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This work presents: 1.) the results obtained from measurements of temperature profiles in pillars and at working faces of three coal mines located in Colorado and New Mexico, 2) a comparison of the experimental results with theoretical predictors based on linear heat flow models, and 3) temperature profile predictions based on a two dimensional coal mine model with an inclined crack located in the roof or wall of the opening. The thermal properties of the coal and shale samples taken from the mines were used as input data for the computer model. Good agreement was found between the measured profiles and the theoretical values obtained with the one dimensional model. The two dimensional model results show that a visible crack (0.01-0.07-ft thick) in a coal roof causes a surface temperature difference from 0.2 to 1°F at the edge of the crack for rock exposed to air from 1 hr to 288 hrs and with the air to rock temperature differences from 2°-6°F. A temperature difference of 0.3 °F was found between solid and broken rock in a shale roof with a 0.03-ft thick crack inclined 45° to the horizontal after a ventilating time of 48 hrs and the air to rock temperature difference of 2.1°F.

Jan 1, 1972

As part of its research and development activities concerning coal mine operational/emergency communications sys terns, the Bureau of Mines commissioned several contractors to conduct electromagnetic (EM) noise studies and measurements that would aid the development of improved coal mine operational/emergency communications systems. The bulk of the noise studies and measurements were conducted in 1971. The Pittsburgh Mining and Safety Research Center (PMSRC) inherited the responsibility for monitoring the electromagnetic noise activities by mid-to-late 1971, and initiated a review and evaluation of the current and planned electromagnetic noise work. Arthur D. Little, Inc., (ADL) was asked by PMSRC to assist it in performing this review and evaluation by placing stronger emphasis on certain tasks of existing Contract No. H0122026. This technical memorandum report presents the findings, conclusions, and recommendations of our review and evaluation of the electromagnetic noise measurements of the five contractors we were asked to examine. Our review and evaluation effort included meetings and telephone discussions with technical staff of each contractor; serving as Technical Discussion Leader of a "Contractor's Round Table Meeting on EM Noise, Surface and Subsurface, Operating and Non-Operating Mines" called by the Bureau of Mines; examination and discussion of contractor reports and relevant open literature; sample verification calculations; and the documentation of our findings, conclusions, and recommendations by this report.

Jan 1, 1972

By Sandip K. Mukherjee

This report presents the results of the economic analysis of several applicable alternatives to increase airflow in four underground coal mines. Pressure-quantity surveys were conducted underground and measurements were also made at the main mine fan(s). The existing ventilation networks were modeled using the modified Penn State ventilation simulator. The applicable alternatives were simulated. Performance data obtained from these simulation runs were utilized to conduct the cost-effectiveness analysis. The costs for each of the alternatives included capital, operating and operating costs. These costs were expressed as annual ventilation costs per active section in terms of dollars per cfm taking into account the economic life associated with each of the alternatives. The benefits were expressed as increased airflow quantity in the critical sections. A section of this report also deals with comparison of simulator predicted air quantity values against air quantity values measured under-ground. This volume constitutes Volume II of the report and contains the outputs of the computer simulation runs.

Jan 1, 1983

By William L. Rice

This Bureau of Mines Open File Report on nickel is one of a series of minerals availability commodity deposit abstracts. Nonconfidential information from the Minerals Availability Program data base covering domestic and foreign nickel properties and deposits has been abstracted for use in this report. Abstracts include applicable data on location, published reserves and resources, geology, mine and beneficiation systems, and operation information.

Jan 1, 1984

By Virgil A. Marple

It was the purpose of this contract to conduct research in several different areas of instrumentation used to determine the quantity of respirable dust in the mining atmosphere. One area of research was in evaluation of instruments including several respirable dust monitors, several types of photometers, and a QCM cascade impactor. An instrument evaluation chamber was developed to aid in evaluating the instruments in a dust atmosphere. Another area of research was investigations into new instrumentation concepts, such as a virtual impactor/photometer instrument, a new optical device which can be used as either an optical particle counter or photometer, a new personal respirable sampler, which employs an impactor instead of a cyclone as a preclassifier, and the development of a new cascade impactor, which deposits the particles uniformly on the impaction plate. Another area of research included the use of many of these instruments in two field studies, including a silica sand plant and a tungsten mine.

Jan 1, 1981

By Steve C. Albrecht

The objective of this study is "to assess the impact of surface mining on soil compaction in the Midwest". The study revolves around a unique field sampling program targeted at four mine sites utilizing four distinct types of soil movement of midwestern prime land. Through the preparation of a final report for use as a guidebook, an assessment is made of the degree to which surface mining operations contribute to the soil compaction problem. The final report is formulated through the use of field study data as well as information gathered in an intense literature review. The final report centers on applying collected data to practical field applications. Soil sampling on the four mine sites centers on a comparison of natural and replaced soils for moist bulk density. This characterization evaluates changes in density and texture throughout the soil profile to a depth of 48 inches. Fertility of the topsoil is also assessed for natural and replaced soils. During field sampling and observations, a base of information has been gathered to compile a case study on each mine site. The report accesses the regulations in the prime farmland areas through the use of a matrix. The regulatory matrix allows easy access of mining personnel to State and Federal regulations.

Jan 1, 1982

By W. L. Cooley

The report provides a detailed analysis of 23 electrical accident countermeasures contemplated for use in the metal/non-metal mining industry. The costs and potential benefits of implementing groups of these countermeasures are estimated, and methods arc outlined by which the operator ran choose countermeasures in an effective manner. The analysis is based largely on an extensive electrical accident event tree which is developed in detail. For those countermeasures which are not currently technically feasible, several prototype devices were developed to help speed development. These included a trolley arc eliminator and a safer mine electricians multimeter.

Jan 1, 1982

The U.S. Bureau of Mines has been concerned for many years with the general problems of underground coal mining and the particular problems due to the methane content of the coal. The Bureau and others have worked diligently to improve the health and safety conditions for underground coal miners. It has been recognized for many years that the methane in coal would have some value if it could he recovered and used, Also its removal before coal mining began or during the mining cycle itself would make mining safer and more economic due to a potential saving in ventilation costs. The work covered in this report was carried out to review methods of removing methane from active and inactive regions of operating coal mines and to determine how the methane could be concentrated and utilized economically.

Jan 1, 1975

An evaluation of blasting procedures in surface mining operations was undertaken to determine means for improving safety. The objectives of the study were to: 1. Develop guidelines for safer blasting practices 2. Specify changes or additions in regulations concerning the use of explosives 3. Identify areas in which additional knowledge needs to be developed. As a basis for the evaluation, an idealized blasting cycle was prepared. Developed in the form of a scenario of surface mining operations, this synthesis of good mining practices served as the standard against which observed activities were compared. Blasting hazards were divided into two categories: those known to exist and those which are potential. Known hazards were identified in terms of situations which have actually resulted in explosives-related accidents. The evidence for known hazards was obtained primarily from MESA records of mine accidents. Potential hazards were identified by observation of mining activities and consultations with mining, explosive industry and government regulatory agency personnel.

Jan 1, 1977

By L. B. Phelps

A method is presented for the burial of potentially toxic spoil in high density zones or packages within spoil piles. Such burial could reduce the outflow of pollutants and thus minimize contamination of groundwater flows. Laboratory model studies using ammonium bromide tracer were performed to quantify the expected outflow mixing that could be achieved through package construction in spoils. Field drilling and geophysical density logging of spoils was carried out at three sites in Pennsylvania and Ohio to obtain a range of field spoil bulk density measurements and spoil samples. These data are analyzed to determine the relationships between spoil density and the controlling factors of lithology, depth, age, particle size distribution and mining method. A separate series of spoil permeability tests were performed in the laboratory to investigate the relationship between permeability and its related parameters. Research results are applied to the toxic package method to suggest guidelines for pack-age size, shape, density and placement for future field prototype development.

Jan 1, 1981

By Robert Torbin

The objectives of the Continuous Shaft Lining (CSL) System are to reduce the costs, safety hazards, and time currently required in lining mine shafts with concrete. The CSL will line machine bored shafts downward from the shaft collar on a continuous basis using an inverted, pressurized slipforming technique. The technique for slip-forming downwards has been demonstrated and refined under this program. The approach taken involved laboratory scale testing of key features of the CSL concept. These feature tests included concrete distribution, concrete sealing, concrete slipforming and development of a reliable concrete mix. Based on these results, a full scale above-ground test facility and CSL were designed and fabricated. The objectives of these tests were to demonstrate the viability of the basic concept; to establish operating limits; and to provide input data and information for the design of a second generation shaft lining system. The results of the program have led to a CSL design and operational philosophy which will need to be tested in an underground environment before industry will accept the technology. However, the next generation CSL promises to meet all the original program technical objectives.

Jan 1, 1983

By Floyd C. Bossard

Major air-cooling facilities have been installed and are operating underground in U.S. copper mines (at Butte, Montana and Superior, Arizona), South African gold mines, European coal mines, Zambian copper mines, Kolar gold mints in India, Coeur d'Alene mines of Idaho, plus other locations. Mining districts that utilize spot cooling and local air-cooling facilities would increase the above listing many times. The principal objectives of underground mine air cooling systems are to; 1. Extract heat and water vapor from the mine air and provide for their removal from the mine via (a) water pumped to surface or (b) discharged mine exhaust air. 2. Provide acceptable artificial ambient conditions for efficient working mine development and production areas. 3. Recondition used air, thus supplementing the limited mine ventilation balance. In deep South African gold mines, when rock temperatures exceed about 105°F, cooling of underground air becomes necessary for the poorly ventilated sections of the mine. By U.S. standards, air conditioning in poorly ventilated mines usually commences when the virgin rock temperature exceeds 100°F. On the other hand, well ventilated deep vein-type mines in the U.S. have been able to forego general cooling of mine air until the mines have been extended to such depths that the virgin wallrock temperatures have exceeded 115° - 120°F. It must be noted that spot-cooling of selected development headings may be required in many mines where rock temperatures exceed 100°F. Such local air-cooling practices permit the driving of long headings for exploration or extended development prior to holings which result in establishment of primary ventilation circuitry. The following summary reports on current practices of cooling and dehumidifying mine air. General system descriptions with important details will hopefully permit the reader to gain an understanding of the subject. A list of references is provided for this serious investigator who desires a more thorough knowledge-base and who is responsible for the design of a mine air-cooling system.

Jan 1, 1973

By K. J. Bathe

The current version of the computer program ADINA/BM (Automatic Dynamic Incremental Nonlinear Analysis for the Bureau of Mines) for linear and nonlinear, static and dynamic finite element analysis of mine structures is described. The complete report is divided into four parts. In Part A the program solution capabilities, the finite element library, the logical construction of the program and storage allocations are discussed. In Part B the theory and numerical techniques used in the program are summarized. In Part C brief problem descriptions and solution results for some sample solutions that have been transmitted as data cases with the program are presented. In the last section of the report, Part D, the users? manual of the program is presented. Program ADINA/BM is a general effective tool for coal mine structural analysis. The program is an extension of the computer program NON SAP (which was developed under an earlier contract with the U.S. Bureau of Mines). The important additional capabilities of ADINA/BM are: (1) the occurrence of all elements is time dependent, (2) all elements can be used in geometric and material nonlinear analysis, (3) the truss element can be used in elastic-plastic analysis, (4) the three-dimensional element can be employed in orthotropic, elastic-plastic and cracking and crushing analysis, (5) the program executes an out-of-core solution and thus allows the analysis of very large and complex coal mine models, (6) the truss elements can be employed as 2-4 variable-number-nodes elements, (7) a rock material model has been implemented, (8) displacement constraint equations can be imposed in the solution, (9) more flexibility in specifying the incremental solution strategy and an acceleration procedure in the equilibrium iteration are available

Jan 1, 1978

By William L. Rice

This Bureau of Mines Open Pile Report on cobalt is one of a series of minerals availability commodity deposit abstracts. Nonconfidential information from the Minerals Availability Program data base covering domestic and foreign cobalt properties and deposits has been abstracted for use in his report. Abstracts include applicable data on location, published reserves and resources, geology, mine and beneficiation systems, and operation information.

Jan 1, 2011

The investigation summarized in this report addressed two primary issues: the determination and use of correction factors, and the development of guidelines for velocity measurement site selection. Other ancillary issues which were addressed include a comparison of measurement methods and devices, aircourse cross-sectional area measurement, and characteristics of mine airways. An exhaustive literature search and analysis was performed; extensive in-mine experiments were conducted; a quantitative analysis of the data was used to develop correction factor tables and site selection guidelines. The reported results of other researchers who have examined the correction factors and site selection criteria, were analyzed in light of the results of this study. The measurement devices included in the experimental phase were: vane anemometer, vortex shedding anemometer, a prototype thermoanemometer, smoke tube, and, oil of wintergreen. The measurement methods include single-point centerline, timed¬-point traverse, continuous traverse for the anemometers, and various distances and cloud positions for the smoke tube and oil of wintergreen devices.

Jan 1, 1983

By P. J. Remington

Field measurements utilizing a seat pad accelerometer were made on 25 underground coal mining machines in order to quantify the vibration levels experienced by the operators. Those data were combined with information on the statistics of the operating times of those machines in order to compare the operator's vibration exposure to the criteria in ISO 2631, "A Guide for the Evaluation of Human Exposure to Whole Body vibration." The comparison showed that about 30% to 40" of all underground coal mining machine operators can be expected to be exposed to vibration exceeding the fatigue decreased proficiency criterion, whereas only 10 to 15% would be expected to experience vibration exceeding the exposure limit. The primary sources of the exposure are shuttle cars and possibly scoop trams. Detailed exposure statistics are presented and the implications of the results are discussed.

Jan 1, 1983

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment: including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that arc recommended in this document, but all of the panic bars are characteristically of the "fire door" type that is frequently encountered on outside exit doors of many public and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes are added to the face equipment machinery for which they arc required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in "Guidelines for the Design and Installation of Devices for Deenergization of Self-Propelled Electric Face Equipment/Automatic Emergency Brakes" by C. E. Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel al the various machine manufacturers and underground coal mines that we surveyed, discussions with G. L. Judy (our consultant), etc:

Jan 1, 1974

By A. Brown

This report details work performed and results obtained in a study of the water management aspects of oil shale mining and retorting in the Piceance Creek Basin. Three specific sites were investigated, and optimal water management systems for both conventional and in-situ extraction processes were generated. Water-related legal and environmental constraints on development were identified and the water management schemes were developed in compliance with these regulations. Limitations on shale oil production implied by limited water supplies were evaluated. Potential Basin-wide effects of development were evaluated using a computer model, and mitigation strategies were developed. Recommendations for additional investigation and analyses were presented.

Jan 1, 1977

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars are characteristically of the ?fire door? type that is frequently encountered on outside exit doors of many public and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes are added to the face equipment machinery for which they are required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in "Guidelines for the Design and Installation of Devices for Deenergization of Self -Propelled Electric Face Equipment/Automatic Emergency Brake s II by C. E. Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. L. Judy (our consultant), etc:

Jan 1, 1974

The panic bars (and associated linkage's and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on Self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars are characteristically of the "fire door" type that is frequently encountered on outside exit doors of many public and soma commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes are added to the face equipment machinery for which they are required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in 'Guidelines for the Design and Installation of Devices for Deenergization of Self-Propelled Electric Face Equipment/Automatic Emergency Brakes" by C. E. Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. L. Judy (our consultant), etc:

Jan 1, 1974