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By Bernard Lewis

This report summarizes fundamental research and technical studies conducted by the Explosives and Physical Sciences Division of the Bureau of Mines from July 1, 1949, to June 30, 1950. It is the fourteenth of a series of annual reports whose aim has been to bring to the reader a résumé of the research results that have appeared in published form during each fiscal year under the authorship of members of the staff. These are referred to throughout the report.

Jan 1, 1951

By J. R. Thoenen, B. H. Clemmons, A. H. Reed

"INTRODUCTION AND SUMMARYOverall red-ore reserves in the Birmingham, Ala., area were estimated in 1910 by E. F. Burchard 4/. Since then mining has progressed into areas classed by Burchard as ""unavailable for exploitation"" under conditions existing at that time. This is understandable when it is considered that red iron ore was valued at $1.19 a gross ton at the mine in Birmingham in 19102/ and by 1948 had risen 300 percent; 6/ that skips had replaced cars in slope haulage; that mechanical loading and rubber-tired haulage had replaced hand loading and mule or locomotive haulage; and that other more efficient mining methods had been introduced. Intensive study during the intervening 40 years has been given to ways and means for upgrading the low-grade ores in the area and combining or blending them with raw red and brown ores for improved blast-furnace feed.It is reasonable to expect that future progress in mining efficiency and increased knowledge of the beneficiation characteristics of marginal ores will permit extraction of red-iron minerals now considered uneconomic.The Bureau of Mines has undertaken to restudy iron-ore reserves of the Birmingham area to determine what tonnage and grades of mineral are present; what is necessary to make them amenable to mining; what further advancement is possible in beneficia¬tion methods; and where increased production may be obtained in the area if and when required. This study has been underway for the past 2 years, but research into the beneficiation of marginal ores has been in progress at the Southern Experiment Station for the past 30 years. Many results of that research have been adopted in commercial practice in the area. Other results have not been published but are pre¬sented here in condensed form as an important factor in assessing marginal deposits with respect to their importance as ore reserves.An interim discussion of the salient features of past history and progress, as well as the data developed during the years of research in beneficiation at this station and the present field investigation, will make for a better understanding of the present position as well as be useful in evaluating future potentialities. Discussion in this paper is confined to the main Birmingham Basin area, which contains the largest concentration of hematite ores in the district."

Jul 1, 1953

By Alfred Petrick

This study gives an analysis of the copper system byproducts and discusses the identification and classification of byproduct metals and their supply systems. Arsenic, platinum-group metals, silver, gold, selenium, tellurium, molybdenum, rhenium, uranium, aluminum, magnesium, and byproduct copper, lead, and zinc from complex ores are covered. The report describes several metallurgical systems, the marginal and incremental products costs of byproduct subsystems, industry structure and organization, and the historical data on price, consumption, and supply. Supply curves are presented for about one-half of the byproduct metals studied. The study develops a conceptual framework for analysis by reviewing the present concepts of byproduct supply and the related price theory. It gives the sources of supply of the individual byproduct metals to indicate the importance of the byproduct supply to the total supply. Mills, smelters, and refineries processing byproduct materials for their metal content are identified by geographic location and company ownership, The study also includes information on the reserves-resource base supporting byproduct output, reserve estimates, and the demand aspects of each byproduct metal.

Jan 1, 1973

By R. A. Isberg

This report describes the design and implementation of UHF radio and closed-circuit television systems in the Black River room and pillar limestone mine near Butler, Pendleton County, Kentucky. Prior to designing the radio system, measurements of signal attenuation on 812 and 466 mHz were made in the slope tunnel and in the straight and level crosscuts in the mine. Two distributed antenna systems fed by two sets of base stations provide approximately 75o coverage of the mine. Passive reflectors are used for extending signals into intersecting crosscuts and two-way signal boosters will be used to extend signals to the perimeter and obstructed areas of the mine. Fourteen mine vehicles were equipped with mobile radios equipped with digital identification, alarm and status encoders. Fifteen portable transceivers also were used. Six closed-circuit television cameras provide surveillance of critical transfer points of the belt conveyor system, and the loading dock at the base of the slope and an ash disposal area in the mine. Two-way radio communication and closed-circuit television have saved considerable man. hours, increased production, reduced maintenance costs and enhanced safety. Innovative developments were the use of passive reflectors and two-way signal boosters for extending signals into intersecting crosscuts, development of lightweight signal margin measuring equipment, modifications of mobile digital encoders to automatically send status information from mine vehicles such as numbers of loads of ore delivered, hot engine, etc., and the use of CATV technology for multiplexing audio, digital and video signals onto coaxial cables from the surface to the mine.

Jan 1, 1981

By Clifford B. Farris

The natural cementation strength of retorted oil shale is the focus of this investigation. The optimum retorting temperature and residence time to obtain natural cementation strength in retorted Green River oil shale from western Colorado were determined as follows: [Optimum Conditions for Natural Cementation Maximum Residence Obtained Retorting Time at Compressive Mode of Temperature Temperature Strength' Retorting °F °C hr psikg/cm-2 Direct 1,520 822 2.0 270 19.0 Indirect 1,530 832 2.9 325 22.8] 1 Scattered samples were tested at strengths as high as 463 psi (32.6 k /cm 2) (Run 8, indirect mode) and 406 psi (28.5 kg/cm2) (Run 48, direct mode), but these high strengths were not confirmed by nearby tests. Minus 0.5-inch (1.3-cm) Green River oil shale was heated in a differential retort under conditions simulating potential full-scale retorting processes. The variables investigated were retorting temperature, residence time, retorting mode, and shale grade. Samples of the retorted Green River oil shale were moistened to optimum plus 2% (25%) moisture, compacted to 95% Proctor density, sealed and cured at 100°F (38° C) for up to 40 days. Lower curing temperatures, which are likely in the field, would probably result in significantly slower development of cementation strength, and might lower the ultimate strength developed. However, these effects were not studied in this project. The cured samples were tested for compressive strength, and correlative equations were developed for the increase of compressive strength with curing time as a function of retorting temperatures and residence time. Petrographic analysis indicated that the cementing mechanisms may be the interlocking growth of acicular hydrated calcium aluminum sulfate crystals between the contacts of retorted shale fragments. Samples of the retorted shale were also tested for optimum Proctor density and moisture. Permeability and quality of the leachate of shale from typical runs were determined. The effect of use of retort rather than tap water on compressive strength and leachate after curing was determined. The retorted shale effectively filtered several mineral constituents from the retort water.

Jan 1, 1979

By Paul M. Tyler

The literature on radium is already voluminous, but mcuh of it is too technical to be intelligible to the average reader, and there is no single publication that covers certain economic features of the radium industry. As a result of the renewed interest in the possibilities of domestic carnotite deposits a number of requests have been made to the Bureau of Mines for information, more particularly with reference to the business aspects of the industry. In order to meet this apparent need, the present paper has been prepared from material available in the files of the bureau. The technical data are compiled from various sources and are believed to be reasonably dependable, but the attempt has been not so much to achieve meticulous scientific accuracy as to brim; together facts of industrial significance and popular interest. GENERAL DESCRIPTION Radium is a brilliant white metal that melts sharply at about 700°C. and volatilizes appreciably at that temperature. With an estimated specific gravity of nearly 6.0, it is more than twice as heavy as aluminum and 25 per cent lighter than irons. Although it has been isolated in its metallic state, it is not used in that form, partly because it tarnishes rapidly even in dry air (forming a nitride), partly because of the greater expense of reducing it to metal, and partly because of the difficulty of dealing with such minute quantities of material. It is used always in the form of its compounds, the most important of which from the vie point of utilization are the bromide, chloride, and sulphate.

Jan 1, 1930

By G. St. J. Perrott, G. W. Jones

"In the course of its investigations pertaining to the promotion of safety the Bureau of Mines is actively engaged in investigating all promising materials that may be of value in rendering methane or other combustible gases, vapors, or solids less inflammable.Added substances are of value if such additions narrow the limits of inflammability, raise the ignition temperature, lower the speed of propagation of flame, or reduce the maximum pressure developed. Of major importance is the effect of added materials on the limits of inflammability, because methane is the chief combustible s liberated in mines, considerable work has been done with extinguishing agents on methane flames. For obvious reasons, a substance to be of value for the extinction flames should be a gas, or a liquid having a sufficient vapor pressure to give concentrations of the vapor in sufficient amounts to extinguish the flames or markedly narrow the limits of inflammability. The substance should be nontoxic, cheap, and noncorrosive and must be incombustible. Solids, such as rock dust, are undesirable and of little value for combustible gases because they soon settle out of the atmosphere, and their flame- extinguishing value is thereby lost. There are at present only a few gases and vapors-for example, nitrogen, carbon dioxide, and carbon tetrachloride-which meet these requirements.The extinction of methane flames by nitrogen, carbon dioxide, and argon has been reported by Coward and Hartwell 4; the extinction by water vapor by Coward and Gleadell 5, and the extinction by helium and carbon tetrachloride by Coward and Jones 6."

Oct 1, 1930

By Wilton Johnson

Native asphalt was produced by three companies in two States, Texas and Utah. Bituminous limestone, used primarily as a paving material for street and road repair, was produced by one firm, R. L. White Co., Uvalde County, TX. Gilsonite, a solidified hydrocarbon found only in Colorado and Utah, was mined by two firms, American Gilsonite Co., a division of Chevron Resources Co. (a subsidiary of Standard Oil Co. of California), and Ziegler Chemical and Mineral Corp. Hydrocarbon Mining Co. (a subsidiary of Oberon Oil Inc., a Utah corporation) closed its mining operation during the year.

Jan 1, 1988

By A. C. Fieldner

This report is the fourth of a series of annual summaries of research and technologic work on coal by the Technologic Branch of the Bureau of Mines. The coal research program of the Bureau has been broadened and made more flexible to adapt it to changing conditions and needs of the coal industry, and as a result information as to the properties and composition of coal has been increased and new and improved practices in mining, preparation, and utilization of coal have been devised. The present

Jan 1, 1940

By S. H. E. Phillips

This report describes the initial feasibility, the development and the field demonstration of a system for shaft sinking employing a high energy mechanical impact rock breaker and a compatible muck disposal system. The increased shaft sinking rates, decreased costs and improved safety conditions obtainable by the elimination of the less efficient conventional drill-blast-muck cycles are discussed. Four shaft sinking concepts utilizing the impact rock breaker in various shaft configurations are developed and the field demonstration in a rectangular shaft is described. The progress achieved, the problems and their remedies and the proposed modifications to improve the machine are described.

Jan 1, 1978

By D. Harrington

Every few weeks United States newspapers of 25 or 30 years age ran scare-heads telling of some mine disaster, which was a first-page attraction for a day or two and then was forgotton until another disaster occurred a few weeks later. Interspersed with these disasters were the so-called sniping mine accidents, causing the death of one or two mine workers. The summation of all types of mine fatalities usually exceeded 3,000 a year. In the period 1906-10, inclusive, there wore 84 major explosion disasters (or about 17 per year) in united States coal mines; the fatalities resulting from those disasters numbered 2,388 for the 5-year period. These frightful catastrophies helped to cause the total number of fatalities in our coal mines for the 5 years (including the fatalities from major explosions) to reach the enormous total of 13,288, an average of 2,658 per year. In addition, some hundreds of other typos of mining accidents swelled the annual fatality list to upwards of 3,000. This admittedly deplorable condition created so much Nation-wide comment that Congress was impressed with the necessity of having something done by the Federal Government with a view to trying to halt at least sonic of the excessive loss of life in our mines; in consequence, the Bureau of Mines was created and began to function in July 1910.

Jan 1, 1935

By Gene R. Reid

The contract objective is the development and in mine testing of an Automatic Fire Control System (AFCS) for mobile underground metal mining equipment. The effort described by this report covers the period from June 21,1975 through June 30,1976 and accomplished the following tasks: ? Preparation of Data Handling Plan and data acquisition which included visits to twenty mine sites in eleven states, visits to Bureau and MESA facilities, and a literature survey. ? Data analysis which determined the most hazardous type of vehicle for use in the demonstration, and design requirements for the AFCS, ? Development of recommended design concepts for the AFCS. ? Design and development of the AFCS including tests on a full-scale mock-up of a load-haul-dump (LHD) vehicle. ? Underground fire tests on an ST-2B-LHD vehicle at the Hecla Lakeshore mine Casa Grande, Arizona.

Jan 1, 1976

By LeRoy D. Loy

The disposal of excess overburden from surface mining can be accomplished by use of a reclamation technique entitled head-of-hollow or valley fill. This report attempts to assess current valley fill regulations and practices, identifies inherent benefits and deficiencies, and develops concepts to enhance fill technology.

Jan 1, 1978

These proceedings consist of an introduction, nine descriptive papers, and a summary. The first paper is an overview of the respirable dust research program, the second paper describes the Mining Enforcement and Safety Administration's proposed changes in the respirable dust enforcement program, and the third paper describes respirable dust measurement. The remaining papers, by Bureau and contractor personnel, describes methods of reducing the amount of respirable dust to which coal miners are exposed. Of the six methods of reducing exposure to respirable dust described, two are methods of preventing or reducing the amount of respirable dust raised during mining operations, two are methods of collecting or removing dust after it has been released into the mine atmosphere, 2nd two describe methods that are combinations of prevention and collecting .

Jan 1, 1977

A general analytical solution of the effect of an inclined contact separating two media of differing electrical properties on a normally incident plane electromagnetic field has been given (Geyer, 1972). These solutions for the electromagnetic response at any observation point P(r, [u]) are given in the form of inverse Lebedev-Kontorovich transforms. Two modes of excitation are considered: (1) case where current density flows across strike of the contact separating the media of differing electrical properties (only Er , E [u] , and Hx differ from zero) and (2) case where current density flows along-strike (only Hr , H [u] , and Ex differ from zero). The electromagnetic fields in the frequency range of interest and for the rock conductivities under consideration are quasi-static in nature so that to a first-order approximation the horizontal magnetic field at the surface of the earth is constant and continuous across the discrete discontinuity in resistivity for case (1) above, and so that the tangential derivative of the horizontal electric field at the surface of the earth is constant and continuous across the discrete discontinuity for case (2) above. Of course, it is well known that where large horizontal gradients in conductivity exist, there also exists large anomalous components of the vertical magnetic field (Weaver, 1963). The recognition of such anomalous components and their magnitudes due to the presence of lateral resistivity changes in the overburden becomes very important in any wavetilt type measurement which may be used to locate a miner. When the lateral change in resistivity becomes quite large, the integral solutions (expressed as Lebedev-Kontorovich transforms) simplify considerably and allow ready numerical evaluation. Examples of the amplitude and phase responses of the radial electric, horizontal electric, and vertical magnetic field in the vicinity of the contrast in resistivity are shown in Figures 2, 3, and 4. Of particular significance is the fact that the anomalous vertical magnetic field is three orders of magnitude larger near the contact than far from the contact. This fact implies that where large resistivity contrasts do occur in the rocks overlying mine workings, that significant errors may be present in wavetilt measurements as used above for location criteria! Another observation insofar as the anomalous vertical magnetic field is concerned is the linear variation of phase as one proceeds away from strike in induction number (increased distance or frequency). For a pulse-excited communications system this phenomena would have a bearing on where the zero crossings would occur (i.e., 'pulse breadth') in the transient coupling between any given source-receiver configuration and at any given receiver site.

Jan 1, 1973

By Parviz F. Rad

The Bureau of Mines conducted groove cutting experiments in marble, lime-stone, granite, and quartzite with a 7-inch disk cutter under a normal thrust of 7,000 lb. The values of muck weight per unit length, specific energy, cutting coefficient, and groove depth for each of these rocks were determined for groove spacings ranging from 0.1 to 4 inches, and from these results the values of optimum and critical spacing were computed" The results indicate that compressive strength may be used to predict some of the cutting characteristics of the independent grooves. Considering all the cutting characteristics, particularly those for the interacting grooves, Shore hardness, coefficient of rock strength, and torsional velocity correlate with cutting characteristics better than do other physical properties. Some of the field applications of the principles established in this report are identified.

Jan 1, 1974

By E. G. King

Heats of formation of three crystalline oxides of rhenium (Re02, ReO3 and Re207) have been determined by the method of solution calorimetry, using an aqueous perchloric acid--ceric perchlorate solvent. Copper metal and cupric oxide were utilized as auxiliary substances. Heats were determined at 298' K for the reactions Re + 2CuO = Re02 + 2Cu, Re + 3CuO = ReO3 + 3Cu, and 2Re + 7CuO = Re207 + 7Cu. Standard heats of formation were derived using the value of -37.23 ±0,15 kcal/mole as the heat of formation of CuO. The standard molal heats of formation of the rhenium oxides were determined: Re02, -107.3 ±0.8 kcal; ReO3, -140.8 ±0.9 kcal; and Re207, -301.9 ±1.8 kcal.

Jan 1, 1969

By Arno C. Fieldner

From July 1, 1949, to July 1, 1950, the Bureau of Mines conducted the research and technologic work on coal and coal products that is summarized in this report. The research, described in this fifteenth of a series of resumes, is presented in more detail in publications (see footnote references) that appeared during the fiscal year, though in some cases research data are given that have not been published elsewhere. Results of research in the experimental coal mine, on explosives, and on gas and dust explosions will be found in Bureau of Mines Report of Investigations 4228, Annual Report of Research and Technologic Work on Explosives, Explosions, and Flames, Fiscal Year 1950. An over-all view of our coal, oil, end natural-gas reserves was presented, and the future possibilities for the, production of synthetic liquid fuels from coal were delineated.3/

Jan 1, 1951

By Ernest A. Curth

Statistics For 1956-66 show that mine transportation accidents accounted for 19 percent of fatalities in bituminous coal mines, second only to roof deficiencies as a cause of death. Productivity per man-shift increased from 10.2 tons in 1956 to 18.4 tons in 1966, but the fatalities per million man- hours of exposure also increased from 0.19 to 0.21 during that same period, indicating that transportation hazards still persist. Consequently, the Bureau of Mines reviewed the transportation fatalities that occurred in bituminous coal mines during 1956-66. The data were processed by computer to find what constitute hazardous conditions and unsafe actions as well as to correlate occupation and age of victims, transportation type, and mine production. Environmental factors and equipment defects which create hazards, as well as unsafe actions of personnel, were determined for each type of mine transportation: Track haulage, mobile nonrail haulage, conveyors, hoists, automotive operations, and front -end loaders, and for transfer stations (loading points, slope and shaft bottoms, surface transfers) and railroad yards. Man-trip accidents, a group with a catastrophe potential, also were analyzed. The basic design and operational features of each transportation type were outlined and procedures considered safe in the light of accident experience were suggested. Findings show that unsafe actions of personnel and hazards created by environmental deficiencies or equipment malfunctions contribute equally in causing transportation accidents. Accordingly efforts should be directed toward improving working conditions, equipment maintenance, and education and training of employees. The trend is toward using safer modes of transportation, notably conveyors. More attention should be given to track haulage operation, railroad yards, and nondestructive field testing of materials.

Jan 1, 1971

By K. C. Dean

During the investigation of the occurrence of manganese deposits in western United States, the Bureau of Mines collected 2-ton samples from three oxide manganese ores in the Columbia and Elberta Mining Districts, Tooelo and Juab Counties, Utah. To determine the amenability of these ores to standard ore-dressing methods: of concentration, extensive laboratory tests were made. The Wildcat property, one of those sampled, is 7 miles east of Fairfield, Tooele County, Utah. The ore is described as a replacement deposit and occurs along fracture and bedding planes of shale and limestone. Experimental work was done on a sample taken from a stockpile at the mouth of the shaft. The Wildcat manganese ore is intermediate in grade (25.7 percent manganese) and contains clay as the principal gangue constituent. A high-grade product was obtained with high recovery of Manganese by simple washing.

Jan 1, 1949