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This Bureau of Mines publication contains the texts of the four papers presented at the May 6-7, 1980, seminar on the role of overburden analysis in surface mining. Coverage includes the geologic distribution of pyrite and calcareous material and its relationship to overburden sampling, overburden sampling and analysis, use of soil-overburden data in mine planning and development, and minesoil classification.

Jan 1, 1981

By Kenneth C. Ko

An engineering investigation was carried out on the technical and economic feasibility of implementing flexible liner/backpacking support systems In an advancing tailgate longwall mine. The system for a model mine consists of a circular tube constructed of liner plates and flyash backpacking. Flyash is pneumatically stowed into the tailgate. Small amounts of cement may be mixed to improve the support capability of the fill In difficult local ground conditions. Water is added inside the nozzle immediately prior to spraying. Results of theoretical analyses and a field test show that the designed system is technically feasible, can be cost-competitive, provides more stable ground conditions, and can Increase productivity and coal recovery, when compared with existing retreat longwall systems. In certain mine layouts, the new system can reduce the direct mining costs by a significant amount. The system would be particularly applicable to deeper coal beds with bad ground conditions.

Jan 1, 1980

By J. J. Shields

This study by the Federal Bureau of Mines concerns different methods of face haulage used with various types of continuous-mining machines, mobile-loading machines, and track-mounted equipment under varying roof and bottom conditions and in coalbeds of varying thicknesses. This report is the ninth in a series on mechanical mining in bituminous coal mines. Reference to the reports previously published is made in appendix III, p. 106. Use of modern mining equipment in bituminous coal mines has resulted in increased productivity at the face. This especially is true where continuous-mining machines are used, and the supervision is good. Previous methods and equipment for moving coal from the face became inadequate and had to be improved to restore balance to the mining systems. Sometimes new equipment was needed to improve the face haulage, and in some instances, a new combination of existing equipment was used. Detailed studies of face haulage methods were made at 13 mines in Pennsylvania, West Virginia, Ohio, and Illinois to compare their effectiveness and to describe fully the conditions under which each method was used.

Jan 1, 1960

By Zsuzsanna Zborovszky

Study of different parameters (minimum discharge voltage, minimum discharge current, wire electrode diameter, speed of separation, electrode materials, overlap of the electrodes, etc.), their direct effect on the power going into the discharge, and their indirect effect on the possibility of obtaining ignition with an 8.31% methane-air mixture from a resistive circuit. Critical evaluation of the Cadmium disc breakflash (the presently internationally recommended test apparatus). Description of experimental setup and apparatus.

Jan 1, 1974

By J. R. Thoenen

This circular is part 6 of the third paper (entitled "Excavation") of a series summarizing the technical problems involved in the production and preparation of sand and gravel. Part 1 discussed the use of power shovels, draglines, and excavator cranes; part 2, power scrapers, slackline cableway excavators, and hydraulic monitors; part 3, hydraulic, clamshall, ladder, and diaper dredges; part 4, haulage equipment, particularly industrial cars with locomotive or hoist as the motive power; part 5, conveyor belt, motor truck, pump and pipe line, towboat and barges, and aerial-trams haulage. This circular discusses the application of these various types of equipment to the different types of sand and gravel deposits and contains a reference bibliography. It completes the discussion of excavating problems.

Jan 1, 1936

By George H. Holmes

The water situation in Nevada mineral and related industries is described in this report. It contains information on the sources and adequacy of supply to current operators, requirements and uses, quality and costs, geography, hydrography, precipitation and evaporation characteristics, and Nevada water laws. Also, information is given on the water requirements of one public utility powerplant, and the source and consumption of water in four major cities. Water distribution at 24 operations is shown on schematic waterflow diagrams. The mineral industries of Nevada in 1962 used 8.6 billion gallons of nee' water and reused 3.8 billion gallons for a total usage of 12.4 billion gal¬lons. The copper industry was the major water user. The 1962 value of all mineral production in Nevada was $85.5 million. The large amount of water required to maintain this high production is obtained principally from ground-water sources in alluvial valleys and the permeable rock formations of some mountain ranges. Some water is also obtained from perennial streams and springs. Sources of water utilized by existing industry ore near most mineral industry operations; however, seven companies are forced to pipe water distances ranging from 2 to 8 miles. Although water supplies of presently operating companies are adequate at most operations, several companies resort to large-scale reuse of water as a matter of conservation and economics. Acquisition of water by new operators is possible but takes considerable negotiation. Water rights, surface and underground, are controlled by the State. The quality of the water is satisfactory for most purposes. Analyses of 19 samples, listed in the appendix, show the range in water quality at various plants throughout the State. Costs of delivering new water to current operations range from 2 to 26 cents per 1,000 gallons with an average of 10 cents per 1,000 gallons for power and maintenance. No firm costs for recirculating water were available; estimated costs range from 1.5 to 2.5 cents per 1,000 gallons. The mineral-product value of the entire Nevada mineral industry in 1962 was equivalent to $10 per 1,000 gallons of new water and $26 per 1,000 gallons consumed. Projection of the 1962 water requirements of the Nevada mineral industry indicates that the demand for new water will increase from 8.6 billion gallons in 1962 to 11.9 billion gallons in 1980, a 43-percent increase. Water requirements ill the year 2000 are estimated as 14.8 billion gallons, an increase over 1962 water demand of 78-percent.

Jan 1, 1966

By Frank E. Cash

The work of the United States Bureau of, Mines is concerned primarily with the prevention of accidents in the mining, petroleum, and allied industries. This report analyzes the fatal accidents in the coal mines of Tennessee and gives the pertinent factors in tabular and descriptive form, with interpretations and suggestions to operators, workers, and the State Division of Mines for the future prevention or reduction of accidents in coal mines. ACKNOWLEDGMENTS This study was made possible through the cooperation of A. W. Evans, chief mine inspector of Tennessee, and his secretary, Miss Hiliary Penny, who made available the department records and assisted in the segregation and assembly of the data.

Jan 1, 1935

By Allan E. Martin

As part of a comprehensive investigation of tie mechanism of desufurization of iron and steel by slags, the Blast Furnace Studies Section, Metallurgical Division, Bureau of Mines, in cooperation with the Institute of Technology-, University of Minnesota, has made a study of the forms in which sulfur occurs in blast-furnace slag. This report presents data on the three sulfides most important in iron smelting, namely, ferrous sulfide, manganous sulfide, and calcium sulfide. The tendency of these sulfides to form colloids in the molten slag was determined by an examination of quenched samples with an ultramicroscope. Vogt5/ conducted experiments on sulfide silicate melts and examined synthetic blast-furnace slags in a partly crystallized condition. His conclusions were that FeS, CaS, and bins, or isomorphous compounds, such as (FexCay)S and (MnxCy)S, were precipitated Prom the melt, depending on the composition of the slag. In all specimens sulfides were visible and were spherical.

Jan 1, 1941

By D. B. Lovett

The work described in this report was directed toward identifying and devising methods to minimize the previously observed variability between working level hour exposures and the alpha particle track densities resulting on Track Etch films exposed to mine atmospheres containing radon and radon daughters. The disequilibrium between radon and its daughters was shown to directly affect this Track Etch film calibration factor. The wide range of disequilibrium states possible in mine situations amply explains the variability in the previous tests. A file of published mine atmosphere composition data was compiled and was used, along with atmospheric compositions derived from several theoretical models ref the atmospheric behavior, to evaluate the variability of several dosimeter configurations and concepts. A nonlinear, iterative regression analyse; was formulated that successfully predicted working levels to within 8 to 10% from only the alpha particle activities (Rn, RA, and RaC') data such as are obtainable from Track Etch films over a wide range of disequrlibrium conditions. A model expressing atmospheric concentrations as a function of radon source strength, plate out rate factor, ventilation rate and the fractional re-entry by recoil of previously platted-out daughters was derived and used in the regression program in addition to preparing a set of reference tables and graphs showing the disequilibrium behavior of the atmosphere. Other factors that can affect the Track Etch Film response writ considered and shown to he less crutial than the disequilibrium state. The results of a series of exposures of a dosimeter concept fixture in the Denver Mining Research Center radon chamber air presented and discussed.

Jan 1, 1976

By Anthony E. Szczuka

The purpose of this design note is to document the data that has been received from manufacturers, coal companies, training centers, government agencies, etc., that pertains to the completion of the Concept Feasibility Study For Training Equipment Designed to Improve Coal Productivity. Revision A documents additional data that has been received. ACKNOWLEDGEMENTS We wish to express our appreciation to the companies, mines, government agencies, unions, and contractor agencies listed herein that furnished the documented data. In most cases, it was furnished willingly and free of charge. In the few cases where the data was purchased, MDEC IRAD funds were used.

Jan 1, 1976

By G. L. Gates

The waters used to waterflood the Wilmington oilfield were studied by the Bureau of Mines, in cooperation with the city of Long Beach, Calif. Increases in the pressure of the injection wells indicated that they were being plugged by materials suspended in the waters. This study was made to identify the suspended materials, determine their origin, and find methods of preventing their formation. The suspended oil-coated materials were iron sulfide, barium sulfate, calcium carbonate, clay, and sand (or silica). Results indicated that the sulfide, which was as high as 90 milligrams per liter, was the product of sulfate-reducing bacteria. The injection of ocean water increased the sulfate content of the waters in the petroleum reservoirs from 3 to 250 milligrams per liter, thereby furnishing sulfate for growth of the bacteria. The waters were supersaturated with barium sulfate. Laboratory tests showed that sulfide could be removed from the waters by adding iron at a cost of 1 to 2 mills per barrel. The solubility of iron sulfide and calcium orthophosphate in the injection waters was also determined.

Jan 1, 1975

It is not uncommon to find large quantities of combustible materials in underground metal and non-metal mines. Support timber is the predominant combustible material. Spontaneous combustion, welding and cutting, shorted or overloaded electrical cables and careless smoking are common ignition sources. More recently, there is increased use of diesel mobile equipment that requires fuel storage and transfer areas. Diesel fuel spillage on hot engine manifolds and motors can result in rapid flame growth and heavy smoke accumulation in a matter of seconds. In-expensive, reliable fire detection and suppression systems are available to provide early warning of fire conditions and to isolate and extinguish fires that originate in fuel storage and transfer areas. This report presents an example of how technology developed and demonstrated under Bureau of Mines Contract H0242016, Mine Shaft Fire and Smoke Protection System, may be applied to protect underground diesel fuel storage and transfer areas. The area application described in this report is a representative example only; the fire protection described includes the concepts of ? Early warning and alarm ? Isolation ? Extinguishment ? Control

Jan 1, 2011

By R. A. Strehlow

This is the final report for U.S. Bureau of Mines contract HO-122122, which was in effect from June 30, 1972 through January 4, 1976. The work resulted in the design and construction of a large laboratory scale coal dust burner and the use of this burner to study gaseous and coal dust flammability. A new technique for determining gas phase flammability was developed and the effect of solid and gaseous suppressants on the propagation of coal dust flames was studied. In addition, a technique for measuring the C/H ratio in the flame was developed and the C/H ratio that was measured in a coal dust flame on this burner showed that the burning process was preceeded by pyroysis of the coal dust. Both experimental and theoretical studies showed that radiative trans-port is very important to the propagation of a coal dust flame.

Jan 1, 1977

During the period 1979 thru 1982, Multi Mineral Corporation conducted a mining research program at the United States Department of the Interior's Bureau of Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and, the results are described in this report.

Jan 1, 1983

Three complete connector assemblies and six separate contacts were submitted to a series of tests to establish the connectors permissibility and compliance with U. S. Bureau of Mines research Contract #H 0110423 D.C. portion. Test Procedure TPC-0118 was coordinated, and the test plan approved by the Bureau as fully complying with the intent of the contract for the direct current connectors. The components and connector assemblies have been demonstrated in testing that they meet or exceed all the requirements of the test procedure.

Jan 1, 1974

By G. W. Jones

One of the major activities of the Bureau of Mines is the promotion of safety in mining and other industries, In this connection, the Bureau determines the explosion hazards' of combustible gases, vapors, and solids and investigates means of controlling and preventing explosions. Many dangers are likely to confront men who must enter a building immediately after it has been damaged. Rescue workers must watch constantly for common gases and vapors that may be present in dangerous concentrations in and about demolished, buildings. Fuel gas is the most common source of danger, although refrigerants, gases from furnaces, flues, fires, sewers, and industrial processes, and gas from bomb, explosions in confined places also constitute definite hazards. To rescuers and trapped casualties, these gases offer the hazards of (1) explosion, (2) toxic effects, including asphyxiation and death, and (3) displacement of air so that the oxygen content of the atmosphere is reduced to or below the danger level.

Jan 1, 1944

By Frank Parrish

History and performance data of 17 water-injection projects in Cooke and Grayson Counties in north Texas are presented for the purpose of studying and comparing operating practices and oil-recovery techniques. Water is injected into Strawn and Canyon sands of Pennsylvanian age. The principal formation flooded is the Strawn, which ranges in depth from 725 to 6,900 ft in the projects covered. Estimated ultimate recoveries range as follows: Primary, 22 to 494 bbl per acre ft; and secondary; 63 to 296 bbl per acre ft. These figures represent the following percentages of original oil in place: Primary, 10 to 46 pct; and secondary, 8 to 23 pct. Shallower projects; 725 to 1,500 ft in depth, had higher average primary and secondary recoveries than did deeper projects. Crude-oil gravity, which ranges from 20° to 45° API, was not relatable to yield of secondary recovery oil. Analysis of the data indicates that five-spot injection patterns will yield the highest percentage of oil remaining at start of flooding; that is, 28.8 pct for five-spot injection patterns, compared with 20.8 pct for line-drive patterns and 11.6 pct for random patterns. Waterflooding in this area appears to be very successful. Secondary recoveries of most projects are expected to nearly equal primary recoveries.

Jan 1, 1963

By P. C. McWilliams

Theoreticians in soil mechanics have been pursuing a probabilistic approach to the factor of safety of an embankment or darn for the past 10 years. The motivation for this work is in contrast to the current practice of deterministically computing a factor of safety and treating it as an absolute with no regard to its inherent statistical variability. Basic to the probabilistic approach is the selection of an appropriate statistical model to represent the histogram or probability density function (PDF) of the factor of safety values, Rather than simply assuming which PDF is appropriate, the Bureau of Mines collected data at two waste disposal embankments for consideration, This report addresses three candidate models, using the techniques of nonlinear curve fitting, and identifies the "best" model. A propagation of error formula for estimating the variability of Fellenius? factor of safety is also discussed.

Jan 1, 1983

By A. R. Taylor

In recent years, thermodynamic data have been used to a greater degree than ever by the chemical and metallurgical engineer as a means of predicting and controlling chemical reactions. To satisfy the spiraling demand for basic physical data needed for the calculations, the Bureau of Mines is studying the heat capacities of a variety of chemical compounds at high and low temperatures. This paper is one of a series presenting such data. The heat capacities of two alkaline earth compounds, strontium bromide and strontium nitrate, were measured in a temperature range of 60° to 300° K. in an adiabatic calorimeter and at temperatures of 300° to about 1,200° K. in a Bunsen ice calorimeter. The construction and operation of the calorimeters are discussed in other reports.3 4 The heat-capacity data presented in this report were extrapolated to 0° K., and smooth values of heat capacity, entropy, enthalpy function, and free-energy function were calculated and tabulated at even 10-degree intervals. The enthalpy data were fitted with algebraic equations by applying the method of least squares; calculations a£ heat-capacity values, entropy, enthalpy function, and free-energy function were made at even 50-degree intervals. The heat and entropy of fusion of strontium bromide were calculated from the enthalpy measurements.

Jan 1, 1962

By R. V. Ramani

Procedures have been developed which permit determining in either existing or new mines the optimum diesel equipment deployment schemes and the effect of. diesel exhaust on mine-air quality. Specifically, the following areas are covered in the report: 1. Description of diesel deployment schemes in four underground coal mines that were visited is provided. 2. Description of the analysis procedure to determine the number of shuttle cars required to maintain maximum theoretical continuous miner (or loader) production rates in typical room-and-pillar mining systems and of exhaust contamination resulting from the deployment of diesel powered shuttle cars are provided. Sensitivity analyses to determine the effect of changes in input variables on production and contaminant concentrations are also discussed. 3. Description of the analysis procedure to develop the locomotive operating parameters is provided. Assessment of both production performance as well as estimates of the magnitude of diesel exhaust contamination of the mine air are also made. 4. Recommendations for extensions of this research are outlined and include developing and testing procedures for 1) determining equipment duty cycles for the diesel equipment, and 2) studying the exhuast contamination of mine air on the basis of these duty cycles.

Jan 1, 1978