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By J. M. Stuve

Standard heats of formation (AH°p) of YbCl3 (c) and TmCl3 (c) were measured by solution calorimetry. Heat of solution data are given for ytterbium and thulium metals and corresponding anhydrous trichlorides in 4.360 molal hydrochloric acid. The derived standard heats of formation of YbCl3 (c) and TmCl3 (c) were -229,370 ±720 and -235,820 ±400 cal/mole, respectively, at 298.15° K. The resulting heats of formation for YbC13 and TmCl3 are about 1 kcal and 6.3 kcal more negative than previously published values.

Jan 1, 1967

By A. K. Schellinger

1. In the United States, the industrial application of centrifugal force for separating phase constituents has been confined almost entirely to aqueous systems at room temperature. This paper presents results for experimental tests on the use of centrifugal force for separating the liquid and solid phases in molten nonferrous alloys. 2. The development and use of a small centrifuge for treating molten metals is described. The centrifugal apparatus was, in essence, a 3-inch diameter spinner pot, which revolved, within -a gas -fired furnace, at speeds up to 3,000 r.p.m.

Jan 1, 1953

By H. R. Beard

The citrate process for sulfur dioxide emission control was developed in pursuit of the Bureau of Mines goal of minimizing the adverse environmental impact of mineral-processing operations. This publication describes the gas analysis procedures used during development of the process. The research required the capability to analyze SO2, H2S, CO, CO2, COS, volatile hydrocarbons, NO, NO2, O2, N2, and H2. The methods described include gas chromatography, electrochemical detection, infrared spectroscopy, and the use of a computer program to predict the product composition in complex reactions. Laboratory and pilot plant applications are discussed.

Jan 1, 1979

By Susan M. Moore

Many challenges are faced by workers in lower-seam (42 inches or less) mines. The lower-seam heights confine mine workers to their knees as they perform their daily tasks such as installing roof bolts, delivering supplies, repairing belt, or cutting coal. Miners working in these lower seams often consider kneepads to be their only line of defense against knee injuries. However, healthy knees do not start and stop with kneepads. Other interventions such as changing postures, proper hygiene, and work station design may also be used to reduce mine workers? risks for developing knee injuries. Incorporating these and many other interventions into a mine worker?s ?way of life? is an important step to ensuring a long, healthy career and retirement. Keeping knees healthy is also a key aspect to reducing costs in low-seam mines as the industry battles rising health care costs, and training/recruitment of replacement workers is time-consuming and costly. Educating the workforce about the possible interventions to reduce knee injury risk is a primary objective for the National Institute for Occupational Safety and Health?s (NIOSH) Pittsburgh Research Laboratory (PRL). Therefore, NIOSH researchers, along with industry and academia, developed a training package to educate the mining com­munity about some possible interventions beyond kneepads that may be used to help decrease knee injury rates. Increased awareness and simple changes are the first steps to reducing knee injuries.

Jan 1, 2008

By Charles Vaught

The U.S. Bureau of Mines evaluated the self-contained self-rescuer (SCSR) donning proficiency of 243 miners. These workers were from eight underground coal mines in the eastern United States. The objectives of the study were (1) to gather information on skill levels, since all miners in the study had prior instruction and opportunity to practice donning the apparatus, and (2) to summarize a quality control procedure useful in conducting periodic evaluations of donning proficiency. The sampling procedure used proved to be both reasonable and efficient in gathering information on training effectiveness. It also provided a good statistical base for making informed site-specific decisions regarding SCSR training needs. Results from the observed samples at each of the eight mines indicate a wide variability across sites. The rate at which miners failed to isolate their lungs varied from 3.3 to 40.0 pet. Concomitantly, proficiency rates (miners either performing adequately or demonstrating a perfect 3 + 3 sequence) ranged from 13.3 to 63.3 pet.

Jan 1, 2010

By A. J. Forney

A high-Btu gas was made at the Bruceton, Pa., laboratories of the Bureau of Mines to demonstrate the feasibility of using the gas as a nonpolluting fuel for automobiles. The pilot plants at Bruceton were revised to combine the processes of coal gasification, gas purification, and catalytic methanation in one overall system. Tests in the Bureau's test automobiles at Bartlesville, Okla., showed the Synthane gas was less polluting than natural gas.

Jan 1, 1972

By John C. Machisak

THIS INFORMATION CIRCULAR contains 1956 and 1957 injury experience and employment data for metal mines in the United States and Alaska. Unlike previous publications, this report covers only metal mining and contains statistical data on injuries and employment pertinent to metal mines and mills reporting voluntarily to the Bureau of Mines on an annual basis. Injury and employment data for the nonmetal industries, which from 1911 through 1955 were published in the same series as the metal industries, for the first time will be published separately as an information circular entitled "Injury Experience in the Nonmetal Industries, 1956 and 1957." The Bureau of Mines is authorized to make requests for injury and employment data, and the information submitted by operators of metal mines and mills is a step forward in promoting safety in the metal-mining industry. Every effort has been made to make this coverage as complete as possible.

Jan 1, 1960

The objectives of this research were to examine and to laboratory performance of several brands of rigid urethane een brands, produced by 13 manufacturers, were examined. was performed in a laboratory under controlled conditions. document the foam. Eight-All testing Preliminary laboratory tests included flame spread evaluations, flame penetration, ignition temperatures, air permeability, and adhesion. Having established arbitrary cutoff values, the original 18 candidates were narrowed to 8. More specialized tests followed. The effects of water immersion and dry aging on flame spread performance and other physical properties were then examined. This Bureau of Mines report was written to provide information for those concerned with using rigid urethane foam as a sealant. Its intent is to describe the various laboratory evaluations performed and to delineate the performance of each candidate. This report neither promotes nor discourages the use of rigid urethane foams. It presents results that will enable those responsible for using or enforcing the use of rigid urethane foams in underground mines to make informed decisions.

Jan 1, 1985

By Eugene T. Sheridan

The annual survey of the fuel-briquet industry by the Bureau of Mines, United States Department of the Interior, revealed that 21 fuel-briquet plants in 11 States were in operation and reported production in 1956. The demand for fuel briquets in the United States has gradually declined since 1948, and the number of operating plants has decreased from 36 to 21. Also, the annual productive capacity of the industry has decreased, although not a proportionate amount because most of the plants that were abandoned were small and in most instances had a designed capacity of less than 25,000 tons per year. In 1956 the 21 active plants had an annual capacity of 3.7 million tons (table 2), which was only 20 percent less than the total capacity of the 36 plants in 1948. This indicates that most of the larger plants have remained active, even though operating at reduced rates, and the average capacity of the industry has increased from 130,000 tons per plant in 1948 to 177,000 tons in 1956. Since 1948 operating rates have decreased from 67 percent to 41 percent of annual capacity.

Jan 1, 1958

By A. W. Fahrenwald

The art of flotation has developed rapidly. Numerous technical staffs and individual investigators have, by their combined efforts, developed practicable methods of concentrating ores which ten or even five years ago were considered complex and impossible of commercial treatment. Also the work of those who have been engaged in pure research on the fundamentals of flotation has helped greatly to expedite the general development of the process. However, in spite of the highly successful practical operation of the flotation process, results are obtained and things happen that we are unable to explain completely, although much is known about the theory of the process. The rapid stride in flotation concentration, it is noteworthy to point out, is due to the freer exchange of facts and data by the staffs of the larger mining companies and the patent controlling corporations, and by investigators in general. Generally speaking, one may visit any mining plant and by presentation of proper credentials, be shown all that is going on or that is being done.

Jan 1, 1925

By William H. Pailes, Vincent Castronova, Daniel Lewis, Norman L. Lapp, George Goodman

"INTRODCJCTIONAlveolar macrophages are free lung cells located on the surface of small airways and alveoli. These phagocytes play an important role in the protection of the lung against airborne bacteria and particles.1 However, hyperactivation of pulmonary phagocytes can lead to excessive secretion of enzymes and reactive oxygen species which could result in lung injury, emphysema, or fibrosis.2,3 Analysis of bronchoalveolar lavage effluents for cell types and cellular activity has yielded information concerning the etiology of various pneumoconioses. For example, emphysema associated with inhalation of coal dust or cigarette smoke has been related to enhanced secretion of reactive oxygen species from alveolar macrophages.4-7 In contrast, hypoactivation of alveolar macrophages has been associated with inhalation of diesel particulates"" and has been related to increased susceptibility to pulmonary infection. s Inhalation of cotton dust has been associated with dramatic increases in lavagable polymorphonuclear leukocytes9 while pulmonary sarcoidosis and silicosis have been related with high numbers of lymphocytes in lavage effluentsl0,11The objective of the present study was to obtain lavage effluents from 8 control subjects, 8 healthy power plant workers exposed to fly ash, 1 healthy coal miner, and 1 rock driller with acute silicosis. These effluents were analyzed for total numbers of alveolar macrophages, lymphocytes and neutrophils and for secretory activity of alveolar macrophages. Data were then analyzed to determine what response patterns were characteristic for given dust exposures.METHODSSelection of SubjectsThe 8 control subjectS were all adult males from the area of Morgantown, WV. Two subjects among the controls had smoked cigarettes for approximately three pack-years and had stopped more than ten years ago. The 8 power plant :workers were all healthy adult male employees of a power facility in Hatfield, PA, approximately thirty miles from Morgantown. One of the power plant personnel was a comparable ex-smoker. The remaining subjects were all lifelong non-smokers. The coal miner was a healthy non-smoking male from Morgantown, WV. The rock driller was a patient under treatment with corticosteroids for acute silicosis. He had shown considerable clinical improvement with this treatment but still manifested significant radiologic and pulmonary functional abnonnalities at the time of lavage. The mean age of the 8 control subjects was 36 years (range: 31 to 49 years); the mean age of the remaining subjects studied was 38 years (range: 29 to 53 years)."

Jan 1, 1990

By John A. Organiscak

Enclosed cabs are a primary means of reducing equipment operators? silica dust exposure at surface mines. The National Institute of Occupational Safety and Health recently performed a laboratory study to evaluate which factors on an enclosed-cab filtration system are most significant. The various factors evaluated were intake filter efficiency, intake air leakage, intake filter loading, wind infiltration, use of a recirculation filter, and the use of an intake pressurization fan. The result of this laboratory testing has shown that the two most important factors for an effective filtration system on an enclosed cab were the efficiency of the intake filter and the use of a recirculation filter. A higher-efficiency intake filter considerably increased the quality of the intake air that was delivered into the enclosed cab. It also was determined that air leakage around the intake filter notice-ably reduced its air cleaning effectiveness. The second key factor is the use of a recirculation filter, which was shown to improve the air quality in the enclosed cab by six to 12.7 times more than the intake filter alone. The reason for the significant improvement was that the cab air was constantly drawn through the recirculation filter, thus continually filtering the dust out of the air.

Jan 1, 2010

By Elizabeth G. Baglin

Research was conducted by the Bureau of Mines to determine the feasibility of using electrokinetic densification to dewater Bayer process red mud, magnetic black mud prepared by pressure digestion of red mud in the presence of ferrous sulfate, and magnetic black mud formed by simu-lated Bayer digestion of Jamaican bauxite with added ferrous sulfate. Tests showed that the solids content of presettled muds could be increased from 25 pct to approximately 40 to 48 pct by gravity draining followed by electrodewatering for approximately 48 h. Electrodewatering may not be practical because of increased reagent and processing costs and because the muds must be thoroughly washed prior to electrodewatering to remove dissolved ions and decrease mud conductivities.

Jan 1, 1988

By R. L. Rankin

The program objective was to conduct surveys of respirable dust concentrations in coal mining operations at locations outby the working face. The results of these surveys were directed toward 1. identifying outby dust sources, 2. evaluating the severity of the major dust sources, 3. establishing dust sampling frequency, 4. establishing dust sampler locations, and 5. assessing the? areas of influence of the dust sources. The study included dust sampling of only nonhigh risk personnel and areas at six dif-ferent mines. Thirteen continuous mining, four longwall and two conventional mining sections were sampled. The severity of outby respirable dust sources such as load points, runways, dump points, beltways, transfer points and main haulage operations were characterized and areas within the mine were ranked according to severity. Information on engineering controls was also acquired. Guidelines for implementing a dust sampling program are presented and include sampler locations, ventilation surveys, dust surveys, effects of shift-to-shift variations, and sampling frequency.

Jan 1, 1980

By Andrew M. Leszcykowski

In 1984, personnel from the U.S. Bureau of Mines examined the 9,550-acre Yatahoney Creek Wilderness Study Area (WSA) for mineral resources. This study area, in southwestern Idaho, is underlain by tuffs and basalt of Tertiary age. Owyhee County mining records and U.S. Bureau of Land Management records, and other references were examined prior to the field study. There are no known mines, claims, or prospects in or near the WSA. No evidence of mineral deposits or occurrences was observed. Oil and gas leases or lease applications are in the southern portion and northeast corner of the WSA. Although placer gold exists in the Owyhee River drainage, there are insufficient deposits of gold-bearing gravel in the Yatahoney Creek WSA to enable mining. INTRODUCTION The U.S. Bureau of Mines (USBM) and the U.S. Geological Survey (USGS) conduct mineral surveys of designated wilderness study areas (WSAs) 1/ to ensure mineral values that may be present are considered in wilderness recommendations. The USBM examines known mines, prospects, and mineralized sites, and the USGS performs geologic mapping, and geochemical and geophysical surveys on an areal basis.

Jan 1, 1986

By James S. Browning

Heavy liquids have been used to separate minerals of different specific gravities for many years.4 5 6 7 8 9/ The method permits substantially quantitative evaluation of a variety of minerals and requires much less time than the usual methods of chemical analysis. This Bureau of Mines investigation was conducted to determine the applicability of heavy liquid mineral separation to the evaluation of certain spodumene and kyanite ores, prepared mixtures, and plant products. After careful standardization of the particular mineral and associated gangue, estimates of chemical analyses could be obtained from results of heavy liquid separations.

Jan 1, 1960

By P. L. Woolf

An investigation was conducted to evaluate the use of a formcoke as the total fuel in the Bureau of Mines experimental blast furnace. The formcoke performed very satisfactorily, and comparisons made with a metallurgical coke showed that the performance with the formcoke was somewhat superior under the experimental conditions used.

Jan 1, 1966

By Ludwig Schmidt

[The use of vapor-tight tanks has proved so effective in reducing the evaporation losses of petroleum that today practically all operators are using this typo of equipment. It has boon shown, however, that vapor-tight tanks should be supplemented with additional measures which will further reduce evaporation. Probably the most effective use of the supplemental measures are found on the small producing leases where the breathing losses from vapor-tight stock tanks materially affect the volume and gravity of the stored oil. The breathing loss from a vapor-tight stock tank that is filled and emptied daily is a negligible quantity. Also, the filling loss, which on the average varies between 0.1 and 0.2 per cent, usually is not of a sufficient quantity to affect materially the value of the crude. However, the combined breathing and filling losses from a vapor-tight tank requiring several days to fill are of sufficient importance to warrant the use of measures in addition to the vapor-tight tanks. The breathing losses are caused by atmospheric variations. Probably the greatest are the changes in atmospheric temperature which cause changes in temperature of the vapors in the tank. During the day, as the temperature increases, the gasoline-saturated vapors in the tank expand and are forced out into the atmosphere. At night the vapors are cooled and contract, drawing into the tank fresh air, which becomes saturated with gasoline vapor and is forced out of the tank during the following day. In Addition to the maximum and minimums temperature variations there are many smaller variations throughout a twenty-four period caused by showers, clouds, winds, and other atmospheric conditions which likewise cause the tank to breathe. The two mist common measures used by lease operators for reducing breathing losses in vapor-tight tanks are, first, operating; lease tanks under pressure, and second, the use of light colored paints anti tank houses. In this report these two methods are discussed together with their adaptability to lease operation. Results of experimental observations are given which show the reduction of evaporation looses where these supplemental measures have been used.]

Jan 1, 1927

By John J. Sammarco

Computer-related accidents have caused injuries and fatalities in mining as well as other industries. Normal accident theory (NAT) explains that some accidents are inevitable because of system complexity. NAT is a classic argument in organizational sociology although it has been criticized as having imprecise definitions and lacking criteria for quantifying complexity. These limitations are addressed by a unique approach that recasts this organizational theory into an engineering-based methodology to quantify NAT complexities of computer-based systems. In this approach complexity is categorized as external or internal. External complexity is defined by the external behavior of a system, and is quantified by these dependent variables: system predictability, observability, and usability. Dependent variable data contain the perceptions of 32 subjects running simulations of a system. The system?s internal complexity is characterized by modeling system-level requirements with the software cost reduction (SCR) formal method. Model attributes are quantified using 15 graph-theoretical metrics?the independent variables. Five of 15 metrics are correlated with the dependent variables as evidenced by structure correlations exceeding 0.25, with standard errors <0.10 and a 95% confidence interval. The results also show that the system predictability, observability, and usability decreased as NAT complexities increased. This research takes a step forward in operationalizing NAT for computerized systems. The research benefits mining and other industries as well.

Jan 1, 2005

By George H. Schnakenberg

Automation of coal mining activities at the face offers improvements in worker safety, health, and productivity. Introduction of integrated computer-sensor systems to current mining machines will enable these machines to perform some of the most hazardous tasks through supervised teleoperation. The U.S. Bureau of Mines is pursuing the development of the enabling technology necessary to achieve this goal. The research program consists of both basic and applied research, each focused on the fundamental issues of computer and sensor technologies. Short-term research is directed to providing computer-assisted, remote supervisory operation of present underground equipment; the long-term goal is the development of progressively more intelligent mining systems. The research program includes a review of robotic machine and autonomous vehicle technologies and of current mining technology, which provides a base for developing innovative mining methods; research in navigation and guidance technology, emphasizing control of a continuous mining machine; research on coal-rock interface sensing technology for horizon control, and rib thickness control in highwall mining; the development of computer systems and hierarchical architectures for real-time control; and development of expert systems for machine system fault diagnostics and predictive maintenance. This report presents a brief background and the current status for each of these research areas.

Jan 1, 1989