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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 Thomas J. Peters

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied a 17,320-acre portion of the 52,143-acre Little High Rock Canyon Wilderness Study Area (CA-020-913/NV-020-008) in order to evaluate its identified mineral resources. The study area is located in Humboldt and Washoe Counties, NV, about 42 miles north from Gerlach. Three areas of epithermal alteration, similar to alteration associated with disseminated gold deposits, were found in the study area. One of the areas occurs along a northeast-trending structural lineament. Southwest of the study area two gold prospects undergoing active exploration, as well JS a gold deposit being prepared for production, occur along the same lineament. The Bureau of Mines examination, however, did not find evidence for gold resources in the study area.

Jan 1, 1987

By William E. Sopper

Heat-dried municipal sludge was applied to a barren burned anthracite refuse bank in 1974. Sludge was applied at rates of 0, 40, 75, and 150 dry metric tons per hectare" Ten species of trees were planted and five species of grasses and legumes were seeded for evaluation. One plot was also irrigated with sewage effluent. The 150 t/ha sludge application rate produced the best overall herbaceous vegetation growth response. The 40 and 75 t/ha sludge application rates produced the best tree seedling growth response. Foliar analyses for trace metals indicated no phytotoxity problems. Analyses of leachate water at the three-foot soil depth indicated that the sludge applications did not impair water quality. Results of the study indicate that treated municipal sludge can be used to revegetate land disturbed by mining activities without adverse effects on the vegetation or water quality.

Jan 1, 1978

The principle activities of the Explosives Research Laboratory from July 1, 1961 to June 30, 1962, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1962; in general, the research reported in these publications antedates the report period. Part 3 gives the results of an investigation which, although too limited to warrant separate publication, merits presentation in some detail because of current interest in ammonium nitrate-fuel oil compositions.

Jan 1, 1964

By Thornton L. Neathery

Geologic investigation of a mineralized zone in eastern Alabama indicates that large quantities of talc and soapstone are scattered over a wide area close to the surface. Laboratory experiments show that this material may be upgraded to a high-quality talc. A market survey indicates that the talc deposits may be of current and long-range interest. The anthophyllite asbestos which is associated with the talc does not appear to occur in sufficient quantities to be considered as a primary commercial source.

Jan 1, 1967

By Bruce E. Stauffer

The report recommends criteria for the design of safe surface mine haulage roads. Information relevant to road design at surface mine sites delineates vertical and horizontal alignment; subbase and surface materials; drainage; cross-slope, superelevation; runaway vehicle protection; and road and vehicle maintenance criteria. An appendix Is included which details the study methods used in compiling the final report information. A bibliography following the main text lists literature referenced for the report data and which is available as a valuable tool for use by individuals involved in haul road design.

Jan 1, 1976

By David C. Uhrin

Two improved methods have been developed to transfer microfilmed mine maps to suitable base maps showing surface features. The methods provide for (1) positioning and orienting maps; (2) merging adjacent maps; and (3) plotting maps at a common scale. One method produces an overlay mosaic of mine maps using an Integrated camera-processor. This photographic method shows the details of mine workings and is most useful for specific limited-area projects. In the second method, outlines of mine maps are digitized, manipulated, and plotted as overlays using a computer. This computer method can plot mine outlines and spatially index large numbers of microfilmed maps. Microfilmed mine maps used in this Bureau of Mines study are on file in the Mine Map Repository of the Eastern Field Operations Center. The base maps are U.S. Geological Survey 7.5-minute topographic maps. The demonstration area is located in the New Kensington East and West quadrangles, Pennsylvania.

Jan 1, 1977

By T. T. Campbell

This investigation was undertaken by the Bureau of Mines to determine if high-purity ductile molybdenum of uniform quality can be prepared by bomb reduction techniques. Molybdenum trioxide (Mo03) and mixtures of molybdenum dioxide (Mo02) and trioxide were reduced by magnesium in closed steel bomb reactors. Very high pressures in excess of 5,000 p.s.i. developed during magnesium reductions of Mo03. The addition of calcium oxide to the bomb charges caused a significant reduction in pressure. Reaction efficiencies higher than 95 percent were obtained during magnesium reductions of either Mo03 or mixtures of Mo02 and Mo03, but high pressures were encountered when the charges contained from 30 to 60 percent Mo02. Reaction efficiencies were usually low (less than 80 percent) when the bomb charges contained more than 40 percent Mo02. The charges with the best composition considering operating pressure, yield, and purity contained from 10 to 30 percent Mo02. The addition of small amounts of carbon to the reaction charges was helpful because some deoxidation occurred during the reduction and also during subsequent arc-melting of the regulus metal. The purity of the bomb-reduced, arc-cast molybdenum metal ranged from 99.2 to 99.8 percent and in some instances the metal contained as little as 5 parts per million oxygen.

Jan 1, 1962

By Clark F. Grain

These investigations were undertaken as part of the Bureau of Mines program for the development and evaluation of high temperature nonmetallic materials. This report consists of thermal expansion and phase inversion measurements by high-temperature X-ray diffractometry on the principal oxides of beryllium (BeO), calcium (CaO), titanium (TiO2 ), zirconium (ZrO2 ), hafnium (HfO2), and thorium (ThO2); all were high-purity commercially available oxides. Thermal expansion values were calculated from unit cell dimensions measured at selected temperatures. Expansion was determined parallel to each major crystallographic axis for the anisotropic oxides: BeO, TOi2, ZrC2, and HfO2. Combined random and systematic errors in the thermal expansion values are considered to be less than 3 percent of the total expansion at 500° C. and approximately 2 percent at 1,000° C. No hysteresis in the expansion curves was noted between heating and cooling cycles. The Bureau's values were compared with published expansion measurements obtained by X-ray diffraction, dilatometric, interferometric, and telemicroscopic techniques. For anisotropic oxides, average linear expansion values were calculated from the volume expansion.

Jan 1, 1962

By Michael G. Zabetakis

The spillage of liquid diethyl ether in rooms at floor level and 3 feet above the floor resulted in flammable vapor-air mixtures in the immediate vicinity of the exposed liquido The liquid temperature was found to decrease by as much as 35° C., with a resultant decrease in vaporization rate. A search of the literature yielded numerous references to unstable peroxide (residue) formed by the autoxidation of ether. Such residues appear to constitute an explosion hazard in the condensed state.

Jan 1, 1962

By Daryl R. Tweeton

This Bureau of Mines publication ill scribes present practices of making injection wells for in situ uranium leaching. Casings, screens, drilling fluids, coring, logging, cementing, and developing are discussed with the objective of aiding those who are starting an in situ leaching operation. Improper choices of materials or techniques can result in wells that are either useless or wells that have an undesirably high resistance to injection. Important factors include careful selection of screen slot size, use of logs for choosing the cementing basket depth, proper cementing techniques, and careful choice, use, and flushing of drilling fluids. The information was obtained through observation of well construction and through discussion with in situ leaching companies, drillers, and suppliers.

Jan 1, 1978

By Clyde L. Holmberg, Paul Zinner

"INTRODUCTION In view of the large tonnage of low-grade iron ore and iron-bearing material known to exist at the western limits of the Gogebic range, the Bureau of Mines undertook an investigation of the area for the purpose of evaluating the iron-bearing formations as sources of iron for possible future utilization.After 6o years of exploration an, development on the Gogebic range, the area investigated by the Bureau represents the known western limit of direct-shipping ore mined from operations on the Gogebic range.An area about 2 miles in length between the villages of Pence and Iron Bolt in Iron County, Vic., was selected for investigation, and trenches wore excavated through the overburden and fully across the iron-bearing formation to obtain 108 bulk samples for beneficiation tests. Exhaustive tests involving gravity and flotation methods, magnetic separation, and magnetizing roasts followed by magnetic separation were conducted on the samples to determine the ammability of the individual formations and the entire iron-bearing zone to beneficiation.Empirical data on the character and mineral content of the formations arc tabulated herein, as well as the results of the beneficiation tests."

Dec 1, 1947

By Franklin D. Cooper

The value of nonfuel raw mineral production in the United States for 1977 increased over that of 1976 by 5%, from $16.7 billion to $17.5 billion. Metals declined by 5% from $6.1 billion to $5.8 billion, chiefly because of strikes in the iron ore industry and a depressed copper market. Subsidization of mining industries in some foreign countries accounted in part for the excess of copper and some other metals on world markets. Weak metal markets and continued slowdowns in the world economy were the main reasons of the virtual absence of new mine projects. Increasing domestic governmental involvement affecting mineral industry activities, such as pricing controls, public land withdrawals, and the Surface Mining Control and Reclamation Act, effective August 3, continued to be controversial and to be criticized by various segments of the industry.

Jan 1, 1980

By C. H. Larsen

The results of a comprehensive investigation of conveyance arrestment devices (safety catches) in United States coal mines are presented. Availability and use, performance, inspection, maintenance, testing, procedures, and regulatory requirements were investigated. Information was obtained from equipment manufacturers, mine operators, and regulatory-agency personnel, as well as from studies of domestic and foreign mining safety regulations. Traditional mine hoists and commercial elevators for mine use were investigated. Results of this and an earlier study of wire-rope practice in United States coal mines show a continued need for conveyance arrestment devices. A wide variety of these devices are in use. Only two types have been proved reliable for stopping a conveyance without injuring passengers or equipment. These are elevator overspeed-actuated wedge-clamp (Type B) safeties and broken-rope-actuated devices for wooden guides using a single-tooth-dog design developed in Ontario as a braking element. Elevators are widely used in U. S. coal mines. When maintained according to American National Standards Institute (ANSI) Specifications A17. I and A17. 2, they appear to present no major arrestment problems. Of 42 coal-mine hoists used for man transport that were inspected, 30 are in vertical and 12 in inclined shafts. Twenty-four vertical shafts use wood guides; 6 use steel. The 12 inclined-shaft systems use flanged-wheel T-rail guidance. Two wood-guided vertical-shaft systems use the single-tooth Ontario-type dog; the other 22 use multi-toothed wedges, cams, or dogs that have been proved highly unreliable. The arrestment devices in the six steel-guided vertical-shaft systems and in six of the inclined-shaft systems cannot be evaluated because performance data are lacking. The remaining six inclined-shaft systems have no arrestment devices at all. Of the 36 hoists with arrestment devices, the devices of 16 are never tested, the devices of 10 are actuated periodically with the conveyance at rest, and the devices of the other 10 are actuated periodically with a slow-moving conveyance. Although high speed is as probable as low speed in an emergency and would provide the best test of arrestment capability, no tests are performed in the United States which demonstrate the ability of an arrestment device to stop a loaded conveyance from high speed. Mine operators indicate little confidence in their conveyance arrestment devices, and manufacturers recognize a need to improve their products. Neither state nor Federal regulations provide a guide to this improvement. Mine operators, manufacturers, and state and Federal regulatory agency personnel would welcome specific guidance. In view of this, a set of application, design, actuation, stopping-performance, and testing and inspection criteria is presented as a guide to eliminating the inadequacies of these devices. Recommendations are included for improving hoist controls and machinery directly affecting conveyance safety.

Jan 1, 1972

By Robert Stefanko

This report, rather than attempting to replace previous annual reports, supplements, and more importantly, coordinates and summarizes the entire effort. Even with such restrictions, the report is voluminous and, therefore, a decision has been made to divide it into two parts. The first volume is basically narrative and includes tabular results and analyses. The second volume is in appendix form giving detailed information. Together, they permit a logical discussion of all aspects of the project (Volume I) without cumbersome distractions but, at the same time, provide all the details to permit others to evaluate and explain the results or develop similar research programs (Volume II). The aim of the original proposal was basically to develop instruments and techniques and then make measurements of suitable power parameters, ground fault currents and ground resistance beds. With such information available, it was possible to develop a meaningful simulator which would permit investigating electrical systems and components on paper without costly trial and error procedures in the third year, a cable splice testing program was added to the project. While there were the usual delays attendant in such original research, these objectives were achieved.

Jan 1, 1973

By William G. Pariseau

The research reported here concerns a four year study of the rock mechanics aspects of two underground hardrock mine study stopes. The first study was conducted at Anaconda Minerals Company's Carr Fork Mine near Tooele, Utah. The second study was conducted at the Homestake Mining Company's Homestake Mine In Lead, South Dakota. Both case studies were cooperative efforts of mining company personnel, the Spokane Research Center of the Bureau of Mines and the Department of Mining Engineering, University of Utah. Large diameter (6 1/2 In.) blastholes were an integral part of the stoplng method at each mine. A true vertical crater retreat (VCR) method was used at the Homestake Mine, while a vertical bench mining method (VBM) was used at the Carr Fork Mine. VCR and VBM methods were developed In the 1970's; they offer significant productivity gain and are now used throughout the world. The new technology, however, brings with It a requirement for more sophisticated engineering design and control. Since there are no personnel in a VCR or VBM stope, all ground control Including dimensioning of stopes and pillars and the layout of cable bolt assays or other artificial support must be done in advance of production blasting. Accordingly, the objective of the research study was the establishment of a procedure for optimizing stops and pillar sizes. The approach taken was In each case a combination of mine measurements of the study stope response to mining, laboratory testing for rock properties and In situ stress measurements of the premining stress field, and theoretical calculations of the study stope response to mining. All calculations were done with the UTAH-II finite element computer program. Simulation of the blasting sequence gave a correlation of 0.88 between measured and calculated extensometer readings (Incremental relative displacements) at the Carr Fork Mine where other 30 Instrumentation boreholes were used to monitor the test stope response. A correlation of 0.84 was obtained at the Homestake Mine where 19 instrumented boreholes were used for monitoring purposes. These high correlations validated the computer mode and calibrated It for rock mass properties. The calibrated model was then used In parametric studies of alternative design layouts.

Jan 1, 1985

By Maria I. De Rosa

High temperatures encountered by mine rescue teams during emergency situations may cause severe physiological strain, hindering the men from carrying out rescue and recovery missions. A prototype ice-cooling garment (ICG) was developed by the Bureau of Mines to alleviate physiological strain due to heat stress. The effectiveness of the garment was tested with acclimatized and unacclimatized subjects at a typical work rate (1,200 Btu/hr) expected during rescue operations and at various hot environments (97° to 113° F dry bulb and 80° to 89° F wet bulb). During exposures with the ice cooling garment, the subjects were able to maintain a safe deep body temperature of 100.4° F or below Without the garment, the deep body temperature rose beyond values of 100.4° F, a condition considered unsafe for continuous work in hot conditions. Both heart rate and skin temperature values were lower while wearing the ICG. Subjective observation also indicated a marked benefit by wearing the ICG.

Jan 1, 1976

By C. E. Wood

A special appropriation made by Congress in July 1940 provided funds for the investigation of methods for recovering manganese from low-grade [ ] domestic deposits. These funds were assigned to the United States Department of the Interior, Bureau of Mines. A committee, identified as the Technologic Committee on manganese of the National Research Council, National Academy of Sciences, was appointed to recommend the allocation of the funds for investigation of the more promising projects.

Jan 1, 1942

By W. J. Boone

The Bureau of Mines has programmed for publication a series of Reports of Investigations of studies it has undertaken on low-temperature phase equilibria of several helium-bearing natural gases. This report is the second of a series of papers of the same general title; it is anticipated that additional reports of this series will be published. The advent of a helium conservation program and the prospect of production of helium by private industry, make it especially desirable to publish these data. This report describes phase equilibria related to a natural gas that is processed for helium at the Bureau's Exell Helium Plant (located about 35 miles north of Amarillo, Tex.). Carbon dioxide and water in the gas were removed before making the study; hence the data obtained are representative of the gas stream immediately after similar preliminary treatment in the plant process. Phase equilibrium data were obtained for conditions from -50° to -275° F. and from 100 to 500 p.s.i.a. Analyses of samples were made as follows: For a given run at a selected temperature and pressure, samples of the vapor and liquid phases were analyzed by mass spectrometer, and an additional sample of the liquid phase was analyzed for helium by means of special apparatus (7). 4

Jan 1, 1962

Bahrain's oil revenue increased from $337 million2 in 1916 to $378 million in 1977. Despite the increase in value, petroleum receipts made up only 584 of all Government income in 1877, compared with 74% in 1976 and 83% in 1975. Bahrain became an oil producer in 1932 with the discovery of the Awali oilfield, and since that time, the Awali oilfield has produced over 600 million barrels of crude oil. Awali production in 1977 was 21.2 million barrels. Bahrain shares the revenue from the Abu Safah oilfield, located in the Persian Gulf north of Bahrain, equally with Saudi Arabia. Revenue from the Abu Safah oilfield was approximately $179 million or 47% of oil revenues in 1977. Output from the Abu Safah oilfield was 48 million barrels, an increase of nearly 30% over 1976 output. The Bahrain Petroleum Company (BAPCO). the nation's only oil-producing company, was owned 40% by California Texas Oil Corp. (CALTEX and 60% by the Govern¬ment. The Government established Bahrain National Oil Co. (BANOCO) in 1976 to administer the Government's share of BAPCO, oversee exploration concessions, and manage domestic marketing of petroleum products. The Government announced its intention to acquire 100% control of crude oil and natural gas production. CALTEX was to retain complete control of the 250,000-barrel-per-day oil refinery near Sitrah.

Jan 1, 1981