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By R. H. Church, William E. Webb, Walter E. Pittman, James R. Boyle

As part of the Bureau of Mines health and safety research program, a short-range locator system, capable of locating miners who have become trapped following a mine accident, has been devised, The system consists of a lightweight, low-power radio transmitter incorporated into a miner's cap lamp battery and a directional receiver carried by rescuers. Prototype transmitters have been constructed, and the propagation of their signals has been investigated, The detectability of the signal in underground coal mines has also been investigated, This research indicates that a short-range location system would serve as an economical and practical means of locating miners from within the mine following an accident,

Jan 1, 1984

By Eugene A. Lang

Mr. Chairman, ladies and gentlemen. As a member of the uranium and coal producing community, I am pleased to participate in a session dedicated to a look at these and other mineral markets.(title slide) before sharing some of my thoughts with you, let me tell you a little bit about rocky mountain energy company. It was established as a subsidiary of union pacific corporation in 1971 with responsibility for coal, uranium, and industrial minerals. We participate in four coal mining operations and a uranium mine and mill all in Wyoming, and an aggregate and an abrasive operation in Utah.

Jan 1, 1984

By K. C. Misra, W. Wrightson Jr.

The Lick Fork prospect shows appreciable nickel sulphide mineralization in a narrow, steeply dipping, layered sequence of metamorphosed hornblende peridotite, gahhro and hornblende gahhro, intrusive into the Pedlar Formation (charnockitic pyroxene granulite) of the Virginia Blue Ridge Complex (Precambrian). Rocks of the intrusion have equilibrated to granulite- facies metamorphism, as indicated by pervasive polygonal texture of silicate aggregates, development of biotite- and hornblende-preferred orientation, compositional equilibration of the silicate minerals, the Mg-Fe2+ (orthopyroxene-dino- pvroxene) distribution coefficients (average 0.57), (MgO + FeO + Fe20 3)/Al20 3ratios in orthopyroxenes, and Ti contents and AI(i\)/A I(\i) ratios of hornblendes. The sulphides, consisting of pyrrhotite-pentlandite (with up to 4 wt% Co)-chalcopyrite-pyrite-marcasite-violarite- bornite—mackinawite, are virtually restricted to the ultramafic unit of the intrusion and constitute 20-30% of the samples of hornblende peridotite studied. Although the basal accumulation of the sulphides may suggest magmatic segregation, sulphide- silicate textures typical of sulphide liquid immiscibilitv are not present, even in the sparsely mineralized gahbro units. On the other hand, the transgressive and relict textures are strongly suggestive of replacement of the silicate minerals by sulphides. These include chaleopyrite ± pyrrhotite ± pentlandite (violarite) ± pyrite ±magnetite veins crosscutting silicates, sulphide penetration into silicates at silicate-sulphide contact zones, rounding of silicate grains against sulphide matrix, and islands of silicate minerals (olivine, hornblende, pyroxene, biotite) in sulphide masses. Metamorphic mobilization of pre-existing sul­ phides is a possibility, but involvement of post-metamorphic, hydrothermal fluids is suggested by the following features: paucity of annealing and deformation textures in the sulphides, replacement of metamorphic and deformed silicates, lack of differential sulphide mobilization and the common occurrence of sulphides along grain boundaries and triple junctions of poly gonal silicate aggregates. The consistent association between sulphides and hydrothermal alteration products of silicates suggests that they are cogenetic. The hydrothermal fluids may have merely mobilized and concentrated the pre-existing, disseminated, magmatic sulphides, or there may have been significant addition of sulphides during this process. This question cannot be resolved unequivocally with the existing data.

Jan 1, 1984

By D. R. Maneval

The Surface Mining Act of 1977 required a study by the National Academy of Sciences regarding the special mine reclamation requirements of Alaska. The status of mines operating and planned in Alaska will be presented. New mines opening in Alaska must establish a baseline inventory of plants and animals in the mine site area as well as determine pre-mining air and water quality. Current work in these areas will be summarized. Reclamation practices in Alaska and other Arctic countries as practiced currently will be described. A summary of current research in Alaska dealing with revegetation on surface mined lanais, re-establishment of animal populations, and water treatment processes necessary in this pristine environment will be discussed. Included will be future predictions of the direction of mine reclamation in Alaska as more mines enter the industry.

Jan 1, 1984

By Terry A. Rightnour

Multiple seam mining is predominant throughout the central Pennsylvania Appalachian coal fields. Wide ranges in individual seam thickness, coal quality, and overburden characteristics are common throughout the region. On typical mining permits, ranging from 404 x 103 to 2023 x 103 m2 (100 to 500 acres), often as many as eight seams are concurrently mined, with each interburden requiring unique economic and environmental consideration in the mine plan. Specifically, this paper presents several planning tools and operational guidelines developed in response to current regulations for the special handling of potentially acid-forming materials as they are related to development and operation of multiple seam mines.

Jan 1, 1984

Provide an inexpensive, remote actuated, stench-gas system which reduces fire warning time to underground work locations. Approach A mine's pager phone hard-wire network is used to release stench gas from pressurized canisters located near working areas. The release is initiated by placing a coded message into a control phone at some central location. How It Works Currently, in most mines, the decision to release a warning stench gas is made by mine management after communication from the mine of a fire or similar potentially dangerous situation. Stench gas is then released into the ventilation air and/or compressed air lines for dissemination throughout the mine. This can result in significant delays in warning time. Often, surface personnel must travel to distant shafts, or other release points, wasting valuable time. Also, the time for ventilation air to circulate from the surface to working locations can be long and the effectiveness of compressed air as a stench transport agent depends on whether the compressed air is being used at the face. The Bureau of Mines, through a contract with MSA Research Corporation, has designed and tested a warning system which avoids these problems. The system consists of multiple, pressurized stench-gas canisters located under-ground in the mine-ventilation network so as to provide quick dissemination of the released stench gas to working areas. Each stench-gas canister is hard-wire connected to a nearby pager phone and from there to a control phone at the surface or at a central in-mine site. In the event of a mine emergency, the canisters are activitated to release stench gas by placing a coded message into the control phone. A low amperage Signal sent from the control phone to the receiver phone closes a relay, which activates a release mechanism on the canister.

Jan 1, 1984

By F. J. Prokoski

The COALSTAR Project, which operated from November 1981 to December 1982, was a research and development project aimed at providing a reliable and inexpensive means of monitoring various waste site conditions via the GOES satellite system. The GOES system provides data transfer from unattended isolated sites where neither power nor telephone lines exist. The reliability and resolution of the data received while using the satellite link were excellent; however, the site instrumentation gave considerable trouble. The disastrous failure of a large coal waste embankment in 1972 led the Bureau of Mines to undertake a comprehensive program to reduce the likelihood of such an occurence again. Part of this program involved the installation of instruments to monitor the stability of a specially-selected embankment operated by Armco Incorporated near Montcoal, West Virginia. Initially, the instruments were monitored by normal telephone lines and used normal commercial power from the local utility. The project described here was initiated to replace this monitoring system with an unmanned, solar-powered data collection system which transmitted data via satellite to a central computer facility. The satellite data network is the National Earth Satellite Service of the National Oceanic and Atmospheric Administration.

Jan 1, 1984

By Stephen C. Blair

Laboratory permeability measurements at elevated pressure and at temperatures ranging from 20º to 150°C have been conducted on samples of Ironton-Galesville sandstone. The purpose of this testing was to identify and characterize important physicochemical processes occurring in association with the injection and withdrawal of heated ground water at the U.S. Department of Energy's Aquifer Thermal Energy Storage (ATES) field site in St. Paul, Minnesota. Results indicate that permeability decreased significantly as temperature was increased and that dissolution of the dolomite and silicate cementing agents and accompanying changes in mechanical properties may occur in the heat storage aquifer at St. Paul. Further, loss of permeability with temperature in laboratory samples may be caused by the change in the mechanical structure of the sample. Tests at ambient temperature to evaluate the effect of particle migration under conditions of reversed flow indicate that this process will not significantly impair formation permeability at the St. Paul site.

Jan 1, 1984

By Dwain K. Butler

INTRODUCTION Characterization of a site for the prediction and simulation of dynamic events requires the determination of mechanical properties of the rock at stress/strain levels and rates and at a scale appropriate for the events and critical structures involved. The structures of interest can be on the surface, underground, or designed to impact and penetrate into the site (projectiles). Dynamic events of interest are equally diverse: seismic waves from distance earthquakes or explosions; close-in phenomena associated with earthquakes and explosions; vibrations associated with heavy equipment or machinery; and stress transients associated with impact and penetration. The complexity of site characterization depends on two factors not specifically related to the nature of the site itself: the stress levels generated by the dynamic event and the sophistication of the prediction and simulation techniques. For very high stress levels, such as occur near a nuclear detonation, and for low stress levels, such as occur during seismic wave propagation, site characterization is simplified, and often certain details of the site are not particularly important, such as shear strength variations in the case of very high stress levels. In the intermediate stress range, however, all descriptive relations are non- linear, a complete finite strain constitutive model is required, and all details of the site, such as lithology and fracture distribution, become important. The site characterization must be complete enough to support the most sophisticated prediction and simulation technique that will be applied to the analysis of the dynamic event. The procedures of site characterization are illustrated in this paper by a specific dynamic event, projectile impact and penetration, and a specific site, an outcrop of Dakota Sandstone near San Ysidro, New Mexico. The structure of interest was the projectile itself: nominally, 1.5 m in length, 0.165 m in diameter, 180 kg

Jan 1, 1984

By D. V. Krefting, D. R. Bennett

"The Cyprus Anvil Mining Corporation established a lead-zinc mine and concentrating plant at Faro in Yukon Territory in 1969. Following some 12 years of continuous operation from a single pit adjacent to the concentrator, the company decided to expand operations into two additional areas on the Vangorda Plateau. The two new deposits, known as Grum and Vangorda, are located some 15 kilometres from the existing concentrator.Confirmation of mining feasibility was followed by determination of the most practical and economical method of transporting the raw ore from the new mine sites to the existing concentrator. This analysis was carried out in two phases. The first phase reviewed the feasibility of alternative transportation systems on an 'order-of-magnitude' cost basis. This work identified systems worthy of more detailed examination. The second phase examined the preferred alternatives in greater detail.Initially, operating principles and parameters were established and catalogued. Then, based on these criteria, complete systems were developed utilizing alternative modes of transportation . In the overview analysis, some transportation modes were judged impractical and discarded, 'order-o f-magnitude' costs were developed for other systems and the most costly were eliminated . In the detailed study, the favourable systems were examined in depth which required development of accurate capital and operating costs, consideration of environ- mental impacts and an assessment of intangibles associated with the operation of a new development."

Jan 1, 1984

By Manuel R. Lastra

Critical to successful dump and heap leaching for gold, silver, copper and uranium are factors such as permeability, solution delivery to the ore, and solution recovery. This paper deals with possible techniques for successful accomplishment of these three factors. New developments as well as older techniques are discussed, together with rationale for use of some techniques in reference to others. The authors hope to present a checklist so that the ideal application to individual mine situations can be achieved. This involves a discussion of the merits of each different method and the situations for most logical application. It is hoped that such discussion will broaden the geographic areas where dump and heap leaching can be applied to include greater winter cold and tropical regions of large amounts of rainfall.

Jan 1, 1984

By John D. Nelson

Unprotected uranium mill tailings impoundments can pose a significant risk to nearby inhabitants and the surrounding environment in the event of a prolonged or catastrophic release of contaminants contained in the tailings. As a result of this potential, reclamation plans for such facilities must include engineering designs to protect against disruption of the tailings and the potential release of radioactive materials. The goals for such engineering designs should be to provide overall site stability for long-term periods with no need for planned ongoing maintenance and to provide a repository for the tailings that will not place a burden on future generations. Although the goal is to provide a maintenance-free system that does not require monitoring, it must be recognized that some period of surveillance would be reasonable. The surveillance period could be relatively short and only needs to assure with reasonable confidence that the reclamation scheme that was implemented is functioning adequately. An investigation was conducted by Nelson, Volpe, Wardwell, Schumm and Staub (1983) entitled Design Considerations for Long-Term Stabilization of Uranium Mill Tailings Impoundments (NUREG/CR-3397). This report assesses the degree of confidence with which long-term reclamation plans can be expected to remain effective over specific periods of time, and to assess the additional effort required to extend the design period from one long-term period to a longer one. This paper presents a summary of that investigation and discusses some of the important conclusions.

Jan 1, 1984

By C. H. Pitt

A jet slurry apparatus has been constructed to test corrosive/erosive wear properties of grinding ball metal. Plain high carbon steel heat treated to a hardness of about 60 RC was used. Slurries of quartz and chalcopyrite ore concentrate were used as the jetting media. Weight loss due to pure corrosion was determined by the linear polarization technique and weight loss due to pure erosion was determined by jetting while cathodically protecting the sample. By comparing the total weight loss with the sum of the weight losses from pure corrosion and pure errosion it was found that there was a synergistic effect between corrosion and erosive wear. Erosive wear rates are given as a function of pH and mineral type.

Jan 1, 1984

By Paul R. La Pointe

GEOTECHNICAL OBJECTIVES OF UCG PROGRAM Underground coal gasification (UCG) is one of several in situ extraction technologies for utilizing deep, otherwise unmineable coal. This technology involves the injection of air or oxygen into the target coal seam, ignition of the coal and recovery of product gases. Geotechnical characteristics of the coal and enclosing rock strata strongly influence the success of this Process. The flame front follows the coal cleats (Hill, 1979), and cleating and bedding control the manner in which coal collapses into the cavity, thereby affecting recovery efficiency (Ramirez and others, 1982). Moreover, coal seams typically behave as fracture dominated aquifers in which cleat orientations govern subsequent contaminant dispersal. For these reasons, the Anaconda Minerals Co. undertook a detailed study of fracturing within the Wyodak-Anderson Coal in the eastern Powder River Basin (PRB) near its Rocky Hill UCG test site (Fig. 1). STRESS HISTORY AND FRACTURING IN THE POWDER RIVER BASIN Vertical jointing, or cleating, in coals may arise from shrinkage shortly after deposition under low confining pressures, or later in time, soon after burial but after the coalification process is well advanced (Ting, 1977). There is much evidence to support the formation of cleating after coalification (e.g. Hawkes and Mellor, 1970; McCulloch and others, 1974), which suggests that the stress state existing at that time strongly influences cleat formation. McCulloch and others (1974) argue that the typically better developed face cleat forms parallel to the plane containing [ol] and [o2]. Where the relation between cleats and stess has been studied (McCulloch and others, 1974; Stone and Snoeberger, 1977; Ward, 1977; Kulander and Dean, 1978), the highly systematic face cleat strongly parallels the [o1] direction. Stone and Snoeberger (1977) report face and butt cleat measurements of N70E and N29W for the Felix Coals 220 m stratigraphically above the Wyodak at the Hoe Creek UCG site (Fig. 1). Structural trends also indicate the past state of stress in the PRB. Glaze and Keller (1963) suggest that the NE-SW regional compression during the late Permian formed major N-S fold lines and basement magnetic anomalies. Mapel (1959) describes folds having N60W and N30W rends in the northern PRB, as well as a large normal fault trending northeast. Glass (1976) also describes normal faults trending northeast. Similarly, Olive (1957) mapped normal faults

Jan 1, 1984

By Charles E. Joachim

Railroad and blast induced vibrations were measured in the vicinity of the proposed Big Bend Cutoff. Peak horizontal and vertical particle velocity relations were developed using least squares regression analysis. The dominant frequencies of these data are in the range of 30 to 50 hz. Therefore, allowable charge weight per 30 msec delay curves were generated for buildings (2 in./sec) and unlined tunnels (8 in./sec). A blasting contour map is presented for this site.

Jan 1, 1984

By R. G. Stickney

INTRODUCTION The Basalt Waste Isolation Project, conducted by Rockwell Hanford Operations under contract to the U.S. Department of Energy, is assessing the feasibility of the disposal of commercial radioactive spent fuel/high-level waste in deep geologic formations in basalts beneath and within the Hanford Site in southeastern Washington State. The Basalt Waste Isolation Project mission is to identify and characterize a potential geologic repository site in basalt and to develop associated facilities and technology required for the potential permanent isolation of radioactive wastes in basalt formations. In support of the Basalt Waste Isolation Project, a laboratory testing program was conducted to evaluate the performance of the Council for Scientific and Industrial Research's "Doorstopper" biaxial strain cell. To support site characterization studies and the design of repository openings, in situ stress measurements will be conducted within the reference repository horizon (~970 m). The Doorstopper is one of the instruments being considered for use in these measurements. It was selected because it requires only a small volume of work to achieve stress relief, which is important in a closely jointed basalt. Also, test durations are short, permitting a large number of measurements to be made within a given time to increase confidence in the results. Within the reference repository horizon, temperatures are expected in the range of 40º to 60°C with a humidity of up to 100%. For this testing program, test conditions were selected to closely resemble those expected within the repository horizon. The Doorstopper test, mainly developed by Leeman (1964), is a strain rosette relief method of measuring rock stress in situ. The Doorstopper consists of a four element, 45º strain gage rosette

Jan 1, 1984

By Keith G. Wallace

The effect of face resistance on ventilation air leakage through stoppings was measured in a twin development heading. Face resistance was varied by alternately tightening or loosening the face line brattice to change the line brattice leakage. Results indicated that tight brattice lines are necessary to maintain acceptable airflow at the face but result in higher leakage throughout the entire system, reduced overall ventilation efficiency, and higher operating costs. Conversely, a low face resistance which simulated an auxiliary fan/duct system gave reduced stopping leakage losses, higher quantities of air at the last open cross-cut and greater entire system efficiencies

Jan 1, 1984

By Jan Wolski

Increasing interest in the Bucket Wheel Excavator (BWE) technology calls for a universally understandable definition of suitable performance factors which would reflect the unique features of this technology. The importance of properly designed and calculated performance factors for the BWE systems cannot be overemphasised. They are used by all levels of management in any mining organization for a wide variety of purposes, in particular for budgeting, for selecting new equipment, for monitoring current equipment and for comparison with other operations.

Jan 1, 1984

By D. Kovachevich, M. A. Pfeifer

"A t remote locations typical of mines and associated ore processing plants, diesel electric generators are ideally suited for power plants due to their inherent operating flexibility, efficiency and reliability. In recent years rapid escalation in fuel and related transportation costs has made extensive waste heat recovery from generating sets financially attractive to a much greater extent than previously.The paper outlines key considerations during planning and design stages for utilizing the various waste heat sources available to best advantage. Based on two /980 mining projects built in the Canadian Arctic, data is presented on potential operating and capital costs savings. A review of heat balances, engineering flow diagrams and major equipment selections for process and building heating systems utilizing waste heat is included.IntroductionResource projects increasingly occur in remote areas requiring on-site self sufficiency in electrical power generation. For such projects, the low- or medium-speed turbo-charged diesel engine is very often the preferred choice as a prime mover for the generating sets . It is inherently reliable, has good response to load changes and has comparatively high fuel efficiency over a wide load range . From a project execution standpoint, It is capital cost- competitive and procurement lead-time normally ' fits ' within tight schedule constraints. In addition, its potential for waste heat recovery is excellent , particularly in northern climates where space heating requirements are usually substantial, and also where there a re requirements for heat for process and plant services.The high cost of fuel , with add-on transportation costs , provides a major incentive to fully exploit the available waste heat recovery potential o f such installations.As a result of the rapid escalation in the price of petroleum products following major crude oil price increases in 1973 and again in 1978-79, liquid petroleum fuels, having the desirable properties of comparatively high heat content and transportability, are no longer 'cheap' commodities and have become so valuable that industry has widely undertaken serious conservation efforts.Currently, it appears that petroleum cost trends of the 1970s may not continue, at least in the near term, and that we may see somewhat reduced energy costs for a time. In the longer term , and certainly within the life spa n of major projects, however, it is generally believed to be inevitable that these fuels will be increasingly expensive . Energy costs are today a major operating cost for remote minerals processing plants and will remain so for the foreseeable future.In order to meet the economic challenge posed by high energy costs, future projects should be thoughtfully planned from the outset with the goal of minimizing energy requirements and maximizing the use of waste heat recovery to meet such requirements. There is also considerable potential for significant energy savings by retrofitting of existing installations."

Jan 1, 1984

By C. Morrow

Deformation studies were performed on tuffaceous rocks fran Yucca Mountain, Nevada Test Site to determine the strengths and coefficients of friction under confining pressures from 10-50 MPa at room temperature. Frictional strengths of 30ºsawcut samples increased with pressure and reached values of around 150 MPa at the higher confining pressures. However, the failure strengths of the intact samples were quite unpredictable. The coefficients of friction ranged between 0.7 and 0.9 for all specimens. These data can be used in conjunction with in situ stress measurements at Yucca Mountain, to evaluate the potential for earthquake activity in the region.

Jan 1, 1984