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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 W. Timothy Adams

The production of natural abrasives varied in quantity and value compared with 1976. Output of tripoli-type materials was approximately the same in both quantity and value. Special silica stone products decreased in quantity and increased in value. Garnet production decreased both in quantity and value. The production of emery increased and the production and value of manufactured abrasive material was approximately the same. Foreign Trade Imports of abrasive materials were 23% more in value than in 1976, and exports plus reexports increased in value 10%. Net imports, the excess of imports over exports and reexports, were $35.3 million. The volume and value of all abrasive materials exported varied.

Jan 1, 1980

By Stephen P. Signer, John L. Lewis

This paper presents the results of a case study conducted in a two-entry gateroad in a coal mine where excessive roof deformation and bolt loading resulted in failure of many roof supports. The instruments consisted of 16 fully grouted, strain-gaged resin bolts, load cells on both full and partially grouted cable bolts, and vertical deflection multipoint extensometers. These instruments were installed on-cycle to measure loading on bolts in an existing support pattern and to determine if cable bolts could be used to improve roof stability. Results showed significant amounts of movement within the bolted zone. In some cases, these movements were enough to load the supports past their ultimate strength. Geology appeared to be a significant factor in localized roof degradation; that is, a very weak rock layer in the immediate roof overlain by a very strong rock layer contributed to the development of shear planes. Only one instrumented bolt had a maximum strain of less than 2,000 microstrain, which was the yield point of the steel. The average maximum strain on all bolts was 20,000 microstrain. However, electrical continuity to many gages was lost and a pattern was noted that would indicate possible bolt failure. Wire mesh and concrete cans installed as secondary support performed very effectively.

By Steven J. Page, John A. Organiscak

Laboratory crushing experiments were conducted on a range of low- to high-volatile bituminous coals to investigate the various factors influencing airborne respirable dust (ARD) generation. This research was conducted to identify the principles of ARD liberation from the coal product. Five U.S. bituminous coals were uniformly prepared and processed through a double roll crusher located in a low-velocity wind tunnel. Experimental factors studied included inherent coal seam constituents, coal grind ability, specific energy of crushing, product size characteristics, dust cloud electrostatic field, and specific ARD generated. The results of this investigation indicate that a combination of several factors are associated with ARD generation. One factor is the effect of coal rank, described by the inherent moist fuel ratio, on the product size characteristics, defined by Schuhmann size function parameters. Another key factor is the effect of air dry loss(ADL) moisture in the coal seam on the breakage-induced electrostatic field of airborne dust. The effect of these factors is that different percentages of <10-m coal particles are dispersed as ARD. A discussion of electrostatic field principles, coal ADL, and its effect on ARD generation is presented.

Jan 10, 1998

By Douglas F. Scott

Zinc, silver, copper, and tungsten are the principal minerals in Dardanelles RARE II area (No. 4982). Zinc with associated silver and copper occurs in a persistent shear zone in metasedimentary rocks and in a massive sulfide vein; tungsten occurs as disseminated scheelite in a tactite zone along a metasedimentary-intrusive rock contact. Since 1883, approximately 100 lode mining claims have been recorded, mainly it the eastern portion of area No. 4982 (fig. 1). Extensive workings on the Alhambra Prospect indicate past production; however, no records were found for the prospect. At the Alpine Mine, 500 tons of tungsten ore had been mined before 1943 (Hopson, 1943, p. 1) and possibly 1,000 tons of tungsten ore mined by 1947 (Benson, 194/, pp. 2).

Jan 1, 1982

By Henry P. Chandler

THE year 1950 was one of increased activity in almost all branches of the abrasives industry, with nearly all abrasive materials showing a marked increase in tonnage and value. New records were made In the production of tripoli, ground sand and sandstone, pumice and pumicite, and garnet. Total production of crude artificial abrasives in the United States and Canada increased 17 percent in tonnage and 30 percent in value. Imports of industrial diamonds increased 100 percent in total value and 72 percent by weight, the 1950 importation being the largest since 1944. Imports of corundum increased 76 percent in tonnage and 4 percent in value.

Jan 1, 1953

By J. E. Urosek, K. L. Cashdollar, D. A. Beiter, G. J. Shemon

The National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted joint research to evaluate explosion blast effects on mine ventilation stoppings at the NIOSH Lake Lynn Experimental Mine (LLEM). After mine explosion accidents, MSHA conducts investigations to determine the cause(s) as a means to mitigate or eliminate future occurrences. As part of these post-explosion investigations, the condition of underground stoppings, including the debris from damaged stoppings, are documented as evidence of the strength and the direction of the explosion forces. The LLEM data showed that a total pressure of 52 kPa (7.6 psi) destroyed the solid concrete block stopping, ~36 kPa (~5.2 psi) destroyed the hollow-core concrete block stopping, and 9 kPa (1.3 psi) destroyed the steel panel stopping. These results will assist investigators in determining the explosion forces that destroy or damage stoppings during actual coal mine explosions.

By Peter G. Kovalchik, Rudy J. Matetic, Susan B. Bealko, Adam K. Smith

Overexposure to noise remains a widespread and serious health hazard in the U.S. service providing and goods producing industries. Excessive noise can lead to poor verbal communication and reduce the ability to recognize warning signals. These dangerous work conditions can also cause stress and fatigue. Occupational hearing loss is a permanent illness, with no recovery currently possible. Method: National Institute for Occupational Safety and Health (NIOSH) has recognized Noise Induced Hearing Loss (NIHL) as one of the ten leading work related diseases and injuries in the United States, and has emphasized its importance as one of the critical areas expressed in the National Occupational Research Agenda. Results: One of the most serious noise problems in the goods producing industries is the operation of continuous mining machines during underground coal mining. In order to minimize occupational hearing loss, noise hazards are “designed out” early in the design process. NIOSH is leading a national initiative called Prevention through Design (PTD) to promote this concept. This paper describes the quiet by design approach of a noise control that reduced noise exposures of continuous mining machine operators by 3dB(A) using the four functional areas of PTD, namely Practice, Policy, Research, and Education.

By Forrest T. Moyer

The National Safety Competition was inaugurated in 1925 by the Bureau of Mines, U.S. Department of the Interior, in cooperation with the Explosives Engineer. In the first nationwide contest, 210 mines and quarries were enrolled. In 1962, the thirty-eighth anniversary of the competition, 910 mines and quarries were enrolled. These participating plants were worked a total of 133,292,989 man-hours. Of the enrolled plants, 415 achieved injury-free operations for the year, the largest number of perfect safety records in the history of the contest.

Jan 1, 1964

By Christopher Mark, Robert J. Tuchman

This proceedings volume contains papers presented at technology transfer seminars sponsored by the National Institute for Occupational Safety and Health (NIOSH) on New Technology for Ground Control in Retreat Mining. The seminars were conducted at five locations: Uniontown, PA (March 26, 1997), Norton, VA (April 8, 1997), Pikeville, KY (April 10, 1997), Charleston, WV (April 17, 1997), and Evansville, IN (April 22, 1997). The papers presented here describe several new, highly practical technologies developed by the NIOSH Pittsburgh and Spokane Research Centers3 to improve safety during pillar retreat operations. Two central issues are addressed: pillar design and mobile roof supports (MRS&apos;s). Proper pillar sizing is essential for safe pillar extraction. The Analysis of Retreat Mining Pillar Stability (ARMPS) program and its large data base of actual mining case histories are presented. LAMODEL, a second computer program, can be used for analysis of multiple-seam and other complex mining situations. Other papers address pillar design to avoid massive pillar collapses and the proper role of coal strength testing. MRS&apos;s have greatly improved safety where they are used for pillar line support. We studied the application of MRS&apos;s at 20 mines throughout the Eastern United States. Conclusions regarding the most effective section layouts, cut sequences, and support placements are reported. Field and laboratory tests of MRS&apos;s are also described.

Jan 1, 1997

By Danny Riley, Brian Curry, Sandya Govindaraju, James Bain

Acute vibration causes vasoconstriction in naïve human subjects1. Vibration-induced decrease in skin perfusion has also been reported in the rat-tail vibration model 2. After vibration exposure, rat-tail arteries demonstrate vacuoles in smooth muscle cells, similar to that caused by pharmacological vasoconstrictors3. This study addressed the effects of different frequencies, durations and patterns of vibration on lumen size and vacuole formation using the rat-tail vibration model in male Sprague-Dawley rats (~300 g). Methods The different groups were: 4-hr continuous vibration at 30, 60, 120 and 800 Hz; continuous exposure durations of 5 min, 1 hr and 4 hr at 60 Hz; and 4-hr cumulative exposure of 60 Hz delivered intermittently in cycles of 10 min on and 5 min off. Acceleration was set at 49 m/s2 r.m.s. for all frequencies. Unanesthetized rats were restrained in cages on a nonvibrating platform with their tails placed on a vibrating stage driven by a B&K motor (4809). The sham control animals were also placed in the vibration apparatus but not vibrated. Room temperature was controlled at 25 ± 1°C. Ventral arteries from proximal tail segments 7 were immersion fixed in aldehydes, embedded in epon-araldite and sectioned (0.5 µm) for morphological analysis. Vascular lumen sizes were measured as the percent ratio of the lumen perimeter to internal elastic membrane length using Image J software (NIH). The number of vacuoles in the smooth muscle layer of each artery section was counted. Results Fig 1: Semithin sections of arteries. A. Sham control. B. 4-hr vibration 60 Hz. In vibrated arteries, the lumen decreases in size, and smooth muscle cells (SMC) exhibit vacuoles (arrow). Bar equals 40 µm for each panel. [ ]

Jan 6, 2006

By M. J. Jackson

MIGRATOM is a third-generation PC-based computer program developed by the U.S. Bureau of Mines for geophysical tomography. Like its predecessors, BOMTOM and BOMCRATR, MIGRA TOM was developed to enable users to address a variety of mining-related problems by mathematically reconstructing the distribution of physical properties in a rock mass, using measurements of travel time or amplitude of wave energy propagated through the rock mass. Examples of applications include lithologic characterization, fracture detection, fluid monitoring, stress evaluation, and blast assessment. The resolution and accuracy of tomographic reconstructions generally depend very strongly on the geometry of source and receiver locations. In many practical applications, such as cross-borehole tomography, limited coverage results in nonunique reconstructions. MIGRATOM follows the precedent of BOMTOM and BOMCRATR in allowing the user to constrain the inversion, in order to reduce the nonuniqueness problem. A new approach to application of constraints implemented in MIGRATOM is based on fuzzy logic techniques. Refraction of wave energy is modeled in MIGRATOM using an approach based on Huygens&apos; Principle. Propagation of a continuous wavefront is modeled as a constructive interference phenomenon, which obviates the shadow-zone problem that affects conventional ray-tracing calculations. MIGRATOM has been tested with both synthetic and field data sets.

Jan 1, 2010

By Charles Vaught, JON VOLKWEIN, ROBERT PETERS, ERICA HALL

Since 1999, the CWP level among miners with 25 years or more experience, for instance, has risen from slightly more than 4% to 9% (See Figure 1). While it is obviously necessary to protect all miners’ lungs, there is now a technology to improve the chances that new miners’ lungs will be protected from the day they begin work.

In 2005, a total of 263 metal mining operations reported employment to the Mine Safety and Health Administration (MSHA). Metal mines were the smallest mining commodity sector, comprising 1.8% of all mining operations. ? Gold mines comprised 46.0% (n=121) of all metal mining operations. Other common types of metal mines were iron ore (n=32; 12.2%), copper ore (n=31; 11.8%), and lead and/or zinc ore (n=16; 6.1%). ? Nevada had the largest number of metal mines (n=52; 19.8%), followed by Alaska (n=27; 10.3%).

Sep 1, 2008

By Charles L. Kimbell

In 1988, the aggregate value of total world international export trade in mineral commodities was estimated at nearly $542 billion in current (1988) dollars, which was about 8.6% above the 1987 level, but still 23.7% below the record high set in 1980. Comparable comprehensive data for 1989 were not available in time for inclusion in this chapter, but 1989 returns for developed market economy countries only were 1 1.8% above those for 1988. These countries accounted for about 50% of the total mineral commodity export trade in 1988. It would be unsound to utilize the overall 11.8% growth rate for mineral commodity export trade for these countries to extrapolate the growth in total world mineral commodity trade because these developed market economy countries account for substantially different shares of the five major mineral commodity groups listed in table 2. Specifically, developed market economy countries in 1988 accounted for 56% of world export of ore, concentrate, and scrap, 74.7% of world exports of iron and steel, 71.7% of world exports of nonferrous metals, and 57.8% of all exports of crude nonmetals, but only 26.6% of world exports of mineral fuels. Moreover, even within each of these groups, the actual product mix included in developed market economy country aggregates differ from that in developing market economy country aggregates and in centrally planned economy country aggregates. Nonetheless, an increase of 9% to 12% in the value of world mineral commodity export trade seems indicated by available returns.

Jan 1, 1992

By Earl F. Hastings

The Pilgrim mine, operated by the Pioneer Gold Mining Co., is 9-1/2 miles west of Chloride in the Pilgrim mining district on the eastern slope of the Black Mountains, or River Range, Mohave County, Ariz. In March 1937, 100 tons of gold ore per day were being mined and milled at the property by a total force of 5i men. Climatic conditions allow year-round operations. Due to present activity in the county there is an ample supply of labor for the requirements of the mine. The Pilgrim is the only producing property within s radius of 6 miles; recently, however, the South Pilgrim Mining Co. has launched a development campaign on claims that adjoin the Pioneer Co. property to the south.

Jan 1, 1937

By F. W. Smith

To determine whether preheating coals before carbonization would improve the coking properties of the coals, particularly the weaker coking coals, 3 coals, 1 each from Illinois, Kentucky, and Pennsylvania, and a blend of the Illinois with a Pocahontas coal were preheated before testing for coking properties in the Bureau&apos;s BM-AGA pilot oven. The effects of preheating on the chemical and physical proper-ties of the coals and on the yields of carbonization products and strength of the coke produced from the preheated coals were determined, as were also the effects of bulk density, gaseous atmosphere, and residence time during preheating. Most benefit from preheating was found with weaker or oxidized coking coals, whereas the more strongly coking coals and blends showed little effect. Direct charging of preheated coal to the coke oven without cooling gave better coke, increased yield of tar, and decreased yield of gas. INTRODUCTION Although 94 percent of today&apos;s coal production comes from fields east of the Mississippi, the Eastern States have only about one-third of the Nation&apos;s recoverable reserves. West Virginia, which now produces more than any other State, has much smaller reserves than Utah, Colorado, and Wyoming.5/ However, the manufacture of iron and steel in Western States, which has increased greatly since World War I, is handicapped by the scarcity of high-grade coking coals, such as are plentiful in the Appalachian region. Unless a practical method of improving the cokemaking property of local coals is developed, ferrous metallurgical industries in the West must continue to use inferior coking coals and to pay high shipping charges for better coals.

Jan 1, 1958

By James R. Boyle

The value of Alabama&apos;s nonfuel mineral production in 1983 was $361.3 million, an increase of $61.9 million over that of 1982. The increase reversed a downward trend that started in 1980 and established a new record high for value of nonfuel minerals in the State. Output of most nonfuel minerals increased to some degree with unit value increases creating the record-high value year. Cement, clays, lime, sand and gravel, and crushed stone were the major commodities produced in Alabama. Alabama led the Nation in the production of crushed marble; was second in bauxite; fourth in ferroalloys, dimension marble, common clay, and fire clay; fifth in bentonite and kaolin; and sixth in masonry cement and lime.

Jan 1, 1985

By Frank E. Cash

Published or available data on safety in quarries are few except those pertaining to blasting issued by manufacturers of explosives. During the past 25 years the quarrying industry (including various types of quarries producing many different materials) has had a markedly improved accident experience. The downward trend has not been phenomenal or has it been uniform from year to year, owing to occasional major disasters; but from the information at hand it appears that improvement during the 25-year period has been definite.

Jan 1, 1941

By Dennis J. Grigal

The objective of this contract was to monitor operating conditions of, four flooded, fibrous-bed filter panels used during normal underground mining operation and to analyse clogging and structural problems. After observing structural and clogging problems and conducting laboratory and field tests, a final, Flooded, fibrous-bed filter design which minimizes clogging and structural problems was recommended to the Bureau of Mines. This report also describes the dust sampling procedures used to determine the dust concentration at the flooded, fibrous-bed scrubber intake duct.

Jan 1, 1979