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By Mark P. Meyer

A mineral investigation of the Chugach National Forest, Alaska was conducted jointly by the U.S. Geological Survey and the U.S. Bureau of Mines from 1979 to 1983 as part of the RARE II program. The U. S. Geological Survey remapped the geology and distribution of mineral resources. The Bureau investigated mines, prospects, and mineral occurrences. Previously unreported mineralization in three areas, Long Bay, Wells Bay, and Miners River were discovered in the western portion of the SOUND study area. Copper, lead, zinc, gold, silver, nickel, cobalt, fluorite, and arsenic were found in north-northeast to north-northwest trending shear zones, veins, felsic dikes, and granitic intrusives in Tertiary Orca Group metasedimentary rocks.

Jan 1, 2011

By Donald O. Capstick

A mineral survey of a 5,700-acre portion of the 11,510-acre Upper Deep Creek Wilderness Study Area (ID-111-44B) in southwestern Idaho was conducted by the U.S. Bureau of Mines in 1985. No mining claims have been located, no minerals have been produced, and no resources have been identified in the study area. Three reconnaissance samples of alluvium from the Deep Creek drainage contained $0.21, $0.22, and $2.72 per cubic yard in placer gold, higher than usual for the Owyhee River canyonland area. The samples of near-surface material contained very fine gold in values too low to support large-volume commercial placer operations, but the quantity and size of the particles of gold in the alluvium is expected to increase near bedrock. Consequently, the area may be a target for recreational as well as small commercial suction dredge operations. The physical characteristics of the individual pieces of gold (bright and angular) indicate that it may have recently come from an unidentified nearby source.

Jan 1, 1986

The Objective: To reduce the noise generated by the exhausting air from a pneumatic roof bolting drill to a maximum of 90 decibels. Any attachment used for this purpose must be lightweight and must not cause a significant increase in back pressure. The Approach: Absorb the noise with a properly designed muffler that will permit sufficient airflow without affecting the normal operation of the drill. How It Works: The air exhausted by the drill enters the muffler through perforated disks into a resonator chamber. It then passes through a series of expansion and contraction chambers and is expelled to the atmosphere through another perforated disk. The basic muffler design for the pneumatic drill was established by using both digital computer analysis and experimentally simulated noise tests. The measured parameters used in the computer program consisted of inlet and outlet pressures, temperatures, airflows and exhaust areas. United

By R. Barany

This report contains the results of experimental work conducted by the Bureau of Mines to obtain the heats of formation at 298.15° K. of analcite, dehydrated analcite, lawsonite, anorthite, hexagonal anorthite, and leonhardite. Thermodynamic data for these minerals have applications in ceramics, extractive metallurgy, and particularly in geochemistry. Except for data on anorthite, no previous similar data existed. The present results will be a substantial aid in deriving the temperature-pressure-equilibrium relationships among these minerals. The heats of formation were determined by solution calorimetry, with hydrofluoric acid as the reaction medium. The results were expressed both in terms of the constituent oxides and in terms of the constituent elements. The heat of formation data were combined with related entropy values to obtain the free energies of formation at 298.15° K.

Jan 1, 1962

By T. A. Raczek

Materials for stronger ventilation tubing for underground use in hardrock mines were developed. The new material composites were evaluated in performance characteristics and compared to currently used materials. The materials were compared on tear, tensile, puncture and flammability properties. Based on cost versus performance data, a polyester film bonded to a polyester fabric was selected as the candidate material for field testing. Ventilation tubing fabricated from the selected material was field tested in two underground uranium mines for four-month periods. The test results indicated that the new composite showed an increase in useful life in the majority of applications, However, the cost performance ratio was not significantly improved to warrant commercialization of the product. When connected directly to some blowers, the material in close proximity to the blower deteriorated. However, material which was punctured or torn by mechanical means did not have further propagation of the tear. The high tear strength of the material prevented further damage. Improved methods of repairing inflated ventilation tubing were investigated and developed. All the repair methods were portable and self-contained. Repair kits based on adhesives, pressure sensitive tapes, and mechanical means were evaluated. Plier staplers and patch systems based on pressure sensitive adhesive proved to be most functional.

Jan 1, 1980

By R. G. Lett

Gaseous products resulting from rapid pyrolysis of coal and coal/inhibitor mixture's by a ruby laser and a flash-tube were monitored on-line by time-of-flight mass spectrometry. The distribution of stable gases from the coal is not Greatly influenced by the addition of small quantities of powdered flame inhibitors. Preliminary studies of the reaction of elementary radicals with coal and coal/inhibitor mixtures are described. The different types of experiments are discussed with regard to possible modification and application to studies of flame inhibitor action.

Jan 1, 1973

By John G. Palmer

Continued development of an especially impregnated silica gel capable of reversible chemical detection of carbon monoxide (CO) was reported. The affects of changes in mine-related ambient conditions on the detection catalyst's response were explored. Temperature, humidity, and several interfering gases were found to affect the detection catalyst. The interferents include hydrogen sulfide, nitrogen dioxide, acetylene (and methylacetylene), and ammonia. High humidity decreased the detection catalyst's sensitivity to carbon monoxide for some formulations. Increasing temperature generally decreased the reaction time of the detection catalyst with carbon monoxide. Badges and carriers for the visual presentation of the detection catalyst were constructed. Several variations of these devices included provisions for absorbants and filtering agents which help protect the detection catalyst from gaseous interferents. A variety of catalyst support agents were tested in an effort to find the most suitable. Included were alumina, magnesium oxide, magnesium silicate, and several forms of silica gel. In addi tion to free-flowing forms of these sorbents, thin layer chromatography plates coated with cellulose, alumina, and silica gel and newly developed PTFE entrained silica gels were examined. A limited physical, chemical, and mechanistic characterization of the detection catalyst and the materials used to prepare it has been carried out. Metal component ratio studies, spectral, analytical, pH, and rate measurements were done.

Jan 1, 1982

By Walter W. Fisher

A study of copper cementation on iron was initiated to determine the effect that deposited copper has upon subsequent cementation. A microscopic investigation of cementation on an iron surface showed that cupric ion precipitates predominately on a growing copper deposit attached to the iron surface. A kinetic study of the cementation process in a revolving drum showed that the cementation rate is enhanced by the copper deposit attached to the iron surface and by the discrete copper particles of a cement copper slurry. The kinetic study also indicated that the character of the deposit is affected by the major anion in the solution. The cementation process is visualized to occur as a series of electrochemical cells in which cupric ion precipitates on copper dendrites attached to the iron surface.

Jan 1, 1973

By John C. LaScola

The Bureau of Mines investigated coal storage silos to determine how gassy coal must be for methane accumulations in a silo to become hazardous and where such accumulations are likely to occur. Methane concentrations were measured in the open space above the stored coal pile, in the pile, and in the reclaiming area. No methane layering was found in closed-top silos. Reclaiming areas were as gassy as the top part of the silos. Coal samples were collected from the conveyors entering the silos in order to assess the gassiness of the coal. No simple correlation was found between the gassiness of the coal stored and the measured methane concentrations. However, at mines where the average 24-hour gas emission from the conveyor belt samples was 14 ft3/ton or more, fans or open tops were used. It appears that a large fraction of the methane released during storage remains in the void space between the coal particles.

Jan 1, 1980

By Andrew B. Cecala

The Bureau of Mines conducted a brief laboratory study on the 10-mm diam Dorr-Oliver nylon cyclone to investigate (1) whether high wind speed (>300 ft/min), or sampler inlet orientation with respect to wind direction, can introduce errors when sampling respirable dust, and (2) whether any such errors can be reduced by using an inlet shield. Being preliminary in nature, the study was not structured to produce definitive results, but rather to discern likely trends and to indicate whether or not a more in-depth study of the problem is warranted. Photometric mass sensing measurements suggested that as the wind velocity increased, the cyclone sampling directly into the high-velocity airstream tended to oversample, relative to the cyclone sampling in a low-velocity airstream. Orientation of the sampler introduced measurable differences in sampling efficiency at higher wind velocities. A shield placed around the cyclone diminished the effects of wind velocity and sampler orientation on sampler performance. Results of this work offer sufficient evidence to substantiate the need for a more in-depth study.

Jan 1, 1983

By Roy L. Wilfong

The thermal decomposition of the ammonium sulfate, carbonate, nitrate, oxalate, and sulfate salts of praseodymium, neodymium, and samarium was investigated thermogravimetrically in the temperature range 25° to 1,500° C. Each salt was decomposed at a heating rate of 2.5° C, per minute. The pyrolytic sequences have been identified and the temperatures of formation of inter-mediates, the minimum oxide formation temperatures, and values for loss on ignition have been determined. The nonstoichiometric ranges between Pr6011 and Pr203 and the extent of these ranges have been determined for oxides derived from the carbonate, nitrate, and oxalate salts of praseodymium. The alum and sulfate salts of praseodymium produced the sesquioxide without forming the intermediate non-stoichiometric oxides. The temperature limits of formation and regions of stability for the alums and sulfates were better defined than were those for the carbonates, nitrates, and oxalates. The minimum oxide formation temperature increased in the order of samarium, neodymium, and praseodymium irrespective of the anion.

Jan 1, 1962

By R. V. Ramani

One area of study in the Coal Mine Injury Analysis project was to illustrate and enhance the ability o mine safety management personnel to apply analytical techniques to Injury experience data and to justify requests for funds for safety enhancement actions on a cost/benefit and other quantitative basis. Four volumes of this final project report detail (1) the objectives and scope of the mine safety management research, (2) the results of literature review, and case studies, and (3) models developed for mine safety management. The four volumes are titled as Volume III: Mine Safety Management, Volume IV: Analytical Techniques for Mine Safety Management; Volume V: Mine Safety Management Case Studies and Volume IX: Training Cost Model. In this volume, the application of the quantitative procedures to mine-specific accident/injury experience data is discussed in detail in the form of case studies. The accident data from three mines are analyzed, and recommendations for training are proposed for each of the mines on the basis of this analysis. The procedures to apply cost-benefit analyses are described along with the cost benefit ratios for the training program/policies for the mines.

Jan 1, 1993

This publication summarizes, for potential contractors and other interested parties, the research, development, and demonstration contract projects programed by the Bureau of Mines for fiscal year 1982 (October 1, 1980 -September 30, 1981) under its Minerals Health and Safety Technology program. Contingencies may require that a significant port ion of the program be deferred into fiscal year 1983. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the systems technology required to create a healthier and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1981

By Fred S. Karn

Inhibitors are used in coal mines as a precaution against accidental dust explosions. Although rock dust is the usual inhibitor many others have been tested. To facilitate testing a screening process using laser irradiation was proposed. The procedure includes irradiation of a coal-dust mixture followed by mass-spectrometric analysis of the evolved gases and an evaluation of the flammability characteristics of the gases. Carbonate-type inhibitors decreased the percentage of combustibles in the gases generated and inhibitors like NaCI (thermally stable salts) decreased the total gas generated. A suitable test procedure did not result from the investigation, demonstrating the inadequacy of fast heating, non-combustive techniques in rating inhibitors of coal dust explosions.

Jan 1, 1973

By Frank S. Wartman

"The experimental flotation work described in this paper was undertaken to test the conclusions derived from a previous microscopic and chemical study of several samples of converter slag. That study3 resulted in the conclusion that approximately 90 per cent of the copper content of a converter slag wad in either the sulphide or metallic form, and that if the slag were cooled slowly the copper-bearing material would be in particles of such size that they would be freed from silicate and magnetite grains by grinding the slag to pass a 150-mesh sieve. If this were true, it should be possible to separate the copper-bearing grains from slowly cooled, converter slag by the flotation process.Many attempts, of which the author has seen no published account, have been made to treat slags, especially converter slags, by flotation. In every case these trials have been made with chilled slags, in which, as shown in the preceding report, the copper-bearing material is top finely disseminated, to be freed by any reasonable degree of grinding.The flotation tests described in this paper have shown that it is possible to recover by flotation about 30 per cent of the copper content of a converter slag containing 3 per cent copper and to obtain flotation concentrates which have a copper content of 35 per cent.Acknowledgment is made to G. L. Oldright, supervising engineer of the section of nonferrous metallurgy, U. S. Bureau of Mines, for valuable assistance and direction; to W. A. Sloan for chemical analyses; and to Alfred P. Towne for assistance in experimental manipulation."

Apr 1, 1931

By Loren R. Anderson

A probabilistic slope stability computer model was developed at Utah State University and independently evaluated by CH2M Hill Consulting Engineers as a design and analysis tool. Volume I of this report describes the model and Volumes III and IV are users manuals for the computer programs. This volume (Volume II) constitutes the report by the CH2M Hill. It includes a description of a field investigation and stability analysis of an existing tailings dam. Based on the results of the analysis, the tailings dam was evaluated for redesign using probabilistic considerations. Conclusions are made regarding the usefulness of the model as a design tool.

Jan 1, 1982

By H. P. Rue

The Bureau of Mines has recently collected two samples of crude oil from wells in the Greasewood Flat area of northeastern Colorado. Sample 31310 was taken from the Continental Oil Co.'s well Briggs No. 1 which care in or September 27, 1931, with a maximum production of 940 barrels per day. Sample 31311 was taken from tie Reiter-Foster Oil Co. Is well Ida Johnson No. 1 which came in on August 24, 1931 with a maximum production of approximately 1000 barrels per day.

Jan 1, 1932

By Natesa I. Jayaraman

A field study was conducted by the Bureau of Mines to determine the feasibility and effectiveness of a secondary ventilation system retrofitted onto an Eickhoff EDW 340L double-drum shearer as a technique for controlling respirable dust generated during a longwall mining operation. An airflow duct was formed by enclosing the bottom of the undercarriage with steel plate and cutting air channels through the ends of the undercarriage frame. Air intakes were provided behind each cutting drum and at several locations along the undercarriage. Grills were installed at the intakes to prevent the broken coal from entering the ducting. A dust collector consisting of 5,000-ft3/min fan, water sprays, and a minicyclone panel was installed on the shearer at the tailgate end. Field results indicated that the secondary ventilation system reduced respirable dust more than 60% along the face. Reduction was less near the intake airway and when secondary dust sources occurred.

Jan 1, 1977

By Edmond Chin

The land mass of the Asia and Pacific region comprises 11 million square miles or about 15% of the total Earth's land area. The bulk of the region is contained on the Asian continental land mass. Australia, the world's largest island or the world's smallest continent, alone is almost as large as the continental United States. The islands of New Zealand, New Guinea, Borneo, Sumatra, and Honshu are among the largest in the world. Collectively, they constitute a land area of 1.1 million square miles or an area about one-fourth the size of the United States. The countries in the Asia and Pacific region represent some of the most vibrant economies in the world. Japan is undisputed as one of the world's leaders in manufacturing and commerce. Hong Kong and Singapore are significant both as entrepôt and banking centers. The economies of Australia, the Republic of Korea, and Taiwan compare favorably to the level of the industrialized countries in western Europe. Indonesia, Malaysia, the Philippines, and Thailand have maintained strong economic growth during the past two decades. All these countries in the Asia and Pacific region collectively constitute a significant bloc as to raw materials production and consumption, as to manufacturing, and as to world trade.

Jan 1, 1992

By J. I. Paige

The Bureau of Mines studied methods for recovering unreacted titanium minerals and petroleum coke from titanium chlorination plant wastes prior to neutralization treatment with lime. The objective was to recover valuable raw materials and to reduce the amount of waste materials that must be treated for disposal. Samples of solid wastes were physically beneficiated by gravity concentration (tabling) to recover titanium minerals containing 69.0 to 92.4 wt-pct Ti02 and by selective carbon flotation to recover petroleum coke containing 94.0 to 96.8 wt-pct C. Laboratory data indicate that the recovered titanium mineral would decrease the amount of solid waste to be disposed of from 32.8 to 53.9 wt-pct. The recovery of coke would further decrease the amount by additional 32.9 wt-pct. Preliminary tests conducted on recovering vanadium, chromium, and columbium from liquors obtained by leaching chlorination residues also have shown that (1) 97 pct of the vanadium was extracted from leach liquors in a two-stage solvent ex-traction procedure and (2) 58 pct of the columbium and 40 pct of the chromium were separated from the leach liquors by an ion exchange technique using a strong acid resin.

Jan 1, 1982