Search Documents

By Robert L. Lagace

[Suuple Iheorctrccil models are I'M lllolalcd to cltaraclerl/c medium frequency (MF) radio vase pi opaiation in undcrgiounli room arid pillar coal mines fur the purpose of predleiln the most lavolable operating fIegtucncics,md nr,ixunum communic;IIIoil ranges for pottahIe rldu)s with I top antennas. I or conductul IrCC areas, at hree layer propaeaIion IltodcI wit II a Iiallsmissloil IIIIi- lhlllllIIal'u11 lot the plupa!edti ii unlstallt Iris been dcvcloped ;md verified experimentally. 1 lie mode u1 propaCaUetl lakes Ills form of i parallel plane (0,t)) TIM lransnussu)nhne 1% PC of mode with the electric held vertical and the magnetic held hoti/cntal t itliin a planar coal scam in which the tunnels Can he ignored and which 1s hounded above and below hp richer conductivity rock. 1lie model lilt the data best river the 200 io 1000 kH/ frequency hand and exhibits a rc;;lon of optlnrul1l Pelffelntance, with respect Io maxnluiulg radio Communication range, between 300 and 100 klf/. Maximum cunununlcatrorl ranges are sliongls dependent oil the sigiial alleilliatroil sale, ant) Illelclulc on the electrical conductivltles of the coal seam and surrounding ruck. These ranges v;ny tutu about ,,5 Io 100 nleleis Ill a high Iuss scam such as the Ilelllit No. fl to about .100 to 400 meters in a low loss seam such as the Pittsburgh foil portable intrinsically safe radios. The ieslllls die haled on the comparison oftheorc' and experiment for eleven n n. ill sesen coal seams. V OT ate is dice: a conductor such as a power Cable, is present a model has been developed for the coupling of loop antennas to a low loss Coaxial TEM ti;u?smisslon line mode in which the cable acts as the inner conducl,lr and the rock above and below acts as the outer conductor. The electuc and md' nctic Itelds for till` (node are apprlixitllatcly transverse to the cahlC and fall oil expontially with distance in the transverse plane. The principle of reciprocity is used to simplify the analysis. More expelitnental data arc needed to help resolve discrepancies between the theory and the limited data available to date.]

Jan 1, 1980

As part of the Bureau of Mines program for conserving domestic mineral resources, a survey was made of the methods used for identifying scrap metals. Because of the large number of alloys currently being scrapped, correct identification of these materials is essential if they are to be recycled effectively. The methods and instruments used to identify scrap metals are described and evaluated. These include object recognition, color, density, magnetic testing, spark testing, chemical spot testing, thermoelectric measurements, eddy current measurements, and elemental analysis by chemical and instrumental methods. Other potential techniques are discussed also.

Jan 1, 1982

By James C. Barker

A uniquely mineralized area extends from northwestern Canada through Alaska into eastern Siberia. Some of the metals found there are relatively rare in the conterminous United Stales. Among these are cobalt, the platinum-group metals, and chromite. Geologic evidence suggests that cobalt and the platinum-group metals may be present in deposits that could constitute nationally important reserves. Chromite in potentially minable deposits is known, but it may be relatively less abundant. Limited reserves of these metals have been delineated, but most of the favorable terranes and reported occurrences throughout the vast expanse of Alaska remain unexplored. As part of the mineral studies mandated under the Alaska National Interest Lands Conservation Act, the Bureau of Mines' Alaska Field Operations Center and the Bureau's research centers at Albany, Oreg., and Reno, Nev., are cooperating in a long- range program to investigate occurrences and delineate reserves of cobalt, the platinum-group metals, and chromite in Alaska. Studies of other critical and strategic minerals will be phased in during succeeding years, as ongoing projects are completed. This first in a series of annual reports summarizes available information about deposits and past production of cobalt, the platinum-group metals, and chromite, and describes current and planned Bureau investigations of these minerals.

Jan 1, 1981

By Bill York-Feirn

The Colorado Mine Safety & Training Program (MSTP), in late 2005, completed and began distributing two new training tools; one geared to underground coal mine foremen and the other to surface aggregate employees. Through strong partnerships with MSHA, Colorado Coal Mine Board of Examiners, Colorado Mining Association and the Colorado Rock Products Association, the MSTP continues to create innovative and interactive training tools for not only Colorado, but for the national mining community. "Although we shoot and produce these materials in Colorado, it's important to us to make sure they are useful nationally," said Bill York-Feirn, MS TP Manager. The interactive DVD program "Underground Mine Foreman Certification Study Guide (Coal)," was completed in October 2005. It won the 2005 Grand Prize at the MSHA National Training Materials Competition in Beaver, West Virginia. [ ] This program is fully based upon the requirements of Title 30 Code of Federal Regulations (30 CFR) Parts 48, 50, 70 and 75 for underground coal mine foremen. It contains eight modules plus immediate access to relevant laws in the appendix. Topics covered include: Federal Law, Practical Math Skills, Mine Gases, Ventilation Maps, and scenarios addressing a variety of practical mining concerns. The DVD is designed for self-¬paced study and practice.

Jan 1, 2006

By C. M. McCulloch

A geologic study of Mines 32 and 33 in Cambria County, Pa., was conducted as part of a methane control research program. Areas of high methane emission and roof instability are encountered which are related to the structural and stratigraphic features that characterize the geologic setting of these mines. Locally the folds trend N 20° E ±2°, the direction of the butt cleat in the Lower Kittanning coal. The face cleat strikes at N 69° W ±2° and the systematic rock joint in the surface bedrock strikes N 67° W ±2°. This suggests that a directional stress oriented N 70° W produced the folds and influenced the directions of coal cleat and systematic joint sets. Analysis of SLAR indicates three directions of prominent regional lineation: N 39° E, N 31° W, and N 70° W. Little gas was encountered during development mining; large volumes of gas are encountered when roof falls. Most of the gas comes from strata above the mined coal; therefore, to control methane, roof instability must be controlled. Roof falls and high rates of methane emission are most likely where less than 30 feet of many thin layers of limestone, shale, and sandstone occurs between the Lower Kittanning coal and the next coal and in zones along the margins of a sandstone channel.

Jan 1, 1973

By George K. Schenck

This Bureau of Mines publication describes and evaluates a Standard Industrial Classification (SIC) based end-use data system for minerals that is designed to link the demand for minerals to economic activity in commercial uses. The new data system is two-dimensional. The first dimension of technical product classes (TPC's) measures the consumption of minerals in major primary intermediate products. The second dimension measures the consumption of these TPC's in SIC end-use sectors in sufficient detail to identify the major determinants of demand for each TPC. Intercomodity comparisons are achieved at the level of SIC two-digit major groups. The methodology was developed so that all available sources of information from Government and industry can be utilized at minimum cost. This information will be supplemented with additional data to be obtained by modifying existing Bureau of Mines canvasses so as to elicit additional quantitative responses from mineral producers. The new data system is expected to improve significantly the ability to forecast demand for minerals, and provide an information base that would, for the first time ever, permit resolution of such questions as trends in substitution among materials and the intensity-of-use of materials in end-use sectors. For the 42 TPC?s identified in the report, data are available for the new system from current sources or, except for three TPC?s that require new canvasses, can be obtained by modification of existing Bureau canvasses.

Jan 1, 1982

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions 5/ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1962

By A. G. Kim

Methane and other hydrocarbon gases, byproducts of coalification, are emitted from coal at widely varying rates and often present ventilation problems during mining. The air in some coal mines apparently contains no methane. To determine if coals from mines which bid no history of detectable gas emission contained adsorbed methane, samples of coal at the shaft bottom and at an active face were obtained and placed in sealed metal cylinders. The atmosphere around the coal was sampled and analysed by gas chromatography. Methane, ethane, ethylene, propane, propylene, and butane were found to have been desorbed from these coals. Hydrogen and helium were also detected. An estimate of the amount of residual gas per ton A coal indicated that coal samples from the active face generally contained more adsorbed gas than coal samples obtained from the shaft bottom, although in both instances the total amount of gas was relatively small.

Jan 1, 1973

By W. A. Calhoun

This report gives results of metallurgical investigations performed by the Bureau of Mines on mineral samples taken during April 1959, from Hawaiian bauxite deposits on the islands of Kauai, Maui, and Hawaii. The bauxite samples were tested at the Bureau's Rolla Metallurgy Research Center, Rolla, Mo., to determine if alumina could be extracted. The results were encouraging. Extraction of the alumina by the American Bayer type digest of crude ore samples from Kauai, Maui, and Hawaii recovered 78.8, 73.1, and 70.0 percent, of the total alumina, respectively. These recoveries were increased to 82.8, 85.5, and 79.5 percent by modifying the treatment, which consisted essentially of calcination and weak caustic desilication to provide a residue. The residue was then treated with calcium oxide and digested in a strong caustic solution to extract the alumina.

Jan 1, 1962

By M. Didyk

The final objective of a mine ventilation project is to find a way of supplying the working faces with the necessary quantity of air to dilute all the possible air contaminants to safe limits and to maintain the temperature, humidity and oxygen content within desirable limits. To accomplish the aforesaid, decisions have to be made at early stages of planning and design of a mining operation. That is, ventilation and mine planning are closely related and interdependent, and experience has proved that improvisation as related to mine environment is rarely optimal in ventilation engineering. Mine management should be concerned with two general aspects of ventilation problems. The first is related to the statuatory requirements which are usually the minimum standards that have to be maintained. During the last two decades, mining laws have become increasingly stringent and management of operating mines had to face the effects of these externalities. In some cases these required either a production rate reduction or additional mine development. The second aspect that management should not overlook is the technical and economical importance of mine ventilation on the overall mining cost. In coal mining it is necessary to move, on an average, five tons of air through the mine for each ton of coal produced. The power cost incurred is perhaps the single most important direct cost assigned to ventilation but it is not the only one. Other costs that should be considered include the supervisory labor cost, fan depreciation and maintenance, doors, stoppings and regulators construction cost and maintenance, the additional mine airways development and maintenance because of ventilation requirements. That is,

Jan 1, 1977

By Patrick J. Coleman, John C. Kerkering

Problem: Mining in the United States remains one of the most hazardous industries, despite significant reductions in fatal injury rates over the last century. Coal mine fatality rates, for example, have dropped almost a thousand fold since their peak in 1908. While incidence rates are very important indicators, lost worktime measures offer an alternative metric for evaluating job safety and health performance. The first objective of this study examined the distributions and summary statistics of all injuries reported to the Mine Safety and Health Administration from 1983 through 2004. Over the period studied (1983 2004), there were 31,515,368 lost workdays associated with mining injuries, for an equivalent of 5,700 person years lost annually. The second objective addressed the problem of comparing safety program performance in mines for situations where denominator data were lacking. By examining the consequences of injuries, comparisons can be made between disparate operations without the need for denominators. Total risk in the form of lost workday sums can help to distinguish between lower and higher risk operations or time periods. Method: Our method was to use a beta distribution to model the losses and to compare underground coal mining to underground metal/nonmetal mining from 2000 to 2004. Results: Our results showed the probability of an injury having 10 or more lost workdays was 0.52 for coal mine cases versus 0.35 for metal/nonmetal mine cases. In addition, a comparison of injuries involving continuous mining machines over 2001 2002 versus 2003 2004 showed that the ratio of average losses in the later period to those in the earlier period was approximately 1.08, suggesting increasing risks for such operations. Discussion: This denominator free safety measure will help the mining industry more effectively identify higher risk operations and more realistically evaluate their safety improvement programs. Impact on Industry: Attention to a variety of metrics concerning the performance of a job safety and health program will enhance industry's ability to manage these programs and reduce risk.

By C. R. Kuzell

This paper, describing the concentrator practice of the United Verde Copper Co., is one of a series being prepared by the Bureau of HISTORY The United Verde concentrator was constructed in accordance with recommendations based on certain novel reasons which were quite different from those usually justifying the expenditure of such an amount. Concentrator operations started in March, 1927, although the metallurgical staff had considered for several years the eventual addition of a concentrator department.

Jan 1, 1930

A compilation of papers presented at the Third WVU Conference on Coal Mine Electrotechnology in Morgantown, West Virginia, on August 4-6, 1976. Papers cover areas of electric power, electronic communications, detection and location of trapped miners, and electronic sensors and monitoring systems.

Jan 1, 1976

By O. C. Blade

The use of Diesel fuel as a source of power is continuing to increase in the United States. The latest available figures indicate that refineries are delivering in excess of 10,000,000 barrels of this type of fuel per month. Factors contributing to this increased consumption are conversions by a number of railroads from steam to Diesel locomotives and the growing use of Diesel engines in buses, trucks, tractors, earth-moving machinery, water craft, and stationary power plants. The increasing importance of Diesel fuel has led to a need for more information on its characteristics, particularly on the grades and qualities currently being marketed. To supply this information the American Petroleum Institute and the Bureau of Mines, United States Department of the Interior, under a cooperative agreement, are conducting annual surveys of Diesel fuels produced in refineries in this country. Samples of Diesel fuel were analyzed by the manufacturers in accordance with instructions from the Motor-Fuels Survey Panel of the Automotive Research Committee of the American Petroleum Institute. Results of the analyses were transmitted to the Bureau of Mines where the data were studied am compiled as shown in the tables of this report. The first survey was made in 1950 and was published as a Bureau of Mines report. The present report shows the results of a similar survey made during 1951.

Jan 1, 1951

By David E. Van Dillen

The computer program described in this user's guide provides for the static, three-dimensional, linear and nonlinear analysis of structural and geological systems by the finite element method. The guide describes the capabilities and general features of the program and shows how input is prepared. A number of recent advances in finite element theory and computer technology are incorporated in the program. Nonlinear material properties are provided for, including isotropic, anisotropic, and time-dependent material properties, gravity loading, simulation of a sequence of excavation or construction, and a slip or joint element. The finite elements include beam, rod, axisymmetric and plane quadrilateral, hexahedron, thick shell, axisymmetric and plane joint, and a three-dimensional joint. The program also has an automatic mesh generator to minimize user input preparation for continuum finite element meshes.

Jan 1, 1981

By I. Liebman

The Bureau of Mines conducted experiments on coal dust explosion suppression. The investigation took place on a beltway in the double-entry of the Bureau's Experimental Mine. Using conditions that simulate those in a working mine, the investigation showed that a coal dust explosion can be readily initiated in a conveyor belt entry. Also, the explosion can spread into adjacent entries through opened crosscuts (stopping destroyed by explosion) to propagate for long distances even though the adjacent entries are rock dusted in compliance with regulations. Passive water barriers (water-filled tubs) were found to be effective in suppressing explosions on a beltway; however, barrier efficiency was reduced by opened crosscuts. The study indicated that the beltway barrier should be the distributed type consisting of continuous rows of water-filled tubs covering long distances along the entry. A plan is outlined for the installation of a water barrier system in a working coal mine for the protection of a beltway.

Jan 1, 1981

By E. J. Gleim

A list of permissible mine equipment, tested and approved by the Bureau of Mines previous to January 1, 1942, was published in Bureau of Mines Information Circular 7207.3/ The list of that date was complete as to equipment then available and in current use. Information Circular 7240,4/ published as a supplement thereto, listed equipment approved curing the calendar year 1943. The present list is another supplement covering approvals issued during the calendar year 1943. The items are numbered to indicate the consecutive order in which each type of machine or device was approved in its particular classification. Thus, Information Circular 7207 gave 19 drills and drilling machines on the Bureau's active list. No additional approvals were given in 1942, but the three issued in 1943 bring the total to 22. Item 102, under Loading Machines and Conveyors, also appeared in Information Circular 7207, and items 120 and 124 appeared in Information Circular 7240. These numbers are repeated here to show that approvals were granted during 1943 for additional voltages on machines previously listed for one voltage only. Equipment listed in these circulars is approved by the Bureau of Mines only when found upon inspection and test to comply with minimum standards of safety as outlined in schedules prepared on the basis of many years of experience in dealing with safety problems of the coal-mining industry. The use of such equipment in mines known to be gassy, as well as in those that may become so, is earnestly recommended in the interests of safety. This circular is published so that the industry may be kept

Jan 1, 1944

By C. A. Geffen

This report, sponsored by the U. S. Bureau of Mines, presents the results of an examination of the safety of the impactor shaft sinking system in comparison to conventional shaft sinking technology. Detailed study of the impactor system was also performed to identify and recommend design changes for optimum safety conditions. A comparison of the impactor machine and its support systems with conventional shaft sinking was made on the basis of relative risk levels. Risk incorporates measures of both the frequency and the potential consequence of accidents. A safety evaluation of the com¬ponent operations of the impactor shaft sinking system was performed using a Failure Modes and Effects Analysis (FMEA) methodology. The results of this analysis show generally that the impactor shaft sinking system is safer than conventional shaft sinking. The potential risk of conventional shaft sinking operations could be reduced by an average of over 35 percent with use of the impactor shaft sinking system. Design change recommendations to further improve the safety of the impactor system include a revised fire suppression system, improved access to and from the operator cabs, reliable noise attenuation measures and improved communication systems. An operational safety manual was also developed for the impactor shaft sinking system.

Jan 1, 1982

Norton Co., the world's largest producer of abrasives, is enlarging its proppant operation. Proppants are strong chemical particles used to wedge open rock formations in deep oil wells, thereby increasing the well flow rate, sometimes as much as tenfold. Norton" aluminum oxide-based proppant is rapidly displacing less durable materials. The company is building the world's largest proppant plant in Fort Smith, AR. ALUMINUM--See also REFRACTORIES The price of primary aluminum ingot was increased by several producers in July. Kaiser Aluminum & Chemical Corp., and Revere Copper & Brass Inc. increased the price of primary aluminum to 63.0 cents per pound, effective July I. Reynolds Metal s Co., Anaconda Aluminum Co., Howmet Aluminum Corp., and Marti n Marietta Aluminum Inc. increased the price of 99.5% primary aluminum ingot to 63.0 cents per pound, effective July 5, The Aluminum Company of America increased the price of aluminum ingot to 62.5 cents per pound, effective July 9. The range of prices at the end of the month was 58.5 to 63.0 cents per pound.

Jan 1, 1979

By E. Chin

The Asia and the Pacific region has large mineral resources of antimony, barite, bauxite, bismuth, copper, fluorspar, gold, graphite, iron ore, magnesite, mica, rare earths, salt, talc and pyrophyllite, titanium, zinc, and zirconium. The region overall lacks large resources of oil and natural gas, but it has large resources of anthracite and bituminous coal. In terms of exploitation, many minerals, metals, and fuel are produced in significant quantities in the Asia and the Pacific region as shown in table 1. Collectively, the area accounts for a substantial amount of the world production of antimony, barite, bauxite, fluorspar, gold, graphite, ilmenite and rutile, iodine, iron ore, lead, magnesite, manganese, nickel, salt, tin, tungsten, and zinc. Total coal production of the region exceeds 1.6 billion metric tons. The production of bituminous coal accounts for more than 80 % of the total output. China is the region's largest coal producer, with an output of almost 1.1 billion tons. Other major producers are Australia and India. The combined production by Australia, China, and India is more than 1.5 billion tons or 93 % of the area's output. The remainder of the coal output in the region comes from Afghanistan, Cambodia, Indonesia, Japan, the Korean peninsula, Malaysia, Mongolia, New Zealand, Pakistan, the Philippines, and Taiwan. The production of crude oil throughout the Asia and Pacific region is close to 2.4 billion barrels. China and Indonesia together account for 67 % of the total output. The remainder of the output is primarily from Australia, Brunei, India, and Malaysia. Indonesia is the largest producer of natural gas in the region with an output of close to 58 billion cubic meters, followed by Malaysia and Australia with 23 and 22 billion cubic meters, respectively. Other producers in the region of lesser stature by output include Brunei, China, India, and Pakistan.

Jan 1, 1993