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By R. J. Gunderman

Redesigns of the operator compartments on a continuous miner and on a face haulage vehicle are described. The objective was to optimize the compartments within limitations of existing equipment and functional configurations. Both safety and production should be improved through more comfort for the operator and more natural placement of controls. Design guidelines supplied by the Bureau from a previous contract were used along with human factors analyses to determine requirements. Mock-ups were fabricated from layouts and used to refine design details. The new compartments were implemented and the machines evaluated underground. Comments and reactions to both machines were favorable.

Jan 1, 1978

By E. J. Kloos

The Bureau of Mines evaluated all previously approved gas masks to determine their ability to provide respiratory protection against each of the following six selected amines: ethylenediamine, diethylamine, n-butylamine, ethylamine, methylamine, and hydrazine. Minimum requirements were a 24-minute service life at a flow rate of 64 liters per minute (32 liters per minute for hydrazine) and an amine concentration of 1.0 volume-percent (0.5 volume-percent for hydrazine). The three masks meeting these requirements were the LG4, Willson Products Division, The Electric Storage Battery Co.; the GMD-SS, Mine Safety Appliances Co.; and the 084-PHOV-R, Acme Protection Equipment Co.

Jan 1, 1966

By R. J. Gunderman

Cable reel systems for shuttle cars were investigated to determine whether an improved system could be identified. Interviews and mine visits were conducted to better define limitations and problems with present systems. Although simple and relatively inexpensive, present cable reel systems are not fully satisfactory. Several concepts for a different technical configuration were formulated and evaluated. An all ectric system using electronic control and external sensors was recommended for further development.

Jan 1, 1980

By G. R. Hopkins

The average quantity of heat needed to refine a barrel of crude oil in 1934 was 638,000 B.t.u., or about as much heat energy as contained in 5 gallons of fuel oil. Although the total heat utilized in 1934 was slightly above 1933, crude runs to stills increased 4 percent, hence the average requirement per barrel declined from 660,000 B.t.u. in 1933 to 638,000 B.t.u. in 1934 (see fig. 1). The average for 1934 constitutes a new record for firing efficiency, being just under the previous low of 1929. Heat consumption at refineries depends on many factors, of which the trends in yields of gasoline and lubricating oils are probably most important. The yield of gasoline is indicative of activity at cracking plants, which type of plant utilizes more than the average amount of heat per gallon of product. The yield of lubricating oils is indicative of the extent to which credo oil is refined; that is, it takes considerably more heat to refine a barrel of crude through lubricating oils than it does to separate only gasoline and kerosene. The yield of gasoline decreased from 43.7 percent in 1933 to 43.4 percent in 1934; on the other hand, the yield of gas oil and fuel oil increased. Although the yield of lubricating oils increased slightly in 1934 the theoretical increase in fuel requirements probably was offset by technical improvements, such as solvent refining.

Jan 1, 1935

By WL Wagner

This report presents a quality control approach to the derivation of strategies for monitoring a work environment; specifically, the environment in underground mines where diesel-powered equipment and blasting agents are used. The approach is presented as a series of 22 steps called the Monitoring Strategy Development Scheme. The scheme is an orderly method for selecting from a number of options a strategy or tactics to cost effectively meet the requirements of a chosen objective related to the monitoring of breathing zone air quality. The scheme provides a format to quantify many of the factors that influence the selection of on strategy or tactic over another, and to ensure that important considerations are not neglected. The premise that breathing zone air in work environment can be considered to be manufactured product and that, therefore, conventional quality control approaches are applicable, is introduced. Typical approaches to the quality control of manufactured products and how these approaches can be applied to the selection of monitoring strategies are discussed.

Jan 1, 1983

By Charles L. Kimbell

The estimated value of world crude mineral production in 1989 was nearly $1,420 billion in terms of current dollars or more than $1,168 billion in terms of constant 1983 dollars. This latter figure was almost 4.7% above the 1988 level but did not attain the historic high of $1,207.1 billion 1983 dollars set in 1980. The accompanying tabulation provides the latest available revised time series for the value of world crude mineral production in terms of both constant 1983 dollars and current dollars. It also provides one of the two statistical bases for the estimation, this being the data on the value of production of a group of key commodities that was compiled for and published in the authoritative French language mineral industry periodical Annales des Mines for years up to 1983.l It should be stressed that the values just discussed and those presented in the tabulation are for crude minerals only and by no means reflect adequately the role of the entire mineral industry in the world economy. These figures represent only the value of mineral materials as they are mined or otherwise extracted from the earth. They do not reflect the value added to these materials through downstream processing within the facilities commonly accepted as mineral industry plants. That is, value added through beneficiation of ores, smelting, refining, and similar processing is not included in these figures. Comprehensive world data on the value added by such processing are not available; however, a conservative estimate of [ ] the total value of processed output from mineral industry plants derived wholly from primary (newly mined) materials would be on the order of about $2,800 billion constant 1983 dollars or $3,400 billion in terms of 1989 dollars.

Jan 1, 1992

By John E. Hamak

The identified helium resources of the United States were estimated by the U.S. Bureau of Mines at 617 Bcf, as of December 31, 1992. This includes 285 Bef of demonstrated reserves, 85 Bcf of demonstrated marginal reserves, and 37 Bcf of demonstrated sub-economic resources. The identified resources also include 166 Bcf of helium in inferred reserves and inferred marginal reserves and 44 Bcf in inferred sub-economic resources. The identified helium resources contained on Federal lands are approximately 172 Bcf, including 32 Bcf in underground storage in the Cliffside Gasfield near Amarillo, TX. Undiscovered helium resources in the United States are estimated at a most likely volume of 104 Bef, with a maximum volume of 249 Bcf and a minimum volume of 41 Bef. Also reported are 51 Bcf of helium in nonconventional and low-helium-content natural gases. Extraction of helium in the United States occurs mostly from natural gases produced from the Hugoton gas area in Kansas, Oklahoma, and Texas, and the Riley Ridge area in southwest Wyoming. Helium extracted from natural gas in the United States in 1992 was 3.3 Bcf. Some shortfalls in helium supply may occur in about 5 to 10 years.

Jan 1, 1995

By Sidney Katell

The reaction of coal, oil, or natural gas with air and oxygen and/or steam yields a gas containing varying amounts of impurities. Depending on the raw material and the end use of the product, these impurities include solids, such as dust or slag, and gases, such as hydrogen sulfide, carbon dioxide, and nitrogen. Considerable effort has been expended in developing and operating purification systems, and the literature is replete with equipment data and operating results. The research problems, the design, and the operation of the various systems have been the subjects of patent applications, journal articles, and textbooks.

Jan 1, 1959

By J. N. Geyer

In coal mining it is essential to maintain the roof over working places and roadways in the safest condition possible. To this end every effort should be made to win the coal with the least injury to the immediate roof strata, as broken strata certainly present a greater hazard than a sound roof. The chief causes of injury to the roof in mining are inherent in the method of development and recovery and the blasting practices followed. The first, which may produce severe stresses in the roof, weakening it over comparatively large areas has been discussed in previous papers3 and will not be treated here. The second cause is local in effect, but with the same general method of blasting being employed throughout a mine having uniform roof conditions, similar effects on the roof may be expected. In the Bureau's investigation of accidents caused by falls of roof and coal it has been necessary to make a careful study of blasting practices and their effect on the immediate roof. The purpose of this paper is to show the effect of the observed methods of blasting on different types of roof and to point out methods that have been proved to be least harmful to the roof strata. The data used in preparing this paper have been compiled from reports made by Bureau engineers engaged in the study of falls of roof and coal, and embrace mines opened in the Pittsburgh coal in Ohio and Pennsylvania and the Pittsburgh and Sewickley coals in West Virginia.

Jan 1, 1933

By Doerner H. A.

From thermodynamic calculations Maier predicted that zinc oxide and methane would react at specified temperatures substantially according to equation (1). (1.) ZnO + CH4 = Zn (gas) + CO + 2H2. Other reactions that may take place are (2.) CH4 = C + 2H2. (3.) ZnO + CO = Zn (gas) + CO2. (4.) ZnO + H2 = Zn (gas) + H2O. Maier predicted that 870°C would be the critical temperature above which reaction (1) would take precedence over reaction (2) and that reaction (1), at equilibrium, would be substantially complete at or above 927°C. Theoretical considerations indicate that reaction (1) is reversible: this is supported, but not proved, by experimental data. The other reactions are known to be reversible. At low temperatures reaction (2) requires a catalyst and it is slow below 1000°C. Reactions (3) and (4) are rapid, but the equilibrium constants are such that only small concentrations of CO2 or H2O can be produced below 1000°C. Maier calculated that CO2 should not exceed 0.5 per cent at 870°C., and the calculation for water vapor gives a still smaller order of magnitude.

Jan 1, 1931

By W. E. Wallace, B. L. Razzaboni, P. Bolsaitis, M. J. Keane

"Therma1 and chemical treatment of respirable size silica dusts samples is shown to induce marked changes in their hemolytic activity. The cytotoxicity of crystalline a-quartz (Min-U-Sil), and fumed silica (Cab-0- Sil) particles, as measured by a hemolytic activity protocol, is decreased by calcination and can be related to the dehydroxylation of the surface. The hemolytic activity of P-cristobalite particles of respirable dust si7.e was also determined and found to be lower than that of a-quartz. The change in the surface structure resulting from thermal treatment is detectable by photo-acoustic infrared spectroscopy and zeta-potential measurements. The absorption band in the 3200-4000 cm-1 frequency region of both Cab-0-Sil and MinU- Sil disappears upon heat treatment while a sharp band, identified with single silanol groups, at 3750 cm-1 increases in intensity. The zeta potential-pH profile, in the pH range of 4.0-7 .0, of the calcined, siloxane surfaced particles is more negative than that of material with a silanol surface.The cytotoxicity of the crystalline and fumed silica dusts was also found to be strongly dependent on particle size. Fumed silica of large surface area (small particle size) exhibits an initial increase in hemolytic activity upon calcination. This result confirms other experimental observations pointing to a particle size of maximum toxicity. INTRODOCTIONThe toxicity of silica and other mineral particles, as manifested by their role in inducing pneumoconiosis, fibrosis, silicosis and other pulmonary disorders is largely traceable to the characteristics of particle surfaces and to particle morphology. The great wealth of data on the physical and chemical properties of silica is still insufficient for a comprehensive understanding of the specific parameters to be associated with fibrogenic activity and, correspondingly, with the optimum means for characterizing and quantifying the toxicity of dusts, and the design of possible preventive or therapeutic methods.The great diversity of parameters that have been proposed and tested for correlation with cytotoxicity suggest that more than one mechanism may be involved in the fibrotic activity of silica particles. The crystalline structure of the material (more active tridymite versus less active crisobalite and passive stishovite), freshly formed surfaces and free radicals associated therewith, silicic acid adsorbed onto silica surfaces, the concentration of hydroxyl groups at silica surfaces, particle size and morphology, among other properties, have been investigated and found to conelate in tests of cytotoxicity."

Jan 1, 1990

By Russell Levens

A strategy for prioritizing mining health and safety research by evaluating the potential for risk reduction through interventions is proposed. Mining has one of the highest incidence rates of injury and disease found in major industries. The main premise of this paper is that often the best opportunities to reduce these rates are not revealed by retrospective analysis of injury and illness data. Instead, a proactive approach is needed that accounts for risks to specific hazards that can be abated by engineering or behavioral interventions. The process proposed here begins with development of prospective interventions. The degree of reduction in risk to be expected from an intervention then is determined from statistics on the mining worker population, the expected degree of success of the intervention, and the expected change in the severity of injuries resulting from the intervention. Three disparate mining health and safety concerns are presented to demonstrate common problems in assessing risks of injury and illness and describe additional data needs. Information on events preceding injuries and illnesses and more detailed demographic data on the mining work force are needed to analyze injury and illness data more precisely. Detailed information on exposure to specific hazards is necessary to evaluate the potential for an intervention to reduce risk of injury or illness.

By Ted C. Briggs

A special high-pressure Burnett-type compressibility apparatus was constructed and used to determine compressibility factors for pure helium, pure nitrogen, and nine helium-nitrogen mixtures containing 89.47, 79.04, 69.69, 60.09, 49.24, 41.02, 30.99, 20.53, and 10.67 mole-percent helium. A total of 161 runs were made consisting of 2,355 observed pressures. Data were obtained at 0°, 25°, and 50° C and at pressures to 1,000 atmospheres. A power series in the reciprocal volume, commonly called a Leiden series, is used to represent the compressibility factors. Three parameters in the series are required to represent helium, five parameters to represent nitrogen, and from three to five parameters to represent the mixtures. Compressibility factors are believed to be accurate to better than 0.1 percent over the entire pressure, temperature, and composition range.

Jan 1, 1972

By Robert N. Roby

The Hornsilver lead-zinc property was examined by the Bureau in 1942 and again in 1944. A project was started on the property in April 1946 and completed in January 1947. Silver was first discovered in this district in 1883, and while complete production records are not available, it is known that a substantial tonnage of high-grade silver ore was shipped before 1887. All of the ore was mined from surface or near-surface workings. When the high-grade oxidized ore was exhausted, the district became inactive and remained so until the 1920's. In 1928 and 1929 some activity was shown in the district, but the Hornsilver mine was not reopened until November 1937. Between 1939 and 1946, the mine produced about 16,000 tons of ore of 531 ounces of gold, 283 ounces of silver, over a million pounds of load, and nerdy 2 million pounds of zinc. The property is now controlled by the Era Mining & Development Co., which has acquired the Last Chance and Ella groups of claims, in addition to the Hornsilver mine.

Jan 1, 1948

By John E. Trombly

System objectives and design criteria for an in-mine visual personnel paging system are discussed. Display technologies are evaluated and tradeoffs leading to display selection are described. The prototype dispatcher's console, battery/receiver box and visual display assemblies are functionally described. The report includes circuit descriptions, schematics, parts lists and equipment cabinet drawings for the three assemblies. The report concludes with an estimate of the manufacturing cost for each assembly.

Jan 1, 1975

By Edward P. Barrett

This investigation was a part of the Bureau of Mines program for the production of critical and essential materials needed for the war. The Boykin Committee for investigating the steel shortage aided in obtaining an appropriation to be expended by the Bureau of Mines in studying the utilization of North Dakota lignite in the manufacture of hydrogen that could be used in the production of sponge iron from the low-grade iron ores of Minnesota. This investigation was conducted by the Bureau of Mines to determine the workability of the proposed shaft-furnace process and its possible use in connection with an experimental plant for the gasification of lignite operated by the Coal Division of the Bureau of Mines at Grand Forks, N. Dak.

Jan 1, 1948

By H. R. Shell

The systems MgO-MgFa-SiO2, at 2 and 4 weight-percent Li2O and at 3.8 and 7.7 weight-percent Na2O were investigated by solid state reaction at 1,200° C. The results are summarized in four ternary diagrams. Besides the expected humites and simpler silicates or fluorides, proto-amphibole and water-swelling fluormicas or fluormontmorillonoids were found in the systems containing lithium and monoclinic fluoramphiboles, water-swelling fluormicas or fluormont-morillonoids, and nonwater-swelling fluormicas were found in the systems containing sodium. These latter compounds were not in the base system MgO-MgF2-SiO2.

Jan 1, 1962

By Sam S. Taylor

[The discovery of many oil fields in Illinois since 1936, and their rapid development have brought the problem of brine disposal to the foreground in that State. The ultimate magnitude of the problem is not yet known, but already it is treat enough to warrant technical investigation. The Bureau of Mines, therefore, has made a general survey of the methods of handling oil-field b brines in Illinois rend has studied in detail three subsurface disposal systems.]

Jan 1, 1940

By Edward L. McHugh

In 1986, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 5-acre Zwagg Island Wilderness Study Area (OR-12-14) in order to evaluate its identified mineral resources. The study area is located in Curry County, OR, immediately west of Brookings. There is no evidence of mining activity on or near Zwagg Island, and no mineral resources were identified. The steep-sided, flat-topped island is normally accessible from the mainland by way of a sandy beach. The island consists mainly of marine sandstone, mudstone, and conglomerate of the Jurassic Dothan Formation. Dothan Formation sandstone has been used locally as construction material. Rock along the coast has also been used for construction of jetties to improve harbor access; additional work has been proposed at the port of Brookings. Although suitable for other construction uses, stone from Zwagg Island would probably not meet physical requirements for jetty stone. Development of a stone resource on the island is unlikely.

Jan 1, 1987

By L. B. Pankratz

The Bureau of Mines measured heat capacities of alpha and beta spodumene (LiAlSi2O5) and of beta eucryptite (LiAlSiO4) over the temperature range 51° to 298° K. The entropies at 298° K were found to be 30.9 ± 0.2 cal/deg mole for alpha spodumene, 36.9 ± 0.3 cal/deg mole for beta spodumene, and 24.8±0.2 cal/deg mole for beta eucryptite. High-temperature heat content measurements above 298° K were conducted for the same compounds. Measurements were made to 1,150° K for alpha spodumene, 1,600° K for beta spodumene, and 1,470° K for beta eucryptite. Tables of heats and free energies of formation are given from the elements and from the constituent oxides.

Jan 1, 1967