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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 Alla D. Mah

Thermodynamic calculations for antimony and its compounds have been hampered by the lack of adequate basic thermal data; much work rains even to fill the more important gaps. This paper supplies heat and free energy of formation values at 298.15° K, for the sesquioxide and tetroxide, based upon new measurements conducted by the Bureau of Mines. The heats of formation were obtained by combustion (bomb) calorimetry, and the free energies of formation were obtained by combination of heat and entropy data. The new values are believed to substantially improve the accuracy of thermodynsunic considerations involving these oxides.

Jan 1, 1962

By R. V. Thurston, Edmund S. Leaver

"During the development of the sulphur dioxide leaching process for the treatment of ""mixed"" copper ores at the Southwest experiment station of the Bureau of Mines*** the pulp from treatment of roasted cupriferous pyrite with sulphur dioxide gases and water showed an unexpected amount of sulphuric acid. After following out several false premises it was found that this was due to iron in the solution, and also that this iron tended to oxidize to the ferric state if the concentration of sulphur dioxide in the roaster gases used did not rise above a certain figure. While the percentage of iron present was email it was enough to cause an entirely different set of conditions from those of the original sulphur dioxide leaching process and to promise a much wider application of the general idea. Sulphurous acid dissolves only certain copper minerals, sulphuric acid solutions certain additional minerals and ferric sulphate solutions certain further additional copper minerals, so this observation was of importance in connection with possibilities in the hydrometallurgy of the so-called ""mixed"" or partly oxidized copper ores.The work has been carried along by a number of experimenters. L. R. Eckman, junior chemist of the Southwest station, contributed largely to the early developments. L. Roberts, W. D. Bonner and C. G. Maier each in turn physical chemists at the Pacific Experiment station, (Berkeley, Calif.) have studied the reactions involved. A complete report of all the work on this process will be prepared later under the direction of O. C. Rolston. The purpose of the present paper is to place a summary of the more practical phases of this seemingly important piece of work before those interested."

Dec 1, 1923

By Kenneth M. Earl

In its program of investigation of deposits of strategic minerals, the Bureau of Mines did some development drilling at the Tapley deposit in an endeavor to find an additional source of copper. There are accounts that many years ago the property had some production; there are several old, inaccessible shafts apparently sunk on a vein in rhyolite or diabase. The waste dumps of these shafts contain considerable sulfides, chiefly pyrite and chalcopyrite. To cut the vein below the old mine workings, the Bureau of Mines? diamond-drilled five holes aggregating 1,204 feet. No significant copper mineralization was found.

Jan 1, 1950

By W. T. Benson

In May l942, the Bureau of Mines started exploring for manganese on the Black Poch manganese property, Esmeralda County, Nev., to determine possible reserves of manganese in the deposits. The work was done by the Bureau in cooperation with the Federal Geological Survey and comprised a study of the geology, mapping the area, and exploring by trenching, test pitting, and sampling. All ore bodies were examined and sampled, and the three most important areas were explored by trenching and test pitting. This report notes the location, ownership, and history of the deposits; explains the physical features of the district; mentions briefly mine workings and metallurgy; and describes the geology and ore bodies. The Bureau erected a temporary camp, repaired 5 miles of temporary road, constructed 1,000 feet of new road, dug 3,173 foot of trenches with a vertical crone section of 4 x 10 feet and 91 test pits with a cross section 3 x 6 feet, averaging about 6 feet deep, and cut 134 samples.

Jan 1, 1950

By George S. Rice

There have appeared, from time to time, comparisons of various features of coal mining practice in the United States and Great Britain. A recent, article, appearing in a British journal, points out that the American miner produces 3 1/2 times as much coal per shift as the miner, at one-half the cost, and proceeds to explain the natural industrial, and engineering causes which lead to this result. Amon« he reasons advanced. is that the American coal miner enjoys the advantage of more easily worked seams of coal, due to the fact that the coal mining industry in the United States is of more recent date than in Great Britain. The latter qualification is not correct, because where these advantages exist, they will persist. The coal beds of the United States are not buried deeply, except in the remote parts of the country, as in the Uinta Basin of Utah. The article referred to states that many of our miners are still employed on out seams reached by "adits", (which we term entries), or by vertical shafts of moderate depth. It is probable in fact that the great bulk of the coal of the United States is taken out from a depth of less than 400 feet.

Mar 1, 1920

By D. Cummins

This Information Circular presents a brief history of the lead-acid battery and describes ways to prevent serious injury from battery explosions when servicing and charging lead-acid batteries, particularly in the surface mining industry. The Mining Safety and Health Administration (MSHA), U.S. Consumer Product Safety Commission, battery manufacturers, and the mining industry have all contributed information as well as recommendations for injury-free handling for this report.

Jan 1, 1980

By Jr. Harty

Intensive work on the deoxidation of steel with manganese-silicon alloys by the U. S. Bureau of Mines has shown that the use of those alloys, which may be produced from our domestic manganese ores, would decrease the ferromanganese requirements of a very large tonnage of our steel by from 60 to 80 per cent and in some cases by 100 per cent. The open-hearth heats made with these alloys have been of excellent quality. The tonnage of our ferro-grade ores Which has been made available by the bureau's ore-dressing studies, combined with the products resulting from such processes as those developed by the bureau and by Bradley for Cuyuna ores, should easily fill our reduced ferromanganese requirements when manganese-silicon alloys and ordinary Spiegel are used in the way described in this report. There are no technical difficulties in the application of this practice, and any difficulties involved in its wide and immediate application would only be those arising from habituated ideas of the necessity of ferromanganese. General acceptance of this practice and development of the available sources of domestic ferro-grade material by already proven processes should make this country independent of foreign ores. This paper resents the results of work done under a cooperative agreement between the Pittsburgh Experiment Station of the United States Bureau of Mines and the Carnegie Institute of Technology, the Metallurgical Advisory Board, and the University of Pittsburgh, Pittsburgh, Pa.; between the Mississippi Valley Experiment Station of the United States Bureau of Mines and the Missouri School of Mines and Metallurgy, Rolla, Mo.; between the North Central Experiment Station of the United States Bureau of Mines and the University of Minnesota, Minneapolis, Minn.; and between the Rare and Precious Metals Experiment Station of the United States Bureau of Mines and the University of Nevada, Reno, Nev.

Jan 1, 1931

By C. H. Herty

Intensive work on the deoxidation of steel with manganese-silicon alloys by the U. S. Bureau of Mines has shown that the use of those alloys, which may be produced from our domestic manganese ores, would decrease the ferromanganese requirements of a very large tone of our steel by from 60 to 30 per cent and in some cases by 100 per cent. The open-hearth heats made with these alloys have been of excellent quality. The tonnage of our ferro-grade ores which has been made available by the bureau's ore-dressing studies, combined with the ,products resulting from such processes as those developed by the bureau and by Bradley for Cuyuna ores, should easily fill our reduced ferromanganese requirements Then manganese-silicon alloys and ordinary spiegel are used in the way described in this report. There are no technical difficulties in the application of this practice, and any difficulties involved in its wide and immediate application would only be those arising from habituated ideas of the necessity of ferromangenese. General acceptance of this practice and development of the available sources of domestic ferro-grade material by already proven processes should make this country independent of foreign ores.

Jan 1, 1931

By A. W. Khair, S. J. Jung

"A fundamental study of fragment size distribution and characteristics of fracture pattern is presented for the dynamic penetration of a conical bit into coal block. In this paper, damaged zones during crater formation and fragment size distribution were studied. Bit with a sharper tip angle and a smooth body configuration performed better penetration. Results suggest that in coal cutting the trend should be toward the face cleat direction using a sharper angled tip bits which consumes less energy for an optimum range of penetration depths, thus attaining maximum cutting efficiency and reducing fine fragments.1. INTRODUCTIONMuch research in the past has been done on energy requirements and mechanism of energy dissipation for ideal rock fragmentation in cutting process. However the mechanisms of energy dissipation or failure criteria for rocks in cutting process in order to evaluate the efficiency of energy requirements in specific rock fragmentation is not well understood. The formation of a crater in rock under the impact blow of a bit has been observed experimentally (Hartman, 1959). It is known that directly beneath the edge of the bit the rock is crushed into fine powder, toward the sides of the crater it chips out into relatively large fragments. (Sikarskie & Cheatham, 1973). Singh et al. (1967) investigated the cratering process under the two different conditions of static and dynamic loading. They found that the amount of energy consumed per unit volume of crater is unequal for the two different loading conditions. A complex network of fractures often extends downward and laterally into the rock below the bit. The surface of the specimens showed that the dynamic loading damaged larger area then the static loading."

Jan 1, 1989

By J. D. Davis

From the chemist's point of view it would be ideal if specifications for coke for any stated purpose could be written on the basis of chemical composition and burning characteristics. Unfortunately this is not possible. In fact, the physical properties of a coke are often of such major importance as to render any specified chemical requirements totally inadequate to show the quality of coke desired. For example, a furnace coke may admirably fill all chemical requirements, such as for low phosphorus, sulphur, moisture, and high fixed carbon, and still be too soft to support the burden of the furnace without excessive crushing. Again, a domestic coke though a good fuel as judged from Chemical analysis, may be of unmarketable size. Thus one can not define the quality of a coke for a specified purpose without taking into account both its chemical and physical characteristics even when this has been done the specification may fail because neither coke user nor producer can accurately define by quantitative tests the qualities most desired. In other words, there is need of accurate test methods for measuring the properties of coke and, what is equally important, for correlating the results with the behavior of the coke in use. Coke quality is determined by the kind of coal used, the coking process, and the type of equipment used in the coking process. Chemical analysis of the coals, together with small-scale coking tests, will give a good indication of their suitability; but, in general, coke must be produced on an industrial scale and tested in the equipment for which it is intended before conclusive information as to its quality is obtained.

Jan 1, 1928

By Terry J. Close

The Gates of the Mountains Wilderness study area is underlain by intrusive and sedimentary rocks, mainly limestone. No limestone has been produced from the study area; suitable material is more readily available elsewhere. Small amounts of gold, sapphires, and corundum were produced from a placer deposit along the banks of the Missouri River. The remaining gravel contains low mineral values. Other alluvial deposits along the Missouri River and Beaver Creek contain no identified economic resources other than sand and gravel. Some deposits could provide suitable construction material for local use.

Jan 1, 1984

By F. W. Hoertel

Near-optimum parameters were determined by the Bureau of Mines for vapor deposition of rhenium on heated copper substrates by hydrogen reduction of rhenium hexafluoride (ReF6). High-purity deposits of nearly 90-percent theo¬retical density were obtained with the reaction chamber at 250° C, with an H2 to ReF6 volume ratio of 25 to 1, and with an ReF6 flow rate of 5 grams per hour. Some rhenium deposited as a loose, black powder. When the established near-optimum parameters were carefully followed, this could be minimized but never completely avoided. Varying the reaction chamber pressure, both above and below atmospheric, yielded excessive quantities of rhenium powder. Deposition efficiencies, based on only the coherent metal, ranged between 70 and 75 percent. Massive deposits contained only spectrographic traces of impurities. The average microhardness (Knoop, 100-gram load) of vapor-deposited rhenium was 907. Limited research on the deposition of rhenium-tungsten alloys by reduction of the mixed hexafluorides produced deposits in which linear composition gradients were pronounced; this nonhomogeneity was attributed to the wide variation in optimum hydrogen-reduction temperatures of the two hexafluorides (250° C for ReF6 and 550° C for WF6). Using deposition temperatures between 250° and 550° C did not eliminate the composition variations.

Jan 1, 1967

By O. M. Bishop

The Douglas fluorite property is in the Empire district of eastern Pope County, Ill., which lies near the west boundary of the productive Southern Illinois fluorspar field in Hardin and Pope Countios. Production from mines on the Douglas property accounts for about one-half of the 72,000 tons of fluorspar with which the Empire district is credited. This output was from the Sycamore, Pierce, Slapout, and Empire veins, which are normal fissure veins of little displacement along which there has been local wall-rock replacement by fluorite.

Jan 1, 1949

This Part is concerned with the theoretical study of UHF radio communication in coal mines, with particular reference to the rate of loss of signal strength along a tunnel, and from one tunnel to another around a corner. Of prime interest are the nature of the propagation mechanism and the prediction of the radio frequency which propagates with the smallest loss. Our theoretical results are compared with measurements made by Collins Radio Co. This work was conducted as part of the Pittsburgh Mining and Safety Research Center's investigation of new ways to reach and extend two-way communications to the key individuals that are highly mobile within the sections and haulage ways of coal mines.

Jan 1, 1974

By John C. Ferm

This report contains a summary of Phase I and complete results of Phase II portions of a study of geologic factors associated with roof falls in mines on the Pocahontas #3 coal seam in southern West Virginia and southwestern Virginia. Principal objectives of Phase I was the selection of five mines that best portrayed the spectrum of roof and mining conditions and Phase II consisted of a measurement and documentation program for each of the five mines. The documentation measurement program included reconnaissance mapping, detailed mapping, joint measurements and coring roof rock. 1.2 PHASE I RESULTS The results of Phase I consisted of the selection of the following five mines for detailed study: Virginia Pocahontas #3 (Island Creek Coal Company), Bishop (Consolidation Coal Company), Shannon Branch (Allied Chemical Company), Keystone II (Eastern Associated Coal Company) and Macalpine-East Gulf (Westmorelenad Coal Company). In addition, Phase I results, which were based on questionnaire data, indicated that the kind of rock in the roof --gray sandstone, crystallized sandstone, laminated sandstone and shale, grey shale, slickensided shale, and rider seams could be associated with good and bad top areas. Also presence of vertical separations, bolt length, entry and cross-cut width, length and torque on bolts and depth of overburden seemed to be related factors. These data provided a focus for the Phase II measurement program.

Jan 1, 1975

By Frank E. Cash

The iron-ore ranges in the Lake Superior district are the liarquette in Michigan, Menominee and Gogebic in Michigan end Wisconsin, and the Vermilion, Mesabi, and Cuvuna in Minnesota. These ranges produce about 85 percent of the iron ore mined in the United States. Accident experience in connection with this production is better than that of the regions producing the remaining 15 percent. Production and shipments vary slightly from year to year but closely approximate each other over a period of years. During the 4-year period 1940 to 1943, inclusive, 323,667,599 long tons of iron ore was shipped from the Lake Superior district.4/ Michigan and Wisconsin shipped 65,386,608 tons, or 20.2 percent of the total, and employed approximately 15,000 men; Minnesota shipped 258,280,991 tons, or 79.8 percent of the total, and employed approximately 10,000 men. The tons produced per man employed is much, greater in Minnesota than in Michigan and Wisconsin owing to the large open-cut production in Minnesota.

Jan 1, 1945

Reduce the time, complexity and expense of dissolving metal and mineral samples in solution in preparation for chemical analysis. Approach In earlier research, the Bureau of Mines developed a rapid and inexpensive method for the dissolution of mineral and metal samples in plastic pressure bottles heated in a boiling water bath. Using this technique, samples could be prepared for chemical analysis in less than one hour compared with several hours by traditional dissolution methods (see Technology News No. 85, December 1980 for further details). By heating in a microwave oven, sample dissolution time can be reduced to approximately 5 minutes.

Jan 1, 1983

By Jerry E. Olson

In 1986, at the request Of the Bureau of Land Management, the U.S. Bureau of Mines studied the central portion, encompassing 20,727 acres of the 32,261-acre Badlands Wilderness Study Area (OR-005-021) in order to evaluate its identified mineral resources. The study area is located in Crook and Deschutes Counties, OR, about 12 miles east from Bend. No mineral resources were identified. The area studied is underlain by Tertiary and Quaternary basalt flows which are largely covered by a veneer of sand and silt. No mines, prospects, or mineralized areas occur within or near the study area, but some sand and gravel has been removed from alluvial deposits at the east and west sides of the area. Slab lava of marketable grade and quantity was not found in the study area. None of the study area is of current interest for geothermal resources, but the eastern third of the wilderness study area is leased (1984) for oil and gas.

Jan 1, 1987

By Dale E. Wittmer

Nonoxide ceramic materials could substitute for high-temperature alloy steels containing imported critical and strategic materials such as cobalt, chromium, and nickel if their high-temperature properties can be improved. An important result of this substitution would be a reduction of the Nation&apos;s need for imports of critical and strategic materials. In this Bureau of Mines investigation, the primary objective was to produce high-purity u1trafine (particles <5 ~m equivalent spherical diameter (ESD)) alpha-silicon carbide (a-SiC) powders with improved high-temperature properties using the Bureau&apos;s patented turbo-milling process. A secondary objective was to determine the feasibility of using polymer mill construction materials as a means of eliminating metal contamination from the turbomill. U1trafine a-SiC powders with BET (Brunauer-Emmett-Te11er) surface areas from 30 to 35 m2/g (~0.06 ~m particle ESD) were produced in an all-polymer turbomi11. These high-purity powders (with I-pct Band I-pct C additions) hot-pressed to greater than 99 pct of their optimal density and exhibited properties commensurate with those of commercially available a-SiC. The most promising of the construction materials tested for the major wear surfaces of the turbomi11 was u1trahigh-mo1ecu1ar-weight (UHMW) polyethylene, a polymer thermoplastic.

Jan 1, 1984