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By L. B. Berger

In this investigation, the ampoule type of carbon-monoxide (CO) detector which is manufactured under license of U. S. Patent 1,644,014 (October 4, 1927) was tested for sensitivity and reliability. This detector was devised primarily for examining the air of manholes and sewers for possible dangerous contamination with CO before workman enter those places, but dine to the simplicity of the device it may have a more general usage for examination of atmospheres which are known or suspected to be contaminated with CO. Some of the suggested uses are the examination of the air in garages, tunnels, mines, around blast furnaces, gas plants, and in the home.

Jan 1, 1930

By John Henderson

If you missed this year?s Texas State Holmes Safety Association meeting, you missed a great one. On January 23 & 24, 2009, we held the meeting that was rescheduled when Hurricane Ike threatened Corpus Christi in September 2008. Sixty-five persons from across the state attended the meeting held at the Holiday Inn Emerald Beach. The weather was 82 degrees, and the sky was clear and perfect for a safety meeting. Evaluations submitted by the attendees gave the presentations, the networking, and even the food top marks. There were eight councils represented; Big Country, Central Texas, Costal Bend, Heart of Texas, Hill Country, North Texas and North Central. Presentations included Workplace Examinations, Emergency Preparedness, Screen Safety, Contractor Responsibilities, Powered Haulage, Supervising for Safety, and Basic Inspections of Slings and Rigging. Mr. Edward Lopez, SC MSHA District Manager, gave the State of the District Address.

Jan 1, 2009

By H. V. Makar

A study was conducted by the Bureau of Mines to determine problems associated with the use of ferrous fractions from urban refuse as melting stock for steelmaking and to evaluate the resulting steel products. The study involved 50-pound ingots from laboratory melts and 50-pound ingots from 1-ton electric-arc-furnace melts. The 50 pound ingots from the laboratory melts and the arc-furnace melts were hot rolled to provide material for mechanical and corrosion testing. Results obtained in the study include the following: Most steels rolled successfully and exhibited acceptable surface and edge condition. Tensile strengths of the plain carbon steels were not significantly affected by copper up to concentrations of 0.65 pct and were not affected by tin content up to 0.16 pct. Yield strength increased with increasing copper and tin contents, and impact strength decreased with increasing tin content. Hardness increased slightly with increasing copper content. In general, properties of the steel produced were not measurably affected by charge composition (that is, melting stock), melting practice, or method of scrap preparation.

Jan 1, 1975

By G. W. Grove

Coal-mine officials and those who are preparing to become officials should be familiar with the instruments and devices that are employed rather commonly in and around mines and should know how to use them with safety and efficiency. Among these axe instruments and devices used in determining the pressure, velocity, volume, and certain other conditions of ventilation and in detecting the more common mine gases, such as methane, carbon monoxide, and hydrogen sulphide, or a deficiency of that very important agent, oxygen. Water gages, anemometers, barometers, psychrometers, flame safety lamps, lamp-testing boxes, and methane, carbon monoxide, and hydrogen sulphide detectors are described and their use and operation discussed in this paper.

Jan 1, 1938

By A. Gene Collins

The Bureau of Mines conducted a research study of the geochemistry of the Smackover Formation to determine what geochemical relationships are useful in exploration for and production of oil and gas. Samples of oil, gas, brine, and rock were collected and analyzed. The oilfied brines were analyzed by methods recommended by the American Petroleum Institute and by tentative methods of the American Society for Testing and Materials. The crude oils were analyzed by Bureau of Mines methods; the gas, by Bureau of Mines methods; and the rocks, by wet-chemical, atomic absorption, and neutron activation methods. The results were correlated and interpreted, and several geochemical relationships useful in exploration and production were found. These include the type and class of brine, organic constituents in the brine, redox potential, in situ temperature and pressure of brine, degree of sulfate and carbonate saturation of brine, and halide concentrations in the brine.

Jan 1, 1974

By D. R. Tesarik, R. W. McKibbin

Material properties affecting slope stability were measured in a large 50-year-old, partially consolidated rockdump located in an active open-pit mine. Field tests included single-ring infiltration and density. In addition, a nuclear depth-moisture gauge was used to measure water content in six stainless-steel-cased drill holes on the crest and an upper bench of the rock dump. Precipitation, evaporation, wind speed and direction, and temperature data were collected at a weather station installed on the dump’s crest. Laboratory tests included particle-size distribution, specific gravity, Atterberg limits, and water content. By measuring material properties of a rock dump presumed to be stable, the safety of miners working on or at the toe of old rock dumps constructed of similar material and located in a similar climate can be assessed.

Jan 1, 1999

By Uwe Kaulbars

Vibration measurements at the workplace are often complicated and expensive. The assessment of the risk in conformity with EC Directive 2002/44/EC “Vibration” (which lays down the minimum requirements of laws in Europe for occupational safety and health) can therefore be carried out on the basis of an estimate based on information from manufacturers as well as by measurement conforming to ISO 5349. The characteristic values (emission values) determined by manufacturers in laboratory conditions may deviate from the exposure values measured at source at the workplace. Equally, deviations may arise as a result of the delay in the changeover of test methods from the single axis of measurement to the total vibration value for the three axes of measurement conforming to ISO 20643. To prevent faulty estimates, the manufacturer’s information has to be corrected by a tool-related factor in accordance with CEN/TR 15350. By taking the example of masonry and stone working machines, the empirically determined tool-related correction factor is checked and confirmed. Methods Vibration measurements were carried out in accordance with ISO 5349 in practical application conditions on 10 selected typical eccentric and orbital sanders, concrete and disc grinders as well as on wall chasers and stone saws. Results The total vibration value obtained for the investigated tools rangedfrom ahv = 3.6 m/s² to ahv = 11.6 m/s². When the values from the practical measurements are compared with the manufacturer’s vibration values, the underestimation of the risk occurring in some cases can be largely compensated for by the tool-related factors conforming to CEN/TR 15350 (see Figure 1).

Jan 6, 2006

By W. R. McDonald

The Bureau of Mines, U.S. Department of the Interior, conducted small-scale field tests on acidic copper tailings as part of its effort to develop, improve, and demonstrate technology for stabilizing mining and mineral-processing wastes. Two successful demonstration revegetation plots were established on an abandoned copper-tailings pond located on public land adjacent to Holden Village, Wash. The tailings were neutralized with treatments of either dolomitic lime or limerock and fertilized with processed sewage sludge and/or commercial fertilizer. Excellent plant growths covering 70 and 24 percent of the surface were achieved on 1/8-and 1-1/2-acre test plots planted in 1973 and 1974, respectively. Regar brame, Tegmar intermediate wheatgrass, and tall wheatgrass provided the best plant growth and surface coverage. The target pH of tailings neutralization was 6.8; however, good plant growth occurred in areas where the soil pH ranged from 2.9 to 5.8.

Jan 1, 1978

By Fredrick L. Johnson

No mineral resources were delineated during our investigation of the Antelope Wilderness Study Area (WSA). Only a few claims have been located in the area and only four workings were found. There has been, however, considerable exploration and mining activity in and near the south end of the study area. The Morey mining district, just southeast of the WSA, produced silver, and lesser amounts of gold and lead, sporadically from the mid-1860's through the mid-1960's. Long Lac Mineral Exploration (Texas), Inc. is actively exploring a large block of claims for hot-spring type, low-grade, large-tonnage gold deposits. Their claim block extends into the study area. The WSA, located midway between Tonopah and Eureka, encompasses approximately 87,400 acres. It is underlain by Tertiary rhyolitic and latitic volcanic rocks and by Paleozoic sedimentary rocks. At least three areas in the Paleozoic rocks have many of the favorable criterion for hot-spring type gold deposits; they have been faulted, silicified, brecciated, and hydrothermally altered, and have anomalous concentrations of precious metals and pathfinder elements. With additional exploration in the south part of the Antelope WSA, gold resources may be discovered.

Jan 1, 1986

By Donald M. Hausen

Diamond-bit performance and cost data accumulated by the Bureau of Mines in core-drilling schists reveal significant trends of economic interest. Low-quality, small-size drill bort were the most economical. The percentage of core recovery, type and size of bit, and bit matrix are also correlated with bit performance and costs. Detailed analyses of the factors affecting diamond-bit performances and costs are assessed in the tables, graphs, and discussion.

Jan 1, 1956

By R. E. Lindstrom

Effective separation of rare-earth mixtures is obtained using hydrogen as a retaining ion at 200° F with ethylenediaminetetraacetic acid (EDTA) eluant. Results obtained in Bureau of Mines bench-scale apparatus and large columns with hydrogen as a retaining ion closely parallel those obtained with copper as a retaining ion. The use of hydrogen as a retaining ion permits EDTA and water, collected before rare-earth breakthrough, to be recovered in a form that allows the material to be recycled without extensive processing. With the exception of yttrium and dysprosium, separation of rare-earth mixtures is improved and throughput is increased by elevated temperatures. Separation with 1,2-diaminocyclohexanetetraacetic acid (DCTA) eluant increases markedly on increasing temperature from ambient to 250° F; however, on the basis of separation efficiency, DCTA does not compare favorably with EDTA.

Jan 1, 1962

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

Mine ventilation can be broadly defined as the branch of mining engineering primarily concerned with the controlled flow of air through mine airways to maintain an acceptable atmospheric environment wherever men work or travel underground. Martinson (1976) has defined three elements of mine ventilation, 1) an engineering element concerned with establishing quality control (removal of dust and gases), quantity control (regula¬tion of air direction and magnitude) and climatic conditioning (temperature-humidity control), 2) a biological element in which an understanding of biological response is used in assessing the mine environment, and 3) a philosophical element requiring judgements as to the degree of risk or worker discomfort that is socially acceptable. Most texts on ventilation, such as Hartman (1961), limit themselves to a discussion of the engineering element. Although also limiting his text to engineering control, Weeks (1928) thoughtfully addresses the other elements in the preface of his book where he states: "Life is brief and happiness elusive under the best of conditions; so beside the commercial aspect must be placed the humanitarian. Is it not reasonable that the operator should give his men a chance to spend their working hours in a comfortable environment, with the danger of sudden death or disability reduced as much as possible?" The statutory requirements of ventilation are, in most countries, established on the basis of biological response as determined by basic research or are dictated by social awareness, often touched off by major disasters, resulting in demands on regulatory bodies for more stringent requirements. To a limited extent, the philosophical and biological elements of ventilation are intertwined in that social awareness may

Jan 1, 1977

By H. P. Greenwald

About mid-December 1936, the safety director of a large coal corporation visited the authors at the Bureau's Experimental coal mine to discuss a rock-dust barrier he had invented primarily for use in trackless entries of coal mines. The rock dust in this device was carried in its original paper containers and means were provided for ripping these open so that the dust might be scattered in the path of an explosion. The inventor termed the device a "bag barrier", and this term has been adopted in the present paper for convenience. At that time the device was in an early stage of development, and the inventor felt that the barrier should be tested to determine whether it had enough promise of being successful to justify further development. The matter was taken under consideration and finally three tests were made during the week of February 15, 1937. It was concluded that while the device did stop an explosion in two of the three tests, it was much loss effective than ordinary rock dusting, and that too few data were obtained to permit direct comparison with tests of other barriers. Apparently, the conditions under which the device could, be successful were somewhat limited, out the limits could not be defined without additional tests.

Jan 1, 1938

By Wilder D. Foster

In estimating the hazardous qualities of a dusty atmosphere it is frequently desirable to determine the composition of the air-borne dust. Samples collected from ledges or from the rock itself are Likely to be unsatisfactory for this purpose owing to the possibilities of differential disintegration of the rock and of variations in settling rates of the different components of the minerals. It may be necessary, therefore, to collect samples of dust from the air. Samples collected from the air may be analyzed chemically, by X-ray diffraction, and by the petrographic microscope. Chemical methods are unsatisfactory owing to the small samples usually available and to the limitations and complexities of: present methods. X-ray technique requires expensive apparatus not ordinarily available except in research laboratories. Owing to the simplicity and rapidity of petrographic is examination of atmospheric mineral dusts, it was considered worthy of further study.

Jan 1, 1938

By James H. Scott

A technique of seismic refraction data analysis has been developed in which a digital computer is used to generate a two-dimensional model representing a layered-earth depth interpretation. Travel times are picked on seismic records by the human interpreter. These times, together with shot point and geophone locations and refraction layer control information, are submitted to the computer on punched cards. A first approximation delineation of each refraction horizon is obtained by a computer adaptation of the delay-time method. The approximation is then tested and improved by the computer through the use of a ray-tracing procedure in which ray travel times computed for the model are compared against field-measured travel times. The model is subsequently adjusted in an iterative manner so as to minimize the discrepancy between computed and measured travel times. The Fortran program is listed in the appendix of the report together with instructions for preparing data cards and examples of results.

Jan 1, 1972

By Jr. Harty

Intensive work on the deoxidation of steel with manganese-silicon alloys by the U. S. Bureau of Mines has shown that the use of those alloys, which may be produced from our domestic manganese ores, would decrease the ferromanganese requirements of a very large tonnage of our steel by from 60 to 80 per cent and in some cases by 100 per cent. The open-hearth heats made with these alloys have been of excellent quality. The tonnage of our ferro-grade ores Which has been made available by the bureau's ore-dressing studies, combined with the products resulting from such processes as those developed by the bureau and by Bradley for Cuyuna ores, should easily fill our reduced ferromanganese requirements when manganese-silicon alloys and ordinary Spiegel are used in the way described in this report. There are no technical difficulties in the application of this practice, and any difficulties involved in its wide and immediate application would only be those arising from habituated ideas of the necessity of ferromanganese. General acceptance of this practice and development of the available sources of domestic ferro-grade material by already proven processes should make this country independent of foreign ores. This paper resents the results of work done under a cooperative agreement between the Pittsburgh Experiment Station of the United States Bureau of Mines and the Carnegie Institute of Technology, the Metallurgical Advisory Board, and the University of Pittsburgh, Pittsburgh, Pa.; between the Mississippi Valley Experiment Station of the United States Bureau of Mines and the Missouri School of Mines and Metallurgy, Rolla, Mo.; between the North Central Experiment Station of the United States Bureau of Mines and the University of Minnesota, Minneapolis, Minn.; and between the Rare and Precious Metals Experiment Station of the United States Bureau of Mines and the University of Nevada, Reno, Nev.

Jan 1, 1931

By C. H. Herty

Intensive work on the deoxidation of steel with manganese-silicon alloys by the U. S. Bureau of Mines has shown that the use of those alloys, which may be produced from our domestic manganese ores, would decrease the ferromanganese requirements of a very large tone of our steel by from 60 to 30 per cent and in some cases by 100 per cent. The open-hearth heats made with these alloys have been of excellent quality. The tonnage of our ferro-grade ores which has been made available by the bureau's ore-dressing studies, combined with the ,products resulting from such processes as those developed by the bureau and by Bradley for Cuyuna ores, should easily fill our reduced ferromanganese requirements Then manganese-silicon alloys and ordinary spiegel are used in the way described in this report. There are no technical difficulties in the application of this practice, and any difficulties involved in its wide and immediate application would only be those arising from habituated ideas of the necessity of ferromangenese. General acceptance of this practice and development of the available sources of domestic ferro-grade material by already proven processes should make this country independent of foreign ores.

Jan 1, 1931

By G. E. McClelland

During the 1970?s, the Bureau of Mines investigated a particle agglomeration technique for improving the flow of leaching solution through heaps of clayey or crushed, low-grade gold-silver ores, wastes, and tailings. This technology has been adopted on a broad scale by the precious-metals-processing industry. This report presents information on five commercial operations that have benefited from agglomeration technology and that represent a cross section of current heap leaching practice. The technology is cost effective because of decreased leach times and improved precious metal recoveries.

Jan 1, 1983

By Richard F. Hewlett

The mining industry utilizes a vast store of knowledge, wisdom, and engineering talent in designing mining systems. However, the complexity of the required systems and the presence of numerous variables frequently necessitates raking important decisions without having adequate accurately detailed information. That many of the decisions made in the past were nearly correct, in the long run, is substantiated by the number of successful mining enterprises that exist in the world today. Subsequent to 1940, the disciplines of operations research and systems engineering were developed. The disciplines have produced methods of providing better information to persons responsible for making decisions.

Jan 1, 1963

By Terry S. Cory

This report is a comprehensive summary of the results of the propagation measurements program conducted for the US Bureau of Mines under Contract H0366028. Data was gathered in the MF frequency range from a cross sample of six mines representative of the industry having typical wireless requirements. From the raw data which was gathered, a logical method of data reduction is presented which culminates in a set of average attenuation characteristics for all mines visited. These characteristics define a typical MF wireless system when the communication range requirements are known. Direct through-the-earth propagation and the range enhancement mechanism due to coupling on and off conductors are evaluated and related to the planning of a typical wireless MF communications system.

Jan 8, 1977