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By S. H. Lorain

The Minah silver-lead mine in the Wickes district, Jefferson County, Mont., produced substantial quantities of silver-lead ores in the 1890's. The mine has been abandoned since the "silver panic" of the early 1900's. As a part of the Bureau of Mines: program to develop new sources of lead to overcome the growing shortages of that metal, a development project was started at the Minh mine in April 1946 and continued until June 1947, during which 5,600 feet of angledozer trenching and. 1,093 feet of core drilling were completed on the main vein and nearby parallel veins: As a result of this work, interest in the property was stimulated and private operators are now engaged in reopening the mine. This report discusses the past history, geologic setting, and the recent and early operations of the mine.

Jan 1, 1948

By D. S. Kingery

Recent Federal coal-mine inspections have revealed some good and some definitely hazardous practices and systems for transporting; handling, and storing lubricants in and about coal mines. Improper storage or handling of. lubricants in coal mines has caused disastrous mine fires or, by supporting combustion, has made fires from other sources more difficult to fight. Careless handling of grease and oil around electrical equipment wastes much oil and permits entrance of grit and foreign substances into the working parts, which causes excessive wear and increases the possibility, of electrical ignition.

Jan 1, 1943

By Len Blackman

The Absaroka-Beartooth Study Area is a tract of approximately 1.4 million acres of National forest land in southern Montana, part of the Greater Yellowstone Area. This study evaluated the mineral potential of four mineral terranes containing undiscovered resources in the area. The geological data is probabilistic, with estimates of the possible number: of deposits and their grades and tonnages. Possible future development scenarios range from no development to many mines, including some very large. As two thirds of the study area is within the Absaroka-Beartooth Wilderness, the future development scenarios reflect the area's mineral potential, not what we expect to see in the foreseeable future. Based on the analysis performed on these four terranes, the most likely future scenario for the study area would include the potential for two medium sized, (predominately) gold, mines, each employing a few hundred workers. There is a small chance, less than 5%, that a large Porphyry Copper or Superior Iron deposit would be discovered and be economically feasible to develop.

Jan 1, 1994

By Gary A. Kingston

Chromium resources in the United States are estimated at 1.8 million tons of recoverable chromium contained in 22.5 million tons of chromite-bearing material. Additional resource is presumed existent in large, but as yet undetermined, quantities of material containing less than 10 percent Cr203. No domestic resources are being mined presently (1969). Excluding transportation charges to domestic consuming areas, the total 1.8 million tons of chromim is estimated to be available, in ore or concentrate, at costs up to $0.64 per pound; 63 percent of the total is available under $0.11 per pound; and 38 percent under $0.08 per pound. It is judged that transportation from the resource areas to the existing market centers would add nearly $0.05 to the cost of a pound of chromium contained in ore or concentrate. Technically effective beneficiation methods have been developed for much of the known domestic resource, and further development might reduce costs of processing these materials. However, at present, domestic chromium resources are noncompetitive with foreign sources.

Jan 1, 1970

By James A. Wasson

This Bureau of Mines report summarizes the application of pilot flooding in the evaluation of a potential waterflood project. Aspects of pilot flooding discussed include choice of pilot location, confined and unconfined waterfloods, operational precautions, and comparison of predicted with observed performance. Summaries of published methods of pilot flood data analysis for determination of full-scale waterflood feasibility are presented and their use illustrated for example pilot flood data.

Jan 1, 1974

By Mackenzie Burnett

A high efficiency ejector has been developed which solves the abrasion problem associated with remote pneumatic stowing. The system can also produce cemented fills. The ejector is capable of moving the fill material over 70 ft from the injection point and filling the mine opening to the roof level for a distance of about 30 ft in all directions from the borehole. This system operates by the transfer of momentum from a supersonic air stream to the fill material. The momentum transfer results in a horizontal stream of fill material and air at a velocity of about 100 fps. The ejector fits on the bottom end of a 3 in diameter vertical pipe. Fill material is fed into the ejector at a controlled rate through a hopper mounted over the borehole. High pressure air used to operate the ejector is fed through a second 3 in diameter pipe. This system has the additional feature of mixing water in the air stream which increases the potential momentum of the air stream. Where necessary, cement can be added to the gravel to create a cemented fill. The design parameters and test results for four versions of the ejector are presented in this report.

Jan 1, 1991

By G. W. Birge

Carbonizing properties of the principal coal beds of Butler County, Pa., are described in this report by the Bureau of Mines. Eight samples, representing the Upper Freeport, Lower Freeport, Upper Kittanning, Middle Kittanning, Lower Kittanning, Clarion, and Brookville beds, were carbonized at 900° C. by the Bureau of Mines-American Gas Association (BM-AGA) method. Butler County coals rank as high-volatile A bituminous and are generally characterized by high sulfur content compared with Appalachian coals used for industrial coking. If cleaned, the Brookville and one sample of Upper Freeport coal would be acceptable as the major component of metallurgical coking blends. The other Butler County coals tested would be unsuitable for this purpose because of either excessive sulfur or poor coking properties.

Jan 1, 1962

By Fred D. Wright

A drill unit designed by Bureau of Mines engineers for testing various types of rotary bits has been in use since April 1950 at the experimental oil-shale mine near Rifle, Colo. The unit has a hydraulic drill and feed system, which provides the wide range of operating conditions necessary for adequate testing of drill bits and for obtaining data needed for the design of production scale equipment. Through the use of this unit, it has been proved that rotary drilling of vertical holes for mining the benches of the oil-shale mine is much cheaper than percussion drilling, and it is believed that in the near future the rotary drilling of horizontal blast holes in the top heading of the mine will prove equally economical.

Jan 1, 1952

By H. R. Babitzke, H. Kato, R. E. Siemens

An investigation was made to provide further information for evaluating columbium- hafnium alloys for use as high - temperature structural materials . The columbium- hafnium system was investigated between 700 ° and 2,400 ° C by melting point , thermal analysis , X - ray diffraction , electrical resistivity , and metallographic techniques . The equilibrium diagram is the beta isomorphous type , with columbium tending to stabilize the beta phase . Addition of 60 atomic percent columbium stabilizes the beta phase at 700 ° C. The allotropic transformation temperature of hafnium is 1,750 ° ± 20 ° C. A minimum melting point occurs near 75 atomic percent hafnium .

Jan 1, 1964

By Oren C. Baptist

[Several new oilfields have been developed in northwestern Wyoming during the past 10 years, production is obtained from discontinuous, permeable sands enclosed within impermeable shales. The energy to drive the oil to producing wells in supplied by gas in solution in the oil. Most of the wells had high-initial potentials, but rates of oil production have steadily declined, indicating a dissipation of the driving energy and the possibility that large volumes of oil will remain unrecovered in the reservoirs. The studies reported in this paper were undertaken to develop laboratory data of the type most likely to be needed by persons studying the susceptibility of the Newcastle sand reservoir to secondary-recovery methods.]

Jan 1, 1957

By R. B. Schluter

The objective of this Bureau of Mines investigation was to determine the effects of adding manganese compounds and ores to iron ore pellets. Manganese dioxide, carbonate, sulfate and chloride, plus six manganiferous ores from the Minnesota Cuyuna Range were tested as additives to increase the manganese content of iron ore pellets. One to 5 percent manganese, as a compound or ore, was added to five magnetite concentrates and one hematite concentrate. These concentrates were ballad, indurated (1,300° C), and tested for reducibility. Manganese sulfate and chloride were unsatisfactory additives causing cracking and degradation of the pellets during reduction. Manganese dioxide, carbonate, and the ores were satisfactory additives. The additives increased pellet compression strengths with a corresponding loss of reducibility, as compared to the pellets without manganese additions. The changes in compression strengths and reducibility were caused by the formation of Jacobite spinel and slag within the pellets. However, when the induration temperature was lowered from 1,300° to 1,200° C the reducibility and compression strengths were comparable to the pellets without manganese additions indurated at 1,300° C.

Jan 1, 1974

By H. E. Powell

Magnetic susceptibilities were determined by the Bureau of Mines fur 19 cobalt- and nickel-bearing minerals and for a suite for synthetic cobalt-nickel diarsenides analogous to the rammelsbergite and safflorite series. Relations between susceptibility and composition were found to be nonlinear for both impure natural minerals and pure synthetics.

Jan 1, 1967

By R. L. Handy

The objective of this research was to devise and test an apparatus to rapidly evaluate the cohesive and frictional strength of coal in situ, in order to increase the safety and percentage of coal recovery from underground coal mines. During the first year device was designed utilizing the bore-hole shear test principle from soil shear strength testing: Two opposing corrugated plates are forced outward to exert a controlled contact pressure against the sides of a previously bared hole, and then the plates are very slowly pulled along the axis of the hole to cause shearing of coal in contact with the plates. Results with the device are expressed in terms of a friction angle[_] and a cohesion c. The [ ] angles obtained from an Iowa coal arc in close agreement with and fall between results from triaxial and direct shear laboratory tests on the same coal. The measured cohesion was found to be much less than from the comparable laboratory tests. It may be increased by pre-stressing and other techniques to embed the shear plate teeth for the first shear test point.

Jan 1, 1973

By D. J. Bauer

A primary amine extraction system was investigated for fractionating a cerium-group, lanthanide sulfate mixture. Addition of diethylenetriaminepenta-acetic acid (DTPA) to the amine extraction system resulted in separation factors as high as 5.4 for lanthanum-cerium, 8.0 for cerium-praseodymium, 3.7 for praseodymium-neodymium, and 7.0 for neodymium-samarium. In multistage studies on a cerium-free lanthanide mixture, 96 percent of the lanthanum was recovered with a purity of 95 percent.

Jan 1, 1968

By J. D. Kalasky, Stephen Krickovic

A degasification experiment was conducted in a Pocahontas No. 3 coalbed mine in Virginia. It involved (1) drilling holes in the coalbed in the out- side headings of a set of five being developed in virgin area, and (2) conducting a methane emission rate study as mining progressed and additional holes were drilled. Degasification from all drill holes except the longest in each of the outside headings and the first three drilled (excluding the in-situ pressure hole), was erratic and inconsequential in methane emission rates. The two longest holes liberated 66 and 79 cfm of methane, which is significant for the coalbed, but such quantity lasted a relatively short time; the first three were uniform but low in methane emission.

Jan 1, 1972

By F. R. Cattoir

This report presents the results of preliminary studies for the evaluation of some fused-salt electrolytes for refining tungsten metal, and describes the equipment used. Some impurities could be eliminated with electrolytes composed of sodium chloride, sodium iodide, or sodium tetraborate in combination with tungstic oxide or sodium tungstate. Electrolytes composed entirely of chlorides were unusable because of the volatility of tungsten chloride. Refining 96-to 98-percent tungsten to produce a commercial grade was more successful than further refining of 99.9-percent tungsten. No electrolyte tested yielded a product pure in all respects. Electrolyte temperatures of about 900° C were necessary to maintain a good dissolution rate at the anode and acceptable cell operation. Cathode current densities at the beginning of a deposition cycle were limited to approximately 1 ampere per square inch. Higher current densities resulted in a finely divided product that frequently failed to adhere to the cathode. The most conspicuous impurities in the tungsten produced were carbon, iron, and molybdenum; the former two came from the iron cell and the graphite cell liner. Electrolytes com-posed of tungstic oxide or sodium tungstate in sodium iodide, or 2Na, 0.B203, were capable of producing tungsten carbide.

Jan 1, 1963

By Forest J. Sur

"This report describes an exploratory project conducted by the Bureau of Mines on a fluorite deposit near Vado, N. Mex. Results of trenching are given. Together with analyses made upon samples of the ore. The Federal Geological Survey3/ completed a preliminary geologic study and mapped the deposit during the summer of 1944. A Bureau engineer examined the deposit in August 1944. As a result of these investigations, it was concluded that the deposit contained substantial inferred ore reserves. Exploratory work was recommended to obtain information that might possibly lead to production from the property. Assistance was given the Bureau by the Geological Survey.A gasoline-powered air compressor, other equipment, and supplies were delivered to the property from January 20 to 25, 1943. Trenching began under the direction of a Bureau of Mines engineer on January 25, 1947, and ended on March 15, 1945. The results of trenching and sampling form he basis of this report.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. IT is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, R.G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervisions of Dr. R. S. Dean, assistant director."

Sep 1, 1946

"One of the functions of the United States Bureau of Mines is to investigate the ability of electrical mining equipment to operate in a gassy mine without danger of igniting explosive atmospheres. To accomplish this purpose, tests are made in which mixtures of gas and air are ignited in the equipment while it is surrounded by explosive atmospheres of the same composition. In such tests, records of pressures developed by the internal ex-plosions are obtained and observations are made of any flames, sparks, or smoke which may issue from bearings and joints. Occasionally the explosion pressures in a mining machine rheostat or a compartment of some other machine reach a value which is judged to be excessive or abnormal.A number of factors are known to influence the explosion pressures, and both German and. British investigators have irate extensive research on their effects. Much of this work had been done with artificial compartment which certain conditions could c held, constant while others were being varied. The U. S. Bureau of Mines has not made any research on a scale to compare with that of the British or German investigators; however, special studies have been necessary from time to time to determine the cause and remedy for high pressures obtained in the routine test of some piece of mining machinery. Thus it has been possible to verify some of tee theories established on a purely experimental oasis by practical tests of machines as actually built for mine use.Some of the factors determined the pressure that will result when an explosive mixture in a compartment or connected compartment is ignited are: (1) The volume of explosive mixture ignited, (2) the percentage of as in the mixture, (3) the amount of coal-dust in the compartment or compartments, (4) the degree of movement or turbulence of the mixture at the time of ignition, (6) tightness of the joints and bearings, (6) the size of opening between, compartments, (7) the distance between the point of ignition and openings, and (8) the cooling, effect of surfaces and of material inclosed in the compartments."

Dec 1, 1929

The first phase of our work for PMSRC on this contract was devoted to a comprehensive and in-depth assessment of electromagnetic (EM) noise measurements and data taken by several contractors for use in the design of operational and emergency mine communications. Pertinent measurements and data of other selected investigators were also included in the evaluation. This assessment treated the measurements and instrumentation used, the data analysis and presentation methods, and the utility of the final results. This phase concluded with the identification of the most useful results and methods, the remaining data gaps, the contractor most qualified to fill these data gaps, and the definition (with PMSRC and this contractor - NBS, National Bureau of Standards) of a follow-on noise measurement program, instrumentation system, and data processing methods tailored to obtain the necessary but missing noise data. A partial bibliography of references related to electromagnetic and seismic noise and propagation in the frequency bands of interest was also compiled during this first phase. The body of this Part of the final report presents a summary of the findings of our EM noise assessment, together with detailed recommendations regarding the new noise measurements to be taken and the instrumentation and data processing methods to be used. This work was done during the latter part of 1971 and the early part of 1972. During subsequent phases of the contract ADL was asked to perform on-going evaluations of the continuing program of electromagnetic (EM) noise and propagation measurements made by Bureau contractors, and to utilize pertinent data from these measurements to make performance estimates for

Jan 1, 1974

By Christopher Mark

Australia and the United States both have large, modern underground coal mining industries. Many companies have invested in both countries, and there is growing awareness that technological developments in one country can rapidly affect the other. Yet the ability of technology to pass between the countries depends on comparability of ground conditions. Many Australian observers believe that their ground conditions are significantly poorer than typical U.S. conditions, but some U.S. professionals are not convinced. The author recently visited 10 Australian longwall mines and two room-and-pillar mines. Each mine visit included determination of the Coal Mine Roof Rating, roof support installed, pillar design, and an in-depth discussion of ground control experience. The Australian conditions observed are compared with an extensive data base from U.S. mines. The paper also offers observations on geotechnical data collection, monitoring, and the roles of the mine inspectorate and research community.