Search Documents

By R. E. Head

[Surveys of the manganese situation conducted by the Geological Survey and other agencies have distinctly established the fact that the tonnage of high- grade manganese ore in the United States is relatively small. It is therefore obvious that large-scale production of manganese is possible only through beneficiation of low-grade material. ]

Jan 1, 1941

By R. E. Head

[Surveys of the manganese situation conducted by the Geological Survey any other agencies have definitely established the, fact that the tonnage of high-grade manganese or in the United States is relatively small. It is therefore obvious that large-scale production of manganese is possible only through beneficiation of low-grade material. Deposits of low-grade manganese ore are being examined by engineers of the Mining Division of the Bureau of Mines to determine their size and possibilities as sources of manganese on a tonnage basis. The Metallurgical Division of the Bureau is developing and perfecting beneficiation processes with the objective of utilizing such low-grade ores. Microscopic study of these ores represents one phase of the research.]

Jan 1, 1941

By Elaine Cullen, Launa Mallett, Mike Jenkins, C. M. K. Boldt, Thomas Camm

The material in this Information Circular was presented at the National Institute for Occupational Safety and Health’s (NIOSH) open-industry briefing held during the 2004 Northwest Mining Association conference in Spokane, WA. The open-industry briefing discussed results of recently completed and on-going mine safety- and health-related research conducted at NIOSH’s Spokane and Pittsburgh Research Laboratories on the human side of mining—the miner. The first paper sets the stage for what mining has achieved and what we mean by “getting to zero.” The second paper, “Help Experienced Miners Become Great On-the-Job Trainers,” distinguishes between experienced miners and trainers. This paper provides some key concepts for turning great miners into great trainers. “The Power of Story-Telling in Getting Through to Miners” explains the history and importance of stories in the culture and training of miners. Finally, “Understanding Self in Stressful Working Environments,” describes the personal and social aspects of the working environment, much of which parallels familial theories. The downward trend of deaths in U.S. mining has been remarkable. The number of miners killed or injured each year has decreased steadily over the past 100 years. Some charts show these trends overlain with important events such as World War II and the Mine Safety and Health Act. However, this downward trend in mining fatalities has flattened out. How can you get to zero accidents? Do you concentrate on technological advances and equipment maintenance to avoid malfunctions? Do you concentrate on developing work processes and organizational structures that minimize risk? Do you combine them and take a systems approach that links one to the other with an evaluative loop? Safety efforts in mining have used all of these approaches. What more can we do to get to zero? Getting to zero will require two objectives: A clear and unshakeable belief that it can be done and attention to the human side of mining. Getting to zero is not a new idea; it has been used by mine companies and safety professionals for years as the safety goal. But getting to zero is not so much a physical goal as it is a belief that there are no insurmountable barriers to achieving the goal.

Jan 3, 2006

By C. H. Gorski

Evaluation of raw materials for mineral wool is one phase of the Bureau of Mines broad program for the more effective utilization: of our mineral resources. The experimental work and test-evaluation results on several raw materials as useful components for the production of mineral wool are presented in this report. Samples from all sections of the United States, including copper slag from Tacoma, Wash., pebble phosphate slime from Florida, and granites from Massachusetts and Minnesota, have been blown into mineral wool successfully in the laboratory tests. Maximum conservation of the Nation's mineral and manpower resources requires maximum utility of those resources. Al though the domestic reserves of oil, gas, and coal are tremendous, judicious use of these fuels through the use of proper insulation will insure the highest thermal efficiency. The effectiveness of mineral wool as a heat-insulating material has assumed an increasingly important role in the national economy, and it has become a fuel saver in countless applications. The most immediate concern to many is the use of mineral wool in the home, which promotes uniform temperature and minimizes drafts by reducing heat transfer through the walls, ceiling, and floors. There are, however, many industrial and commercial uses that require large volumes of mineral wool each year.

Jan 1, 1951

By C. Özgen Karacan

This study presents the results of core-log analyses from the exploration boreholes, the analyses of face advance rates, and the results of downhole monitoring studies performed in gob gas ventholes for calculation of changes in hydraulic properties in the longwall overburden at a mine site in southwestern (SW) Pennsylvania section of Northern Appalachian Basin. In the ?rst part of the study, coal measure rocks in overburden strata were analyzed and the locations where possible fractures and bedding plane separations would occur were evaluated. In the second part, the hydraulic conductivities were computed by two different slug test analyses methods using the water level changes measured in gob gas ventholes as longwall face approached. Hydraulic conductivities were analyzed with respect to the changes in overburden depth, the locations of the borehole, and mine face advance rates. These data were used to interpret the potential productivities of the gob gas ventholes as a result of fracturing and changes in hydraulic conductivities. The general results showed that the probability of fracturing and bedding plane separations in the overburden increase between strong and weak rock interfaces. Also, the probability of bedding plane separations increases as the interface is close to the extracted coal seam. Evaluation of slug tests showed that the hydraulic conductivity developments in the boreholes and their potential production performances are affected by the underground strata and the roof materials. In situations where the roof material is stiff and thick, the development of high permeability fractures around the borehole will be less. Results also indicated that borehole location with respect to face position affects the fracturing time and permeability evolution as well. Greater overburden depths generally cause earlier fracturing as longwall face approaches, but eventually result in lower hydraulic conductivities and potentially less effective boreholes. Increasing mining rates also resulted in generally lower hydraulic conductivities in the overburden. The results of this study were intended to improve the interpretation of gob gas venthole performance and to provide better siting of these boreholes.

Jan 1, 2009

By R. W. Van Dolah

An important function of stemming used to confine explosives in shot holes in underground coal mines is to minimize the chance of ignition of firedamp or coal dust by the detonation products. Until 1952, the Bureau of Mines approved only the use of fireclay or similar incombustible material for stemming permissible explosives. At least 2 feet of stemming were required except in holes less than 4 feet deep; in such short holes the stemming was required to be half the depth of the hole. Over the years, several special stemming devices have been proposed in the United States as substitutes for fireclay. Many economic and safety advantages were claimed for these devices, but only one approved device has been marketed in this country. Bureau requirements for stemming explosives in coal mines were modified at that time to permit the approved stemming device to be used as a substitute for the required fireclay.

Jan 1, 1961

By L. C. IlsLey

Investigations for safety of electrically operated mine equipment, safety lamps, and gas detectors are made at the Pittsburgh Experiment Station in accordance with published regulations termed "schedules." These schedules are revised from time to time, not only to keep in step with the progress of the industry, but also to permit much freedom of design as possible without lowering standards of safety. The following schedule covering electrical equipment, safety lamps, and gas detectors are now active: Schedule 2D. Explosion-Proof Mine Equipment. Requirements for Approval of of Storage-Battery Locomotives and Power Tucks, Junction Boxes, and Electric Motor-Driven Equipment.

Jan 1, 1939

By John J. Mulligan

The Bureau of Mines investigated reports of mineral deposits within 10 miles of the route of the proposed pipeline from Prudhoe Bay to Valdez. No producing lode deposits or lode prospects of possible national economic significance were found. Measured placer deposits in the route are or slight value except possibly some deeply buried gold placer deposits in the Fairbanks and Livengood Quadrangles. The pipeline corridor crosses five belts of minerals having potential economic value: (1) The north slope of the Brooks Range (oil, gas, oil shale, coal, phosphate); (2) the south slope 01 the Brooks Range (copper, gold); (3) the Livengood area (gold); (4) the Fairbanks area lead-silver, antimony); and (5) the Wrangell Mountains-Denali copper belt (copper-gold). The Jarvis Creek coalfield, an eastern extension of the Nenana coalfield, is on the north side of this belt. Scattered along the corridor across the Chugach Mountain and in the vicinity of Valdez are a wide variety of metallic deposits that make up the eastern margin of the Chugach gold belt but do not seem to constitute a well-defined zone.

Jan 1, 1974

By J. J. Jakowsky

[The legislation in many States against the present method of producing carbon-black by the incomplete combustion of natural gas, and the continually increasing demand for gas for otter purposes, indicates that the supply of carbon-black may Gradually be decreased and that new methods for its production, utilizing a greater parentage of the carbon in the has should be developed. In the course of investigations of the effects on hydrocarbons of high voltage discharges, it was noted that under certain conditions natural gas could be decomposed and that carbon-black could be produced. The effects of several tyres of electrical discharges on natural gas have, accordingly, been studied' in order to find out the fundamental factors underlying the reactions and their possible influence in the recovery of a greater part of the carbon content of natural gas than is now possible. Present commercial plants using natural gas for the manufacture of carbon-black recover from 0.9 to 1.5 pounds of carbon-black per thousand cubic feet of gala consumed, or less than 5 per cent of the total Gabon in the gas: It should be noted, however, that the, present methods involve heating the gas to incandescense by burning it as a luminous flame, and a considerable part of the gas is thus consumed as a source of hest. If this heat can be supplied from some other source, or if a more efficient method of applying the energy con. tamed in part of the gas, to the decomposition of the rest of it, can be worked out, then a greater yield of carbon-black per thousand cubic feet of gas care be expected. The present abort paper contains a brief summary of tie investigations so far conducted upon natural gas.]

Jan 1, 1922

By Jr. Watts, B. K. Cantrell, D. H. Carlson, K. L. Rubow

"Abstract — The use of diesel equipment in underground coal mines is controversial because the National Institute for Occupational Safety and Health (NIOSH ) regards ""wholediesel exhaust"" as ""a potential occupational carcinogen."" Threshold limit values (TLVs ) are recommended for the gaseous pollutants CO, CO2, NO, NO2, SO2 and some hydrocarbons emitted in diesel exhaust. There is, however, no TLV recommended for diesel exhaust aerosols (DEA) nor is there a standard method for sample these aerosols.The University of Minnesota and the USBM have collaborated to develop a personal diesel exhaust aerosol sampler (PDEAS) that utilizes size selective, partial impaction and gravimetric analysis. During the field tests of this sampler, numerous air quality measurements were conducted in underground coal mines that used diesel equipment. The objective of this report is to present these data and to assess the impact of diesel face haulage equipment on mine a quality.Air quality data were collected in four underground coal mines. The mines used continuous miners and diesel haulage equipment. Daily samples were collected at the section intake, haulage way and on haulage vehicles. Both full- and partial-shift samples were collected using a variety of aerosol instruments. These included the PDEAS and the micro-orifice uniform deposit impactor (MOUDI) that sample the mine aerosol diesel exhaust fraction. Two of the mines were also monitored for the major gaseous constituents found in diesel exhaust CO,CO2, NO, NC, and SO2. These measurements were made by either collecting bag samples for subsequent gas analysis or by Palmes dosimeters.Concentrations of CO, CO2, NO, NO2 and SO2 were well below regulated levels. The mine average DEA concentration determined by the PDEAS in the haulageway for the three mines surveyed was 0.79 mg/m4, with a standard deviation of 0.19 mg/m3 DEA contributed 65% of the respirable aerosol, at this location. These results were the same as the mean DEA concentrations calculated from size distribution measurements obtained using the MOUDI. This was 0.78 mg/m3, with a standard deviation of 022 mg/m3."

Mar 1, 1992

By Raymond B. Ladoo

SOAPSTONE

Feb 1, 1922

By Michael P. Moore, Christopher J. Rise

"Over the past twenty years, there have been numerous studies which have attempted to correlate the prevalence of Coal Workers' Pneumoconiosis (CWP) with different characteristics of the coal seam. Some investigators have tried to find a relationship, or the lack of a relationship, between the rank of coal seams and the incidence of CWP. Others have attempted to show that there is a positive correlation between the mean mass of respirable dust in the mine atmosphere and the prevalence of CWP. Still others have tried to determine the influence of the quartz content of respirable dust on the incidence of CWP. Unfortunately, many of these different investigations have conflicting conclusions.One area of research with conflicting conclusions deals with the relationship between the rank of the coal and the incidence of CWP. For example, an inves¬tigation conducted in Pennsylvania and West Virginia coal mines concluded that the prevalence of CWP increases with an increase in coal rank (1). A study in Great Britain also observed a close relationship between the rank of coal and the prevalence of CWP (2). However, another study involving 312 Appalachian coal miners concluded that the association between coal rank and CWP might be fortuitous and that other factors may be more important (3). In addition, an investigation involving 2,600 miners during a period of twenty years in Great Britain established that there is only a weak correlation between the prevalence of CWP and the rank of the coal (4). Consequently, it appears that there is still uncertainty as to whether or not the rank of the coal seam has an influence on the development of CWP.Another area of investigation concerns the relationship between the mean mass of respirable dust present in the mine atmosphere and the prevalence of CWP. A study involving 4,122 miners over a period of ten years in Great Britain noted a high correlation between the mean mass of respirable dust and the incidence of CWP (5). Another investigation involving 3,154 British face workers con¬cluded that the overall mass of respirable dust is the factor most closely related to the ten-year attack rate of CWP (6). However, a study conducted in thirty-one mines in the United States concluded that it is doubtful that the quantity of respirable dust alone is responsible for the difference in the prevalence of CWP (7). Even though there are conflicting conclusions, there are many more investigators who confirm, rather than deny, the relationship between the mean mass of respirable dust and the development of CWP.The third subject of investigation is the role of quartz in the incidence of CWP. For example, two studies in Great Britain concluded that the quartz content in coal mine dust has no relationship to the prevalence of CWP (8,9). But a study involving 312 Appalachian coal miners revealed that the level of exposure to free silica plays an important role in the development of CWP (10). Once again, the conclusions reached by different researchers are conflicting.Probably the most important factor in the discrepancy among the studies is the variability among different coal mines. A mine operating in an inherently ""dusty"" seam may have a low concentration of respirable dust while a mine operating in a less dusty seam may have a high concentration of respirable dust. This discrepancy is a result of variables such as the effectiveness of ventilation or the efficiency of the water sprays. Consequently, it is very difficult to compare the dustiness of different coal seams by in-mine measurements of the respirable dust concentration. A laboratory test would more accurately characterize a coal seam according to its respirable dust production."

Jan 1, 1988

By Foster Fraas

A separator for minerals of low magnetic susceptibility and fine particle size in a water suspension is described. A ring-shaped matrix of ferromagnetic fragments rotating so as to pass successively through magnetic-field and field-free regions provides for the separation. Application is illustrated in the separation of hematite and ilmenite from quartz.

Jan 1, 1966

By Arthur L. Murray

The first thought in the case of an accident or contagious disease is naturally that aroused by our humane instinct , how serious is the case and will the person recover ? The economic effects of such cases , owing to their many ramifications , are seldom realized either by those directing mining operations or those engaged in the labor of producing . This paper is based on the accident experience of the State of Utah and the number of cases of two well known preventable diseases , typhoid fever and smallpox , in that State for the fiscal years 1917-1918 , 1918-1919 , 1919-1920 , and 1920-1921 . The data and figures presented are from coal -mining camps only . W. W. Adams , mine- accident statistician of the bureau, contributed valuable corrections and suggestions . The economic results of accidents are considered first , and those of the two preventable diseases later .

Apr 1, 1922

By E. G. King

Existing thermodynamic data for compounds of the rare-earth metals are few in number and often inaccurate because, in the past, it was difficult to obtain samples that were pure enough and reasonable in cost--a situation that is rapidly improving. This paper reports the results of low-temperature heat-capacity and high-temperature heat-content measurements for cerous fluoride (CeF3) and supplies the first such published data for a rare-earth fluoride. The low-temperature heat-capacity data cover the temperature range 51°-298° K. and serve to evaluate the entropy at 298.15° K. The high-temperature heat-content data cover the temperature range 298°-1,799° K., including the temperature and heat of fusion. The results are assembled for ready use in thermodynamic calculations. Cerous fluoride is one of the important intermediate compounds in the production of cerium metal.

Jan 1, 1959

By Richard A. Winters

In 1985 at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 9,400 acres of the 10,005-acre Duncan Creek Wilderness Study Area (ID-111-78) in order to evaluate the mineral resources. The study area is located in Owyhee County, 10, about 36 miles southwest from Bruneau, ID. No mining districts are in the study area, nor were any mines or claims recorded or found. The southern half of the area was covered by oil and gas lease applications, all of which were cancelled prior to June, 1985. No economic concentrations of minerals were found in the study area. INTRODUCTION This report describes the USBM (U.S. Bureau of Mines) portion of a cooperative study with the USGS (U.S. Geological Survey) to evaluate mineral resources and potential of the Duncan Creek study area at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will be used to help determine the suitability of the study area for inclusion into the National Wilderness Preservation System. Although the immediate goal of this and other USBM mineral surveys is to provide data for the President, Congress, government agencies, and the public for land-use decisions, the long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at a reasonable cost.

Jan 1, 1986

By James S. Browning

The Bureau of Mines conducted laboratory batch and pilot plant flotation tests to determine the technical feasibility of recovering commercial-grade mica from a California micaceous schist. Best results in the laboratory batch tests were obtained using sodium carbonate and sodium silicate for pH control and quartz depression, and a combination of fatty acid and cationic reagents as the mica collector. In continuous pilot plant flotation tests, an alkaline fatty acid-cationic method recovered about 70 percent of the mica in a concentrate analyzing 95.6 percent mica.

Jan 1, 1965

By Carl N. Anderson

This paper, which is one of a group presented by the United States Bureau of Mines covering mining practice in different districts, deals in particular with the methods employed in mining the horizontal type of zinc-lead orebodies of the West Baxter area of the Tri-State zinc and lead district. These orebodies, locally termed "sheet-ground" bodies, with their relatively low working faces and low tenor of zinc and lead, require changes in the mining practice which is used in the balance of the district. In addition to the general mining methods, this paper also describes the system of hand sorting employed prior to the direct milling of the ore. The Hartley mine is situated mile west of Baxter Springs, Kans., as indicated in Figure 1. Its general outline and the location of the shafts with respect to the milling plant are shown in Figure 2.

Jan 1, 1932

By W. L. Schmidt

The effect of a water-repellent film in sandstone cores on the effective permeability-saturation relationship was investigated as part of a cooperative research program between the Bureau of Mines and the American Gas Association. The repellent film was formed by the reaction of methyltrichlorosilane3 with the connate water in the core. Other researchers have reported on the use of silicone chemicals to alter the flow characteristics of porous media (1-3, 5-7, 9, 10).4 The previous studies, however, dealt almost entirely with oil-water or oil-gas systems and not with water-gas systems. The primary purpose of this study was to determine the feasibility of using silane to retard the influx of water into natural-gas storage wells and to determine the necessary requirements for achieving this result. The success or failure of silane treatment as a remedial measure depends on its effect on gas-production rate and attendant water production.

Jan 1, 1961

By John P. Capp

Addition of sintered fly-ash/bottom-ash mixtures to rubber formulations failed to increase the skid resistance of the resulting products. Wear, tensile and hot-tear strengths, and resilience of the ash-rubber material, as determined in laboratory tests, were significantly less than that of comparable rubber. The material appeared unsatisfactory for automobile and truck tire manufacture, but might prove suitable as a filler in other rubber goods. Raw fly ash could not be satisfactorily compounded with rubber.

Jan 1, 1972