was a leading catalyst in promoting growth of the country. Australia was the world&apos;s largest producer of alumina, bauxite, diamond, ilmenite, monazite, opal, rutile, sapphire, and zircon. It was the premier exporter of alumina, coal, ilmenite, refined lead, monazite, rutile, and zircon, and was the second leading exporter of iron ore, after Brazil. Ranking behind China, the United States, the U.S.S.R., the German Democratic Republic, Poland, and the Federal Re-public of Germany, Australia was the seventh largest producer of coal (all grades) in the world. Australia was the fourth largest gold producer in 1988, after the Republic of South Africa, the Soviet Union, and the United States. It was the second largest producer of zinc, the third largest producer of nickel, the fourth largest producer of uranium, and the seventh largest producer of copper. 2 The country&apos;s mineral wealth was so extraordinary that it was virtually self-sufficient in most mineral commodities. Endowed with abundant resources of coal, natural gas, liquefied petroleum gas, and uranium, Australia was one of the few market economy countries that was a net exporter of mineral fuels. About 90% of Australia&apos;s consumption of crude oil was supplied by domestic production; this was expected to decline significantly about 1990, unless significant new oilfields were discovered.

Jan 1, 1990

By Michael J. Jorgensen, Anoop Polsani, Khurram S. Khan

Riveting operations in aircraft manufacturing involves the use of power tools for manually drilling holes for the rivets, power drills for the setting of the holes for the rivets, as well as rivet guns to drive and set the rivets. To close the rivet, the rivet is driven against a metallic bar commonly called a “bucking bar”. The bucking bars are typically held firmly to increase the quality of the riveting, as well as keep the bucking bar from “dancing” against the metal piece being riveted. Thus, employees in aircraft manufacturing involved in riveting are exposed to hand-arm vibration from several sources, and epidemiological evidence suggests that vibration-related musculoskeletal disorders are associated with long term exposure to riveting tasks in the aircraft manufacturing of aircraft.1,2 Recently, tungsten technology has been introduced into aircraft manufacturing for bucking bars, which are heavier than traditional steel bucking bars of the same size. Rivet guns with tungsten pistons instead of steel pistons have also recently been introduced with the objective of reducing vibration exposure to the riveter. The objective of this study was to assess vibration characteristics of steel and tungsten bucking bars and rivet guns to identify the combination that simultaneously reduced the combined exposure to both the “riveter” and “bucker”. Methods Vibration (10g tri-axial accelerometer, Biometrics S2-10G-MF Series 2) was measured from eight experienced employees using seven different rivet guns on size 6 rivets, with the same person bucking for all subjects. Vibration was also measured on two different bucking bars for these same eight subjects, with the same person driving the rivets using the various rivet guns. The rivet guns consisted of three E4 steel piston guns with different RPMs (Guns A-E4, B-E4, C-E4), an E4 vibration dampened rivet gun (Gun D-E4D), an E3 steel piston rivet gun (Gun E-E3) and an E3 and E4 tungsten piston rivet guns (Guns F-E3T and G-E4T). The bucking bars were made of 90% tungsten (1694g) and cold-rolled steel (843g), and were the same shape and size. A two-way repeated measures analysis of variance was performed on the vibration (mean frequency weighted resultant acceleration) on both the rivet gun side and the bucking bar side, and mean rankings were used to assess the vibration simultaneously for the rivet gun and bucking bars to investigate which combinations provided the lowest vibration exposure. Results Frequency weighted resultant acceleration was significantly lower on the E3 tungsten (F-E3T) rivet gun than the E4 steel piston (B-E4) and the E4 tungsten piston (G-E4T) rivet guns (Figure 1). When measuring vibration on the bucking bar, the E4 (A-E4) steel piston rivet gun resulted in lower vibration on the bucking bars than the E4 tungsten piston (G-E4T) and E4 vibration dampened (D-E4D) rivet guns (Figure 2). Additionally, use of tungsten bucking bars resulted in a 35% decrease in resultant frequency weighted acceleration than when using steel bucking bars.

Jan 6, 2006

By W. D. Mcmillan

During the fall of 1943 the Bureau of Mines put down four churn-drill holes totaling 435 feet of bore at the McGregor zinc lead mine near Potosi, Washington County, Mo., after the property had been examined by John Soule, an engineer of the Bureau, in the fall of 1942. A small production of lead and barite ore had been maintained at this property for many Years from shallow deposits in residual clays. A few shafts had penetrated the underlying dolomites and exposed a network of narrow fractures containing galena, sphalerite, barite, and marcasite. The drilling by the Bureau tested conditions at depths ranging from 80 to 130 feet. This report sets forth the data resulting from the work.

Jan 1, 1948

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 T. M. Ruff, W. G. McCoy, M. J. Beus, S. Iverson, W. Hasz

Technology to enhance safety during mine hoisting has been developed by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. Assessment of current hoisting technology suggests that monitoring conveyance position and load directly from the skip or cage top offers several significant safety advantages. Wireless data transmission schemes and a package consisting of sensors, batteries, and a charger mounted on the wire rope and skip have been developed. A state-of-the-art automated hoisting test facility was constructed to test the concept in a controlled laboratory setting. Field tests in a fill-size shaft are underway.

By Wilbert J. Huff, Raymond H. Moore

"Black powder is employed widely in peace and war. Its properties are therefore of considerable interest to many. The Bureau of Mines frequently is asked to furnish information on its use and safe handling in the mining and mineral industries in times of peace and is now engaged in studies of its application to the arts of war.Black powder has been the agent in many accidents - some very disastrous - and its handling and use are deemed very hazardous. The belief is widespread that the hazards are due principally to the ease with which the powder is ignited by a hot spark or flame in contradistinction to high explosives; these usually are ignited only with difficulty, and some burn incompl0tely and to a certain extent are self-extinguishing. Primary precautions, .therefore, should be taken to prevent the access of heat, spark, and flame.In black powder manufacturing operations a frequent source of disaster is the initiation of fires and explosions in the wheel mills in which the sulfur, charcoal, and nitrate are incorporated. Long experience has indicated that the wheel mill probably will fire if the powder is not kept moist enough; manufacturing supervision calls for the maintenance of a minimum moisture content, at least during the milling. Accidents occur elsewhere in the manufacturing line, and in an endeavor to minimize these, particularly those happening in corning mills, one of the writers suggested many years ago that a suitable humidity be maintained in other operations in the hope that it would serve protectively as in the wheel mill. The experience of one company for many years with this practice was favorable. It seemed desirable therefore, to explore the question experimentally."

Nov 1, 1944

By Fredrick L. Johnson

In 1984, at the request of the U.S. Forest Service, the U.5, Bureau of Mines began a study of the 94,370-acre Arc Dome study area (4-667) in order to appraise its mineral resources, The Bureau of Mines mapped and sampled mines, prospects, and mineralized sites in and near the area, The study area is located in the Toiyabe National Forest, about 54 mi north of Tonopah, Nye County, NV, It is estimated that over 500 claims have been staked in the study area since the mid-1800?s. In January 1986, there were 108 active mining claims completely inside and 59 on the boundary. Another 283 active claims were outside the study area but within 1 mi of the boundary, In addition to the large number of claims staked, exploration activity is also reflected by the almost 700 inactive workings that were found during field investigation.

Jan 1, 1989

By D. Randolph Berry

The U.S. Bureau of Mines awarded a contract to Foster-Miller Associates, Inc. (FMA) to provide recommendations on the safest, most practical methods for complying with new regulations requiring that all underground coal miners have a self-contained, self-rescuer (SCSR) -a device capable of supplying, in an emergency, 1 hr of self-contained oxygen (no breathing of mine air). This report develops information and recommendations which could be used during the early stages of nationwide compliance, especially in the areas of inspection, testing, and underground storage of SCSRs. Volume I contains an Executive Summary, Introduction, Definitions, Recommended Guidelines for District Managers and Mine Operators, and a Storage Plan Checklist and Sample Form.

Jan 1, 1981

By G. V. Sullivan

This report summarizes the results of metallurgical investigations by the Federal Bureau of Mines of manganese oxide ore, averaging 23 to 25 percent manganese, stockpiled at the Butte-Philipsburg depot of General Services Administration (GSA). The oxide ores were stockpiled in two general classifications, straight oxide ore and mixed oxide-carbonate ore. Continuous-circuit flotation tests at the Albany (Oreg.) Metallurgy Research Center of the Bureau of Mines showed that each of these ore types could be concentrated by an oil-emulsion scheme to produce a concentrate that could be sintered to meet program specifications. About 88 percent of the manganese was recovered in the concentrate from the straight oxide sample, with the sintered concentrate containing 48 percent Mn. The sintered concentrate from the mixed oxide-carbonate sample contained 41 percent Mn with a recovery in the concentrate of 95 percent.

Jan 1, 1961

This publication summarizes the research (in-house and contract projects) programmed by the Bureau of Mines for fiscal year 1985 (October 1, 1984-September 30, 1985) under its Health and Safety Technology Program. The objective of these projects is to provide an ordered and sequenced advance toward the Bureau&apos;s overall goal of providing the system technology required to create a more healthful and safer working environment for the Nation?s mining and minerals processing workers.

Jan 1, 1985

By Edmund S. Leaver, Charles E. Van Barneveld

In response to numerous requests from metallurgists and operators for information regarding the status of the sulphur dioxide leaching process , developed at the Southwest experiment station of the U. S. Bureau of Mines , Tucson , Ariz . , the following statement has been prepared . A more complete report is now in course of publication and will appear as Technical Paper 312. This process was devised to provide a cheap and efficient method for treating the so- called "porphyry " copper ores of the Southwest which generally contain both " sulphide " and "nonsulphide " copper minerals , mixed in such proportions that they can only be satisfactorily treated by a method which will concurrently recover both the sulphide copper and the nonsulphide copper . The latter term has been adopted to include all the minerals commonly referred to in operating phraseology in the mills of the Southwest as " oxidized" , " oxide " , or " soluble " copper . confident that the sulphide dioxide leaching process , as developed by us with the cooperation of the Miami Copper Co. and the Arizona Copper Co. , is suitable and commercially available for a wide range of ores .

May 1, 1922