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By Ted C. Briggs

The Bureau of Mines is evaluating the thermodynamic properties of helium and helium-containing mixtures. Twenty-two compressibility runs were made with helium at 0° C and pressures to 800 atmospheres using a Burnett-type apparatus. Data from the 22 runs were treated simultaneously and as separate runs while different functional forms and weighting factors were used. A fourth-degree-polynomial equation in the pressure gives a statistically satisfactory representation of the compressibility factor when the data are treated simultaneously and a weighting factor of Pr-3/4 is used. The second virial coefficient of helium at 0° C from this investigation is 11.997±0.015 cm3 mole-1. The stated uncertainty is the random error standard deviation. Compressibility factors determined by this investigation are precise to better than 0.01 percent and are believed to be accurate to better than 0.02 percent.

Jan 1, 1969

By R. P. Beyer

A FORTW IV computer program has been written to calculate thermodynamic properties over a desired temperature range from spectroscopic data. This program computes heat capacities, enthalpies, and entropies for monatomic, diatomic, linear, and nonlinear polyatomic gases. This research is part of the Bureau of Mines effort to provide thermodynamic data for the advancement of mineral technology.

Jan 1, 1981

By Philip W. Holland

This U.S. Bureau of Mines (USBM) report describes a chromatographic method that is used for rapid field determinations of carbon dioxide in natural gas streams at a USBM helium production facility. The method employs a commercially available portable gas chromatograph that is equipped with a 10-m fused-silica capillary column coated with a porous polymer. The instrument operating parameters permit determinations to be performed over a concentration range of 10 ppm to 10 pct with a frequency of 20 samples/h. The speed at which determinations can be performed is an important factor when evaluating efficiency or troubleshooting processes at the helium facility.

Jan 1, 1994

By F. S. Crawford

Untreated timber in a mine or elsewhere may fail prematurely because it may "rot out before it wears out." If such timber is treated with a satisfactory preservative, decay will be retarded for many years, and it's serviceable life will beg prolonged to several times that usually obtained from untreated timber.4/ Treated timber has many advantages, and although it has been used extensively by railroads and other large consumers of structural timber, the relatively small use in mines seems strange indeed. Timber does not decay if it is kept dry, cool, and well-ventilated or if it is kept constantly wet or sumberged in water. At a mine in Canada the temperature in the upper levels was only 44° F., and the timber did not decay. As operations deepened, however, warmer ground was opened, and, with high humidity, conditions favored timber decay. The life of untreated timber may be only 2 to 3 years under such conditions.

Jan 1, 1951

Federal lands often contain extensive mineral resources and decisions affecting access to those lands are made with knowledge of the possible minerals-related consequences. Information is provided to the Bureau of Land Management (BLM) in this report for use in preparing environmental impact statements on the Western Mojave Management Area (WMMA) and the Desert Tortoise Priority Habitat (DTPH). To augment U.S. Bureau of Mines (USBM) efforts such as the Mineral Assessment of the Planned Foil Irwin Expansion, Modified Silurian Valley Alternative, San Bernardino County, California which is in progress, and the Economic Analysis of the Minerals Potential of the East Mojave National Scenic Area; California, the USBM studied mineral deposits and estimated the potential impacts of mining in a segment of the California desert; the 8.7-million-acre WMMA, an area which includes the 1.2-million-acre Desert Tortoise Priority Habitat (DTPH). In addition, this information is intended to assist administrators, legislators, and the concerned public in understanding the economic importance of mineral resources in the California desert, especially that portion designated as the WMMA. See figure 1.

Jan 1, 1993

By L. C. IlsLey

Coal mining is more widely distributed throughout the United States than is generally known, as 30 States are credited with having coal mines. In 1919 twenty-three of these States each produced at least a million tons of bituminous coal, and all the States produced about 560,000,000 tons. In addition, Pennsylvania produced about 85,000,000 tons of anthracite. Twenty-eight States have regulations prepared by commissions or have enacted laws governing the operation of coal mines. Pennsyl¬vania has separate codes for the anthracite and bituminous fields. The codes may be classified as follows: Twelve distinctly coal¬mining codes; eight codes that are essentially coal mining, but also apply to other mines; five codes that are subdivided, referring partly to coal mines and partly to other mines; and four codes that are essentially metal mining, but apply in part or in whole to coal mining. The first State to have a coal-mining law was Pennsylvania, which enacted a law, for Schuylkill County only, in 1869. The first State to enact a coal-mining law governing all the coal mines in the State was Illinois in 1872, followed by Ohio in 1873. Pennsylvania in 1879 enacted a law for anthracite mines only, but did not enact similar laws for bituminous mines until 1577. At least 10 other States enacted coal-mining laws between the years 1870 and 1890. Before 1890 electricity was little used in coal-ruining operations and therefore practically no provisions governing the installation, inspection, or maintenance of electrical equipment were made in any of the laws enacted up to 1890. In the law of Colorado, approved April 8, 1885, there is a reference to the use of telephones, probably the first reference to electrical equipment of any kind in a State-mining code. Most of the mining codes have been changed from their original form by amendment or by complete revision. In some of the early changes a casual reference is made to the use of electricity or to the handling of electrical equipment. In 1911 Pennsylvania added

Jan 1, 1920

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 D. B. Dow

This report on methods employed for dehydrating oil-field emulsions, is the second of a series prepared as a result of a study of oil-field emulsions recently completed by the writer. The first paper2 dealt with the factors responsible for the formation of emulsions. A third paper will discuss the physical chemistry involved in the formation and resolution of such emulsions. In the early development of the oil fields of Pennsylvania, no emulsion troubles of any consequence were encountered, nor to any serious extent in the oil fields of other Eastern States: However, with the development of fields west of the Mississippi in Oklahoma, Kansas, Texas and California, where heavier oils of different characteristics were found, the problem of dealing with cut oil soon became of great importance.

Jan 1, 1925

By D. K. Dysinger

In this U.S. Bureau of Mines study, neodymium metal of 99.8 pct purity was prepared by electrolysis of Nd203 salts dissolved in a molten fluoride electrolyte. The metal was electrowon in a molten state at current efficiencies of 50 to 60 pct. Oxygen and carbon were the major impurities detected in the product. During operation of the small-scale laboratory cell, a number of technical problems including anode effect, low oxide solubility in the electrolyte, high neodymium metal solubility, reactivity of the metal with the cell materials, and back reaction of the metal with the anode gases were encountered. Approaches to improve cell operation and prospects for commercial adoption of the electrolytic production of neodymium metal are discussed.

Jan 1, 2010

By George H. Schnakenberg, Aleksandar D. Bugarski

This report reviews the performance and applicability of technology for the control of emissions from diesel-powered equipment used in underground coal and metal/nonmetal mines. The methods discussed include Mine Safety and Health Administration-approved low-emission engines, engine derating, fuels, fuel additives, diesel oxidation catalysts, and diesel particulate filters. The potential of each of these technologies is examined individually and in combination. The performance estimates are derived from the published literature and presented in narrative and Tabular form. The purpose of this report is to help the mining industry select the most appropriate method to reduce underground exposures of miners to diesel exhaust in the context of the recently developed diesel regulations. It is important to note that the control technologies discussed in this report have received limited evaluation in underground mines. Additional research is ongoing, and some engineering design changes may need to be implemented before all of these diesel emission control technologies can be safely and successfully used in underground mines.

Jan 1, 2002

By Hal H. Engel

This publication was written in response to numerous requests for information about the Federal Bureau of Mines' "Demonstrated Lecture on Flame Propagation and Permissible and Explosion-Proof Electrical Equipment." The requests came principally from: (1) Persons wanting to know more about the demonstration before requesting it for groups they represented; (2) persons wishing advance information to help publicize a meeting where the demonstration was to be given; and (3) members of audiences desiring something to help them remember the salient points, facts, and figures presented during the lecture and demonstration. The purpose of the demonstration that accompanies the lecture is to show: (1) Variations in flame speed and pressure at various percentages of flammable gas within the flammable range; (2) effect of flame speed on the "pressure piling" within the area confining the mixture; and (3) the application of flame speed and pressure piling to the combustion of surrounding gas and to the design and maintenance of electrical equipment used in hazardous locations.

Jan 1, 1960

By Joseph L. Condon

High-speed movies were taken of crater experiments in two-dimensional plates of Tennessee marble to study craters being formed primarily by stress-wave action. The contribution of gas action to the cratering process was minimized because the two-dimensional models did not contain the expanding gases from the explosive. Four burdens were studied for solid plates and one burden for a segmented plate. After cratering, the plates were reassembled for dye penetrant studies of fracturing. Flyrock velocities were calculated and related to the degree of fracturing, and compared with those from quarry shots. In general, the smallest burdens produced the highest flyrock velocities and the least amount of fracturing. Flyrock velocities compared favorably with initial flyrock velocities in quarry blasts, but did not show step accelerations due to gas effects as did the quarry blasts. The test with a segmented plate was used to simulate cratering in a jointed material and showed that stress-wave effects can be important for crater formation in jointed rocks.

Jan 1, 1972

By S. L. Payne, E. F. Foerster, C. W. Schultz, G. R. Zellars

The vapor pressure of copper in a series of liquid copper - nickel alloys was determined by the carrier gas method . The activity and activity coefficient of copper were calculated over the entire range of alloy composition . These data show a slight positive deviation from ideal behavior . The activity coefficient of copper was highest ( 2.10 ) at 0.05 mole fraction copper and approached unity at concentrations above 0.85 mole fraction copper . The results for nickel were calculated from the copper data by the graphical integration of the Gibbs - Duhem equation .

Jan 1, 1964

By R. D. Currie

The practicability and dependability of two permissible methane-indicat- in detectors recently developed were proved conclusively by extensive tests in the return airways of all mines operating in the anthracite region in most of which samples and readings were taken with one or the other of the two in- dicating detectors. These detectors roved dependable and accurate within practical limits, and their general use should be encouraged as an aid to bet ter ventilation, more accurate control of air currents, and greater safety in mines.

Feb 1, 1936

By David E. Emerson

The Bureau of Mines has developed a mass spectrometer method for deter-mining the helium-3 content of high-purity helium. The work was performed to evaluate experimental methods for removing helium-3 from high-purity helium and to better determine the composition of pure helium used in research. This was accomplished by increasing the inlet sample pressure, ionizing current, and amplification of the current produced by the ions collected on a conventional mass spectrometer that had been modified. With these modifications, the helium-3 content was determined in the parts-per-million and parts-per-billion range in helium-4.

Jan 1, 1976

By R. V. Ramani, K. Bode

"IntroductionIn part 1 of this paper, the results of the experimental work in a wind tunnel under controlled conditions were presented. To understand the spatial and temporal behaviour of airborne dust under mine conditions, experiments were performed in the Lake Lynn Experimental Mine of the US Bureau of Mines. The mine airway experiments were designed to study the variations of ambient concentrations along the length of an airway, and the deposition rates and deposition velocities in an airway cross section. Other objectives of the study were to investigate the spatial and temporal behaviour of airborne dust with regard to air velocity and particle density, the size distribution of the airborne dust cloud as it travels in the airway, and the size distribution of the dust particles deposited along the airway. Other objectives of the study were to compare wind tunnel results with In-Mine results, whenever appropriate.Experimental ProcedureLocationA complete description of the Lake Lynn Laboratory Mine of the US Bureau of Mines (USBM) can be found in the US Bureau of Mines Information Circular 8911 (Mattes et al., 1983). This mine provides excellent facilities for dust experiments. The airway dimensions are similar to those of a coal mine airway. The mine has a drift (D Drift, see Figure 1) that extends almost 500 meters without interconnecting airways, stoppings, or bends. The D drift measures approximately 6m in width and 2,25m in height.The Lake Lynn Laboratory Mine· is ventilated by a variable speed, 75 kW (100 hp), 28,3 m3/s (60 000 cfm) blower fan installed on the top of the ventilation shaft. Air velocities of 1, 1,3 and 1,8 m/s, respectively, could be obtained in the D Drift. However, the temperature changes at the surface can cause small variations in air quantities and velocities underground. The low background dust level in the mine reduces the problem of sample contamination from other sources of dust. Extended periods of uninterrupted data collection can also be scheduled. Mine airway parameters which are important for the analysis include the dimensions of the airway and the ventilation data such as the air velocity, and the pressure loss in the drift. All these data were acquired during altimeter surveys which were conducted prior to each of the experiments."

Dec 1, 1995

By T. M. Ruff

A prototype mucking machine designed to operate in narrow-vein stopes was developed by Foster-Miller, Inc., Waltham, MA, under contract with the U.S. Bureau of Mines. The machine, called a compact loader-trammer, or minimucker, was designed to replace slusher muckers in narrow-vein underground mines. The minimucker is a six-wheel-drive, skid-steered, load-haul-dump (LHD) machine that loads muck at the front with a novel slide-bucket system and ejects it out the rear so that the machine does not have to be turned around. To correct deficiencies of the tether-remote-control system, a computer-based, radio-remote-control system was retrofitted to the minimucker. Initial tests indicated a need to assist the operator in guiding the machine in narrow stopes. An automatic guidance system that used ultrasonic ranging sensors and a wall-following algorithm was installed. Additional tests in a simulated test stope showed that these changes improved the operation of the minimucker. The design and functions of the minimucker and its computer-based, remote-control system are reviewed, and an ultrasonic-sensor-based guidance system is described.

Jan 1, 2010

By Sarah P. Guerrino

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also are the tables that show the principal nonfuel mineral commodities exported from and imported into the United States and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of Volume I and in the State chapters of Volume II of this edition of the Minerals Yearbook. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is normally termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines.

Jan 1, 1987

By E. Chin

Natural gas was Bangladesh's only significant exploited mineral. A few other minerals or mineral-based commodities were produced for local consumption. The most valuable were nitrogen fertilizer, salt, cement, and clay for brick.2 The most important mineral industry development of 1987 was the start of modest production of crude oil, the first discovered and produced in the country. PRODUCTION AND TIADE Production of natural gas from the nation's huge reserves continued to increase but was limited by the lack of residential and industrial demand. Gas reserves of 7 trillion to 16 trillion cubic feet were sufficient for far more production than the country could efficiently utilize for many years. The country's consumption-to-reserves ratio was one of the lowest of the developing nations. Mineral exports have been insignificant, comprising a small amount of nitrogen fertilizer. Nitrogenous fertilizer exports could become important when planned new capacity comes on-stream. Mineral imports were dominated by crude petroleum.

Jan 1, 1989

By D. Harrington

The occurrence of dusts in underground workings creates many difficult and, in some instances, contradictory and conflicting problems for workers, operators, and all others interested in health and safety in mining and tunneling. Moreover, there are many misconceptions both as to the actual effect of most dusts which may be encountered in underground work and as to remedial or alleviating measures. Although the harmfulness of mine dusts to health of miners has been mentioned by man; writers in ancient times, much of our really authentic knowledge of the effect of underground dusts upon health or safety in both coal and metal mines has been pained during the past 30 or 35 years. There has been, however, a considerable amount of generalizing from some local condition or occurrence or theory rather than arriving at conclusions after extended studies and observations made not only in mines and tunnels but also in town, camps, and plants, and comprising date on as many different mining and tunneling localities, conditions, etc., as could be secured with reasonable expenditure of time or money. This paper dives sortie observations based on the writer's 30 odd years of experience in and around both coal and metal mines, including approximately 20 years? close study of dust disease with detailed surveys and reports on dust occurrence and effects in considerably more than 100 mines in probably 20 States of the Union. The observatio are those of an engineer and in many respects conflict the with "going" ideas of doctors, pathologists, and others who have written on dust disease. Were the word dust is used in this p: per in connection with respiratory disease, it refers to solid particles which float or can float in the air breathed by workers. Although these particles are usually dry, they may be wet; in general, their dimensions are so small as to be invisible to the nailed eye. Dusts in coal mines which may be involved in the initiation or extension of explosions, are generally thought to be those which are smaller than 20-mesh in size but chiefly finer than 20-mesh; coal-mine dusts which are harmful to health of workers have essentially the same general physical characteristics as other dusts, but usually consist of smaller particles.

Jan 1, 1936