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This publication summarizes, for all interested parties, the research, development, and demonstration in-house projects programed by the Bureau of Mines for fiscal year 1981 (October 1, 1980 - September 30, 1981) under its Minerals Health and Safety Technology program. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the system technology required to create a healthier and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1981

By Piyush K. Dutta

This report describes the design, development and manufacture of a prototype quiet hard rock stoper drill and results of its field tests. It is shown that the stoper drill noise level can be reduced from 118 dBA to below 100 dBA by using this design. The design concept of this drill is based on a valveless independent rotation system, use of an integral muffler and pivot mount. The drill was manufactured in a standard commercial drill manufacturing setup and organization. The design and production technology proved that commercially viable quiet drills can be made available for mine use.

Jan 1, 1985

By Albert L. Toenges

The fuel requirements for industrial and domestic consumers in New England, in normal times, are supplied almost entirely by fuel oil, anthracite, and bituminous coal. A shortage of these fuels occurred during the war. This shortage was caused by: (1) The diversion of oil to military uses; (2) the use of railroad and boat facilities that ordinarily would transport coal for the transportation of war material; (3) the inability of coal mines to apply the increased demand for coal which resulted from the conversion from oil to coal by domestic and industrial consumers; and (4) the increased demand of war industries for coal. Because of this Critical fuel situation, an investigation was made of possible sources of fuel nearer to points of consumption in New England.

Jan 1, 1948

By Louis C. Srichta

The rapid depletion of known high-grade ore deposits of the Tri-State district and the recognized need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores led to Bureau of Mines examination of several abandoned mining areas for possible deposits adapted to strip mining. Examination of the North Empire tract in Cherokee County, suggested that mineralized zones contiguous to previously mined 2e deposits presented probabilities of meeting the requirements for an open-pit mine - hence the tract was selected for further investigation by churn drilling. The zinc-lead deposit on the property is in a sink-hole structure that has been subjected to intense deformation and silicification. Numerous shafts, mine dumps, and surface caves are evidences of exploitation of an extensive area. The reported active mining period was 1895 to 1905. No production records are available, but it is generally stated locally that the value of the mill products exceeded $2,000,000 which represents considerable production, considering the low metal prices of that epoch.

Jan 1, 1950

By R. B. Prater

The Bureau of Mines conducted research to separate the F from byproduct Zn concentrates obtained from fluorspar (CaF2) production, as part of the Bureau's effort to devise efficient, environmentally acceptable technology for recovering Zn from resources considered undesirable by Zn producers. Sulfuric acid (H2SO4) was found to be effective in F removal, while ammonium carbonate [(NH4)2C031 was not. The most important variables for reducing the necessary residence time were found to be temperature and agitation. Optimum leaching conditions were 75° C and 500 r/min for 2 h at 40 pct solids with 0.2 g acid per gram of concentrate, which resulted in a 98.3-pct F extraction. Zinc losses during F removal were in the range of 2 to 3.3 pct. Other elements such as Fe, Cd, Ca, and Cu were also partially dissolved. About 93 pct of the F was removed from the leach solution by neutralization and precipitation with calcium hydroxide [Ca(OH)2]. Additional treatment might be necessary to limit the buildup of soluble elements in the recycled leach solution.

Jan 1, 1985

By P. E. Churchward

The Bureau of Mines developed a process using amines for recovering tungsten as ammonium paratungstate from alkaline leach liquors without producing synthetic scheelite as an intermediate product. Over 90 pct of the tungsten in low-grade scheelite or ferberite concen-trate was recovered as ammonium paratungstate by (l) autoclave leaching the concentrate with Na2CO3, (2) solvent extraction of the acidified leach liquor with kerosine solutions of either a quaternary amine (Aliquat 336) or a primary amine (Primene JM-T), (3) stripping the tungsten values from the quaternary amine with ammoniacal NH4C1 or from the primary amine with NH4OH, and (4) crystallization of ammonium paratungstate from the strip liquor. Reagent consumption in pounds per pound of W03 recovered was, for the quater¬nary amine, 3 Na2CO3, 3.5 H2SO4 , 2.2 NH4Cl, 1 NH3, and 0.4 glacial acetic acid; for the primary amine, it was 3 Na2CO3, 3.5 H2SO4, .06 NH4Cl, and 0.9 NH3. Both reagents extract molybdenum along with tungsten. Silicate and phosphate are partly extracted and contaminate the product; leach liquors containing these impurities require preliminary purification.

Jan 1, 1966

By Nirander M. Safaya

Revegetation success on surface mined lands is dependent upon the nature of the plant growth media. Soil physical and chemical properties dictate the needs for specific reclamation and subsequent management practices. Field experiments were conducted at six coal mine sites in Oliver and Mercer Counties, North Dakota to determine the subsequent effects of a single application of selected amendments on spoil and topsoils over the five year period, 1974-1978. Considerable variations in the physical and chemical properties were found in mine spoils from site to site. The texture of spoils ranged from sandy clay loamy at North Beulah I to loamy at Glenharold, and from sandy loamy at North Beulah 3 and South Beulah sites to loamy sands at the Center site. The pH of the sites ranged from 6.5 at South Beulah to 8.2 at North Beulah 3. In many cases, the pH values of mine spoils were not significantly different from the topsoils. The electrical conductivity (ECe) did not exceed 6 mmhos cm-1 at the test sites even though in other studies much higher values were recorded in the same vicinity. The spoils from Glenharold and North Beulah test sites can be classed as moderately saline, and those from Center and South Beulah as non-saline. The sodium adsorption ratios (SAR) varied from less than 1 to 32, with highest values in the spoils of North Beulah 3 followed by Glenharold; all other sites were nonsodic. Lowest SAR values (less than 1) were found in the topsoiled sites at South Beulah and Center. Spoils of North Beulah 3 test site were highly calcareous, followed by North Beulah 2 and Glenharold. Center mine spoils which were the least calcareous of the test sites, showed the calcium carbonate equivalent three times higher than that of the topsoil. The average calcium concentrations in the spoils of North Beulah 3 and South Beulah test sites were -13 and 14 me 100g -l while at North Beulah 2 and Glenharold test sites 25 and 22 me 100-1-1 were recorded, respectively. The overall magnesium concentrations ranged from an average of 4 to 16 me 100g 1. Sodium concentrations in all sites never exceeded 10 me 100g-1. Phosphorus concentrations on the average at North Beulah 1, North Beulah 2, and Center were 10.2, 4.6, and 22.2 µg g -1 spoil, respectively. Concentrations of potassium ranged from 200 ppm at South Beulah site to more than 375 pp in at the Glenharold site. High concentrations of sulfates (239-2778 µg g-1) seem to contribute to the salinity in these spoils. Chloride concentrations of spoils were low and never exceeded 40 µg g-1 spoil. Based on established critical levels of deficiency for micronutrients in agricultural soils, it seems that none of these were deficient. However, controlled environment experiments did reveal increased plant growth responses when some micronutrients were added to the mine spoils. Treatment effects were highly site specific depending on the nature of the soil/spoil characteristics and, of course, the properties of the various treatments. While slack coal amendment to the spoils at North Beulah 2 site affected significant increases in a large number of variables (both major and trace elements), amendment of the topsoils at the South Beulah test site with leonardite resulted in significant decreases in a number of variables, particularly trace elements. Spoils at Glenharold and North Beulah 3 demonstrated the fewest significant changes due to amendments. Calcium, magnesium, strontium, organic matter and nitrogen were consistently increased from site to site with the addition of lignitic materials. Other spoil/topsoil physical and chemical properties (30 variables) as affected by amendments and time are discussed.

Jan 1, 1982

By Frank E. Williams

Nuclear detonation data were accumulated, studied, and evaluated by the Bureau of Mines to visualize how nuclear explosives might be used in a shale?-oil industry, The evaluation shows that the Green River Formation at the semi-isolated locale of Piceance Creek Basin, in northwestern Colorado; is thick and widespread enough to warrant consideration of nuclear mining in lieu of conventional methods, Because cost data for nuclear explosions are limited; cost comparisons are made largely by assumptions. Also described are the history of the shale-oil industry, the geology and size of oil-shale resources; and conventional mining methods and processing technology.

Jan 1, 1969

By R. Hogg, S. Chander

"An overview of various physical and interfacial characterization methods for use in mineral processing is presented in this paper. The availability of a large number of characterization techniques and commercial instruments requires that the reliability and limitation of each be carefully examined. The choice of a method may depend upon the manner in which the information is to be used, for example in development of new processes, plant and process design, plant control, problem solving, etc. IntroductionThe behavior of particulate systems, in mineral processing and other applications, is primarily affected by the physical characteristics (size, shape, surface area, pore structure) of the particles and the nature of the different solid-fluid interfaces present. Mineral processing operations in general are either designed to modify and/or control physical and interfacial properties (grinding, classification, agglomeration, etc.) or are strongly influenced by them (flotation, flocculation, solid/liquid separation, etc.). Characterization of physical and interfacial properties should be an integral part of the development of new processes, plant and process design, and routine plant operation.Our purpose in preparing this article has been to present an overview of the current status of characterization, to point out areas of weakness, and to discuss the reliability and limitations of the various techniques, procedures, and instrumentation available. For more detailed discussion of methods, etc., the reader is referred to standard references.Sampling particulate solids.Sampling is a critical factor in any procedure for characterizing particulate materials — the reliability of characterization data is ultimately limited by the extent to which the sample used was truly represen¬tative of the population from which it was taken.Sampling from particulate solids involves two basic problems: (1) the selection of a random', unbiased sample and (2) choice of the appropriate sample size.The problem of sample selection involves the design of a sample collection procedure that ensures that every kind of particle in the population has the proper chance of being included in the sample without bias. Specific procedures such as the well-known cone-and-quarter technique have been developed and are discussed at length in the literature on particle characterization (Allen, 1981: Herdan, 1960: Gy, 1982)."

Jan 1, 1989

By Raja V. Ramani, Robert L. Frantz

"The House/Senate Joint Conference Committee has instructed the Bureau of Mines to have the Advisory Committee on Mining and Mineral Resources Research review on an annual and simultaneous basis each generic mineral technology research center (GMTC). In order to accomplish that review promptly and uniformly, committee members have revised and approved an in-depth questionnaire. That document formed the basis of their review. The information provided by that questionnaire was an important factor in their recommendations concerning the future direction of the program; a presentation was made at the last National Plan Update.The comprehensive nature of the questionnaire and the scope of the information contained therein make it an excellent retrospective of the Center. Having a clear vision of where the Center has been and knowing where it is now will help guide it into the future. It is felt that such a detailed view of the Center's facilities and research program will be of value to Center personnel and Advisory Committee members.Each aspect of the questionnaire has been examined, answered in detail, and documented throughly. With the completed questionnaire as a guide, this volume examines the research program, Center personnel presently active on GMTC projects, number of graduate degrees granted with GMTC support, GMTC publications, degree of individual interaction, technology transfer, the reference center, GMTC equipment and facilities, and any envisioned plans for future research. It is hoped that this volume will serve as a review of the years 1984-1988, the first four years of the Center's operation."

Aug 31, 1989

By W. H. Oppelt

The continuous gasification of lignite in an externally heated alloy-steel re-tort was investigated by the Bureau of Mines, Grand Forks, N. Dak., from 1945 to 1951. The main objective of the long-term experimental program was to obtain data on the mechanical performance of this type of gasification retort, particularly the alloy-steel heat-transfer surface of the retort, when operated on large pilot-plant scale. At the same time, extensive experimental data were obtained concerning the effect of process variables and the effect of a limited number of design modifications on gasifier performance. In the period covered by this progress report 4 pilot-plant runs totaling 2,879 hours of operation were completed with the rolled-plate, 310-alloy reaction tube. Over 30 million cubic feet of gas, having H2-CO ratios from 2.1 to 4.4, was made by the partial gasification of 636 tons of 1-1/2-by 3/8-inch natural lignite. Rates of gas generation were from 8,200 to 14,300 cubic feet per hour. Three of the four runs were carried out with the lowered gas offtake or continuous-annulus design modification of the gasification retort. In the final run of the series, gasification of lignite from seven different mines in North Dakota and Saskatchewan, Canada, was investigated at similar combustion-space temperatures and lignite and steam feed rates.

Jan 1, 1955

By A. L. Engel

Production of chromite in California has been from many small, high-grade mines. The opening of the Purchase Depot at Grants Pass, Oreg., in 1951 has stimulated chromite mining in California, and a large number of properties are being reexamined as there is a possibility that some low-grade ores from many of these properties can be beneficiated to meet the purchasing schedule. The Bureau of Mines in its program of conservation is continuing ore-dressing tests on chromite ores to better evaluate their potential. This report is a compilation of preliminary concentration tests on samples from five different properties in California. The concentration tests were made on ores from the David mine, Butte County, the Seiad Creek mine, Siskiyou County, the High Plateau mine, Del Norte County, Bud's mine, Tuolumne County, and tailings from the Miller concentration plant in San Luis Obispo County, Calif., to determine the possibility of beneficiating these ores so that they will meet the specifications for the Government stockpile.

Jan 1, 1956

By S. H. Ash

THIS REPORT covers the second in a series of five projects into which the Conowingo tunnel system has been divided for geographical and practical reasons. It outlines the construction work contemplated-to sink two shafts on the line of the main tunnel that are designated the Nos. 9A and 11 shafts, to turn off from the No. 9A shaft the Lansford and Lykens laterals, and to drive portions of the main tunnel. An emergency pumping plant, consisting of 2 separate pumprooms, each containing 3 horizontal-type centrifugal pumps of 100,000-gallons-per-minute (g. p. m.) capacity, will be constructed at the No. 9A shaft. From the No. 11 shaft will be turned off the Trevorton lateral and portions of the main tunnel, which will connect with the section driven from the No. 9A shaft. Under the proposed project, the Lansford lateral will be driven for a distance of 2 miles, the Lykens lateral for a distance of 10.56 miles, and the Trevorton lateral for a distance of 20 miles. To drive the Lykens and Trevorton laterals for the distance indicated, several construction shafts and slopes must be sunk to permit efficient and safe construction.

Jan 1, 1955

By Charles M. McCulloch

This Bureau of Mines report discusses the principles of using computers to draw maps and plot geologic data of mining areas. The types of maps that can be drawn by a computer are reviewed, using as examples two separate areas where poor roof and gas emissions caused mining problems. Such maps can be used not only to help identify problem areas, but also to predict areas where problems could occur, thus giving mine operators time to work out solutions prior to mining. The average cost of a computer-drawn map for a mine property is less than $100, including computer time and man-hours for data preparation.

Jan 1, 1976

By L. C. IlsLey

Permissible electric nine lamps are approved with the. understanding that if actively marketed they will be listed in Bureau of Mines publications so that state mine departments, compensation bureaus, mine operators, miners, and others interested in safety equipment for mines may know the permissible lamps available and the important safety features of each. The last list of permissible electric mine lamps was issued as Report of Investigations 33045 in June 1936, a supplement to Bulletin 332.6 All lamps described in Bulletin 332 are either obsolete or have been materially modified, as covered by extensions of the original approvals. These modified lamps and the new designs approved since 1930-totaling 12 cap lamps and 23 lamps of miscellaneous types-comprise the present list of actively marketed permissible electric mine lamps. This bulletin presents the Bureau's test requirements and procedure relative to permissible electric mine lamps and describes briefly the lamps, giving tabulated details of each.

Jan 1, 1942

By George T. Motock

The author prepared the following report as the result of a trip to Germany in the summer of 1945 for the Technical Industrial Intelligence Commitee Subcommittee on Metals and Minerals. The purpose of this committee, which functions under the Joint Intelligence Committee of the Joint Chiefs of Staff of the United States Armed Forces and of which the Bureau of Mines

Jan 1, 1946

By John G. Parker

Many of the so-called minor metals are derived as byproducts from the processing of lead and zinc concentrates in which they occur as minor constituents. Concentrates from some lead-zinc mineral deposits are more enriched in metals such as cadmium, arsenic, bismuth, silver, and selenium than are others, and these sources offer a continuing, assured supply of certain of these metals. Despite the age of the data collected, the Bureau of Mines feels it to be highly desirable to publish due to its relevance to the objective of the study which was to ascertain the flow of minor metals from certain smelter feeds Efforts to trace these metals through the complicated lead and zinc processing steps included trying to ascertain losses and mode of loss of these metals. Losses of some metals in processing may be surmised as occurring in gaseous and other emissions, or possibly in slags and residues.

Jan 1, 1979

By Herman W. Sheffer

This report describes and discusses present-day leaching technology employed to recover copper from low-grade mine and dump materials derived from the exploitation of copper ore deposits in the Western United States. Illustrations of the integral parts of the leaching, precipitation, and recovery operations at several copper-producing companies are presented. Schematic drawings are included to present typical flowsheets of leaching and precipitation operations. Operational problems common to most copper leaching and precipitation plants are discussed. Areas of present and future research to improve leaching techniques are cited.

Jan 1, 1968

By M. P. Ahola

This U.S. Bureau of Mines report presents an overview of the use of three unique numerical modeling methods to analyze cutter roof problems in underground coal mines. Cutter roof failures are common in coal mines where the immediate roof is comprised of thin laminae exposed to highly biaxial tectonic stress fields. The predominant mechanism for failure is assumed to be excessive shear stress at the entry corners exceeding the shear strength of the rock. Early work in this area utilized the finite-element method and then the boundary-element method to analyze several cutter roof control measures. Various stress control measures were simulated to estimate their respective effects on reducing the high levels of shear stress at the entry corners. More recent studies made use of the discrete-element method. This method was used to take the analyses beyond the elastic continuum limits to simulate the propagation of a shear fracture and subsequent redistribution of stress within the mine roof. A simple roof bolt model was implemented to show the benefits of bolting to increase the resistance to shearing and separation along horizontal bedding planes and maintain roof stability.

Jan 1, 1991

By D. Harrington

For several years, or from about 1932 to 1935, inclusive, the coal industry of the United States had an excellent record as to coal-mine explosions. In 1937 and in 1938 to date there has been a definite increase in the number of explosions attended by considerable loss of life and property damage. In most of these explosions one important underlying and contributing cause has been lack of sufficient (or at least efficient) ventilation to properly dilute and remove explosive gas from the mine. This increase in explosions indicates that. the lesson taught through bitter experience, many times in the not far-distant past, of the need for good ventilation is frequently being overlooked, partly because the relatively good experience of the industry in the past several years has made many mining people forgetful. Moreover mining practices are rapidly changing, and in some instances the changes are being made with little if any regard for safety. It appears, therefore, that a review of some ventilation principles and practices should be of value in preventing further disasters; this paper has been prepared with that object in mind. In coal mining the need for thorough ventilation of all underground working places is recognized by both mining practice and law; such ventilation is generally obtained by the use of fans that circulate a quantity of air much in excess of the quantity of coal produced, by weight as well as by volume. For example, in a relatively small mine producing 1,000 tons of coal per day and circulating 100,000 cubic feet of air, which is by no means abnormal, 2,000,000 pounds of coal and approximately 10,900,000 pounds of air would be moved out of the mine every 24 hours. Because of the need for adequate dilution and removal of methane issuing or likely to issue from mine strata and for removal of the carbon dioxide formed by coal and timber oxidation up-to-date coal mines usually provide an air volume which if adequately coursed not only removes these gases but also the gaseous products of the detonation of explosives (which may include carbon monoxide, hydrogen sulphide, nitrogen oxides, carbon dioxide, and nitrogen) and the carbon

Jan 1, 1938