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By R. Larry Grayson

In the October 1998 issue of the Holmes Safety Association Bulletin, NIOSH authors Mark Stephenson and Carol Merry wrote the article Hearing loss among miners and measures to protect hearing, which focused on the extensiveness of hearing loss among miners and the use of hearing protection to prevent hearing loss. While the primary importance of engineering controls in preventing hearing loss was discussed, since miners do not generally have control over their work en­vironment or assignments, the article focused on the importance of consis­tent use of hearing protection. In this article, all aspects of a compre­hensive approach to the prevention of hearing loss in miners will be covered. The discussions will do the following: ? describe application of the hierarchy of controls in preventing hear­ing loss in miners, ? give an example for each type of control measure and its impact, ? explain the major provisions, be­yond the hierarchy of controls, of the recent NIOSH document en-titled Criteria for a Recommended Standard: Occupa­tional Noise Exposure, Revised Criteria 1998 relative to a hearing loss prevention program, and ? summarize important points on control of noise exposure for every miner to remember, equipment in most facets of operations. Miners are well aware of noisy areas in or around equipment, icluding extraction machinery such as draglines, power shovels, longwall shearers, and continuous mining machines; powered haulage equipment such as load-haul-dumps, shuttle cars, large trucks, and continuous haulage units; roof bolting machines; jackleg drills and stopers; auxiliary equipment such as compressors, fans, and pumps; size reduction equipment, etc. They are not well aware of the insidious nature of pro­gressive hearing loss, which is per­manent, but they are generally aware of what levels of noise are hazardous and what measures can be taken to reduce their personal noise exposure. Behaviorally, however, there are many reasons why miners choose not to use hearing protection faithfully.

Jan 1, 1998

This report is a proceedings of a briefing recently sponsored by the Bureau of Mines at which Bureau personnel presented findings from their research efforts to improve steelmaking techology currently used in the United States. The papers contained in this report address many areas of concern to the iron and steelmaking industry. Among these are improving arc stability in electric arc furnaces, preheating ferrous scrap to reduce energy consumption, fluorspar substitutes in steel-making, basic steelmaking refractories, corrosion of iron-based materials, improvements in stainless steel acid pickling processes, recycling of stainless steel dusts and other wastes, and use of wastes as a source of zinc for electro/galvanizing.

Jan 1, 1988

By G. L. Oldright

This paper is the second of a series that is to appear on smelting in the lead blast furnace. The objects of this investigation are to determine the conditions obtaining within the blast furnace by direct experimentation, and to correlate the behavior of the furnace at various times with the main factors governing the operation of the blast furnace, and metallurgical losses. The writers wish to express their appreciation to the management of the International Smelting Company at Tooele. Utah, for their kind cooperation which made possible the assembling of these data.

Jan 1, 1929

The United States is rapidly depleting many of its most important minerals and fuels. The first two Annual Reports by the Secretary of the Interior, under the Mining and Minerals Policy Act of 1970, made us acutely aware that the natural resources that enabled this Nation to attain an unprecedented growth in terms of economic well-being, and to set an example of independent strength through the democratic process, are finite. Once they are depleted, large imports will be required. Simultaneously, competition for available supplies, especially of petroleum, is increasing in the expanding European and Japanese industrial communities and in the underdeveloped nations of the world. Even before the crisis of late 1973, the oil-producing nations of the world, principally in the Middle East, but including Canada and Latin America, were recognizing that the worldwide need for crude oil, petroleum products, and natural gas could be translated into an unprecedented economic bargaining position. Thus, the members of the Organization of Petroleum Exporting Countries (OPEC) raised the price of their crude twice during the first 6 months of 1973. By yearend the energy situation had be-come acute, and it seemed probable that regardless of current political developments, the era of cheap energy was over.

Jan 1, 1973

By R. L. Marek

"The number of persons fatally injured in the petroleum industry in California in 1930 was 50, a decrease of 20.6 per cent from 1929, when 63 men accidentally lost their lives. The decrease in the number of fatalities for 1930 has caused the first downward trend in the fatality curve of the California petroleum industry since 1927 and is coincident with a period of little active development in new fields, the shutting in of many wells, and reduced activity in the older fields of the State. That a direct relationship exists between the number of accidental deaths and the rapidity of new field development is particularly emphasized by the fact that in 1929, a year of intensive field development in California, 48 men were killed in the drilling and producing division, whereas in 1930, a year of less development work, only 25 men were killed in this division,The figures for the average number of drilling and producing wells in 1930 decreased appreciably from comparable figures for 1929 and a greater percentage of producing wells were shut—in in 1930 than in 1929."

Dec 1, 1931

By J. M. Provost

1. Estimates have been made for eight coal beds in Marion County, but only the Pittsburgh is important from a production standpoint at this time. The Pittsburgh bed has the largest recoverable reserve, and the Sewickley is second in importance. 2. Known measured and indicated reserves thickness of 14 inches and on 1,800 short tons estimated at 3,141 million tons, as of January lion tons is in beds 28 inches and more thick in all beds, based on a minimum per acre-foot of coal in place, are 1, 1955. Of this total, 2,983 mil-Areas in each bed were omitted from the estimate because available data relative to the bed characteristics were too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956

By Alla D. Mah

THERMODYNAMIC data for manganese and its inorganic compounds have not been critically surveyed since the work of Maier (31) 3 in 1934. At that time data were lacking or inadequate for many of the important metallurgical compounds. Experimental work, conducted during the intervening years, has supplied so many new thermodynamic values that it is again desirable to examine the available data and compile them into a single publication for handy reference. This paper consists of three main sections. The first summarizes the basic metallurgical thermodynamic data for manganese and its compounds, including heat capacities, entropies, heat contents, temperatures and heats of phase changes, vapor pressures, and heats and free energies of formation. All data available to May 1959 have been considered. The second section contains heats, free energies, equilibrium pressures, and equilibrium constants of reactions of manganese compounds, with special emphasis on metallurgical reactions. The third section supplies basic thermodynamic data for other elements and compounds encountered in metallurgical reactions of manganese, thus making it possible for the reader to conduct thermodynamic calculations without recourse to other literature.

Jan 1, 1960

By Dale W. Richardson

Ductile hafnium was not obtained consistently by the conventional Kroll process. The bimetal reduction modification produced a more ductile hafnium by lowering the impurities, especially oxygen, in the sponge metal. Hafnium oxide was chlorinated in the presence of carbon to form anhydrous hafnium tetrachloride, which was reduced by sodium and magnesium in an inert atmosphere to produce sponge hafnium metal. After vacuum distillation to remove the byproducts, the sponge was arc-melted into ingot and rolled into strip. Metallic impurities were decreased by evaporating the hafnium tetrachloride from a fused salt. An excessive amount (over 1,200 parts per million (p.p.m.)) of aluminum was contained in some of the hafnium oxide, much of which remained as aluminum chloride in the hafnium tetrachloride during chlorination. Evaporation of the hafnium tetrachloride from a fused NaCI-KCI mixture during the Mg-Na reduction greatly lowered its aluminum content, as most of the aluminum and some of the other metallic impurities were retained by the fused salt.

Jan 1, 1961

By Robert S. Sanford

Intensive investigations of domestic manganese deposits were conducted by the Bureau of Mines and the Geological Survey during the earlier part of the war minerals investigations when there was doubt that the quantity of manganese needed to produce the greatly increased tonnage of steel demanded for war supplies could' to obtained from its customary sources. Domestic deposits of ores that contain sufficient manganese for direct production of ferromanganese essential in steel Manufacture are generally small, and the bulk of the supply is imported. One of the few large deposits of low-grade manganese ore known in the United States is in the Artillery Peale district in southern Mohave County, Ariz. Manganiforous sediments underlie a very large area. Several large groups of claims, covering the most of the manganese-bearing ground, wore assembled in 1929 and 1930. The greater part of this area was leased by the M. A. Hanna Co. in 1937. Investigations by engineers and geologists for this company revealed that the average content of manganese is very low; but that the Maggio Canyon area, about 180 acres, contains higher-grade material. The company put down 28 vertical diamond-drill holds to explore this ground, under the direction of B. N. Wobbor, geologist.

Jan 1, 1948

By C. W. Smith

The U.S. Bureau of Mines conducted research to determine the effect of ground water control on the dewatering of phosphatic clay wastes. Two storage impoundments were constructed. One impoundment was surrounded on three sides with a series of well points (shallow vertical wells) to lower the ambient water table and the second impoundment served as a control. Ground water was pumped from the area surrounding the test impoundment for a period of 490 days. A constant pumping rate of 60 gal/min resulted in a water table drawdown of 13 ft, approximating the bottom of the impoundment. At the end of the test period percent solids in the test impoundment was 35 pct, while in the control impoundment percent solids was only 26.8 pct. Percent solids of greater than 30 pct is required for capping and final reclamation using fertile overburden.

Jan 1, 1989

By C. J. Hall

Twenty eight pulse release sulfur hexafluoride tracer gas field tests were run in a multi-level multi-vein hard rock mine to measure leakage ventilation. The mine had numerous underground booster fans and gob filled old stoping areas and consequently numerous leakage paths. The tests proved that the equipment and methods developed by the USBM can be used successfully in complicated ventilation circuits. The leakage quantities varied each time a major change was made in the main ventilation circuit. Usually leakage quantities had to be remeasured after a main ventilation change, but measurements could be duplicated for anyone configuration except under certain defined circumstances. The characteristics of an individual leakage path could be determined from the difference between the measured sum of two paths and the calculated characteristics of one of the paths. Many leakage paths could not be evaluated accurately on one shift. Comments are made on equipment performance and field techniques. Programs for the calculation of gas concentrations and recirculation from measured data and for the mechanical integration necessary for a calculated leakage characteristic have been written for an HP 9810 and are included.

Jan 1, 1975

By Daniel I. Carey

Current and potential dragline reclamation usage was evaluated for the U.S. coalfields based on data gathered and analyzed during field surveys, literature reviews and contacts with manufacturers. It was concluded that current wining plans have been adapted to federal and state strip mine and reclamation laws in ways which limit the potential for drag line reclamation systems at active mine sites. At abandoned conventional contour mine sites in steep-sloping areas such as central Appalachia, however, it was found that dragline reclamation systems have great potential application and may be the only practical solution to many reclamation problems. Alternative dragline systems were examined for restoring abandoned sites, and it was concluded that a tower excavator system offered superior characteristics and should be evaluated and developed under field conditions. A testing program was developed to provide a framework for the monitoring and analysis of cost, production and environmental data during a field demonstration of a tower excavator system.

Jan 1, 1981

By R. S. Rosso

A program to investigate the effects of hardened washers on the uniformity of roof bolt tension and the resulting ground control in an underground mine was carried out. The complete roof bolt installation and roof bolt loads, mine convergence, and bed separation were monitored for a period of five months. The results show no evidence to support or refute the theory that mechanical roof bolts offer better support when they are installed with a high uniformity of tension. Also shown is the fact that if the bolts are installed with a maximum deviation from the mean torque of ±15% the addition of hardened washers significantly improved the uniformity of the installed tensions in the roof bolts.

Jan 1, 1977

By Fred Hodges

This paper describing the concentrator practice of the Hurley Plant of the Nevada Consolidated Copper Co. at Hurley, N. Mex., is one of a series of papers on milling methods and costs being prepared by the United States Bureau of Mines. The Hurley concentrator has a normal daily capacity of 13,500 tons of ore, and for the first four months of 1930 the heads of the concentrator averaged 1.32 per cent of copper and 3.14 per cent of iron. The recovery for this period was 83.98 per cent and the concentrates produced averaged 27.54 per cent of copper.

Jan 1, 1931

By R. E. Heithecker

Zwolle oil field of Sabine Parish, La., is different from most oil producing areas of the State in that the oil is obtained from marl and chalk-rock formations. The thickness of the reservoir rocks averages 500 feet; but production is not continuous throughout this thickness, as the oil apparently is localized in vertical and nearly vertical solution cavities and channelways or in porous zones of limited horizontal extent. The nature of the oil accumulation has caused two outstanding peculiarities of the field: (1) About 60 percent of the tests drilled were dry holes and (2) there were many instances of well interference. Commercial production was discovered in November 1928, after 17 years of prospecting in and around the present limits of the area now developed which has a length of about 22 miles and a maximum width of 4 miles. The field had produced 10,266,896 barrels of oil to January 1, 1934. The oil ranges in gravity from 400 to 420 A.P.I. Although the field is divided into several districts which are more or less clearly defined and separated by unproved territory the term Zwolle field", as used in this report, includes the entire area from Blue Lake on the west side, through Zwolle proper, and eastward, including the Many or Eastern extension.

Jan 1, 1934

By Donelson A. Robertson

Literature was searched and cases of alleged water well damage were investigated. Occurrence of ground water in Appalachia is primarily in low yield, fractured, water table aquifers. Four test sites were chosen based on geographic and geologic diversity. Test wells were drilled at each site and base line data on water quality, static water level, and drawdown characteristics were obtained before surface mining commenced. Blast induced ground vibrations were measured at the surface by the wells at levels up to 5.44 inches per second maximum resultant particle velocity. Measurements made at the bottom of wells indicated that vibrations were considerably attenuated at depths of 140 to 160 feet. No direct evidence of change in water quality or well performance was produced by blast vibrations, but removal of downslope support by excavation does cause lateral stress relief which permits the water-bearing fractures to become more open. This additional storage capacity causes the static water level to drop and for well-bore permeability to improve. Static water level recovers if sufficient recharge is available and well performance is

Jan 1, 1980

By Wiliam L. Crentz

The importance of Somerset County, Pa., as a coal producer is due in large measure to the presence reserves of low-volatile bituminous coals. Although many coal beds of minable thickness are present, the important reserves are to be found in those beds underlying the Pittsburgh bed. The Kittenning beds and Freeport beds, which are responsible for the bulk of the present coal production in Somerset County and contain the largest reserves to meet future coal requirements, are usually thin and entirely free from impurities. The Pittsburgh bed, which has been such an important coal deposit in the coal areas immediately west and south of Somerset County, is of secondary importance in this county. Although generally rather friable, Somerset County coals have enjoyed wide receptability as excellent coals and to some extent have been utilized in the metallurgical market.

Jan 1, 1951

By J. D. Davis

THE carbonizing properties of one medium- and and five low-volatile coals from West Virginia and one high-volatile A and two medium-volatile coals from Pennsylvania were determined by 800° and 900° C. BM-AGA carbonization tests and expansion tests in the sole-heated oven. Plastic properties of the coals and the yields and quality of their cokes and other carbonization products were determined. The low-volatile coals comprised a mine and a coke-plant sample of Pocahontas No. 6-bed coal from the. Black Eagle No. 1 mine, Wyoming County, W. Va.; a mine sample of Pocahontas No. 6 bed from the Louisville mine, Mercer County, W. Va. ; Davy Sewell bed was sampled at the Twin Branch mine, McDowell County, W. Va.; and Fire Creek bed was sampled at the Dunedin No. 1 mine, Raleigh County, W. Va. The medium-volatile coals were from the Fire Creek bed, Laurel Creek mine, Greenbrier County, W. Va.; Lower Kittanning bed, Springfield No. 4 mine, Cambria County, Pa.; and Upper Kittanning bed, Springfield No. 6 mine, Clearfield County, Pa. The high-volatile A coal represented the Upper and Lower Freeport beds, Kent Nos. 1 and 2 mines, Indiana County, Pa. In addition to the coals listed, high-volatile A coal from the Pittsburgh bed, Warden mine, Allegheny County, Pa., a standard blending coal, was used in blends in this investigation.

Jan 1, 1950

By G. W. Birge

Carbonizing properties of the principal coal beds of Perry County, Ky., are described in this Bureau of Mines report. Seven samples, representing the Hindman, Flag, Haddix, and Fire Clay beds, were carbonized by the Bureau of Mines-American Gas Association (BM-AGA) method, and yields of products and physical properties of cokes were determined. Carbonizing properties of blends of Flag and Fire Clay coals, with 20 and 30 percent Pocahontas No. 3 low-volatile coal from McDowell County, W. Va., also were determined. Expanding properties of the Flag and Fire Clay coals and their blends were determined in the Bureau of Mines sole-heated oven. The Perry County coals tested are high-volatile A bituminous in rank and, with the exception of the Hindman-bed sample, which contained excessive sulfur, were chemically suitable for metallurgical use. The three coals tested in the sole-heated oven contracted less than normal for Appalachian coals of similar rank, Blending the Fire Clay and Flag coals with 20 or 30 percent low-volatile coal increased coke strength appreciably but increased the expansion beyond normal limits for industrial blends.

Jan 1, 1962

Nineteen eighty-seven was a year of significant change in the Bureau of Mines-change to help it better adapt and respond to the wide range of new challenges facing the U.S. mineral industry. The Bureau has been regarded as the world's premier mineral information and research agency. Its authoritative, comprehensive data and its pioneering research have contributed significantly to the minerals position of the United States. Yet no organization in today's complex, dynamic world, with its rapidly advancing technologies, can afford to rest on its laurels. Mission and program must be constantly fresh and relevant to the day's issues and problems. Moreover, rather than reacting to events, the organization must strive to anticipate and prepare for them. It must have a sense-a vision, if you will-for the future.

Jan 1, 1987