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By R. P. Bush

The U.S. Bureau of Mines performed Cu exchange capacity (CuEe) tests on Ca and Na mont-morillonites and attapulgite clays. Mathematical models were developed from the data that the CuEe's are derived from for each clay as a function of pH, Cu concentration, and the concentrations of metal ions, which compete with Cu for exchange sites. An analysis was made of the impact of competing ions on Cu losses due to ion exchange. The results show that the CuEC's of clays, and hence Cu losses, are decreased by the presence of competing ions, and that AI and Mg have the largest impact of those cat-ions normally present in Cu leaching solutions.

Jan 1, 2010

By Yael Miron

The presence of pyrite (FeS2) in coal can cause or contribute to several problems for the coal mining industry. These problems, which include spontaneous combustion, roof falls, floor heave, and accidental explosions in coal surface mining when ammonium nitrate fuel oil (ANFO) explosives are used, result from pyrite oxidation. Pyrite oxidizes exothermically in the presence of air and moisture to form a large variety of products, including hydrated ferrous and ferric sulfates, and sulfuric acid. Some of the products are reactive chemicals and strong oxidants. The volume of many of these oxidation products exceeds the original volume of the pyrite; as a result, the adjacent coal disintegrates and its surface increases, rendering it more susceptible to oxidation. The heat from pyrite oxidation raises the temperature of the adjacent coal, accelerating the oxidation and self-heating rates of the coal. These combined chemical, physical, and thermal effects are the cause of the aforementioned problems. When ANFO is used in surface coal mines and contacts ferrous sulfate, a highly exothermic reaction ensiles. Additional hazards are fires or explosions caused by the frictional ignition of methane when the pyrite in the coal is struck by a cutting bit during mining.

Jan 1, 1994

By S. Don Brown

Between 1987 and 1988, the Bureau of Mines studied the mineral resources of the White River National Forest and part of the Arapaho National Forest to appraise the resources present and to determine the types of deposits, and their location, that could be mined economically if sufficient demand and metal prices existed. The study included a comprehensive literature search and a limited amount of field investigation of minerals and mining activity in and near the Forest. This report summarizes a more comprehensive minerals report on the Forests prepared by the Bureau of Mines and was written for a general audience without a background in geology or related fields. Mineral resource information indicates that in the Gore Range-the area between Tennessee Pass and Gilman may contain large base-and precious-metal deposits, and could be the focus of exploration activity in the near future. The Breckenridge mining district was found to have a moderate to high likelihood for mineral exploration and possible development of gold. Recent exploration and minor development work has occurred in several other areas: Montezuma, Kokomo-Tenmile, and Upper Blue River districts, and portions of the Sawatch Range.

Jan 1, 1990

By Marcia L. Harris

Toxic fumes produced by detonating explosives in surface mining and construction operations pose potential hazards to workers and the public. Blasting operations produce both toxic and nontoxic gaseous products; the toxic products are mainly carbon monoxide (CO) and the oxides of nitrogen (NOx). Since 1988, there have been 17 documented incidents in the United States and Canada in which carbon monoxide (CO) is suspected to have migrated through ground strata into occupied enclosed spaces as a result of proximate trench blasting or surface mine blasting. These incidents resulted in 39 suspected or medically verified carbon monoxide poisonings as well as one fatality. At worst people may be fatally poisoned and the least to be expected is increased public objections to blasting. Local and state agencies could demand a cessation of the blasting requiring more expensive mechanical means to break the rock. This paper discusses the most feasible means of preventing CO migration, mitigating CO that has migrated, and detecting CO in an underground enclosed space and may help reduce the exposure of unsuspecting area residents to carbon monoxide and help prevent the implementation of unnecessary regulations and limitations on blasting. Single-hole shots and small-scale multiple-hole blasts were performed that indicate promising means of prevention and mitigation.

Jan 1, 2008

By Aleksandar D. Bugarski

Three types of uncatalyzed diesel particulate filter (DPF) systems, three types of high-temperature disposable filter elements (DFEs), and one diesel oxidation catalytic converter (DOC) were evaluated in underground mine conditions for their effects on the concentrations and size distributions of diesel aerosols. Those effects were compared with the effects of a standard muffler. The experimental work was conducted directly in an underground environment using a unique diesel laboratory developed in an underground experimental mine. The DPF systems reduced total mass of aerosols in the mine air approximately 10-fold for light-load and 20-fold or more for high-load test conditions. The DFEs offered similar reductions in aerosol mass concentrations. The efficiency of the new DFEs significantly increased with accumulation of operating time and buildup of diesel particulate matter in the porous structure of the filter elements. A single laundering process did not exhibit substantial effects on performance of the filter element. The effectiveness of DPFs and DFEs in removing aerosols by number was strongly influenced by engine operating mode. The concentrations of nucleation mode aerosols in the mine air were found to be substantially higher for both DPFs and DFEs when the engine was operated at high-load modes than at low-load modes. The effects of the DOC on mass and number concentrations of aerosols in mine air were relatively minor when compared to those of the DPF and DFE systems.

Jan 1, 2009

By J. J. Geraghty

U.S. Bureau of Mines researchers investigated the development of an innovative transport system for underground coal mining. A one-half commercial-scale bench model was constructed. Novel magnetic levitation (mag-lev) technology was developed. Frictionless and contact-free transport of a prototype materials container and payload has been demonstrated.

Jan 1, 2010

By Owen W. Terry

During the summer of 1943 the Bureau of Mines conducted an investigation and program of churn drilling on the McIlhon and adjoining Pearson land in the Mineral Point district of Iowa County, Wis. Sixteen holes, aggregating 1,570 feet .of bore, were completed. The work was undertaken as part of a general investigation of the zinc-and lead-producing area of southwestern Wisconsin at a time when great effort was being made to increase the production of Metals important to the war program. The Bureau's drilling program supplemented a previous drilling pro-gram conducted by the Vinegar Hill Zinc Co., and demonstrated the presence of a strongly mineralized zone at relatively shallow depths.

Jan 1, 1948

By Edward D. Thimons

This Bureau of Mines report presents expected levels of air pollutants in the face areas of oil shale mines, based upon data collected by the authors and previous investigators. Ventilation requirements to maintain these pollutant levels below their threshold limit values and Federal and local mine air quality standards are discussed. Two practical face ventilation systems are discussed in terms of actual in-mine test experience.

Jan 1, 1986

By Franklin D. Slagle

Porosity and bulk-and sand-grain-density values were determined for 2,040 core samples of 30 formations from 47 wells in New York, Ohio, Pennsylvania, and West Virginia, and are compiled for petroleum industry use in well-log evaluation and geologic studies.

Jan 1, 1967

By Leonard Obert

Between 1927 and 1957, sodium borate minerals were mined by underground methods in the Kramer District, Kern County, Calif. In 1957, surface mining methods were initiated, and during the next two or more decades it is probable that most of the production from the district will be obtained from open pits. However, part of this borate deposit is sufficiently deep that surface mining may not be economical and, hence, at some future date underground methods may again be employed. This report was prepared to document the underground mining methods employed in the district before 1957. The general geology of the district and the detailed geology of each of four mine sites are presented, together with a mineral and mechanical description of the ore and enveloping rock. The report also describes the stoping, extraction, pillar support, methods of artificial support, and other factors that affect the structural characteristics of these mines.

Jan 1, 1962

By H. S. Chiang, S. S. Peng

"SummaryAir velocity distribution surveys on four mechanized longwall faces are presented and discussed. Although there are discernible patterns in the velocity distribution, there are wide differences in distribution in the cases examined. This can be attributed to differences in mining and face geometry. An important factor is air leakage into the goaf.IntroductionOver the past two years several intensive air velocity surveys have been carried out in West Virginia coal mines as part of a programme aimed at understanding dust transport mechanisms on mechanized longwall faces. These are presented here and some of the patterns of velocity distribution are discussed.Ventilation survey methodologyThe air velocity vector consists of three mutually perpendicular subvectors; the vertical subvector is directed toward the roof, one of the horizontal subvectors is parallel to the coal face and the other pointing to the gob. The air velocity which was measured in this paper is the horizontal subvector parallel to the coal face.To record the velocity distributions at the longwall faces, the surveying stations and the surveying points were established as follows.(1) The first station usually was set at the third support from the headentry T-junction. Within the first few supports, the air coming from the intake airway encounters a sharp right-angle turn at the T-junction, and forms a turbulent region close to the coal face. The intake air in this region is also influenced by the motors that drive the face conveyer. But when the air reaches the different. But for the same face the number was the same. The main air-travelling area was divided into six to 12 equally sized sub-areas, and each surveying point was situated approximately at the centre of the sub-area.The velocity survey was carried out by two persons, one reading the meter and the other taking down the readings. A complete survey at one station took about 5-8 min. Usually, the dimension of the cross-sectional area was measured during that time.A third person used the smoke tubes to observe the following: (I) the air movement patterns at different locations; (2) the extent and the direction of the air leakage; and (3) the machines' influence on the main airflow. At the same time he observed and recorded the roof conditions and the compactness of the roof-caving in the gob."

Mar 1, 1989

By L. A. Schutz

Personnel of the Bureau of Mines have conducted investigations in the principal asbestos mines and mills in the United States, to determine the concentration of airborne asbestos fibers in the workplace, and to establish the exposure of workers to such fibers. 'The surveys were conducted using the sampling and evaluation method recommended by the National Institute for Occupational Safety and Health. The method consists of collecting the air-borne sample on filters and, after appropriate sample preparation, counting the fibers utilizing phase contrast microscopy. The results of the investigation show that fiber concentrations are low in the asbestos mines but high in the asbestos mills, ranging well above 5 fibers/ml of air based on a count of fibers greater than 5 urn in length.

Jan 1, 1973

By H. R. Hardy Jr., E. J. Kimble Jr., H. W. Shen

"The primary objective of this research project is to study the character of the bit-coal interaction during coal cutting and its influence on the size and shape distributions of the generated dust. Secondary objectives include the investigation of the acoustic emission technique as an indirect method for coal dust characterization and remote bit wear monitoring. The results of the project will be useful in developing efficient coal cutting techniques which significantly reduce the harmful coal dust components, and in providing methods for remote monitoring of bit condition and associated coal dust character. This paper will outline recent experiments carried out on coal under uniaxial compression, linear single-bit cutting, and cutting using a laboratory-scale, single-bit shearer. During the experiments acoustic emission and a variety of other mechanical parameters were monitored. · A commercially available artificial intelligence computer package, namely: JCEPAK (Intelligent Classifier Engineering Package), has been utilized to provide a powerful and objective means for AE waveform analysis. This program is able to evaluate a number of features of each AE event and to make objective comparisons between AE signals associated with different loading or cutting parameters. Finally, the paper will discuss the results obtained from a variety of coal breakage tests.INTRODUCTIONStudies to date clearly indicate that the reduction of the severity, and eventual elimination, of Coal Workers' Pneumoconiosis (CWP) depends on gaining fundamental understanding in a number of major areas. These include dust generation and entrainment, transportation, suppression, medical effects of dust and possible treatment. At present a project is underway by the authors to investigate the character of the bit-coal interaction during coal cutting and its influence on the size and shape distributions of the generated dust. An important aspect of this on-going project is the development of acoustic emission (AE) criteria which will make it possible to carry out remote monitoring of coal cutting operations. Suitable on-line analysis of monitored AE data would allow engineers to evaluate factors such as shearer bit condition and cutting efficiency, and to quantify the particle size and shape distribution of the generated dust. The on-going AE studies are fundamental in form and were undertaken to evaluate the general feasibility of AE monitoring techniques using simplified coal cutting procedures. This paper will outline recent experiments on coal under uniaxial compression, linear single-bit cutting, and cutting using a laboratory-scale, single-bit shearer. Additional information on these studies are presented elsewhere [4]."

Dec 1, 1996

By Walter R. Storms

The Iron Mountain tungsten deposits first were visited by a field party of the Federal Geological Survey in May 1942 while beryllium deposits in that district' were being examined . Later they were examined by F. A. Rutledge , an engineer of the Bureau of Mines , and an exploration project was recommended , work upon which began in March 1943 and was terminated in April 1943 after intensive trenching and sampling had been completed .

Mar 1, 1947

By Michael M. Hamilton

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied a 37,542-acre portion of the 57,002-acre Riordan?s Well Wilderness Study Area (NV-040-166) in order to evaluate its mineral resources. The area studied is located in Nye County, NV, about 60 miles southwest of Ely, NV. Subeconomic mineral resources of limestone and sand and gravel were identified in the study area. The Troy and Irwin mining districts, 4 miles to the west, were active between 1868 and 1963, producing small amounts of gold, silver, lead, and tungsten from mines well outside the study area. Except for minor prospecting activity, most mining activity in the study area has been since 1980, consisting of claim locations and geochemical surveys.

Jan 1, 1987

By E. P. Youngman

The mining laws referred to by those who furnished the reports mentioned in the preceding paragraph are : General Austrian Mining Law of 1854 and the Law of 1868 , which prescribes for Hungary (as well as for Transylvania ) the full text and decisions of the General Austrian Mining Law; Government Decree 18346 , 1859 ; Parliamentary Decree of 1861 ; the Law of 1871 ; the Commercial Code , Law 37 of 1875 ; the Industrial Lar of 1884 ; the Law of 1386 ; the Decree of the High Court of Justice , 5540 , of 1399 ; Laws 6 and 7 of 1911 ; Law of 1921 ; Laws 23 and 24 of 1922 ; Laws 5 and 21 of 1927 ; and Law 40 of 1928. ( Lev 21 of 1927 and Law 40 of 1928 are labor laws . ) A compilation of the mining laws of Hungary , " Magyar Banya Jog , " or the " Hungarian Mining Law, " was made use of in part . This volume is the second edition of a school textbook , which ras prepared by Dr. Bela Balkay and Dr. Imre Szeoke , and which was published by the Apollo Press ( V. , Sas -utca 13 , Budapest ) in 1909 .

Jun 1, 1931

This Information Circular from the National Institute for Occupational Safety and Health (NIOSH) documents and supplements the information presented in a series of workshops held during 2002 and 2003. The primary intended audience consists of all who are involved in developing and conducting miners' training. According to the Mine Safety and Health Administration (MSHA), mine operators reported 240,000 full-time equivalent workers and independent contractors reported 42,000 full-time equivalent workers working on mine property during the year 2000. Unfortunately, these workers have a relatively high risk of suffering serious work-related injuries and illnesses. The mining industry has the highest rate of occupational fatalities among all U.S. industries. The fatality rate is 30 deaths per 100,000 workers compared to 4.6 for all private industry (Morbidity and Mortality Week Report, 2001; NIOSH, 2002). Compared to workers in other industries, miners also have a relatively high rate of nonfatal lost-time injuries, and their injuries tend to be more severe (Bureau of Labor Statistics, 1999). Many miners are also exposed to significant health hazards, including coal and silica dust, diesel exhaust, and noise. More than 1000 U.S. miners die of lung disease each year (NIOSH, 1999). Mine safety and health professionals have long recognized training as a critical element of an effective safety and health program. Federal regulations (30 CFR, Parts 46 and 48) require mine operators to provide initial safety and health training to all new miners, as well as a minimum of 8 hours of refresher training each year. The time and money being spent to train U.S. miners is substantial, and so there is a strong and steady demand for new and better mine training materials and methods. A growing concern among mine safety professionals regards the training of new workers. A major change in the mining workforce is anticipated within the next decade. In major segments of mining, especially coal, relatively few workers have been hired since the 1970's. Thus, as an entire cohort of miners in the current workforce nears retirement, the replacement of these employees will require an influx of new workers. New miners may be young people who lack the ability to recognize and respond to mining hazards in an appropriate manner. They may also have had different educational experiences than their older counterparts. Many safety professionals believe that these two cohorts require different approaches to training. The papers in this report should help prepare mine trainers for the changes about to occur in the workforce and acquaint them with strategies they can use to enhance the effectiveness of their training. The first three papers present basic principles for teaching adults. The five remaining papers are intended to illustrate how these principles can be applied to the development and imple¬mentation of effective training for miners. Below is an overview of these papers. 1. Kowalski and Vaught review the process and principles of adult learning. The learning model they present includes a discussion of goals, content, delivery, assessment, and remediation. Adults are viewed as active learners, experienced-based, expert in their own right in specific areas, independent, real-life centered, task-centered, problem-centered, solution-driven, skill-seeking, self-directing, and internally and externally motivated. Basic aspects of curriculum development are briefly reviewed. For further information about adult learning, see Camm and Cullen's paper. 2. Mallett and Reinke's first paper discusses issues related to training new miners who have recently or will soon be entering the mining workforce. These new generations of miners have different learning style preferences and training needs than Baby Boomers and other older miners. Even trainers who have been highly effective in the past should reassess their training styles and their classroom materials to determine if they are prepared to meet the needs of these young new workers. This paper provides information that will help mine trainers communicate across the generation gap. 3. Mallett and Reinke's second paper provide an overview of training evaluation. Trainers and decision-makers are given a framework for planning and assessing training evaluation strategies. The authors present Kirkpatrick's (2001) model of evaluation categories and discuss how to start an evaluation plan and various ways to collect data. They do not provide detailed instruction in evaluation methodologies, but give trainers a review of the things they need to consider when developing an evaluation plan. A good evaluation plan can inform revisions to a training course, assess trainee learning, and/or answer managers' questions about program effectiveness. 4. Brnich, Derick, Mallett, and Vaught discuss a technique for incorporating worker participation into fire prevention and safe equipment operation training. This technique involves development of short (5 to 7 minutes) videotapes coupled with toolbox talks that ground the content of the videos within the context of a miner's workplace. An example of one of these training modules is presented, along with the results of an evaluation performed on its effectiveness at improving miners' understanding of what types of information they should be sure to communicate during a mine emergency. 5. Wiehagen, Conrad, Friend, and Rethi discuss on-the-job training (OJT) as a method for teaching miners safety and production skills. Much of the training is done by experienced workers. This paper describes how small investments can help improve the effectiveness of on-the-job training. Effective on-the-job training involves some structure and planning in the transfer of responsibility for task performance from the trainer to the novice. Assisting the trainer could involve helping develop up-to-date job analyses and offering strategies for teaching and evaluating job skills. This paper addresses organizational considerations supporting structured on-the-job

Jan 1, 2002

By J. B. Janus

This Bureau of Mines publication updates a series of reports on the quality of coal purchased under specifications for Government use. Listed are analytical data on the composition and quality of tipple and delivered samples of coal collected during the period July 1975 through September 1976.

Jan 1, 1977

By Benjamin W. Haynes

This research was conducted as part of the U.S. Department of the Interior, Bureau of Mines program to recover metals, glass, and a combustible fraction from municipal solid waste (MSW). The objective of this analytical study was to determine the concentration of antimony, arsenic, and mercury in samples taken from various sampling areas in the Bureau of Mines raw refuse recycling plant and to compare these values with those for coals used in the generation of electricity. To provide the necessary analytical data, sensitive reproducible ashing-chemical digestion-atomic absorption procedures were adapted from published procedures. It was determined that antimony and mercury concentrations in the combustible fraction of MSW are approximately an order of magnitude higher than those found in coals presently used for power generation;' the arsenic concentration is similar in both fuels.

Jan 1, 1978

By H. Kenworthy

The purpose of the study described in this publication is to develop methods for recovering simple master alloys or single metal components from discarded and scrapped S-816 alloy, The Bureau of Mines started this investigation late in 1955 after the need became apparent for a method of reclaiming high-temperature alloys from an ever-increasing accumulation of rejected and wornout jet engine turbine buckets. Laboratory studies showed the following: (1) Pyrometallurgical separations are not selective enough, (2) several methods can be used for effective chemical dissolution of the major constituents of the alloy, (3) a master alloy or complex salts of cobalt and nickel can be separated, (4) chromium, contaminated by several other metals, may be segregated, and (5) more time and effort need to be expended in separating the minor constituents and improving the purity of the major metals removed. Difficult and incomplete chemical separations were attributed to the complexity of alloy composition, as were the long tedious chemical analyses o' products. For determination of several of the metallic components, standard methods of separation and routine analytical procedures had to be considerably modified to achieve satisfactory results. The overall technical problems involved in separating S-816 components do not appear to be insurmountable; however, refinement of several of the methods used in this investigation is desirable.

Jan 1, 1961