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By J. E. Zeilinger

This Bureau of Mines report describes the preparation characteristics of the significant coalbeds of Clay, Gilmer, and Lewis Counties, W. Va. In 1966, almost 1.3 million tons of coal was mined in these counties, of which more than one-half was from the Pittsburgh coalbed. Washability analyses were made of 16 coalbed samples. Of these, only 11 samples could be upgraded to metallurgical quality. For steam or power generation five of the coals were of low sulfur content as received. The remaining samples were generally of medium sulfur content even after upgrading.

Jan 1, 1969

By Patrick D. McMaster

"INTRODUCTION According to the Roane Iron Co. of Rockwood, Tenn., the Chamberlain. Barnardville iron deposit produced approximately three million tons of iron ore previous to 1928. The deposit is divided into two synclinal bodies termed the north and south synclines. Production has come from the northern extremities of both bodies.The need for developing additional iron-ore reserves during the war prompted the Bureau of Mines to initiate an exploratory program on the Chamberlain-Barnardville deposit in February 1944, which continued until December 1944.ACKNOWLEDGMENTSIn its program of exploration 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 exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director."

Oct 1, 1946

By A. Gene Collins

This report discusses some of the chemistry and geochemistry of cesium and rubidium. Knowledge of the cesium and rubidium content of oilfield waters aids in resolving the origin of waters and petroleum, exploring for petroleum and other valuable minerals, discovering water pollution sources, and augmenting the knowledge of geologic formations. The methods described in this report permit the detection of less than 0.01 mg/l of cesium and/or rubidium in a complex oilfield brine or water. Solvents possessing high-dielectric constants were evaluated for their ability to extract cesium and rubidium tetraphenylboron from oilfield waters and for their flame emission characteristics. Nitroethane was selected and used for the extraction and flame spectrophotometric determinations because it gave the highest sensitivity. Cesium 137 and rubidium 86 were used to determine the extraction efficiencies, which were about 87 percent and 58 percent respectively using a single 10 ml nitroethane extraction from a distilled water matrix. The standard deviation of the determination was 0.0008 mg for cesium and 0.0007 mg for rubidium in the 0.01 mg range.

Jan 1, 1965

By Thomas A. Giordano

Portable communications equipment is becoming increasingly important in underground mining. Proper selection of microphones and hearing devices to be part of these communication systems is essential if the messages are to be transmitted intelligibly. In this program a thorough study of the requirements for these transducers was made with respect to intelligibility, mechanical configuration, human factors and safety. A computer analysis was made to predict how several combinations of transducers would perform at typical mining noise levels. A survey has been made of those microphones and hearing devices on the market today that might be applicable to the miner communication system. Several systems are proposed and evaluated.

Jan 1, 1976

By S. J. Pearce

The Bureau of Mines has prepared, as circumstances have dictated, a series of Schedules setting forth the minimum requirements that various types of equipment should meet to be considered safe and satisfactory for use in certain hazardous or unhealthful conditions. These Schedules cover a wide variety of devices ranging from explosives to electrically operated mine locomotives. This paper deals with those Bureau of Mines Schedules under which respiratory protective devices are tested and approved, and its purpose is to explain the function and operation of these Schedules. Provisions have been made for testing and approval of the following types of respiratory protective devices: Self-contained breathing apparatus,2/ supplied-air respirators,3/ gas masks,4/ dispersoid respirators,5/ and chemical cartridge respirators.6 These devices are tested at the Central Experiment Station of the Bureau of Mines in Pittsburgh, Pa. Self-contained breathing apparatus is tested by the Safety Branch, and the other types of respirators are tested by the Health Branch.

Jan 1, 1951

By D. L. Yopps

In research conducted by the U.S. Bureau of Mines, platinum-group metal (PGM) flotation concentrate from the Stillwater Complex, MT, was subjected to biooxidation using Thiobacillus ferrooxidans in an effort to break down the sulfide minerals and liberate the associated PGM's for subsequent chemical leaching. Bacterial preleaching oxidized up to 94 pct of the sulfide present, destroyed the PGM-bearing pentlandite [(Ni,Fe)9S8] mineralization, and dissolved most of the nickel in the concentrate. Cyanidation at 80° C proved to be the most attractive chemical leachant, removing 34 pct of the platinum, 76 pct of the palladium, 94 pct of the rhodium, and 97 pct of the gold from the biooxidized concentrate. Research also indicated that increased sulfide oxidation during the preleach phase led to improved PGM recovery in the subsequent chemical leaching phase.

Jan 1, 2010

By Sean Gallagher

Study Design. A split-plot experimental design was used to evaluate the influence of posture, trunk angle, and rotational velocity on peak torque output and myoelectric activity during maximal trunk extension maneuvers. Objectives. To determine whether the kneeling posture alters extension torque capabilities in isometric and isokinetic exercises as compared with standing. Also, to ascertain whether recruitment of trunk muscles is modified by such a postural change. Summary of Background Data. Factors such as workplace geometry may force workers to adopt awkward or unusual postures in the performance of manual tasks. An understanding of the limitations placed on strength in unconventional working postures is crucial to the proper design of jobs. Methods. Twenty-one healthy male subjects (mean age = 36 years 7 SD) performed 12 trunk extension exertions in standing and kneeling postures. Isometric tests were performed at 22.5°. 45°, and 67.5° of trunk flexion. isokinetic tests were done at three velocities: 30°/sec, 60°/sec, and 90°/sec. Electromyographic data were collected from eight trunk muscles to assess muscle recruitment under each condition. A prior; orthogonal contrasts were specified for analysis of both torque and electromyographic data. Results. The kneeling posture was associated with a 15% decrease in peak torque output when contrasted with standing; however, no concomitant change in trunk muscle activity was evident. Trunk hyperflexion (isometric tests) and increasing rotational velocity (isokinetic tests) were associated with reduced torque in both postures. Trunk muscle activity was primarily affected by changes in trunk angle and velocity of contraction. Conclusions. A reduced extensor capability exists in the kneeling posture, despite equivalent trunk muscle activity. The similar activation patterns in both postures suggest that the strength deficit does not result from alterations in trunk muscle function. Rather, it may be the consequence of a reduced capability to rotate the pelvis in the kneeling posture, due to a disruption of the biornechanical linkage of the leg structures. [Key words: electromyography, isokinetic, isometric, low back pain, posture. strength1 Spine 1997;22:1864-1872

By D. B. Dow

The study of oil production methods with reference to the amount of oil originally pressent in the oil-bearing, formations has developed the fact that-ordinary methods-of production remove only a part of the oil actually present. In fact, it is generally realized that when a field is abandoned more oil remains in the sand than has ever been removed. As a consequence of this realization, the petroleum engineer has devoted considerable tine in recent years in devising methods for increasing the percentage of recovery. His studies have indicated that in most cases the total production of a field is dependent upon the available gas rather than upon the available oil. Mien the gas in the sand is exhausted, oil production ceases even though there may be enormous quantities of oil remaining unrecovered. Consequently, any method of conserving the gas or increasing the supply of gas will increase the ultimate recovery from a field. The practice of producing oil under vacuum increases the effectiveness of the gas remaining in the sand, as well as furnishing more gas by evaporating the light fractions of the crude. Pumping ' compressed gas or air down selected wells of a lease has been found to increase the production of oil from the surrounding wells. Studies of oil and gas ratios have indicated that much of the available gas has been wasted as far as its effectiveness on oil production is concerned. his has led to the development of "stop cocking"3 and the practice of producing under back pressure3, which methods aim, to obtain more effective work from the gas with reference to the amount of oil delivered to the well.

Jan 1, 1926

By R. S. Olsen

Although aluminum is easily leached from calcined clay with boiling mineral acids, the presence of fines and slimes in the leached residue has hindered the application of acid leaching processes. A feed preparation method was, therefore, devised that provided a dense, smooth-surfaced, fine-grained clay. The important factors affecting feed quality were determined to be (1) crushing the raw clay to the size desired for the leaching process, (2) moistening the crushed clay with a fine mist of water while tumbling on a rotating disk, (3) drying the misted clay, and (4) calcining the dried clay at 750° C in a fluidized bed. Clay treated by this method was leached with HCI, and its residue was washed by water displacement in 4-ft-deep beds. Bed permeabilities on the order of 47 darcys or 4.6 x 10-7 cm2 were obtained with the leached residues.

Jan 1, 1983

By M. M. Wong

The Bureau of Mines, under a cooperative research program with four lead companies, has investigated a nonsmelting process for the production of lead metal. The process, which would eliminate sulfur dioxide generation and minimize particulate lead emissions, involves ferric chloride leaching of galena concentrate to produce lead chloride, followed by molten-salt electrolysis of the lead chloride to yield lead metal and chlorine. This chlorine is used to regenerate ferric chloride in the leaching solution. The process was tested in an experimental unit with a capacity of 500 lb of lead metal per day. The tests were performed in three 10-day and six 5-day campaigns, during a period spanning 28 mo. The study was carried out using a southeastern Missouri lead concentrate. Typical lead recovery was about 98 pct. Process problems related to impurity buildup and control were studied. When copper and silver impurities were removed from the leaching solution, a lead metal purity of 99.999 pct was obtained. Lead-in-air levels and lead-in-blood levels of operating personnel were monitored. The process has potential for producing lead with minimum pollution, but is not ready for commercial utilization. Operation of a prototype commercial electrolytic cell and a full-scale pilot-plant investigation by industry are needed to evaluate the commercial viability of the process.

Jan 1, 1983

By Douglas W. Fuerstenau

A detailed experimental study of breakage kinetics in a batch rod mill indicates that while the system is inherently nonlinear, the feed disappearance kinetics for the finer sizes and the coarser sizes at high holdups is well represented by first-order behavior. The set of breakage distribution functions was found to be normalizable and independent of particle holdup in the mill. The size discretized initial breakage rate functions were found to be inversely proportional to particle holdup and almost directly proportional to particle size. A linearized grinding model that results from the first-order Taylor's series expansion of the breakage rate expression was found to give good simulations of the mill product size distributions without recourse to any parameter improvement routines. Material transport through rod mills was evaluated by investigating the effect of operating variables on the holdup and residence time distribution of particulate solids flowing through the mill. Identical experiments performed in a continuous ball mill helped delineate the fundamental differences in particulate transport through these two types of mills. Mechanistic interpretations of the observed transport phenomena are presented, and their implications in the context of tumbling mill analysis and design pointed out.

Jan 1, 1980

By Lloyd A. Morley

The problems associated with the presence of organic materials and of water in explosion-proof enclosures used in high voltage, high capacity applications were examined through a literature search and theoretical reasoning. Information on volatilities is presented. The conclusion is reached that explosive pressures are significantly enhanced by inclusion of these materials.

Jan 1, 1976

By H. A. Watson

This circular, which is a revision and combination of two previous publications,3 4/ presents information on the different types of equipment that may be used to analyze mine atmospheres, with particular reference to the application and limitations of each type. Such information is frequently requested by mining companies, State mining departments, and other agencies concerned with safety in mining who wish advice regarding methods of analysis of mine atmospheres and the equipment necessary for establishing laboratories for that purpose. Since the Haldane-type apparatus is particularly applicable to the accurate determination of carbon dioxide, oxygen, and combustible gases such as methane in mine atmospheres, that apparatus and the method of operation are described in detail. The circular presents results of a critical study of the accuracy attainable with the Haldane-type apparatus in the determination of methane in concentrations of the order of 0.25 percent, by volume. Analytical procedures involved in the other methods discussed are presented in publications referenced in this circular. Information is given also on the various accessory equipment needed in a laboratory for the analysis of mine atmospheres, and suggestions on laboratory design are included. INTRODUCTION 'The analysis of mine atmospheres plays an important part in promoting safety and maintaining safe conditions in mining operations, particularly in coal mining, where the flammable gas methane presents a continuous hazard in Nome mines and may be encountered unexpectedly in others.5/ Methane has been encountered also, often unexpectedly and with disastrous results, in noncoal mines and in tunnels under

Jan 1, 1956

By H. Tomlinson

"PURPOSE OF REPORTFatalities from falls of roof and coal are responsible for the death of more than 1,000 miners annually in the bituminous coal mines of the United States or practically one—half of the total fatalities in and about these mines. The men are killed by falls singly or in small groups and little or no publicity is given these accidents as they lack the spectacular features of gas and dust explosions. As a result, the public and even the miners have the impression that accidents from falls of roof and coal are just one of the unavoidable hazards of the coal—mining industry. This belief is not true. Accidents caused by falls can be avoided largely by the application of sound engineering principles, by education, and by proper leadership in the industry, just as gas and dust explosions and accidents caused by explosives have been reduced in recent years.The necessity for studying falls of roof and coal becomes apparent by referring to the following data from a table by Adams and Chenoweth:3"

Jan 1, 1933

The number of railroad coal cars (open top hoppers), dominated rail car orders and deliveries in 1975 according to announcements made February 11, by the Association of American Railroads and the American Railway Car Institute. Acting to keep ahead of increased coal production, the railroads installed 21,748 new coal cars in 1975, the most since 1957. The 1975 installation resulted in a net increase of 6,560 coal cars and an overall gain of 4.5 percent in the total capacity of the hopper car fleet. With most of the new coal cars going into unit train service --where car utilization is greatest --the railroads actual coal-carrying capacity was increased far more than 4.5 percent. The AAR estimated that unit train operations now move 50 percent of all rail-hauled coal compared to only 42 percent 2 years ago. COBALT - The Societe Miniere de Tenke Fungurume (SMTF) copper-cobalt project in Zaire reportedly was suspended in January for an indefenite length of time. According to officials, the deferment resulted from a number of adverse factors, one of which was exceptional increases in capital costs. The project was scheduled for completion in early 1978, with an eventual production of 14.3 million pounds of cobalt per year. Reserves of cobalt were reported to be 505 million pounds. SMTF is a consortium and includes American, British, French, Japanese, and Zairian interests.

Jan 1, 1976

By H. M. Thorne

The Union of South Africa has been interested in oil shale for a long time, and deposits of oil shales, torbanites, and similar rocks have been found in many parts of the country. (Fig. 1.) Samples differ markedly in oil yield and in the characteristics of the oil. The strata vary in thickness, and most of the deposits that have been found are in unfavorable locations because of remoteness from markets or absence of transportation facilities. This report deals mainly with the torbanite deposit near Ermelo, Transvaal, in the Union of South Africa, and the operations of the South African Torbanite Mining and Refining Co., Ltd. (hereafter referred to as Satmar), in mining the torbanite, retorting it, and refining the crude oil.

Jan 1, 1954

The Bureau of Mines is the engineering arm of the Government for mineral resources. Its mission is to carry out laboratory and field studies that will assure the wise and effective development and use of our Nation's minerals, fuels, and underground domain in order to preserve the security and enhance the welfare of our people. Specifically, studies are directed to the means by which current and emerging demands may be met, the real cost of such achievements, and the assessment of related social and economic factors. Ways are sought to fulfill our material needs in a manner that minimizes occupational hazards to workers in the industry, reduces waste, and ensures that mineral raw materials are supplied and mineral-based products are used and are disposed of efficiently, without objectionable social and environmental costs. The headquarters of the Bureau of Mines is located in Washington, D.C. The Bureau's research and development program, however, is conducted at 19 research centers and laboratories located throughout the United States.

Jan 1, 1971

By Robert L. Grayson, Syd S. Peng

"An airborne dust study was undertaken at a Southwestern Pennsylvania underground bituminous coal mine by the Pennsylvania Department of Mines and Mineral Industries in 1964 for the purpose of making recommendations and requirements regarding compliance with health and safety aspects of The Bituminous Coal Mining Laws of Pennsylvania, approved by the legislature on July 17, 1961. The study was designed to accurately represent the airborne dust conditions of the subject mine. Sampling by midget impinger of specific worker locations throughout the mine was accomplished. Sample analyses yielded dust concentrations to mppcf, particle size determinations in cumulative per cent less than specified cut-off diameters, and determinations of free silica percentages in total dust samples. The data from this study is further analyzed, and the results are presented.INTRODUCTIONThe Bituminous Coal Mining Laws of Pennsylvania, enacted in 1961, prompted a study of respirable coal mine dust by the Department of Mines and Minerals Industry in 1964. In recognition of their obligation for ensuring the health and safety of bituminous coal miners, the department set out to characterize the airborne dust of mines throughout the commonwealth. The purpose of the studies was to make recommendations and requirements for compliance with the law and for control of airborne coal mine dust in Pennsylvania mines.One such study was undertaken at an underground bituminous coal mine operating in the Pittsburgh Seam in Southwestern Pennsylvania. The study was desig11ed to sample specific worker locations throughout the mine site and characterize the respirable dust relative to each of them. A midget impinger was used to gather respirable range dust samples during an 8-hour shift. Continuous miner operator, roof bolter, stoper bolter, loading machine operator, shuttle car operator, gathering motorman, mainline motorman, and rotary dumper jobs were sampled underground. In addition, barge mover, coal sampler, fine coal operator, heavy media operator, and boiler room attendant occupations were sampled on the surface. The surface sampling was over a 71-hour shift because of UMWA contract provisions."

Jan 1, 1988

A mobile vacuum sweeper to remove loose coal and coal dust from underground coal mine workings was designed, built, tested, and evaluated. The design was based on an extensive test program. Pick up and conveying rates vs. air volumes, velocities, and nozzle shapes were determined for coal rubble in a laboratory pneumatic handling system. A gas/solids separation system was developed and tested in the laboratory capable of separating the solids loading from the vacuum system air stream to the very high degree required to preclude degradation of the ambient (mine) air. Two designs were made, one for belt conveyor and one for general district cleanup. The belt cleanup machine was chosen for test and demonstrated in an underground coal mine performing cleanup work in belt haulageways and on ribs.

Jan 1, 1975

By L. M. Chan, D. R. Carlson, J. H. Johnson

"This paper presents an apparatus and procedures to implement a methodology for controlling ambient air quality in a confined working environment, such as an underground mine, an underground storage area, or a tunnel. The air quality control methodology is directed at limiting the quantities of exhaust pollutants emitted by diesel-powered vehicles into the confined space by identifying vehicles that are excessive polluters. The methodology is based on tailpipe and ambient air measurements in the confined space, and the ambient air threshold limit values (TLVs) for the various diesel exhaust pollutants. The methodology consists of two computational methods; a deterioration criteria computational method to identify excessive polluting vehicles, and an engine performance computational method to determine engine performance and to provide information needed to diagnose engine faults. The methodology is designed for implementation in conjunction with a preventive maintenance program.The first part of the paper describes the mine air and tailpipe emissions measurement apparatus and techniques used to obtain data. This is followed by sections discussing the deterioration criteria and the engine performance computational methods. A section discussing some common engine emissions-related faults is also presented lastly, a proposed procedure to implement the methodology including a possible hierarchical structure for mine personnel involved to implement the procedures is presented.INTRODUCTIONDiesel-powered mining vehicles are gaining Popularity in underground coal mines and are almost universally used in underground non-coal mines due to their mobility, flexibility, and higher productivity. However, noxious gases and particulate matter in diesel engine exhaust are a concern because of the potential for being harmful to the health of miners. Diesel exhaust pollutant concentrations out the tailpipe of a mine vehicle change with time due to engine wear, inadequate maintenance, improper adjustments and other factors. This deterioration in pollutant concentrations, if not properly controlled, may adversely affect the air quality in an underground mine. To provide assurance that a clean and healthful work environment are maintained, a program is needed to identify and repair diesel engines that contribute to poor air quality. Also, earlier detection of deteriorated engines will make preventive maintenance possible, thereby eliminating further deterioration and possibly complete breakdown. Preventive maintenance also increases engine life and equipment availability in production which in turn will result in decreased operating costs."

Nov 1, 1995