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By Eugene T. Sheridan

The 22d annual survey of the packaged-fuel industry by the Bureau of Mines, United States Department of the Interior, revealed that 26 plants in 8 States were in operation and reported production in 1956. The demand for packaged fuel in the United States has declined gradually since the end of World War II, and the number of operating plants has decreased from 70 in 1946 to 26 in 1956. Annual productive capacity of the industry has decreased also during this period, and the decrease in capacity was about proportional to the decrease in operating plants. Packaged-fuel plants are relatively small, and 85 percent of the active plants in 1956 had an annual capacity of less than 10,000 tons. The same situation prevailed in 1946, when 84 percent of the plants had a capacity of less than 10,000 tons. Total capacity for the 26 active plants in 1956 was 174,600 tons, an average of 6,715 tons per plant. Operating rates in 1956 were the highest since 1951, and the rate of production for the industry averaged 37 percent of capacity.

Jan 1, 1958

By E. H. Burroughs

HISTORICAL REFERENCES OCCURRENCE-GEOLOGY AND ORIGIN. 4. ARNOLD, RALPH. Conservation of the oil and gas resources of the Americas, Econ. Geol., vol. 11, Apr.-May, 1916, pp. 203-222; June, 1916, pp. 299-326; Proc. 2nd Pan American Sci. Cong., 1915-1916, vol. 3, Conservation of natural resources, pp. 207-237. Shows occurrence of oll, and status and possibilities of oil Industry in each country. Discusses briefly ways in which oll reserves may be conserved. 5. RUTIS, A. A. Petroleum known since remote times. Oil and Gas Jour., vol. 15, Nov. 2, 1916, pp. 33, 37. Gives historical reférences to the use of petroleum from Bible times to its discovery In America. See also Nos. 3, 257, 202, 337, 1843.

Jan 1, 1919

By Wilson Blake

This report presents the results of a 7-year Bureau of Mines program to review, revise, and make an effective engineering tool of the microseismic method of determining the stability of rock structures. The program consisted of developing new microseismic equipment and data analysis techniques and extensive field investigations to demonstrate the effectiveness and potential of the broad-band microseismic method. The guidelines for choosing the components of a microseismic system are presented along with approximate cost figures. Different microseismic systems are discussed, including completely automated systems. Procedures for conducting microseismic investigations and analyzing microseismic data are discussed in detail. Field situations which show the full value of the microseismic technique as an engineering tool are described.

Jan 1, 1974

By John K. Owens, Wayne L. Howie

Mobile roof support (MRS) machines are used as roof support during pillar recovery in retreat operations in lieu of wooden posts, cribs, or hydraulic props. A Mine Safety and Health Administration-permissible load rate monitoring system was developed for the MRS by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. The system uses a dedicated embedded processor to monitor changes in pressure inside the hydraulic cylinders of the MRS through multiplexed data acquisition channels and converts these pressure changes to load rates that sequentially activate three load-rate-indicator lights mounted on the machine. Each light represents a different loading rate to alert mine personnel to dangerous conditions during pillar extraction.

By W. W. Adams

Lower accident rates were the outstanding feature. of the second annual sand and gravel safety competition conducted in 1930 by the United States Bureau of Mines in cooperation with the National Sand and' Gravel Association. Both the frequency and, severity rates for accidents were greatly reduced as compared with those shown by the first year's contest, that for 1929. Three times as many plants were enrolled, and the number of man-hours of work represented was more than doubled. Seventy-six sand-and-gravel plants, situated in 20 States, participated in the Competition, as compared with 26 plants, located in 13 States, in the year before. The number of man-hours of employment, which indicated the amount of exposure to occupational hazards, was 4,915,592, an increase of more than 100 per cent over the previous year's total of 2,259,572 hours. The frequency of accidents declined from 74.4 per million hours for all plants enrolled in the first year's contest to 42.7 per million man-hours for all plants enrolled in 1930. The accident-severity rate was reduced from 9.7 days of disability per thousand man-hours of exposure in 1929 to 5.9 days of disability per thousand man-hours of exposure in 1930. The actual number of accidents reported for 1930 by 76 plants included four deaths and 206 injuries whereas the 26 plants that were enrolled in 1929 reported three fatalities and 165 injuries. Under the rules of the contest all "lost-time" injuries are reported--that is, all injuries that disable an employee for more than the remainder of the day on which the accident occurred. If the employee is physically able to resume his work on the day following the accident, the injury is not classed as a lost-time injury. The contest covered accidents and man-hours worked by all employees at the plant who were employed by the same company, and included work up to the point of delivery of the material directly to consumer or to independent agency of transportation--in other words, to point of relinquishment of control of the material by the producer.

Jan 1, 1931

By K. C. McMahon

This report is the result of the engineering efforts performed by the Mining Equipment Operations of FMC to develop methods of automating a continuous miner. This work was done as part of modification number three of the contract for the development of a miner/bolter system. As the demand for energy places an ever-increasing pressure on the coal mining industry to produce more coal, methods for underground mining which will increase productivity with a con-current increase in safety are being actively sought. Removing the machine operator from his station on the continuous miner and placing him at a safer location behind the machine while retaining his control functions via an umbilical cable or a radio link was an important first step. However, the problems of poor visibility, no control "feel", and the judgmental problems of controlling the sump distance and the shear limits have not been conducive to the productivity increase that is desired.

Jan 1, 1975

The Appalachian Mountains divide Pennsylvania into two distinct coal regions, bituminous and anthracite. The western region of the the state, where the majority of bituminous mines are located, is characterized by mountains and gently rolling hills. Bituminous coal seams underlie about 12,000 square miles in 28 counties. The anthracite coal region, located in the northeast, covers approximately 3,300 square miles. This area contains more than 20 different coal beds that vary in thickness from a few inches to 50 or 60 feet. The anthracite region is characterized by steeply pitching seams that require highly specialized mining techniques and present unique challenges for solving problems such as the mine subsidence associated with abandoned underground anthracite mines. For more than a century, coal has played a major role in the economic and industrial development of Pennsylvania, particularly the steel industry. Estimated bituminous reserves total 23 billion tons, or 5.3 percent of U.S. reserves, and anthracite reserves total 7.1 billion tons, or 97 percent of U.S. anthracite reserves. Pennsylvania received conditional approval of its regulatory program July 31, 1982. Pennsylvania's Abandoned Mine Land Program was approved on the same date.

Jan 1, 1992

By William S. Miska

The study is an economic evaluation of historical, current, and projected refractory uses in the iron and steel industry of the United States. The first part of the report presents a refractories classification and identifies principal trends in the refractories industry; such as, value and volume of shipments, prices of finished refractory products, the number of manufacturers and plants for refractories production and marketing. The main part of the report treats refractory use patterns and technologic developments affecting refractories usage in the iron and steel industry. Changes in use patterns in each furnace type, refractory, and installation costs and the future outlook for refractories in ironrnaking and steelmaking are covered. The last part of the report identifies the principal raw materials used in refractories production and treats trends in refractory raw material consumption. An appendix to the report contains historical time series graphs of shipments of refractory types used primarily by the iron and steel industry and principal refractory raw materials sold or used by producers. An equation of the line of best fit was calculated from the earliest to the latest year in each time series, usually 1950 to 1965; these were extrapolated in order to derive volume estimates for the year 1975.

Jan 1, 1968

More than 400 academic, Government, and industry representatives attended the third symposium on ash utilization and technology held in Pittsburgh, Pa., March 13-14, 1973. Sponsored by the American Public Power Association, Edison Electric Institute, National Coal Association, National Ash Association, and Bureau of Mines, the symposium Featured 26 formal presentations by leading experts from Europe and the United States on all major phases of ash production, utilization, and research. Abstracts of all the papers are grouped right after this introduction, and the full symposium proceedings follow. Sponsoring organizations and their chief representatives were the National Coal Association, James R. Garvey, Bituminous Coal Research, Inc.; Edison Electric Institute, C. E. Brackett, Southern Electric Generating Co.; American Public Power Association, Herbert Blinder, Columbus (Ohio) Electricity Division; National Ash Association, Inc., James N. Covey, Rochester Gas and Electric Corp.; and the United States Department of the Interior, Bureau of Mines, William L. Crentz.

Jan 1, 1974

By Fred W. Snow

This paper describing the mining practices at the Magma mine, Superior, Ariz., is one of a series being prepared by the Bureau of Mines on mining prac¬tices, methods, and costs in the various mining districts in the United States. At present (1929) practically all the mineral production in the Superior district is from the Magma mine of the Magma Cooper Co. The ore is mined for its copper but contains associated silver and gold. Both direct smelting ore and ore of concentrating grade are produced. The mining methods now in use at the Magma mine were adopted or developed as knowledge was gained of the physical condition of the ore bodies and the inclosing formations; the wall rock is soft and crushed and the ore is relatively hard. In general, existing methods have been adapted to fit local conditions, but some of the mining practices used were originated at this mine. Most of the ore is mined by a combination of rill stopes and pillar stopes. The pillars are extracted by underhand mining.

Jan 1, 1929

By W. W. Roepke

The Bureau of Mines has developed an interactive computer program that enables mine operators and others to identify the effect of cut-ting system changes on relative dustiness at the face. The program, which simultaneously evaluates machine parameters, coal seam parame-ters, and operator-controllable parameters, was developed for use on any microcomputer using BASIC programming language. The program allows the user to change one or more of the cutting system parameters at a time to see how these changes affect relative dustiness. A complete program listing and flowchart are included along with operating in-structions and sample outputs. An example showing how to use the program is also included.

Jan 1, 1985

By Jerry J. Gray

Transportation charges for mineral commodity movements in western Oregon and western Washington were determined mainly by a stratified random sample canvass of producers. Total 1965 mineral production value for this area was $53.3 million; the cost or charge to move this production from the mine to the consumer or to the point of consumption was determined to be an additional $38.7 million. Thirty seven companies were contacted as a sample out of a total population of 349; the statistically expanded sample production value deviated 3.6 percent from that obtained by the Bureau's annual canvass. The agreement between the sample results and the canvass totals demonstrated the effectiveness of the sampling method for obtaining data with a predesigned level of accuracy. For comparison, the north-central Idaho and western Montana area was studied, A random sample experiment was designed, but because of the dominance of a few major companies, a random sample technique would have required more visits to producers than if only the larger firms were contacted. Eighty-four percent of the 1966 mineral value ($198.6 million) was accounted for by interviewing 27 firms out of a total population of 199. Total transportation costs or charges for the area were $26.7 million. The significant difference observed between the relationship of minerals production value and transport charges between the two areas investigated can be attributed to the difference in the minerals produced. The western Oregon and western Washington region is a nonmetals-producing area as opposed to the predominance of metals production in the Idaho-Montana region.

Jan 1, 1968

By L. E. Cardwell

This Bureau of Mines publication contains routine analyses and related source data for 495 natural gas samples from 21 States and three foreign countries. Of this total, 376 samples were collected during calendar year 1968. The remaining 119 analyses are of samples collected during previous years, but releases granting permission to publish the results Here not received until 1968. All samples were collected as a part of a continuous survey of the free world for occurrences of helium in natural gas. This survey has been conducted in the United States by the Bureau of Mines since 1917 and in late 1965 was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus which are described in Bureau of Mines Bulletins 4863 and 576.4 Ten previous publications have presented results of 8,165 gas analyses made by the Bureau of Hines Helium Activity prior to 1968. The first three, Bulletins 486, 576,6 and 617,7 contain analyses and related source data on

Jan 1, 1970

By R. S. Dean

[During the past year the Metallurgical Fundamentals Section gave about an equal amount of time to the experimental determination of fundamental thermodynamic constants and to the demonstration of the application of such data to more directly practical metallurgical problems. The first division of the work - the actual experimental measurements of typical thermodynamic constants - was carried out an two problems, termed ?continuing? programs, namely, (1) measurements of Specific Heats at Low Temperatures and (2) Measurements of Heats of Formation and Free Energies. Specific substances chosen for investigation are classified as (n) those that have been the subject of requests for information from the industry and that, upon examination, seem of sufficient practical importance to justify study, and (b) compounds that are difficult to treat metallurgically, or whose specific thermodynamic properties have not yet been determined satisfactorily and for which accurate data might suggest improved or new methods of Metallurgical treatment, or (c) materials recognized as belonging to a social class with exceptional thermodynamic properties and, hence, of scientific as well as technical importance.]

Jan 1, 1938

By Michael J. Beus, Stephen Iverson

BACKGROUND A mine shaft is the lifeline to underground mines. Mine operators depend on safe, uninterrupted, and efficient movement of workers and materials. The shaft and hoisting system provides access to the network of openings used to recover the underground resource, provides vertical transport of miners and materials, and serves as an escapeway in case of an emergency. Accidents involving hoisting can be catastrophic. Such was the case in 1973 at the Markham Colliery in Derbyshire, UK when the conveyance overwound and fell to the shaft bottom, resulting in 17 deaths. Hoist and elevator machinery must meet the requirements specified in the Code of Federal Regulations (CFR), Parts 57 and 75. According to the Mine Safety and Health Administration (MSHA) data, many shaft-related accidents in the United States are associated with the hoisting cycle. MSHA statistics show that there were about 1500 shaft- related accidents in the 5-year period between 1992-1996. Most of these accidents resulted from the action, motion, or failure of the hoisting equipment or mechanism and involved movement of the conveyance which includes cages, skips, ore buckets, and elevators. A hoisting hazard may be characterized as an "unsafe hoist operating condition caused by insufficient or inaccurate information available to the hoist operator" (authors' quote). Earlier investigators have defined safety features and operating and maintenance standards for hoists, and reported on monitoring and control systems and sensors for hoists and conveyances [Farley, 1983; Ward, 19931. However, despite the considerable technological progress and hoisting control improvements in recent years, safety- related issues that require further investigation still remain. The hoist operator must constantly be aware of two important hoist-operating conditions: the position of the conveyance and the tension in the hoist rope. If this information is not available or is inaccurate, the hoist becomes unsafe. Current technology provides this information indirectly from sensors and indicators in the hoist room. However, unlike a building elevator hoistway, mine shaft hoistway problems often include: 1. poor ground conditions and excessive shaft wall and guide displacement; 2. rock bursts in deep mines (resulting in large rock movements and fragments blocking the hoist way); 3. water, ice, and salt buildup (impeding the smooth flow of the conveyance); 4. severe vibration from hoisting (resulting in loose guide support brackets, broken welds, or other alignment and conveyance mechanism malfunctions). The second issue relates to dynamic rope loads applied during normal winding, particularly during loading, acceleration, and stopping. Safety factors on wire rope are based on static load. They are artificially high to account for all cases of dynamic loads, even though the total load history on the rope (static and dynamic) during service is unknown. Therefore the tension, and thus the compliance with wire rope load safety factors, is unknown to the hoistman.

By C. H. Kats, E. G. Meiter, J. J. Bloomfield

"INTRODUCTION.Street manholes for underground power and signal circuits, and for sewers vary in size from small openings that a workman can enter, to large central vaults. As the gas hazards in manholes are similar to those in mines, the mine safety committee of the Bureau of Mines was asked whether the miners' flame safety lamp is a practicable device for indicating inflammable gases in manholes.The coal miner detects firedamp (methane or CH4) with his flame safety lamp by observing the luminous can or the increased length of flame that appears when 1.5 per cent or more of the combustible gas is present. The lamp flame also warns him of lack of oxygen by going out when the oxygen becomes less than 16 to L7 per cent. A tentative rule regarding the proposed use of safety lamps at manholes has been suggested previously as follows: ""Testing for gas: Do not enter manholes until you have .assured yourself that the manholes are free from dangerous gases, by testing with an approved safety lamp, by ventilation, or by other adequate methods."" The Bureau's committee recommended that miners' flame safety lamps are not suitable,testing in manholes because hydrogen gas may be formed therein. The flame safety lamps approved by the Bureau of Mines for use in aseous mines are safe in presence of methane and while not tested against the members of the paraffin hydrocarbon series (CnH2n+2) higher than methane they been have been used therein; the lamps should not be used in hydrogen or acetylene they can initiate explosions in presence of these gases."

Oct 1, 1925

By N. Kumar Kittusamy

Operators of construction equipment perform various duties at work that expose them to a variety of risk factors that may lead to health problems. A few of the health hazards among operators of construction equipment are: (a) whole-body vibration, (b) awkward postural requirements (including static sitting), (c) dust, (d) noise, (e) temperature extremes, and (f) shift work. It has been suggested that operating engineers (OEs) are exposed to two important risk factors for the development of musculoskeletal disorders: whole-body vibration and non-neutral body postures. Method: This review evaluates selected papers that have studied exposure to whole-body vibration and awkward posture among operators of mobile equipment. There have been only few studies that have specifically examined exposure of these risk factors among operators of construction equipment. Thus other studies from related industry and equipment were reviewed as applicable. Conclusion: In order to better understand whole-body vibration and postural stress among OEs, it is recommended that future studies are needed in evaluating these risk factors among OEs.

Jan 1, 2004

By Thomas M. Barczak, Joe Bower, Jinsheng Chen

Pumpable roof supports provide an alternative longwall tailgate roof support and have grown in usage during the past few years. Heintzmann Corporation has been installing pumpable roof supports at the RAG Resources Emerald Mine in western PA since 1998, where they have provided effective roof control in their longwall tailgates. Despite the success of these supports in this application, questions remain regarding critical design issues for optimizing the use of this support technology. The support loading profile is characterized by a high initial stiffness with peak loading occurring at less than one inch of convergence, followed by significant load shedding with a post failure capacity comparable to that of wood cribbing. Therefore, the key to optimizing the support utilization is to provide sufficient load density to prevent convergence from occurring beyond the peak loading capacity. This requires an understanding of how the supports interact with the ground conditions, hence measurement of the ground reaction curve. In order to obtain this information, pumpable roof supports were instrumented to measure support loading. Roof deformation and roof-to-floor convergence measurements in the vicinity of the instrumented supports were also made. The experimental parameters for the installation were the support spacing and water-to-solids ratio of the grout, which controls the grout strength and ultimately the maximum capacity of the support. The study clearly shows that at this mine a 24-inch diameter support is fully capable of providing adequate ground control under depths of cover of 750 ft as only 50 pct of the available support capacity was utilized outby the longwall face. It was also shown that the 2.00 to 1 water-solids ratio, despite providing a slightly softer support response, is sufficient for maintaining the same degree of roof control provided by the traditional 1.75 to 1 grout mix. The 10-ft spacing of the supports did not cause any ground control problems outby the face. However, inby the face the performance of the support is degraded once the peak capacity of the supports is exceeded. It appears that the large load shedding behavior, which is characteristic of this support following peak loading, allows the immediate roof to separate. When this happens, the support is unable to regain control of the roof in time to prevent failure of the immediate roof beam.

By D. D. Southworth

In 1987, the Bureau of Mines initiated a mineral assessment of the 5.7 million-acre Valdez Creek Mining District (VCMD). Following a literature search and interviews with persons knowledgeable about deposits within the district, limited on-site field visits were made to various deposits. Present within the district are the industrial minerals limestone, argillite, granite, basalt, perlite, zeolite, and sand and gravel. At least six limestone deposits of potentially economic size and grade are known to exist within the district. Adjacent to the Parks Highway and marginal to the district, a limestone deposit is currently being mined as a source of agricultural lime. A perlite occurrence near Yacko Creek was evaluated but proved not to be of industrial grade. The sand-and-gravel resources of the district are vast, but high silt content renders many of the glacial deposits unsuitable for use in construction applications.

Jan 1, 2011

This report contains the papers presented at the Technology Transfer Seminar on Ground Control Aspects of Coal Mine Design held by the Bureau of Mines on March 6, 1973, in Lexington, Ky. Seminar attendance consisted of representatives from the coal mining industry, universities, mining consultants, instrument manufacturers, and local, State, and Federal Government. The purpose of this meeting, one of a series of Technology Transfer seminars, was to provide the coal mining industry with detailed information about recently developed techniques, equipment, and instruments which can be used in the solution of coal mine design problems and to discuss results and direction of research in mine design. The report includes opening remarks by Joseph J. Yancik, Acting Assistant Director--Mining; an overview of the Federal Bureau of mines approach to mine design; three papers an problems associated with the design of panels; five papers on coal mine roof problems; three papers on long wall problems; and the comments made by- the participants on the Bureau-industry panel discussion.

Jan 1, 1974