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This report is a compilation of all information obtained in accordance with the requirements of contracts SO122076 and H0232056. A series of eight coal mines were visited to determine their communications usage and requirements. Presently available equipment was surveyed and evaluated to determine its applicability to the needs of the mines. The equipment studied includes that made by the following companies : Anaconda Telecommunications Division Andrew Antenna Bendix Communications Division Collins Radio Group of Rockwell International Executone Communication and Sound Systems Gau-tronics Mine Safety Appliances Company Motorola Communications and Electronics, Inc National Mine Service Company Plessey Communications Systems Corp Pye Electronics Limited Reach Electronics Set Com Corporation Sonex Incorporated Mine visits and in-depth interviews were made alt the following sites: Robena No. 4, Pennsylvania Greenwich Colliery Mines, Pennsylvania Somerset Coal Mine, Colorado Keystone No. 1, West Virginia Harris Mine No. 1, West Virginia Baldwin Underground No. 1 Mine, Illinois Lovilia No. 4 Coal Mine, Iowa Orient No. 3 Coal Mine, Illinois

Nov 15, 1974

By Eldon C. Pattee

THE BUREAU OF MINES began an investigation of tungsten resources of Montana in September 1953. This report presents information obtained from July 1955 to September 1957 on tungsten deposits in and near the Mount Torrey batholith. The batholith comprises part of the Pioneer Mountains of Beaverhead County in the southwest corner of Montana. Included in the report are assays and preliminary-examination data on 22 properties. Tungsten minerals are known to occur in 19 of the properties. The major producer is the Brown's Lake mine which has produced more than 625,000 tons of ore. Nearly all of the deposits are in the Lost Creek, Utopia, and Bald Mountain mining districts along the east and south margins of the Pioneer Mountains. The districts are less than 27 miles from Dillon, Mont.

Jan 1, 1960

Contract No. H0110929 was awarded by the U.S. Bureau of Mines in February, 1971, to DeTer Company, Incorporated, of Mountain Lakes, N. J. The contract provided for the modification of the contractor's Model 5000 Pressure Foam Generator to fit it for the suppression of coal dust in mines, a detailed testing program in a working coal mine, and for additional modifications and testing for the suppression of fires in coal mines. The contractual program was completed in April, 1972. The results of the dust suppression tests showed conclusively that the modified DeTer equipment effectively reduced the level of respirable dust in a working coal mine well below the present and future acceptable levels set by the Mine Health and Safety Act of 1969. The fire tests, carried out in a simulated mine entryway erected on the surface, demonstrated the ability of the DeTer equipment in suppressing fires of varying degrees of severity within an acceptably short time.

Jan 1, 1972

By W. W. Adams

luring the past two years the Bureau of ?,lines has been receiving from 100 to 150 coal mines in various States a report of each accident causing death, permanent total disability, permanent partial disability, or temporary disability lasting beyond the remainder of the day or shift on which the accident occurred. For each 100 accidents in these groups, there are perhaps from 35 to 45 accidents that do not disable the employee beyond the remainder of the day, and of these fraction-of-a-day accidents the Bureau has compiled no statistics. Information revealed by the reports is to the effect that falls of roof and coal in bituminous coal mines are responsible for 28 per cent of the temporary injuries to underground workers and 33 per cent of the days lost from all temporary injuries underground; they also indicate that falls caused 59 per cent of the deaths from all causes underground. Figures compiled by R. N. Hosler, of the Pennsylvania. Mine Rating Bureau, and covering accidents in bituminous; minis in that State, chow that 61 per cent of the deaths underground during the years 1917-1921 wore due to falls. Neither of these percentage figures includes deaths in major explosions; figures for all bituminous mines in the United States during the five years 1920-1024, inclusive of deaths in major explosions, show that 52 per cent of the deaths underground and in shafts were due to falls of roof and coal.

Jan 1, 1925

By Robert R. Perron

The U.S. Bureau of Mines is engaged in many diverse programs for improving mine safety. Of particular interest to the Bureau are new and improved means for minimizing the hazard of fire which can be initiated by prolonged low energy electrical faults on trolley line systems. When a high energy fault occurs on a trolley line, wherein the current exceeds the magnitude normally drawn by legitimate loads, such as locomotives, then the circuit breakers at close-by power rectifier sets trip. Tripping of the breakers not only protects the equipment at the rectifier sets, but also disconnects the energy source from the fault and thereby minimizes the fire risk. However, the fault current is frequently of a level substantially below that required to trip the overload breakers. When the fault is a substantial percentage of the set level of the breakers, the energy dissipated by the fault is frequently sufficient to clear the system by rapidly burning itself clear. Such a fault is often short-lived and does not present as serious a fire risk hazard as a prolonged, much lower energy fault, wherein the energy level is too low to clear the system. The breakdown of a trolley line insulator, in which there was a 20 or 30 ampere leak, would represent such a fault or illegitimate load and a substantial fire risk.

Jan 1, 1974

By J. M. Singer

The Bureau of Mines investigated the threshold of dispersal of monolayers and piles of rock dust, anthracite, and Pittsburgh seam coal dust in a small wind tunnel that simulated a coal mine gallery, with the objective of preventing or limiting the formation of flammable dust clouds. The effect of selected variables on entrainment velocity was examined. Mode of entrainment and flow processes in the wake region of dust configurations were investigated by means of high-speed motion pictures. Significant results were as follows: 1. Local minimum air velocities required for dispersal were only slightly higher for shallow dust ridges than for dust particles. 2. Minimum velocities for entrainment of dust particles from smooth glass and coal surfaces increased in the order rock dust, anthracite, Pittsburgh seam coal. 3. The mechanism for dispersal of dust poles depended significantly on dust pile geometry, cohesiveness of dust, bulk density and compaction of dust, adhesive surface, and vibrations perturbing the supporting surface.

Jan 1, 1969

By John J. Mulligan

Ear Mountain is an isolated mountain mass that rises abruptly from the coastal plain on the northwest shore of the Seward Peninsula. Geologically it resembles the more accessible Brooks Mountain and Cape Mountain areas to the southwest, being composed of a granitic core surrounded and partly capped by metamorphosed sediments. The occurrence of lode- and placer-tin deposits in this area has been known since the early 1900's, when the Seward Peninsula region was prospected extensively for both gold and tin. The Federal Bureau of Mines investigated the tin deposits in the Ear Mountain area during the 1953 and 1954 field seasons. The objectives were to delimit the areas in which tin minerals occur, as a guide to future prospecting, and to determine the amount of tin in the known prospects. Work by the Bureau of Mines included both placer and lode sampling.

Jan 1, 1959

By Constantine C. Popoff

This report reviews and analyzes, by a simple analytical and logical reasoning, the conventional methods of reserve computations of mineral deposits described in various domestic and foreign publications. It brings together, formulates, and evaluates the principles underlying interpretation of exploration data; and ties such principles to the proposed classification of methods. The material is discussed in sufficient detail to allow general application.

Jan 1, 1966

By C. M. Frost

The hydrodesulfurization characteristics of a residual fuel prepared from Wilmington, Calif., crude oil were determined at temperatures from 600° to 900° F, pressures of 200 to 800 pSig, and space velocities from 0.2 to 2.0 Vo/Vc/hr, using cobalt molybdate type catalysts. A prediction equation, developed from the experimental data, satisfactorily predicts the fraction of total sulfur that can be removed under any combination of operating conditions within the ranges investigated. Yields and properties of the low sulfur product are correlated with the fraction of total sulfur removed. Kinetic calculations show that the apparent reaction order and activation energy change with space velocity and temperature.

Jan 1, 1970

By A. W. Fahrenwald

"The rate of progress in the last three years in the development of differential flotation has been rapid beyond the realization of most people. Differential flotation is no longer a ""delicate"" and unreliable process, but is now in wide use. Its ""safety"" is due to the wide use of chemicals which either depress or enhance floatability by definite modification of surfaces.The extent of the development and reliability of differential flotation methods any be emphasized by pointing out that there are now several customall-flotation"" plants in this country treating complex lead-zinc-iron ores from widely separated mines. While these ores differ in chemical composition and apparently in physical nature, the various ores treated in such a plant are passed through the same crushing and grinding equipment and through the same flotation machines and flow sheet with only slight changes, if any, in quantity and kind of chemicals and oils added.Some of the development in differential flotation is due to intelligent research on the part of well-trained chemists and metallurgists; much of It must be attributed to empirical testing.Much of the success in differential flotation is due to more care being given to constant conditions with regard to such factors as (1) fineness of grinding, (2) density of pulp entering flotation machines, (3) quantity and constancy of oils and chemicals added to the pulp, and (4) place of addition of reagents, and time of ""conditioning"" treatment of pulp with reagents."

Aug 1, 1925

By R. J. Tocher

Uniaxial testing was performed on coal specimens to determine the time-dependent response. The testing was carried out on coal from six mine sites throughout the Western United States and Pennsylvania. Testing configurations were varied to allow analysis of moisture dependency, stress level and specimen orientation. Several theories were presented for the behavior of coal due to moisture diffusion. Experimental results showed the correlation between the theories and the actual material response. Coal deformation was found to be highly dependent on the moisture level of the testing environment. Moisture migration causes drying and shrinkage which lead to progressive degradation of the material. The coal tested experienced a rebound if saturated after a period of drying. This type of time-dependent behavior overshadows the dependence on the applied stress level, which, however, still produces a noticeable creep behavior. Analysis of one series of creep test results was performed. A relationship was developed on the basis of a simplified rheological model to describe the coal response to uniaxial stress. Previous empirical formulations in the form of power laws were compared and their deficiencies pointed out.

Jan 1, 1980

By A. J. Barry

A method was developed for testing the anchorages obtained with 3/4-inch, expansion-type, headed bolt and shell assemblies. The apparatus is a modification of that used in testing -inch-diameter, slotted-type bolts. Four makes of expansion-type shells were used in 64 tests made in sandstone and shale roof. The results show that for 3 makes of shells the anchorage effectiveness is independent of the installed land, and for the fourth make of shell a better anchorage is obtained when instilled at a load of 8,000 pounds. The results also show that deformation of the expansion plug influences the majority of the anchorages obtained with two makes of shells. This deformation causes a larger increase in displacement for a given added increment of load. The data from 48 of the 64 tests were combined to establish a relationship between average displacement and increase in bolt load (above the installed load). This relationship can be used to evaluate the anchorage effectiveness of any 3/4-inch-diameter, expansion-type, headed bolt and shell assembly tested in the field.

Jan 1, 1956

By Robert N. Roby

The Hornsilver lead-zinc property was examined by the Bureau in 1942 and again in 1944. A project was started on the property in April 1946 and completed in January 1947. Silver was first discovered in this district in 1883, and while complete production records are not available, it is known that a substantial tonnage of high-grade silver ore was shipped before 1887. All of the ore was mined from surface or near-surface workings. When the high-grade oxidized ore was exhausted, the district became inactive and remained so until the 1920's. In 1928 and 1929 some activity was shown in the district, but the Hornsilver mine was not reopened until November 1937. Between 1939 and 1946, the mine produced about 16,000 tons of ore of 531 ounces of gold, 283 ounces of silver, over a million pounds of load, and nerdy 2 million pounds of zinc. The property is now controlled by the Era Mining & Development Co., which has acquired the Last Chance and Ella groups of claims, in addition to the Hornsilver mine.

Jan 1, 1948

By V. A. Marple, K. L. Rubow, B. A. Olson

"INTRODUCTION Inertial classification, gravitational sedimentation centrifugation, and thermal precipitation arc techniques that can be used to collect particles for subsequent analysis or for particle classification. The inertial classifiers, which include impactors, virtual impactors, and cyclones, are widely used in the sampling or particles. Settling chambers, which include centrifuges as well as gravitational settling devices, are less widely used. Thermal precipitators arc seldom used.Impactors, in particular, have been used extensively, studied both theoretically and experimentally, and arc the instrument or choice for the determination or aerosol mass size distributions. Many versions or impactors arc available commercially and many more have been designed, built, and used in special studies.Virtual impactors are a more recently developed inertial classifier and possess a feature not round in conventional inertial impactors; namely, that the particles remain airborne after classification compared to the conventional impactor, where the particles arc collected on a solid surface. The feature or keeping particles airborne is important for transporting the particles to other particle-analyzing instruments, or to filters, and in concentrating particles larger than the cutsize in a small fraction of the total now."

Nov 1, 1995

By D. R. Tweeton

The U.S. Bureau of Mines has developed tomographic computer programs for geophysical applications and is distributing them as part of a Bureau plan to facilitate the transfer of technology to potential users. These programs were developed for predicting and monitoring the flow pattern of leach solution during in situ mining. The Bureau has also applied them to assessing high-wall blast damage and examining the integrity of mine-related geological structures. This report describes the curved ray program BOMCMTR (Bureau of Mines curved ray tomographic reconstruction), tells how to run it, and gives examples with synthetic and field data. BOMCRATR provides optional mathematical constraints to counteract the nonuniqueness of tomographic reconstructions with crosshole data. These constraints include limiting the maximum and minimum velocities, fixing the velocity at any point to any value, and establishing layers in which velocity does not vary with horizontal position. The user can test for nonuniqueness by varying the initial velocity pattern, The program can perform either curved or straight ray analysis. Ray paths are calculated analytically in triangular pixels, which is faster than incremental numerical approximations,

Jan 1, 2010

By H. M. Thorne

The Petroleum Experiment Station of the Bureau of Mines at Laramie, Wyo., in cooperation with the University of Wyoming, has in progress chemical and refining studies of Wyoming black oils. In general, these crude oils are characterized by their high sulphur, high asphalt, and low gasoline content and are called black oils because of these properties and their color. Characteristics of the various Wyoming black crude oils, as determined by the Bureau of Mines Hempel method of analysis, have been published.4/

Jan 1, 1938

These proceedings consist of an overview of the in situ mining research currently being carried out by the Bureau of Mines. The following papers emphasize two general aspects of the in situ mining method: the environment and productivity. Both areas are extremely important, particularly because in situ leach mining is a relatively new mining method from a commercial point of view. Topics covered include the restoration of ground water, the selection of lixiviants, in situ mining of commodities other than uranium, in situ mining costs, the application of resistance measurements to in situ mining, an acid leach mining case history, and the use of branched boreholes for in situ mining. A bibliography of Bureau of Mines publications on in situ mining is appended.

Jan 1, 1981

The strike of the Canadian asbestos miners entered its seventh month with increasing signs of early termination. Both unions are in the midst of heavy negotiations with management, and an optimistic industry source predicted that work would resume by October 1. Recession recovery in some segments of the asbestos manufacturing industry is being impeded by lack of fibers, CADMIUM - On September 9, St. Joe Minerals Corp. reduced the price of cadmium metal to $2.75 per pound. The producer price bad been uniformly quoted at $3.00 per pound since June 26, 1975. Subsequently, Amax, Inc. and National Zinc Co. reduced their prices to $2.50 per pound. By mid-September all five U.S. cadmium producers were marketing the metal at $2.50 per pound.

Jan 1, 1975

By Raymond P. Maloney

The Rhyolite mercury prospect is on the south flank of Juninggulra Mountain--a large rhyolite intrusive in the Kuskokwim River region about 36 airline miles northwest of Red Devil, Alaska. Bulldozer trenching by the Bureau of Mines exposed bedrock at intervals in a 2,000-by 3,000-foot area where previous prospecting by the owners had disclosed abundant float and several in-place stringers containing cinnabar in widely varying amounts. The additional trenching indicated that the mercury mineralization in the limited area investigated was confined to erratically distributed short stringers and to small lenses, occurring in discontinuous zones in numerous silica-carbonate dikes and sills or along their altered contacts with sedimentary rocks. The geologic relationship of the mercury-bearing silica-carbonate dikes and the nearby rhyolite intrusive is similar to that existing at several other mercury mines and prospects in the. Kuskokwim region. The depth of over-burden and the presence of permafrost were serious obstacles to bulldozer trenching, and only a comparatively small part of the mineralized area was thus investigated.

Jan 1, 1962

By L. D. Wyant

That natural gas-gasoline can be used to advantage as a refrigerant is suggested by the fact that the "make" tanks and other parts of the equipment of gasoline plants frequently become coated with frost. The experiments reported in this paper confirm this assumption and indicate that volatile gasoline can be use used to advantage in many refrigerating plants. The Bureau of Mines is making a study of wax distillates in order to find out why satisfactory lubricating oils and waxes can be made easily from certain crude oils and only with difficulty from others. In the commercial distillation of crude petroleum it is customary to separate the distillates into the following groups: (A) Gasolines and naphthas, (B) Kerosenes, (C) Gas oil, and (D) Wax distillate (consisting mostly of light lubricating oil together with small amounts of paraffin Wax).

Jan 1, 1923