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By G. E. McElroy

As one phase of a general program of enthracite mine-fire research initiated by the Bureau of Mines in September 1935, a study of the records of past fires was considered a necessary approach to a proper understanding of present and future fires because only limited information could be obtained directly from existing active fires on account of their inaccessibility. Through the courtesy of interested operators, all available records of fires that had occurred in a large group of steep-pitch anthracite mines in the Western Middle and Southern fields of the Pennsylvania anthracite district were examined and analyzed for data on the causes, costs, behavior, and control of fires, and this report is primarily a discussion of these factors based on a close study of these particular records. Mining Conditions The records pertain to a group of mines that have contributed about 12 percent of the total Pennsylvania anthracite production and constitute a large proportion of, and well represent, steep-pitch operations in this district. Throughout the area represented, the coal occurs as a series of up to 20 parallel seams in folded slate and sandstone strata and almost entirely on pitches of 400 to 80°, with vein thicknesses of 5 to 60 feet. Practically all are old mines with histories dating back to 1850, or thereabouts, and present operations are either under or adjacent to mined-out areas extending to surface or to the saddles of anticlines. All operations are at relatively shallow depths, that is, within 1,000 feet, vertically, of the surface. Mining methods are largely a heritage of the past and embrace typical breast and pillar operations with practically no mechanized mining and with the coal shot ?off the solid.? Most of the mines are rated as gassy and are operated now on a closed-light basis. Permissible explosives are now used entirely for breaking coal, and dynamites for rock work and chute-starting blasting.

Jan 1, 1938

By J. Burlin Johnson

In small-scale blasting experiments conducted in the Bureau of Mines laboratory, small charges were used to produce craters in blocks of concrete mortar. The results are compared with larger scale experiments of other research workers, and the comparison demonstrates the similarity of the results obtained and indicates that small-scale blasting should be a useful tool for predicting large-scale blasting effects. INTRODUCTION The purpose at this investigation was to conduct blasting experiments in mortar in the laboratory and then, by comparing the results with those from larger scale field blasts in rock to determine to what extent, if any, the laboratory results resemble those in the field. The work described herein was the initial phase of a project aimed at evaluating small-scale blasting as a tool for use in improving blasting techniques. It is evident from the stand-point of control and cost that small-scale blasting would be valuable in the study of rock fragmentation by blasting in mines and quarries, if the extrapolation is valid.

Jan 1, 1962

By Piyush K. Dutta

This report describes the design, development and manufacture of a prototype quiet hard rock stoper drill and results of its field tests. It is shown that the stoper drill noise level can be reduced from 118 dBA to below 100 dBA by using this design. The design concept of this drill is based on a valveless independent rotation system, use of an integral muffler and pivot mount. The drill was manufactured in a standard commercial drill manufacturing setup and organization. The design and production technology proved that commercially viable quiet drills can be made available for mine use.

Jan 1, 1985

By Robert H. Bedford

As a result of the Bureau's general survey of quicksilver deposits in California, the Guadalupe mine area was among those chosen for exploration. Exploration, such as that at the Guadalupe, was aimed primarily at maintaining or increasing production of quicksilver during the critical wartime period. The project as originally planned contemplated sampling the dumps and prospecting some promising surface exposures by bulldozer trenches. Salvage was the objective in the first case and new ore in the second. Later, a program. of diamond drilling was added, designed to add both to ore reserves and to geological information. This report summarizes the history, notes the location and physical features, mentions property and ownership, and presents a brief description of the mine. The geology is outlined, and the work done by the Bureau of Mines is explained and supplemented with accompanying maps. The work involved repairing 1-1/4 miles of roads; bulldozing 13 trenches by removing 2,345 cubic yards of dumps to provide for sampling; digging and sampling 9,284 linear feet of hand trenches, digging and sampling numerous test pits; and drilling 7 diamond-drill holes, totaling 1,000 feet. A total of 419 samples, including 10 percent check samples, were taken. Exploration work in California at the time of this project was under the direction of Spangler Ricker, supervising engineer of the California field office, the late Robert Bedford was in charge of the fieldwork on this project.

Jan 1, 1950

By Robert Stefanko

Test procedures for evaluating underground coal mine trailing cable splices are formulated. The tests are utilized to evaluate several trailing cable splices. The laboratory results are compared with actual field observations and experience. The results are utilized to define quantitatively the generalized terms of the 1969 Health and Safety Act. Recommended specifications and procedures for testing by MESA Department of Approval and Testing personnel are included. Failure points in splices are detailed and presented for use by a MESA training program and manufacturers attempting to improve product quality.

Jan 1, 1974

By Richard L. D?Arcy

This paper describing the mining practice and methods at the United Verde Extension mine, Jerome, Ariz., is one of a series of papers in preparation by the Bureau of Mines presenting the mining methods used in various mining districts of the United States. The United Verde Extension mine is a massive, high-grade deposit of copper sulphide containing some gold and silver and is mined almost exclusively by the conventional square-set method with some local modifications. About 450 men are employed underground and 1200 tons of direct smelting ore is produced per day. Figure 1 is a surface map of the Jerome district.

Jan 1, 1930

By Walter R. Storms

The Iron Mountain tungsten deposits first were visited by a field party of the Federal Geological Survey in May 1942 while beryllium deposits in that district' were being examined . Later they were examined by F. A. Rutledge , an engineer of the Bureau of Mines , and an exploration project was recommended , work upon which began in March 1943 and was terminated in April 1943 after intensive trenching and sampling had been completed .

Mar 1, 1947

By W. M. Mahan

This report describes work carried out by the Federal Bureau of Mines in cooperation with the General Services Administration (GSA). Tests on nickel oxide reduction were conducted at the Pyrometallurgical Laboratory at Pitts-burgh and Bruceton, Pa., and at a rented plant at Canonsburg, Pa. Nickel oxide was reduced to sponge nickel, which was then melted to produce specification-grade nickel ingots containing a minimum of 98.50 percent nickel plus cobalt and a maximum of 1.00 percent cobalt. One purpose of this study was to determine if specification-grade nickel could be made from nickel oxide produced at the United States-Government-owned plant at Nicaro, Cuba, in pilot-plant scale operations involving direct reduction and melting processes. A second and equally important purpose was to obtain cost data on the pilot-plant operation to estimate the cost of producing ingot nickel at an annual rate of 12 million pounds. Laboratory tests verified that nickel oxide, in saggers and in the presence of anthracite fines and dolomite in the ratio of approximately 20:5:1, could be converted to sponge nickel when heated to approximately 1,900° F. for about 2 to 4 hours, depending on the size and density of the oxide charge. The tests also determined the type of saggers suitable for pilot-plant operations.

Jan 1, 1959

By M. R. Yenchek

The U.S. Bureau of Mines designed and constructed sensitive and coordination-free ground-fault relays (GFR's) for use on mine power systems. First, a list of GFR attributes for mine ac utilization applications was compiled. These practical guidelines specified design, construction, transient immunity, reliability, and operating criteria. The time-current characteristics of the ac and dc units, subsequently fabricated, were designed to be below the human electrocution threshold. The significant and highly variable capacitance of high-voltage distribution cables was found to preclude the sensing of ground currents in the milliampere range. However, the coordination-free system developed for high-voltage distribution should enhance safety by significantly decreasing response time to ground faults. Implementation of the sensitive GFR technology in the mining industry has the potential to eliminate the majority of injuries and nearly all the deaths resulting from contact with energized components.

Jan 1, 1990

By W. F. Marshall

This report describes exhaust-emission data from 10 diesel engines: six 4-cycle, direct-injection, naturally aspirated engines; two 4-cycle, direct-injection, turbocharged engines; one 4-cycle, precombustion-chamber, turbo-charged engine; and one 2-cycle, direct-injection engine. These engines were tested over a 3-year period (1968-70). Lowest emissions were obtained with a precombustion-chamber engine. Emissions from the 2-cycle, direct-injection engine fell within the range of emission rates for the 4-cycle, naturally aspirated, direct-injection engines. Excluding the precombustion-chamber engine and excepting one of the 4-cycle, naturally aspirated engines, carbon monoxide emission rates were about the same for all engines tested. Test data on smoke, odor, and emissions of hydrocarbons, oxides of nitro-gen, carbon monoxide, and aldehydes are given.

Jan 1, 1971

By R. Karl Zipf, Z. T. Bieniawski

"Researchers at The Pennsylvania State University are engaged in a project to understand the mechanics of respirable size fragment formation in coal. The project is based on the premise that a thorough understanding of the fundamental mechanics of fine fragment formation may lead to techniques for reduction and better control of coal dust problems in mines. Presently, it is believed that the mode of fracture propagation which can range from pure tensile to pure shear or any mixed mode in between and the loading or displacement rate can influence the amount of respirable size fragments that are generated on new fracture surfaces during the fracture propagation process The essence of any coal cutting process is one of mixed mode fracture propagation. To study the crack propagation process, a unique mixed mode testing rig was designed and fabricated. This rig is capable of applying loads to a prenotched test specimen that range from pure Mode I (tensile mode) to nearly pure Mode II (shear mode) or many mixed mode loading combinations. It is also possible to apply different loading or displacement rates to the test specimen. With this rig, it is possible to create new fracture surfaces via the different fracture modes and under various loading conditions.These new fracture surfaces are examined with a scanning electron microscope (SEM) to characterize the amount of structural damage and respirable size fragment formation that occurs during the fracture process. Initial observations suggest that the amount of fine fragment formation and the new fracture surface appearance is related to the fracture initiation conditions, particularly the fracture mode and the loading rate. Mode II loading and higher loading rates seem to generate more structural damage and respirable size fragment formation that Mode 1 loading at slower rates.With the mixed mode test rig, the mechanics of fracture initiation for a single crack can be controlled to better understand its influence on respirable size fragment formation. Such understanding may lead to methods which characterize the tendency of specific coal seams to produce undesirable fine fragments during the fracture process, or it may lead to rational recommendations and design guidelines or coal mining machines which inherently produce less dust.IntroductionAs part of a larger effort to reduce the incidence of coal workers pneumoconiosis (black lung) in coal miners, researchers at The Pennsylvania State University are engaged in a project to understand the fundamental mechanics of fine fragment formation in coal. This project is part of a com¬prehensive research effort within the Generic Mineral Technology Center for Respirable Dust which is jointly administered by The Pennsylvania State University and West Virginia University.The principal source of the coal dust in underground mining is the cutting operation. The U.S. Bureau of Mines (USBM) and various European research organizations have conducted investigations into the mechanics of coal cutting for many years. These studies of airborne respirable dust (ARD) formation have concentrated on empirical studies of the various cutting parameters and their effect on ARD for¬mation. The parameters study include depth of cut, cutting speed and bit spacing.(1,2) Other studies investigated the effect of symmetric and asymmetric bit wear and various bit geometries and designs (3-5) Roepke(6) summarized the principals of proper coal cutting to minimize dust formation by recommending to ""cut at maximum depth (maximum advance rate) at all times, at minimum RPM, with the fewest possible bits, having the lowest possible included tip angle."" Most coal in the U.S. is mined with the continuous mining machine which inherently cannot meet these design recommendations.(3)It is recognized that respirable size dust particles are formed and/or liberated by a fracture process. One extremely interesting and useful study performed very early in the USBM dust re"

Mar 1, 1989

By Thomas J. Peters

The Danskin/South Fork Boise River study area is 40 air km southeast of Boise, Idaho. The 16,000-hectare, two-segment area is mainly underlain by Cretaceous-age granodiorite and an aplitic and pegmatitic complex of the Idaho batholith, Miocene-age rhyolitic tuffs and lavas, and late Tertiary-age basalt flows. No mineral resources were identified in the study area. One mine, The Flat Creek mine, which produced several ounces of gold and silver, was found in the study area. It is geologically similar to deposits in the Neal mining district, adjacent to the northwest corner of the area; gold mineralization occurs along east-northeast-trending faults and associated quartz veins, which dip moderately to steeply southeast, and within adjacent Cretaceous granitic rock. Samples indicate the Flat Creek deposit is not rich enough to mine underground, and near surface, open-pit-mineable deposit areas could not be identified. However, exploration is warranted there and also in the 7-km interval to mines in the Neal district, and for extensions of those mines. No evidence of geothermal activity was observed, although there are hot springs in the vicinity. Some alluvial (placer) samples from the interior of the study area contained free gold, but no substantial gravel deposits were seen.

Jan 1, 1993

By H. E. Powell

A laboratory mineral-dressing investigation was conducted by the Federal Bureau of Mines on four limonitic and four sideritic iron ores from the North Basin of the east Texas iron-ore district. The samples, composited from drill cores, were considered representative of the iron-ore reserves of the area. The objectives of this research were twofold: (1) To devise a mineral-dressing method whereby the yield from currently mined east Texas iron ores might be increased and the grade improved, and (2) to extend such treatment to include the lower grade ferruginous materials that are not amenable to beneficiation by simple washing and, therefore, are not being exploited. Of the mineral-dressing methods used in this investigation, magnetic separation of roasted are was shown to be the most effective. Results show that, by this method, a laboratory recovery of 82 percent of the iron is attainable at a grade surpassing that obtained by current plant practice and that both limonite and siderite are amenable to concentration by the process. The existence of large deposits of iron are in eastern Texas has been recognized for over 100 years. These ores were first exploited during the Civil War and were mined intermittently until about 1911. From that time until 1944 when the Defense Plant Corporation financed the erection of three blast furnaces to use these east Texas ores, production was almost at a standstill.4/

Jan 1, 1960

By Glenn C. Reed

This report is one of a series describing mineral investigations within the Missouri River Basin in Montana. The primary purposed of these investigations is to provide information to agencies of the Department of the Interior and others concerned with the planning of Federal power developments in the basin. This report is limited in score to consideration of mineral deposits of presumed inventory value within Gallatin County, Mont. The field investigations were made during the fall of 1948.

Jan 1, 1951

By C. C. Hustwit

The U.S. Bureau of Mines formulated a new mathematical model to characterize iron oxidation. The new model is intended to replace the currently used model, recommended by the Environmental Protection Agency (EPA), for most acid mine drainage (AMD) treatment applications. The new model was evaluated in a series of five synthetic AMD treatment tests. The initial ferrous iron concentrations ranged from 800 to 2,400 mg/L. In these tests, the Bureau model underpredicted the measured ferrous iron oxidation rates by a range of 3.24 to 8.03 pct. This was considered to be in close agreement after consideration of experimental error. The model proposed by the EPA was also evaluated using the same test data. The EPA model underpredicted the oxidation rates by a range of 77 to 100 pct in four tests and overpredicted by 19 pct in one test. The model formulated by the Bureau expresses that the rate of iron oxidation is a function of a treatment system's oxygen transfer efficiency and is independent of ferrous iron concentration when treated to near-neutral pH's. A new test method for evaluating oxygen transfer in flow-through reactors is also described.

Jan 1, 2010

By L. M. Demers, D. C. Kuhn, N. El-Ayouby, C. F. Stanley

"Oxygenated metabolites of arachidonic acid (MJ are produced by the alveolar macrophage (AM) and have been shown to mediate inflammatory reactions. We therefore assessed the production of eicosanoids by AM harvested from the lungs of rats ex· posed to a bituminous coal dust for 2 wk in an inhalation chamber in order to determine if AA metabolism was altered in a manner that may promote an inflammatory response in the lung. Exposure to coal dust resulted in a 66% increase in the number of AM harvested, an increase in thromboxane A2 (TxA;i) and leukotriene 84 (LTB,j) production to 222% and 181% of control values, respectively, and a decrease in prostaglandin E2 (PGE:i) production to '62% of control values. In AM harvested from rats allowed to breath clean air for 2 wk following coal dust exposure, PGE2 production returned to control levels but TxA2 and LTB4 production remained elevated. The TxA2 synthesis inhibitor UK 38,485 reduced TxA2 production in dust-exposed AM both immediately and 2 wk following exposure. Thus, exposure of rats to coal dust significantly alters the metabolism of AA in AM, with potentially important aspects of AA metabolism remaining altered even after a 2-wk recovery period. Based on the established role of eicosanoids in inflammatory and fibrotic processes, these results suggest that the alteration of AM eicosanoid production as a result of the inhalation of coal mine dust may be an important factor in the pathophysiology of coal workers' pneumoconiosis.The authors are grateful to Joan Greenwood and Barbara Scheetz for their excellent technical assistance and to Brenda Pavone for the preparation of the manuscript. This research was supported by the U.S. Department of The Interior's Mineral Institute Program administered through the Generic Mineral Technology Center for Respirable Dust under grant 1135142.Request for reprints should be sent to Douglas C. Kuhn, Ph.D., Department of Pathology, The M.S. Hershey Medical Center, Hershey, PA 17033.INTRODUCTIONPulmonary alveolar macrophages (AM) are activated by foreign particles and microorganisms that enter the small airways (Kass et al., 1966; Herscowitz, 1985). This defensive reaction involves phagocytosis, lysosomal enzyme release, and the generation of reactive oxygen species by the AM (Snella, 1986; Rich et al., 1987). A number of agents, including phorbol esters, zymosan, adenosine diphosphate, organic hydroperoxides, and calcium ionophore, have been shown to activate the AM in vitro (Badger, 1986; Marshall and Lands, 1986; Snella, 1986). The AM response to these activators appears to be mediated in part by the oxygenated metabolites of arachidonic acid (AA) (Bertram et al., 1988; Demers et al., 1987; Mcleish et al., 1987).The AM may metabolize AA through cyclooxygenase- and lipoxygenase- catalyzed pathways to produce a variety of eicosanoids including prostaglandin (PG) E2, thromboxane (Tx) A2, leukotriene (LT) B4, LTC4, LTD4, and several hydroxyeicosatetraenoic acid derivatives (HETEs) (Willis, 1970; Camp et al., 1983; Poubelle et al., 1986). The production of these eicosanoids may enhance the. defensive ability of the challenged lung since they stimulate chemotactic cell recruitment to the site of invasion, enhance extravasation of circulating immune cells, and promote local vasodilatation. However, continued stimulation of the AM population, with the consequent production of proinflammatory eicosanoids, may ultimately enhance the disease process by contributing to chronic bronchoconstriction, fibrosis, and the persistent release of toxic oxygen species."

Jan 1, 1990

By Alton B. Cook

A material balance equation was derived for calculating (1) the initial oil volume and (2) the relationship of average reservoir pressure to net gas in storage in reservoirs used for natural gas storage operations. The equation is also applicable to secondary-recovery operations where reservoirs are completely repressured and gas cycled. Using this equation minimized two probable sources of appreciable error in conventional material balance calculations: inaccurate measuring of and accounting for produced gas, and differences between true reservoir pressure and average reservoir pressures as derived from bottom-hole pressure measurements. A new procedure is presented for calculating water encroachment. By solving the conventional material balance equation and the derived equation for gas storage simultaneously, the values for initial oil in place and net water encroachment can both be determined.

Jan 1, 1966

By Thomas J. Peters

In 1987, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied a 12,564-acre portion of the 34,795-acre Rockhouse Wilderness Study Area (CA-010-029) in order to evaluate its identified mineral resources. The study area is located in Kern and Tulare Counties, CA, about 60 air mi northeast of Bakersfield at the south end of the Sierra Nevada. A review of the geologic and mining literature, and a field examination identified a turquoise and a gold prospect in the study area, and another gold prospect and a feldspar prospect within a mile of the study area boundary. Thirty-three rock and 16 alluvial samples were taken.

Jan 1, 1988

By Elmer W. Pehrson

The recent establishment of an official price of 64.64 cents per ounce for silver by the President's order of December 21, 1933, has provoked discussion as to the effects of this move on the various metal-mining industries. To assist those of the mineral industry who are interested in this problem, the Bureau of Mines presents the following analysis of basic statistical data concerning; the relation of the silver price to the value of copper ores mined in the United States. The term "copper ore" as used herein includes all ores in which copper is the most abundant base metal paid for. In 1928, this class of ore contributed 98 percent of the total copper output of the United States.

Jan 1, 1934

By L. F. Willmott

The Bureau of Mines at Morgantown, W. Va., has been investigating, on a pilot plant scale, various methods of gasifying bituminous coal with oxygen and superheated steam to produce synthesis gas, as part of the broader program of finding new uses for coal. Differences in the pressure gasification methods used have depended on differences in the manner in which the pulverized coal is fed to the gasifier. One of the methods of feeding the coal that was investigated was the continuous, integrated coal-water slurry system. Goal and water were first mixed to produce a slurry; then the slurry was pumped through a heated coil. to evaporate the water fraction; the resulting steam was superheated, and some of it was separated so as to adjust the ratio of the residual steam to the coal fraction and make the resulting mixture suitable for partial combustion with oxygen in a pressure gasifier. Both before and during this reported3 developmental work it was necessary to make an extensive literature search into the technology of aqueous slurries in order to establish design criteria for the pilot plant and to correlate results of various phases of the work with that of other investigators, The pilot work coincided with the commercial development of a long-distance pipeline for the transportation of coal as a coal-water slurry, and this fact tended to broaden the scope of the pilot plant work and the extent of the literature search. This bibliography is the compilation of the material that was collected.

Jan 1, 1963