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By B. W. Madsen

Bureau of Mines research to recover arsenic from mining industry waste material and process streams is reported. Batch and column approaches were investigated for adsorbing arsenic from acid leach solutions and ion-exchange eluate solutions with hydrated titanium dioxide granules. A method for producing hydrated titanium dioxide granules was devised to provide material suitable for use in a packed adsorption tower. Selective adsorption of arsenic from acidic leach solutions was achieved. The loading capacity of arsenic on the granules was 14 wt-pct when synthetic solutions were used, but lower when actual leach solutions were used. Other elements in the leach solution were Zn, Cd, and In. The granules were used in an attempt to lower the arsenic content in a solution containing 0.95 g/l W and 0.027 g/l As from a process devised by the Bureau of Mines to treat Searles Lake brine. The arsenic content was lowered to less than 0.001 g/l, but unacceptable amounts of tungsten also were adsorbed by the granules. Adsorbed tungsten was partially stripped with pH 11.5 NaOH, and both tungsten and arsenic were completely stripped with 5M NaOH solution. Repeated loading and stripping of the granules had no effect on the loading capacity for arsenic.

Jan 1, 1983

By Charles E. Whieldon

This report presents the results of a study on part of the Smithfield oilfield, Wetzel County, W. Va. The primary purpose of the investigation was to determine the original and the present volume of stock-tank oil in the formations and to investigate the feasibility of waterflooding the Gordon Stray, Gordon, and Fourth sands underlying the I. D. Morgan lease. The study was based on laboratory core analyses, geophysical well logs, geologic considerations, and various field prediction data from the I. D. Morgan lease. The Bureau found that, of the three sands cored, the Gordon Sand was the best prospect for waterflooding, and that a properly engineered water flood should recover 136 to 230 barrels of oil per acre-foot from this formation.

Jan 1, 1967

By Kevin Connor

Exports of agricultural products, mostly coffee, continued to account for more than 90% of Burundi's foreign exchange revenue. The country's ban on commercial mining was lifted in 1987. Mining of peat for fuel, limestone for agriculture, and clay for insecticides continued as in previous years. At yearend, Burundi's external debt stood at almost $700 million.2 Amoco Burundi, a subsidiary of the Amoco Petroleum Co., drilled two exploration wells in northern Lake Tanganyika in 1987. No oil was found, but preliminary findings were encouraging enough that further seismic surveys and offshore and onshore drilling exploration were planned in 1988. Any oil or gas finds would have substantial impact on the Burundian economy because a major portion of the country's trade deficit was directly attributable to petroleum and gas imports. The Zaire Government agreed in June to let Amoco Burundi explore Zaire's side of Tanganyika using the same equipment and personnel being used in Burundi.

Jan 1, 1989

By Richard J. Mainiero, Michael J. Sapko, Marcia L. Harris

Since 1988, there have been 17 documented incidents in the United States and Canada in which carbon monoxide (CO) is suspected to have migrated through ground strata into occupied enclosed spaces as a result of proximate trench blasting or surface mine blasting. These incidents resulted in 39 suspected or medically verified carbon monoxide poisonings and one fatality. To better understand the factors contributing to this hazard, the National Institute for Occupational Safety and Health (NIOSH) carried out studies in a 12-foot diameter sphere to identify key factors that may enhance the levels of CO associated with the detonation of several commercial trenching explosives. The gaseous detonation products from emulsions, a watergel, and ANFO blasting agents as well as gelatin dynamite, TNT, and Pentolite boosters were measured in an argon atmosphere and compared with those for the same explosives detonated in air. Test variables included explosive formulation, wrapper, aluminum addition, oxygen balance, and density. Major contributing factors to CO production, under these laboratory test conditions, are presented. The main finding is the high CO production associated with the lack of afterburning in an oxygen poor atmosphere. Fumes measurements are compared with the manufacturer’s reported IME fume class and with the Federal Relative Toxicity Standard 30 CFR Part 15 in order to gain an understanding of the relative toxicity of some explosives used in trench blasting.

By B. W. Jong

The U.S. Bureau of Mines investigated anhydrous chlorination and caustic-acid leaching processes to recover Ni, Co, Mo, and W from waste hydroprocessing catalysts. In batch laboratory-scale equipment, the chlorination process extracted 61 to 99 pet of the metals. Final recovery was 65 to 99 pct. The caustic-acid leaching process extracted 81 to 98 pct of the metals. Final recovery was 36 to 99 pct. Chlorination processing included roasting, chlorination, hydrolysis of metal chlorides for recovering Mo or W, water leaching of Ni or Co from the spent charge, purification, and solvent extraction or precipitation of Ni or Co from the purified solutions. Caustic-acid leach processing included NaOH leaching, solvent extraction of Mo or W from the NaOH leach liquor, H2S04 leaching of the NaOH leach residue, purification, and solvent extraction or precipitation of Ni or Co from the purified solution. The estimated fixed capital cost for a commercial-scale plant processing 39,000 Ibid of waste Ni-Mo-AI catalyst was $8 million for the chlorination process and $9.6 million for the caustic-acid leaching process. The estimated operating cost was about $0.20 and $0.40 per pound of the waste catalyst, respectively, for the two processes.

Jan 1, 1989

By W. E. Robinson

Oil-shale samples selected from a core of the Green River Basin (Wyoming) were studied to ascertain differences in the composition and/or chemical structure of the organic material in the samples relative to stratigraphic position within the Green River Formation. This involved a systematic study of the soluble organic material and the insoluble kerogen present in the samples. Emphasis was placed upon the distribution of the alkanes (normal and isoprenoid compounds) in the soluble extract and upon the aromaticity of the kerogen. In general, it was concluded that significant differences exist in the chemical structure of the oil-shale organic material from various strata within the Green River Formation of Wyoming. Most of the compositional and structural changes were not related to burial depth but were related to source material variations, environmental differences, or other factors.

By Basil Dimitriades

Five recently developed methods for determining nitrogen oxides in automotive exhausts have been evaluated from the standpoint of accuracy and applicability in current exhaust studies. Results showed that methods requiring conversion of nitric oxide to nitrogen dioxide as a part of the analytical procedure are subject to errors introduced by the instability of NO2. The extent of some of these errors has been determined and procedures have been developed to minimize undesirable influences. On the basis of the results obtained from this study, recommendations are made regarding procedures for batch type or continuous measurement of nitrogen oxides in exhaust streams.

Jan 1, 1968

By Fred N. Kissell

In this report the importance of diffusion in controlling the emission of methane in mines is examined. An in-situ diffusion parameter is defined and calculated for a hypothetical unfractured lump of coal in the Pittsburgh and Pocahontas No. 3 coalbeds. The values obtained are similar to those obtained with lump coal in laboratory experiments.

Jan 1, 1972

Effective in the 1987 Minerals Yearbook, the following changes have been made: "Asphalt" has been deleted; "Greenland" is included in the "Potash" chapter; "Meerschaum" is included in the "Clays" chapter; and "Staurolite" is included in the "Abrasive Materials" chapter. QUARTZ CRYSTAL Cultured quartz crystal production increased significantly in 198?, following 2 years of reduced production. Consumption of domestic lascas as feedstock for cultured quartz crystal increased. Imports of lascas from Brazil also increased. Although no lascas was mined in the United States during the year, the domestic producer supplied material to consumers from company stockpiles. Specimen-quality natural quartz was very much in demand; quartz crystal for this application is discussed in the Gem Stone chapter.

Jan 1, 1989

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 E. K. Stanek, P. Kantabutra, R. A. Wolf

This paper summarizes the cause and effect of induced voltages in multiple conductor cables supplying alternating current power to equipment in under- ground coal mines. The investigation of this phenomenon revealed that the electrical energy produced by the resultant electric arcing between the frames of mobile electric face equipment was of a sufficient magnitude to ignite explosive methane-air mixtures. The results of laboratory tests and field tests made between equipment frames during actual operation in numerous coal mines are discussed. Several methods of eliminating or suppressing the induced voltages to nonincendive levels are also described. It is the purpose of this paper to convey to the mining industry a knowledge of this problem and to recommend methods of eliminating or reducing these induced voltages or arcing currents to safe levels.

Jan 1, 1975

In the past, mine management has been concerned with removing water from active mining sections primarily because it hampered the movement of mining equipment and aggravated the working condition of the miners. Pumping water to sumps and gravity drainage by ditching have proven successful in mines for minimizing section down time due to water influx. However, with the advent of more strict pollution laws the mining engineer must now be concerned with keeping water out of the section and also with preventing it from causing pollution. A review of the handbooks and textbooks used in the mining engineering curricula reveals that little has been written concerning acid mine water prevention or control in underground coal mines. Additionally, the review of the curricula of mining schools indicates they are not teaching the engineering students the necessary techniques of mine water management as they relate to the abatement of mine water pollution.

Jan 1, 1970

By J. M. Singer

Approximate equations were used to compute the radiant heating of float coal dust by approaching flames for various combinations of particle size, dust path length (flame travel distance), flame temperature, dust concentration, flame speed, and flame length. The computed values of degree of radiant heating and flame travel distance for preheating the coal dust should be useful for estimating the increased fire hazard of different coal dust-flame parameters. Some findings relating to coal mine disaster control are-- 1. Coal dust clouds cannot be preheated to ignition temperatures by flame radiation alone when deflagration speeds are greater than about 10 m/sec. Thus it appears unlikely that radiation alone will cause flames propagating in dust clouds to accelerate to detonation velocities. 2. Small particles in the radiation flame zone caused by burnout and soot formation increase the degree of preheat significantly. 3. The concentration of float coal dust (radii = 3 to 40 microns) for maximum radiant heating usually peaks in the range 50 to 200 mg/liter of air.

Jan 1, 1970

By Joseph C. Zelanko, Christopher Mark

During August, two eastern Kentucky coal miners died in a roof fall during retreat mining operations. They had just finished extracting one pillar block and were moving to the next one when the intersection they were standing in collapsed. Regrettably, this was not an isolated incident. Since the end of 2000, there have been 28 ground fall fatalities in U.S. coal mines. Of these, 10 occurred during pillar recovery operations. Although pillar recovery has been associated with about one third of recent ground fall fatalities, it accounts for only about 10% of U.S. underground coal production. Statistically, a coal miner engaged in pillar recovery is several times more likely to be killed in a ground fall than a miner on an advancing section of a longwall. Pillar recovery is dangerous because it creates an inherently unstable situation. Once the pillars are extracted, the roof is expected to cave. Safe pillar recovery does not mean preventing roof collapse, it means ensuring that it only occurs after the miners have completed their work and have left the area. Fortunately, there are a number of proven techniques that can greatty reduce the hazards of pillar recovery. These include better mine planning, improved roof support, and safer work procedures. The goal of this article is to describe the most significant "risk factors" associated with pillar recovery, and prescribe control techniques that, taken together, can reduce the overall risk to miners. The conclusions are based on extensive studies conducted by the National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) that have included detailed analysis of every fatal retreat mining incident since 1992 (25 incidents resulting in 30 fatalities). Risk reduction strategies for pillar recovery can be divided into three main groups: Global Stability: Prevention of section- wide pillar failure; Local Stability: Prevention of roof falls in the working area; and Work procedures and worker location: Minimizing exposure to hazardous areas.

Roof falls continue to be the greatest single safety hazard faced by underground coal miners. During 1996-99, 44 coal miners lost their lives in rock falls, and nearly 2,400 were injured. In addition, nearly 6,000 noninjury roof collapses were reported. Roof supports are installed to protect the miners, but support system failures contributed to most of these incidents. Reducing the terrible toll taken by ground falls continues to be a major goal of research by the National Institute for Occupational Safety and Health (NIOSH). The purpose of these proceedings is to provide the mining community with a comprehensive survey of coal mine roof supports. Drawing on many years of research undertaken by the NIOSH Pittsburgh and Spokane Research Laboratories, this volume describes what types of support are available, how they work, and when they should be used. The major subjects covered include roof bolts, standing roof supports, cable supports, and longwall shields. Some special topics are also addressed, including an analysis of roof fall accident statistics, techniques for better skin control, material handling considerations, and longwall mining through recovery rooms. This proceedings volume also contains information on several important new technologies, which are described here for the first time: •Guidelines for selecting roof bolt length, pattern, and capacity that were derived from statistical analysis of the roof fall experience at 37 underground mines; •A new design method for longwall tailgate supports; and •A technique for measuring loads developed within cable bolts. The papers in these proceedings were presented at open industry briefings conducted by NIOSH on New Technology for Coal Mine Roof Support. The briefings were held in Norton, VA, Charleston, WV, Evansville, IN, Tuscaloosa, AL, Price, UT, Glenwood Springs, CO, and Washington, PA. The papers were also presented at the Mine Safety and Health Administration (MSHA) Preventative Roof-Rib Outreach Program (PROP) Seminar, which was held at the National Mine Health and Safety Academy near Beckley, WV.

Jan 10, 2000

By R. A. Beall

A series of 45 zirconium ingots has been cast by the consumable electrode arc melting process with the object of analyzing the effects of power input from 50 to 230 kilowatts and reduced pressure furnace atmosphere to improve the quality of regular 8-inch-diameter production ingots made thereby. Electrode consumption rate, molten pool volume, melting efficiency, sidewall quality, arc stability, and yield efficiency are considered. The use of direct current and alternating current is studied. In conclusion, reduced pressure furnace operation is shown to promote electrical efficiency, ingot homogeneity, high metal yield, and are stability. INTRODUCTION Zirconium is a particularly difficult metal to melt because of its affinity for atmospheric gases and its solvent properties when molten. In addition, zirconium sponge as produced by the boll process contains minor amounts of magnesium chloride, which cause severe spattering luring melting, because of these difficulties with zirconium, and its sister metal titanium, near techniques have been developed to permit production of commercial size ingots. Among the more promising is the consumable electrode arc melting method.

Jan 1, 1955

By Forrest T. Moyer

General injury experience in the mineral fuel industries was less favorable in 1965. Of the major industry groups, the coal mining and the coke industries had higher injury-frequency and severity rates than in 1964. The oil and gas industries had an increased Tate of occurrence of injuries although the severity rate improved. However, in the relatively small peat and native asphalt industries, the injury experience was more favorable than in 1964. Overall operating activity for the mineral fuel industries, as measured by the average number of men working daily and the total worktime, was higher than in 1964. Moderate declines in employment and worktime in the coal and peat industries were more than offset by gain in the other groups. In addition to the industry classifications included in this chapter, similar injury, employment, and worktime data on the metal, nonmetal, stone and aggregate industries are presented in volume I. Corresponding data for broad classifications of mineral industry groups arc given by States in volume III of the Minerals Yearbook.

Jan 1, 1967

By J. C. Franklin

An experiment was conducted by the U.S. Bureau of Mines and the Canada Centre for Mineral and Energy Technology (CANMET) to measure the emanation rate of radon from cemented unclassified mill tailings in two dewatered stopes of a uranium mine at Elliot Lake, Ontario, Canada. The radon was monitored upstream and downstream and in both stopes to determine the concentration in the stopes and the amount exhausted from both stopes. The emanation rate was determined to be 0.55 pCi/cm2 sec-1 from the mill tailings, which is approximately 1,000 times higher than the average flux in the mine before backfilling.

Jan 1, 1982

By H. H. Fukubayashi

This Bureau of Mines report describes the development of a pyrometallurgical process for the recovery of the zinc and lead contained in brass smelter flue dusts, which constitute a recycling or disposal problem. Tests on brass flue dust from several sources were made in a quartz tube, heated by an electric furnace to temperatures as high as 1,050° C. The dusts were mixed with carbon and heated in an oxygen-free atmosphere. It was demonstrated that 98 pct of the zinc and 12 to 25 pct of the lead, both in the metallic state, could readily be removed from the dusts. It was also found that 75 pct of the zinc could be recovered, with less than 0.1 pct of the lead, in the absence of chlorides. Pelletization techniques were investigated and 0.6 inch pellets were found to be optimal. Pelletizing results in a tenfold reduction in volume.

Jan 1, 1974

By Foster Fraas

In this Bureau of Mines report, use of the photoemission of electrons to produce electric charges for the electrostatic separation of sonic dispersed minerals, which had previously been ground to pass a 43µ-opening sieve, is demonstrated. It appears that many of the oxides, carbonates, sulfides, and arsenides will respond to photoemission. Minerals least responsive are the oxides of silicon, the oxides of aluminum, and minerals that have a high concentration of these oxides. Although several synthetic ore mixtures did not yield to complete separation in a one-stage operation, it is probable that preliminary neutralization of the initial electric charges produced by powder dispersion will provide complete separation. That the separation can be carried out in air and without the use of reagents or heating, which are required in the present practice of electrostatically separating coarse granular feeds, is of special significance.

Jan 1, 1972