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By Christopher C. Jobes

This U.S. Bureau of Mines report describes a system to determine the position and heading of a mining machine during maneuvers in the face area of an operating mine section. The system is the first step in the development of a guidance system for automated mining machines. The position and heading algorithm is described, and a preliminary error analysis is performed. The sensors employed were linear position transducers mounted on a mining machine with their cables attached to points on a stationary reference. Four linear position transducers were used to provide a data redundancy that increased the reliability of the guidance system. The linear position information obtained from the transducers was processed mathematically via the position and heading algorithm to provide the desired position and heading information. The algorithm takes advantage of sensor redundancy to continually test the accuracy of the sensor data. The major sources of error were determined to be the linear position transducers, the analog-to-digital (A/D) converter used to interpret the data, and the sampling frequency of the measurement system. These sources of error were evaluated to determine their inaccuracies for use in calculating the overall system accuracy.

Jan 1, 1990

By BUREAU OF MINES

This paper is a revision of Reports of Investigations , Serial 2541 , which was published in November , 1923 , for the benefit of State mining inspectors , safety engineers of mining companies , and others interested in electrical safety inspection in mines . It presents the important points that should be watched by inspectors and briefly reviews the work of the Bureau of Mines in testing of electrical apparatus and equipment to determine their permissibility for use in gassy coal mines .

Jan 1, 1929

By D. G. Kesterkel

Low-melting thoriurnrbase binary alloys or metal solutions were prepared by two different techniques involving the electrolysis of ThO2 dissolved in fluoride melts. Experiments were performed at 950° to 1,250° C using electrolytes containing ThF4 and various alkali and alkaline earth fluorides. In the first method, electroreduction of ThO2 and deposition of thorium on a nickel or iron cathode formed a molten alloy that dripped off and collected on the bottom of the cell, or in a tungsten cup. An electrocodeposition technique was used to prepare thorium-base alloys or solutions containing nickel, iron, chromium, or manganese. Electrolytic reduction of the component metal oxides and simultaneous deposition of the two metals on a tungsten cathode yielded a liquid alloy product. Complementary experiments were performed on the fused fluoride electrowinning of dendritic thorium from Th02 at 1,075° to 1,200° C in which thorium crystals were recovered and arc-melted into buttons. Major contaminants were aluminum, carbon, copper, iron, oxygen, and silicon, totaling 0.2 percent.

Jan 1, 1966

By M. F. Dunn

A handbook to provide a quick reference guide for selecting and using jet fans in a variety of conditions was prepared. The document is intended for use by front-line supervision, ventilation engineers, and mine planners. Included are discussions of jet fan characteristics, selection and use critieria, and do's and don't's for easier operation, safety, and performance. The handbook is based on research at three underground metal/nonmetal mines having cross-sectional areas of 900 to 2,000 ft2.

Jan 1, 1983

By Carlon S. Land

The Bureau of Mines investigated the influence of a free gas saturation on oil recovery by water drive. A digital computer was used to calculate the combined oil recovery from solution-gas drive to various states of depletion. Results of these calculations are compared and optimum conditions for the maximum oil recovery are found for various fluid-rock systems. For most of the fluid-rock systems, the calculations show an optimum gas saturation other than zero. Using fluid and rock properties as parameters, graphs are plotted showing the optimum gas saturation and increase in oil recovery brought about by the gas saturation. The effects of fluid properties and relative permeability on the optimum gas saturation are seen in these graphs. The graphs can be used as guides in connection with other considerations in determining the optimum time to start a waterflood. They should also be helpful in determining the MER of a water-drive reservoir. The effects of compressibility and solubility of the trapped gas saturation are investigated for select cases using a backward difference scheme to solve the partial differential equation of three-phase flow. From these calculations, it is observed that some benefit of a gas saturation remains for injection pressures up to 1.5 times the original bubble-point pressure.

Jan 1, 1974

By L. B. Pankratz

Thermodynamic data on the elements, oxides, sulfides, halides, and selected hydrides, carbides, nitrides, carbonates, sulfates, silicates, and miscellaneous compounds were reviewed, evaluated, and compiled at the Bureau of Mines. Values for CP°, S°, H° -H°298, ?Hf°, and ?Gf° are given in tabular form. A brief thermodynamic background and a number of examples and applications are presented.

Jan 1, 1984

By H. R. Beard

The citrate process for sulfur dioxide emission control was developed in pursuit of the Bureau of Mines goal of minimizing the adverse environmental impact of mineral-processing operations. This publication describes the gas analysis procedures used during development of the process. The research required the capability to analyze SO2, H2S, CO, CO2, COS, volatile hydrocarbons, NO, NO2, O2, N2, and H2. The methods described include gas chromatography, electrochemical detection, infrared spectroscopy, and the use of a computer program to predict the product composition in complex reactions. Laboratory and pilot plant applications are discussed.

Jan 1, 1979

By J. D. Zetterstrom

This report supplements an earlier publication on lightweight aggregates of North and South Dakota.3/ The purpose of the investigation was (1) to study the expansion characteristics of large samples of Dakota clays and shales in a 12-inch by 15-foot rotary kiln; and (2) to improve the laboratory bloating test as a tool for predicting the suitability of samples for the rotary-kiln process. This was done by comparing results of the laboratory and kiln tests.

Jan 1, 1956

By A. E. Sands

The Bureau of Mines, S. Department of the Interior) at, its Morgantown., W. Va., station, operating under a cooperative agreement with West Virginia University, is conducting research and development work on the problem of producing synthesis gas from coal. An important part of this work is the study of the gas purification necessary to meet the rigorous standards required to render the gas suitable for use in the Fischer-Tropsch synthesis of liquid fuels. One of the most detrimental impurities is sulfur in all forms, the maximum amount that can be tolerated being one-tenth of a grain per hundred cubic feet. Concentrations as low as this require the use of precise analytical methods to evaluate the performance of processes used for removing sulfur. At the same time the analytical methods should be rapid in order to reveal the failure of purification before damage to the expensive synthesis catalyst results. Although sulfur in unpurified gas is generally present as hydrogen sulfide and as organic sulfur compounds, the latter may be converted to hydrogen sulfide for analytical purposes. Thus a suitable method for the determination of traces of hydrogen sulfide may also be used for the determination of organic sulfur.

Jan 1, 1949

By A. L. Engel

In recent investigations of chloride Volatilization of gold at the Reno Station, it was found that the addition of small amounts of copper and NaCl to the charge brought about improved volatilization of the gold. The investigations described in this report were concerned with the recovery, in an aqueous medium, of fumes from chloride volatilization of gold. It was attempted to discover a suitable aqueous medium that would permit absorption, solution, or precipitation of all the volatilized gold immediately upon contact with the medium. A simple laboratory apparatus was employed to produce fumes by volatilization. To this furnace was attached an absorption train consisting of a series of chambers containing the aqueous medium, through which the fumes were drawn by suction. A satisfactory synthetic ore that contained metallic, gold in a quartz-matrix was made and utilized, enough. gold being present in a' small amount of material to permit an accurate, metallurgical balance of the volatized values' to be obtained in all the experiments.

Jan 1, 1949

By M. O. Serbousek

The load-transfer mechanics of fully grouted roof bolts in coal mines have been investigated in laboratory and analytical studies. The purpose of this Bureau of Mines research is to increase understanding and better interpret data from routine field pull tests and to develop a numerical model of a grouted bolt that can be used in a global computer model of a mine roof. Analytical studies using closed-form solutions and finite-element techniques were compared to experimental results. Laboratory work includes variation of bolt length, hole diameter, and grouL type. Pull tests were pel'fol·med on 4-, 2-, and I-ft bolts in holes of 1-and I-3IB-in diameters. Both polyester resin and inorganic grouts were used as the anchorage medium. Strain gauges were installed on the bolts at several locations to observe the rate of load transfer from the bolt through the grout to the rock mass when a force was applied at the bolt end using standard jack pull testing procedures and equipment. The average anchorage length of 4-and 2-ft bolts was 22 in. Grout type and hole size variations did not produce a significant effect on the rate of load transfer from the bolt to the rock.

Jan 1, 1987

Provide a rapid, reliable means of warning underground miners of a fire or other emergency. Approach An ultalow-frequency electromagnetic signaling system was designed, breadboarded, and tested at various under around mines. How It Works Current fire warning systems for underground mines, such as stench, audible alarms, and messengers, arc slow, unreliable, and seldom achieve total mine coverage. An ultralow-frequency electromagnetic fire warning alarm system with true through-the-earth signaling capabilities was developed to solve these problems. The system was originally designed for high-back room-and-pillar mines where stench systems are unusable due to the low velocity of mine air flow. However, the system has an application to all underground mines.

Jan 1, 1988

By E. P. Youngman

The basic mining law of Esthonia is the law that was passed by the Parliament (Riigikogu), or State Assembly, on March 17, 1927 (effective Avril 1, 1927), superseding the Russian Mining Law Book VII of the Code) issued in 1912. References in this digest are only to articles of the Law of Merch 17, 1927. However, the law concerning all industrial enterprises (Riigi Teataja No. 28, 1920, Law No. 106) governs not only mills and refineries but also mining operations themselves (arts. 2 and 3). No access was ad to that law. Esthonia is not well supplied with minerals; its industries are primari- ly agriculture and dairy farming. Natural gas, prites, lead, zinc, iron ore, salt, and mineral waters have been found but never as yet in deposits of commer cial size. The production of oil shale is of some importance; and peat, which covers as much as 5 per cent of the total area of the country, is mined in sub- stantial quantities. Cement rock, gypsum, fire clay, and phosphate rock likewise are produced, though only on a small scale.

May 1, 1930

By Graham W. Marks

This report is the fourth of a series concerning the development of spectrochemical methods for the analysis of ore samples and related Metallurgical materials by the total-energy method. In this report, the application of this method to the determination of thallium is discussed. This element lies in group III of the periodic tale; one other Clement of this group; indium, has already been investigated.

Jan 1, 1949

The Bureau of Mines has conducted considerable research to improve life support technology for underground mining applications. This proceedings volume presents several new developments that may help increase the chances of mine workers in surviving underground disasters. Several papers address the performance of present self-contained self-rescuers (SCSR's) and provide proposed guidelines for the design and testing of a second-generation SCSR. Improvements In the safety and effectiveness of mine rescue and recovery operations are described, including the design of a low-profile rescue breathing apparatus and a rescue team helmet.

Jan 1, 1987

By L. A. Panek, A. J. Barry, John A. McCormick

"INTRODUCTION During recent years, roof bolting has become widely accepted as a systematic method of supporting both coal- and metal-mine roofs. Today, over 2 million roof bolts are installed monthly. Most of the information on bolt installation procedure reported to date (1,2,3,4,5,6) 3/ has been obtained by trial and error by individual groups or operators. To insure good roof control, experience and field tests have indicated that roof bolts should be installed immediately after the exposure of new roof, and they should be preloaded enough to minimize sag of the roof over the opening. The question of the proper initial preload for roof bolts is under study, although it is a general practice to impose an initial load on a bolt of approximately 10,000 pounds. This created a problem of measuring bolt loads at installations in underground mines, which was partly solved by using a commercial-type torque wrench; a device that permits a direct reading of the torque applied to the nut on a roof-bolt assembly from which the corresponding load can be determined by referring to specifications furnished by the manufacturers. However, considerable apprehension was expressed regarding the accuracy of this measuring procedure because of variations in the manufacture of roof-bolting materials and the degree of care exercised in making bolt installations. In the process of loading a bolt, only a small part of the effort is expended in producing strain in the bolt - the larger part of the effort is used in overcoming frictional effects in the nut-bolt-washer assembly. These frictional effects are subject to many factors, such as condition of threads, type of lubrication, if any, the finish on the nut and bearing plate, and the alinement of the bearing plate on the bolt. The object of this investigation was to determine the accuracy with which the load developed in a slotted-type roof bolt installed in a conventional manner in shale or sandstone roof rock can be determined from the torque applied to the nut.This report is the first of a series relating to basic research in roof bolting in underground mines. A future report will cover results obtained using expansion-type bolts under similar conditions. Other reports will consider the efficiency of bolt anchorages, the long period stability of bolts, and the design of safe and efficient roof-bolting systems."

May 1, 1953

By Ronald S. Conti

Historically, underground mine rescue teams have received training only in the course of actual emergencies, or in simulated mine environments, usually on the surface, with placards to identify objects and hazards. Also, while U.S. Federal Regulations require all underground miners to walk escapeways and conduct fire drills every 90 days, this does not fully prepare them for the conditions that may be encountered in real escape situations, such as smoke filled entries. This paper describes technology and realistic training simulations that have been identified for the general workforce and mine emergency responders. Of all the technology evaluated by underground personnel, laser lights and lifelines were most beneficial in leading personnel to safety and out of the mine in smoke-filled passageways. These technological advancements can improve the state of readiness for rescue personnel and increase the chances of survival for personnel escaping from underground emergencies.

By R. P. Maloney

The Bureau of Mines conducted a reconnaissance of the less accessible parts of the Beluga River coalfield in August 1957 to determine, if possible, which areas were most favorable for developing large reserves of coal suitable for open-pit mining. Several outcrops of subbituminous coal were observed within an area about 30 miles long and 3 miles wide; neither the length nor the width of the coal-bearing area was delineated by the examination. Coal beds 30 feet thick or more outcrop at two places, and beds 5 to 20 feet thick or more outcrop fairly abundantly along the Beluga River and its tributaries The coal measures appear to occur in a series of folds. The overburden comprises glacial gravels and poorly cemented sandstones and ranges from 20 to 400 feet in depth. Few partings were seen in any of the coal beds. Samples ranged in calorific value from 6,240 to 8,246 B. t. u. on an as-received basis. Adequate water is available for stripping by hydraulic methods.

Jan 1, 1958

By Irving Hartman

The results of the first experimental study by the Bureau of Mines on the explosive properties of metal powders were published in 1945. Since that time the explosibility of numerous other industrial dusts and powders has been investigated. Part of this information has been published, but most of the data has not been released to date. This paper summarizes the results of experiments on 22 samples of titanium, zirconium, thorium, uranium, and hydrides of these metals. The major part of the investigation was made under cooperative agreement with the Atomic Energy Commission.

Jan 1, 1951

By Hsin Wei Wu

A real-time Diesel Particulate Matter (DPM) monitor has been developed on the basis of the successful National Institute of Occupational Health and Safety (NIOSH) designed Personal Dust Monitor (PDM) unit. The objectives of a recently completed Australian Coal Association Research Program (ACARP) study were to modify the PDM to measure the submicrometre fraction of the aerosol in a real-time monitoring underground instrument. Mine testing focused on use of the monitor in engineering evaluations to determine how conditions can be improved. Studies, including a selection during Longwall (LW) moves as described in this paper, demonstrated how DPM concentrations from vehicles fluctuate under varying ventilation and operational conditions. Correlation between the current SKC DPM measurement system and real-time DPM monitors were conducted and results from six mines show a correlation between elemental carbon (EC) and the new monitor DPM mass ranging from .51 to .81 with R2 >.90. These differences are suspected to be due to variations from mine to mine in aspects such as mine atmospheric contamination, vehicle fleet variations, fuel type, engine maintenance, engine combustion efficiency, engine behaviour or interference from other submicrometre aerosol. Real-time monitoring readily reflects the movement of individual diesel vehicles and allows pin-pointing of high exposure zones such as those encountered where various vehicles work in areas of constrained or difficult ventilation. DPM monitoring approaches that have been available for some time based on shift average monitoring do not readily allow successful engineering evaluation exercises to determine acceptability of pollution levels. Identification of high DPM concentration zones allows efficient modification of mine ventilation, operator positioning and other work practices t o reduce miners? exposures without waiting for laboratory analysis results.

Jan 1, 2010