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Objective: To continuously monitor, display, and record concentration levels of respirable coal mine dust in mines to an accuracy of ±25% with a 95% confidence level for at least 30 days without servicing.

Jul 1, 1997

By William S. Roberts

The Bureau of Mines has initiated a program to determine the availability of land for mineral exploration and development in Alaska. Researchers involved in this pro-gram are comparing land availability, based on ownership and government policies and regulations, to the distribution of known mineral deposits and terranes. This report on southeastern Alaska presents the findings of the first of six regional studies that will cover the State. The study consisted largely of data compilation and analysis using various mapping techniques. Summary land availability data are presented on copies of U.S. Geological Survey (USGS) quadrangles at a scale of 1:500,000. Five categories of land availability were identified: open to mineral exploration and development (approximately 9.4 million acres, or 38% of the 24.8-million-acre study area), open but with possible use restrictions (4.2 million acres, or 17%), selected (0.5 million acres, or 2%), patented (0.74 million acres, or 3%), and formally closed to mineral exploration and development (10 million acres, or 40%). Of the 1,187 known mineral deposits in the study area, approximately 38% are on land in the open category. Mineral terranes comprise approximately 6.7 million acres, or 27% of southeastern Alaska. Approximately 34% of these terranes are on open land.

Jan 1, 1985

By LeRoy R. Curwick

This Bureau of Mines report presents the results of a study conducted to assess the domestic availability of chromium from superalloy and cast heat- and corrosion-resistant alloy scrap material. Six alloy classes included in this survey were investment cast, hardfacing, and wrought nickel- and cobalt-base alloys, wrought nickel-iron-base alloys, and heat- and corrosion-resistant alloy castings. Data were collected for 1976 on metallic scrap generation, use patterns, and production practices for these alloy producing and using industries. A model was developed that allowed an assessment of the materials flow circuits within the industries that produce these alloys. The types, amounts, sources, secondary products, and ultimate destinations of chromium- containing metallic scrap for the six alloy classes were determined. Regarding the overall recycling efficiency of these alloy producing and using industries, of the 580.9 million pounds of scrap generated from these six alloy classes in 1976, about 72 percent (416.8 million pounds) was remelted by the same alloy-producing industries, about 18 percent (104.9 million pounds) was downgraded into stainless and low-alloy steels, about 3 percent (19.7 million pounds) was exported, and about 7 percent (39.5 million pounds) was lost through landfill or other disposal or service wastage. The lost material is primarily contaminated oxides for which recovery is currently uneconomic. However, the 124.6 million pounds of scrap material downgraded or exported in 197b contained potentially recoverable critical strategic elements. The amount of scrap material lost to the six alloy-producing industries in this manner contained 22.1 million pounds of chromium, 53.4 million pounds of nickel, 5.9 million pounds of cobalt, 35.9 million pounds of iron, and 7.3 million pounds of other alloying elements.

Jan 1, 1980

By Clayton M. Rumsey

The U.S. Bureau of Mines investigated prospects and mineralized areas in and adjacent to the Indian Pass and Picacho Peak study areas in 1983 and 1984. The Indian Pass study area contains 33,640 acres and the Picacho Peak study area contains 5,450 acres. The study areas are located in the southeast corner of California and are underlain by Precambrian gneiss, Pre-Tertiary metavolcanic and metasedimentary rocks, and Tertiary volcanic and non-marine clastic rocks. Low-grade gold-silver resources may be present in hydrothermally altered gneiss in the upper plate and altered schist in the lower plate of the Chocolate Mountain thrust fault. The thrust fault is exposed in the study areas for about 3.5 miles west and 5 miles east of Indian Pass. Mineralized zones in the thrust plates were not discovered until 1983. Earlier prospecting explored areas containing minor copper carbonate occurrences in schist and sedimentary and volcanic rocks that are younger than the thrust. Twenty-three mines, prospects, and mineral occurrences inside the study areas and fourteen outs; de were examined for this study. These surficial copper occurrences have been prospected extensively in the study areas; large areas have been scraped, pitted, and trenched by bulldozers. However, they appear to be of limited economic significance. Slightly mineralized zones are in the northwest part of the Indian Pass study area where granite contacts sedimentary and volcanic rocks.

Jan 1, 1986

By C. C. Furnas

In the course of an investigation3 of the flow of gases through beds of broken solids the author obtained a number of data .on the specific volume of beds of broken solids of variously mixed sizes. A mathematical theory of the limiting conditions has been developed and some generalizations have been made for intermediate cases. A more definite knowledge of the relation between space occupied and size composition would be valuable to all those who are handling large quantities of broken materials. Such knowledge might be advantageously applied to the operation of a coke oven. For example, the output of the oven depends in general upon the number of pounds of coal which can be put in the oven at charging. It is known that the capacity of one battery of ovens was increased several per cent by slightly increasing the proportion of fine material in the charge.

Jan 1, 1928

By D. A. Stanley

The Bureau of Mines is investigating a method of dewatering flocculated fine-particle waste that involves treating the waste with a high molecular-weight polymer such as polyethylene oxide (PED) followed by dewatering on a static screen and/or in a trommel. Dilution of the polymer solution used for dewatering and use of the ion-exchanged form of the montmorillonite clay were found to be major factors determining the amount of polymer required to dewater clay-containing slurries. The amount of polymer, A, required to dewater ion-exchanged montmorillonite can be described by the equation, An = kC + b where n, k, and b are empirical constants and C is the concentration of the polymer solution used for dewatering. Clays that require large amounts of polymer for dewatering also dewater to a lower solids content. The concentration of the polymer solution is important because it affects the radius of the polymer coil in solution and hence its ease of transfer to a bridging configuration by shear. The constant, n, a function of the charge to hydrated radius of the exchange ion, relates to the strength of the bond between the polymer and the surface of the clay through a water bridge. The constant k is related to the hydrated radi-us for sodium or to the unhydrated radius for the other exchange ions.

Jan 1, 1986

By K. B. Rojiani

Surface mining activities disturb large tracts of land resulting in the potential for greatly increased downstream sediment loads. The Surface Mining Control and Reclamation Act of 1977 places increased emphasis on the protection of the environment from the adverse effects of surface mining operations. Surface mining activities must be planned to minimize disturbance to the hydrologic balance, erosion and sediment contributions to receiving streams. Sediment ponds must provide a sediment storage volume equal to the accumulated sediment volume from the drainage area as determined by the Universal Soil Loss Equation (USLE) or other empirical methods established by the regulatory authority. It has thus become extremely important for the mining industry to secure more accurate estimates of potential erosion losses and sediment yield. Accurate estimates of sediment yield are required for the planning, design and successful operation of sediment control systems such as detention ponds and other alternative control structures and for evaluating the effectiveness of land management practices. The principal soil loss prediction procedure available for use is the LISLE. The USLE procedure is inadequate for use in predicting soil loss from surface mine regions for a number of reasons. These include: 1. The USLE was developed to estimate average average annual loss from agricultural soils. It cannot predict accurately soil loss for specific storm events. In surface mine regions a major portion of the soil loss occurs during the initial six months to one year of active mining. Accurate estimates of soil loss over short periods are thus required for the design of control structures. 2. The slope length and gradient factors used in the USLE were obtained from data or cropland having slopes ranging

Jan 1, 1983

By Steven R. Munts

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 8,445 acres of the 20,650-acre Tunnison Mountain Wilderness Study Area in order to evaluate its identified mi nerd 1 resources. The study area is located in Lassen County, CA, about 8 miles northeast from Susanville. No mineral resources were identified in the study area based on literature, field observations, and sample results. No mines were operating in or near the study area in 1985, and no mines, prospects, or claims have been located in or within 1 mi le of the study area. The study area is underlain by Pliocene and Pleistocene volcanic units composed of basalt, andesite, rhyolite, and some pyroclastics. No metallic and only nonmetallic commodities are present in the study area. These included stone and sand and gravel. Although substantial volumes of basalt and andesite (stone) occur within the study area, no identified resources of these commodities were delineated. Sand and gravel is not economic because of small occurrence size and lack of local markets.

Jan 1, 1987

By Howard W. Kilau

The U.S. Bureau of Mines is investigating surfactants added to water sprays to enhance the control of dust during coal mining operations. The objective of the present work was to establish the general applicability of adding sulfate ion to anionic surfactant solutions in order to improve wetting action. This was pursued through laboratory wettability testing of four anionic surfactants and one nonionic surfactant in combination with various concentrations of sulfate ion. The experimental results demonstrated that the addition of sulfate ion enhanced the wetting characteristics of all the anionic surfactants when applied to hard-to-wet coals, while easy-to-wet coal showed more complex wetting behavior. Sulfate ion in the presence of nonionic surfactant enhanced wetting only slightly or not at all. Surface tension measurements of the dilute aqueous surfactant-sulfate anion solutions indicated this property was not important in coal-wetting phenomena, as long as the value was below the critical value for coal. Sulfate ion helps surfactant reduce surface tension but primarily appears to affect wetting action by altering the adsorption characteristics of surfactant on the coal surface.

Jan 1, 1990

By A. U. Miller

Definite progress has been made in accident prevention in Illinois during the past few years; the State Department of Mines and Minerals is receiving excellent cooperation from coal companies and employees, the companies are making greater effort to maintain their mines in good condi- tion, and the employees are eliminating more unsafe practices. As a result, some coal companies have made commendable safety records that prove that coal can be mined with a comparatively low accident rate. However, there is need for further improvement, as the accident rate of the State as a whole is much higher than it should be. During the 55-year period 1882-1936, in- clusive, reports of the State Department of Mines and Minerals show a total of 7,005 (an average of 127.36 per year) men killed in and around the coal mines. Of this number, 6,425 (91.7 percent) were killed underground, 346 (4.9 percent) in the shaft, and 234 (3.3 percent) on the surface. Of the fatalities underground, 3,300 (51.3 percent) were killed by falls of roof, sides, or face coal, 1,167 (18.1 percent) by haulage, 639 (9.9 percent) by handling explosives, 579 (9 percent) by explosions, 151 (2.3 percent) by electricity, and 589 (9.1 percent) by other means. Of the fatalities in the shaft, 171 men (46.5 percent) were killed by falling down the shaft, 14 (41.6 percent) by the cage, and 31 (8.9 percent) otherwise. On the surface, 113 (48.2 percent) of the fatalities were due to railroad cars, 51 (21.7 percent) to machinery, and 70 (29.9 percent) to other causes. The fact that 7,005 lives (an average of 127.36 per year) were lost during 1882-1936 is sufficient evidence that in the past too little interest has been taken in safety by either the management or workers. A realization of this deplorable loss of life should act as an incentive to the industry to make greater effort to prevent accidents in the future. After an accident occurs, the facts pertaining to it become history, and anything that may be done afterward cannot change in any way the damage that has already been done, such as loss of life, personal injury, and destruction of property. The main benefit that can be derived from an acci- dent is that suitable procedure may be adopted and some lesson may be learned to aid in preventing a similar accident in the future. All accidents, par- ticularly serious ones, therefore should be investigated and an effort made

Apr 1, 1938

By W. L. Dare

This paper is one of a series being prepared by the Bureau of Mines on the methods and costs of mining uranium on the Colorado Plateau. The Continental No. l mine is at the south end of the Big Indian mining district, San Juan County, Utah. The mine is on a school section owned by the State of Utah and leased by Continental Uranium, Inc. A 70,000-ton uranium-vanadium ore deposit was discovered as a result of an exploratory drilling program completed in 1954.

Jan 1, 1957

By Charles Will Wright

This paper is one of a series dealing with mining problems and summarizing the data contained in the Information Circulars on individual mines that have been prepared by the managers or superintendents and published by the Bureau of Mines. The purpose of this paper is to present the problems encountered in the development of an efficient mine organization and to show the means used by certain mining companies in promoting efficiency. There is also a discussion of the advantages and disadvantages of the various systems of paying and handling labor and a description of their application at the individual mines.

Jan 1, 1932

By Melvin P. Silverman

The literature on methane-oxidizing bacteria is reviewed in regard to (1) the growth and isolation of cultures by special techniques; (2) the distribution of these organisms in nature and descriptions of individual species; (3) the physiology of methane-oxidizing bacteria as influenced by temperature, light, pH, aerobiosis versus anaerobiosis, and carbon and nitrogen sources; and (4) the biochemistry of methane oxidation revealed by studies with intact cells and subcellular systems. Present practical applications of methane-oxidizing bacteria are limited to prospecting for natural gas and petroleum deposits. Desirable areas for future research are discussed as well as some possible applications such as (1) the removal and/or early detection of methane gas in coal mines by intact cells or enzyme preparations; (2) the generation of electrical energy by microbial fuel cells using methane as fuel; (3) the growth of methane-oxidizing bacteria on methane for their food value; (4) the purification of hydrocarbon gas mixtures using methane-oxidizing or other alkane-oxidizing bacteria; and (5) the synthesis of methane from mixtures of H2 and CO or H2 and CO2 by me thane-forming bacteria.

Jan 1, 1964

By Melvin P. Silverman

The literature on methane-oxidizing bacteria is reviewed in regard to (1) the growth and isolation of cultures by special techniques; (2) the distribution of these organisms in nature and descriptions of individual species; (3) the physiology of methane-oxidizing bacteria as influenced by temperature, light, pH, aerobiosis versus anaerobiosis, and carbon and nitrogen sources; and (4) the biochemistry of methane oxidation revealed by studies with intact cells and subcellular systems. Present practical applications of methane-oxidizing bacteria are limited to prospecting for natural gas and petroleum deposits. Desirable areas for future research are discussed as well as some possible applications such as (1) the removal and/or early detection of methane gas in coal mines by intact culls or enzyme preparations; (2) the generation of electrical energy by microbial fuel cells using methane as fuel; (3) the growth of methane-oxidizing bacteria on methane fur their food value; (4) the purification of hydrocarbon gas mixtures using methane-oxidizing or other alkane-oxidizing bacteria; and (5) the synthesis of methane from mixtures of H2 and CO or H2 and CO2 by methane-forming bacteria.

Jan 1, 1964

By D. A. Reynolds, C. R. Holmes

The Bureau of Mines - American Gas Association ( EM - AGA) carbonization test has been used to determine the carbonizing properties of 66 American coals and a larger number of coal blends . A summary of the results obtained for the first 30 coals , including 6 blends , has been published ,4/ and results for individual coals have been reported as the investigations were completed . A bibliography of all publications pertaining to this work has been issued recently . Many of the coals were carbonized at 800 ° and 900° C. in two sizes of retorts ( 13- and 18 - inch diameters ) ; and , because the quality of coke is affected by changing the size of the retort , this report has been prepared to show the average physical properties of coke from the two sizes . This report also purposes to extend the correlation of the physical properties of coke with the rank of coal made by Fieldner and Davis in their summary of the EM-AGA tests on the first 30 coals .

Jun 1, 1942

By D. Harrington

The record of fatalities from mine explosions in the United States during the past 44 years has been the best in the history of the mining industry, despite the fact that the number of fatalities from this cause during the past fiscal year now is nearly double that of the previous year. During there 4 fiscal years, mine explosions have resulted in an average of 45.5 deaths per year, compared with an average of 153 deaths per year for the preceding 5 years; an average of 542 deaths per year for the 3 years 1907-1909, inclusive, and a yearly average of 265 deaths per year for the 20 years prior to 1929. Other types of mine accidents also have been reduced during this period, but not to the same degree or by as large a percentage as mine explosions. The fact that in this fiscal year ended June 30, 1937, electricity was responsible for 60 percent of the explosions and 85.5 percent of the fatalities resulting therefrom (see tables 3 and 4) is evidence that either mine operators are lax in providing proper electrical equipment or there is laxity in the upkeep and use of electricity in our mines and more particularly in our coal mines. Several large coal-producing States that in the Fast have had numerous disastrous explosions have been free from such disasters for continuous periods of as long as 8 years. The bituminous mines of Pennsylvania, one of the largest coal-producing States, give a good example of what can be done to prevent explosions. 'his State, with its large number of operating mines, many with very definite hazards from gas or dust or both, has had only two major explosions (resulting in 16 fatalities) during the past 7 years; this is a decidedly good record compared with any similar period in the past and when it is considered that during this period about 750,000,000 tons of coal have been produced. Other good records are: Tennessee, without a single fatality from explosions during the past 9 years; Alabama, with 6 fatalities during the past 7 years; Illinois, with no explosions during the past 4 years; and

Jan 1, 1938

By Stephen D. Cramer

The Bureau of Mines conducted a study in which the magnetic fraction of urban refuse was used as melting stock in the preparation of high-strength, low-alloy and carbon steel. Product steels, made from incinerated steel can scrap, nonincinerated-nondetinned steel can scrap, nonincinerated-detinned steel can scrap, and dilutions of these scraps with No. 1 heavy melting scrap, were used in continuing tests in industrial, rural, and marine environments to determine the effect of residual elements and atmospheric pollutants on their atmospheric corrosion resistance. The respective commercial steels were exposed at the same time to establish baseline corrosion data for the test sites. Weight-loss data are reported for atmospheric exposures of 0.5, 1.0, 1.5, and 3.8 years. The marine environment was the most corrosive; the industrial environment was the least corrosive. The atmospheric corrosion resistance of the carbon steel was improved 25 pct by using incinerated scrap and nonin-cinerated-nondetinned scrap in the steelmaking process. In no case was the atmospheric corrosion resistance of carbon steel degraded by using the magnetic fraction of urban refuse as melting stock. The presence of sulfur in the corrosion film was the most important factor affecting the corrosion resistance of the steels. With increasing sulfur concentration, the rate of the corrosion reaction was reduced and the corrosion film became more protective. The residual elements in the product steels most responsible for improving corrosion resistance were copper and tin. These elements tended to increase the concentration of sulfur in the corrosion film. At the levels present in the product steels, Cr, Ni, and Pb had no observable effect on the corrosion resistance of the steels.

Jan 1, 1980

By Theodore Kessler

The purpose of this Bureau of Mines investigation was to determine what new organic compounds or high concentrations of a particular organic species can be formed by exposure of coal derivatives to ultrasonic energy. Tetralin, l-methylnaphthalene, and pyridine were used as model compounds. Gaseous and solid reaction products resulting from the ultrasonic irradiation of these coal derivatives were determined using mass spectrometry. Products from the irradiation of tetralin were studied as a function of time, atmosphere, and sample size. The sonolysis (chemical reactions produced by ultrasonic energy) of tetralin and l-methylnaphthalene produced C2H2, HCN, CH4, H2, CO, and CO2, depending upon the experimental conditions. The ultrasonic irradiation of tetralin also produced diacetylene under certain experimental conditions. The cleavage of organic chemical bonds by ultrasonic cavitation in the absence of water was also observed in this study.

Jan 1, 1967

By R. S. Norman

The objective of this program was to select approximately 100 acoustic materials for flammability evaluation. Noise control programs have been initiated on several types of mining equipment and vehicles which can be used in underground coal mines. Often, the materials which are used in these noise reduction programs have not been tested for flammability properties according to the same reference standard. During this program a variety of materials were selected for measurement according to ASTM E-162 procedures. A radiant heat energy source was used to measure flammability properties of 15.2 x 45.7 cm. samples. In the absorptive materials category, 45 percent of the materials tested had a flame spread index of less than 25. For barrier, damping, and isolation materials the corresponding values were 40, 43, and 9 percent.

Jan 1, 1979

By W. H. Coghill

Numerous investigators have studied grinding. Each has contributed his bit to a literature that is difficult to correlate. Too many of the results have been transformed into curves with so many "inflection points" and "counterflexures" that they obscure the issue. Some of the investigators have neglected the very essence of the problem, namely the power and the amount of material to which a known amount of work was applied. The purpose of this paper is to show the ease with which results can be interpreted when these quantities are duly recognized. Some grinding tests will be given for illustration. Grinding studies are of two kinds: (1) Study of the character of the ore and (2) study of the performance of the machines. Several ores may be crushed by a given machine, or several machines may be used on a given ore. The illustrations given in this report cover both objectives.

Jan 1, 1934