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By M. N. Rubin

This report summarizes the work performed under USBM contract J0100018. The purpose of this work was to document the currently available noise control techniques that can be incorporated into new coal preparation plants during the design stage. This was accomplished by reviewing the related experience of the contractor and subcontractor (Bolt Beranek and Newman Inc.), conducting an extensive literature search, visiting operating coal preparation plants, and contacting various equipment manufacturers. The treatments addressed include equipment substitution, changes in plant layout, and retrofit treatments for existing equipment.

Jan 1, 1982

By Jueun Lee, Jong-Hwa Yoon, K. Rider, Bernard J. Martin

Whole body vibration is known to affect movement accuracy [1], however little is known about changes in the organization of movement and movement strategies used to limit the influences of perturbations. The specific aim of this work is to analyze the motion and coordination of upper body segments of seated operators performing reaching tasks under whole-body sinusoidal vibration exposure and simulated vehicle ride motion. The long-term objective is to model reach coordination and predict the dynamic behavior of the upper body motion under vehicle vibration exposure. Method The reach task consisted of pointing with the right hand index finger to targets located on touch screens placed in front of the subject, 45° overhead and 90° to the right in the mockup cabin of an HMMWV placed on a 6 DOF ride motion simulator. The task was performed under stable (no vibration) and vibration (sinusoidal vibration or simulated ride motion) conditions. A motion capture system was used to record kinematic data of reflective markers to recreate body link trajectories. Joint angles (torso, shoulder and elbow; Figure 1) were then computed using quaternions. Coordination between body links was defined as a) the joints angle-versus-angle relationships between the upper arm and lower arm, and b) the joint motion onset relationships between torso, upper arm and lower arm in the time domain. Results Angle–versus-angle relationships. The relationship between upper arm vs. lower arm angle and torso vs. upper arm angle for a far forward reaching movement in the stable (solid lines) and vibration conditions (dotted lines) are illustrated in Figure 2. Fig 2A compares the control condition with a 4 Hz lateral vibration while Fig 2B compares the control condition with a 6 Hz vertical vibration. It appears that under vibration exposure the reduced upper arm extension is compensated by an increase in torso flexion. This effect is seen in the last phase of the movements (encircled areas). In addition, the lower arm extension is delayed under 6 Hz vertical vibration (Fig 2B left panel). Time of joint motion onset. The timing relationship between torso, upper arm and lower arm is largely a function of the target to be reached. Examples of delays between body links are illustrated in Figure 3. The control condition is compared to a 6 Hz vertical vibration for three

Jan 6, 2006

By W. P. Diamond

The direct method test was developed for general mine safety applications by the U.S. Bureau of Mines in the early 1970's to measure the gas content of coal samples obtained from the relatively shallow depths of eastern U.S. coal mines. Over time, applications for gas content data evolved which required increasingly accurate desorption values. It became evident that some of the inherent weaknesses in the original direct method test could best be addressed by abandoning the water displacement based desorbed gas volume measurements. The ideal gas law based modified direct method (MDM) and associated desorbed gas volume measurement apparatus was developed to provide the most accurate desorption values possible for rock samples obtained from any gas-bearing strata. The MDM has a number of significant advantages, including: (1) increased accuracy, especially for low gas content samples, (2) a test apparatus with an integral sampling port to facilitate the collection of uncontaminated gas samples, (3) an inherent head space effect correction in the periodic MDM desorbed gas volume calculations, (4) measurement of positive and negative desorbed gas volumes, (5) elimination of differential gas solubility effects as a source of error inherent in the water displacement methods, and (6) a compact and rugged test apparatus that along with the elimination of the ?glassware? required for the water displacement methods, facilitates its use in the field.

Jan 1, 2008

By Steven J. Page

Researchers have developed a model to describe airborne respirable dust (ARD) generation on surface coal mine drills. By measuring a few basic parameters and using a graph, a drill operator or engi­neer can estimate the relative severity of drill dust emissions as well as how much of a reduction in ARD can be obtained by changing any given parameter. Geometric parameters include: drill deck cross-sectional area, shroud leakage associated with the deck shroud as well as the operational parameters of bailing air­flow, and dust collector airflow. The rela­tionships yield predictive ARD values which fall in the range measured on oper­ating drills for collector/bailing air flow ratios greater than 2. Overexposure to airborne respirable crystalline silica dust can cause serious or fatal respiratory disease. Exposures of sur­face coal mine rock drillers to respirable crystalline silica are of particular concern. In a 1992 alert on silicosis in rock drillers, the National Institute for Occupational Safety and Health (NIOSH) reported on 23 cases of advanced silicosis (acute, acceler­ated, and chronic) ranging in ages from 25 to 60 with drilling tenures ranging between three and 20 years.1 Most of the cases involved drill operators in their 30?s and 40?s, indicating high silica exposure levels are associated with their occupation. A more recent lung x-ray surveillance study of a 664 volunteer population of surface coal miners showed that the prevalence of silicosis-like abnormalities was 9%.2 The two most significant factors associated with these abnormalities were increasing age and years of drilling experience.

Jan 1, 2008

By Gary L. Hundley

The Bureau of Mines has devised and demonstrated an ammoniacal sulfate leach process for recovering nickel and cobalt from low-grade domestic laterites. Solvent extraction of cobalt, one of the process steps, requires the reduction of hexammine complexes of C03+ to C02+ in an ammo-niacal leach solution. Previously, reduction was accomplished using cobalt metal shot in a column. This report presents experimental results and an economic evaluation comparing two alternate techniques with the shot column: (1) an electrolytic reduction cell with an extended surface area cathode and (2) direct electrowinning from purified leach solution using a cell with a fluid bed cathode. The second alternative eliminates the conventional solvent extraction-electrowinning steps. The costs of the three methods, based on the requirements of a pro-posed commercial-sized plant, including all unit operations, were deter-mined by the Bureau's process evaluation group. The operating costs for the shot column, $1.19/kg Co, and for electrolytic reduction, $1.20/kg, are essentially the same, but the cost of direct electrowinning, $3.77/ kg Co, would eliminate this method as a practical alternative. The cap-ital cost of approximately $14.4 million for reduction in a shot column is much higher than the approximately $4.4 million for electroreduction.

Jan 1, 1985

By L. M. Demers, D. C. Kuhn, N. El-Ayouby, C. F. Stanley

"Oxygenated metabolites of arachidonic acid (MJ are produced by the alveolar macrophage (AM) and have been shown to mediate inflammatory reactions. We therefore assessed the production of eicosanoids by AM harvested from the lungs of rats ex· posed to a bituminous coal dust for 2 wk in an inhalation chamber in order to determine if AA metabolism was altered in a manner that may promote an inflammatory response in the lung. Exposure to coal dust resulted in a 66% increase in the number of AM harvested, an increase in thromboxane A2 (TxA;i) and leukotriene 84 (LTB,j) production to 222% and 181% of control values, respectively, and a decrease in prostaglandin E2 (PGE:i) production to '62% of control values. In AM harvested from rats allowed to breath clean air for 2 wk following coal dust exposure, PGE2 production returned to control levels but TxA2 and LTB4 production remained elevated. The TxA2 synthesis inhibitor UK 38,485 reduced TxA2 production in dust-exposed AM both immediately and 2 wk following exposure. Thus, exposure of rats to coal dust significantly alters the metabolism of AA in AM, with potentially important aspects of AA metabolism remaining altered even after a 2-wk recovery period. Based on the established role of eicosanoids in inflammatory and fibrotic processes, these results suggest that the alteration of AM eicosanoid production as a result of the inhalation of coal mine dust may be an important factor in the pathophysiology of coal workers' pneumoconiosis.The authors are grateful to Joan Greenwood and Barbara Scheetz for their excellent technical assistance and to Brenda Pavone for the preparation of the manuscript. This research was supported by the U.S. Department of The Interior's Mineral Institute Program administered through the Generic Mineral Technology Center for Respirable Dust under grant 1135142.Request for reprints should be sent to Douglas C. Kuhn, Ph.D., Department of Pathology, The M.S. Hershey Medical Center, Hershey, PA 17033.INTRODUCTIONPulmonary alveolar macrophages (AM) are activated by foreign particles and microorganisms that enter the small airways (Kass et al., 1966; Herscowitz, 1985). This defensive reaction involves phagocytosis, lysosomal enzyme release, and the generation of reactive oxygen species by the AM (Snella, 1986; Rich et al., 1987). A number of agents, including phorbol esters, zymosan, adenosine diphosphate, organic hydroperoxides, and calcium ionophore, have been shown to activate the AM in vitro (Badger, 1986; Marshall and Lands, 1986; Snella, 1986). The AM response to these activators appears to be mediated in part by the oxygenated metabolites of arachidonic acid (AA) (Bertram et al., 1988; Demers et al., 1987; Mcleish et al., 1987).The AM may metabolize AA through cyclooxygenase- and lipoxygenase- catalyzed pathways to produce a variety of eicosanoids including prostaglandin (PG) E2, thromboxane (Tx) A2, leukotriene (LT) B4, LTC4, LTD4, and several hydroxyeicosatetraenoic acid derivatives (HETEs) (Willis, 1970; Camp et al., 1983; Poubelle et al., 1986). The production of these eicosanoids may enhance the. defensive ability of the challenged lung since they stimulate chemotactic cell recruitment to the site of invasion, enhance extravasation of circulating immune cells, and promote local vasodilatation. However, continued stimulation of the AM population, with the consequent production of proinflammatory eicosanoids, may ultimately enhance the disease process by contributing to chronic bronchoconstriction, fibrosis, and the persistent release of toxic oxygen species."

Jan 1, 1990

By Leon E. Esparza

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 16,927-acre Pryor Mountain Wilderness Study Area (MT-067-206), part of the 3,955-acre Burnt Timber Canyon Wilderness Study Area (MT-067-205), and part of the 4,550-acre Big Horn Tack-On Wilderness Study Area (MT-067-207) to evaluate their identified mineral resources. The Burnt Timber and Big Horn Tack-On study areas contain 3,430 and 2,550 acres, respectively. The three areas are in Carbon County, MT, and Big Horn County, WY, about 13 miles north of Lovell, WY. No identified resources exist in any of the study areas. Bureau of Mines personnel reviewed literature, searched county mining records and examined prospects, claims, and mineralized areas to determine whether identified mineral resources existed. The three study areas are within the Pryor Mountain unorganized mining district. U.S. Department of Energy production records indicate there were 223,000 pounds of uranium oxide (U308) and 236,000 pounds of vanadium pentoxide (V205) produced from 19 properties within the mining district. The average ore grade was 0.36 percent [3,600 ppm (parts per million)] U308 and 0.416 percent (4,160 ppm) V20S. Only the Pryor Mountain study area has current claims, the 50 claims of the S0S group.

Jan 1, 1986

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 C. Lorimer Colburn

"The diverting of men from industry to combat in the world's war focused the attention of the operators in this country upon mechanical means of doing things. The demand for man-power -was so insistent that every available agency for multiplying it had to be employed. It was during the 1period of the war and immediately thereafter that development of the use of underground loading devices made most rapi4 progress. In all parts of the United States, mining engineers and mine managers were diligent in their efforts to develop mechanical loaders. The mining engineers of the U. S. Bureau of Mines in every section of the country have secured, with the cooperation of the mine operators, data on the actual performance of the mechanical shovels in their districts, and have made them available to the author of this paper.No effort has been made to discuss exhaustively the subject of underground loading devices. It has been the object to collect together in one paper, records of the performance of all machines now in actual use. Improvements in the design of machines are constantly being made the performance records given in this paper relate to operation prior to March 1 1 1921. The records prior to 1920 cay not fully represent the work that could be accomplished with the present models of the same machine.The data secured are given exactly as reported by the mine operators. Since this data were collected there have been two underground loaders, of a different design, put into operation in the iron mines of the Lake Superior District. One is the John Mayne Sub-level loader, being tried by the Cleveland-Cliffs Iron Co., Ishpeming, Mich., and the other is the Cole-Goudie shovel, being tried by the Oliver Mining Company, at Ironwood, Mich. No information has been secured regarding the performance of either of these machines."

Oct 1, 1921

The combined production value of natural abrasives, which consist of tripoli, special silica stone, garnet, and emery, decreased in 1985. Shipments of processed tripoli increased slightly in quantity but decreased 6% in value, Production of garnet, an abundant iron-aluminum silicate, increased 24% in quantity and 20% in value. There was an 11% increase in the quantity and a 7% increase in the value of refined garnet shipped when compared with 1984 shipments, a new record high. Production of crude special silica stone decreased 10% in quantity and 14% in value, and shipments of finished special silica stone products decreased 85% in quantity and 68% in value. Both the quantity and value of special silica stone finished products sold or used were the lowest since 1981. Production of emery, an impure aluminum oxide, decreased 56% in quantity and 61 % in value of product mined and shipped. [ ]

Jan 1, 1987

By Olman Hee

This study investigates the identity and relative importance of factors affecting the future demand for phosphate rock, potash, and nitrogen. The main objective is to analyze demand relationships for these chemical raw materials for some specified past period, and to utilize this information to make projections of consumption into some designated future period. The end-use approach is used, which divides total consumption of each chemical raw material into agricultural, industrial, and export use. Multiple regression analysis is employed to statistically measure the relative effects of the different factors on consumption in each end use. The general method centers on the construction of a consumer demand model, the fitting of the respective equations in the model, and the interpretation of the statistical results. Direct and cross price elasticities of demand are computed for each end use of the chemical raw materials. These give an insight into expected changes in consumption with respect to given changes in price. The results of this study indicate that price, consumer income, and level of technology are factors which measurably affect consumption of chemical raw materials. For phosphate rock and potash, the agricultural and industrial end uses showed an inelastic demand, whereas for nitrogen, all end uses (including export use) exhibited an elastic demand. Among the chemical raw materials, average annual growth of consumption of nitrogen for agricultural and export uses to 1980 is expected to be notably higher than that for phosphate rock and potash.

Jan 1, 1969

By Oliver Bowles

"The town of Monson in Piscutaquis County, Maine is the, center of an important site industry. Monson slate has a nation-wide reputation, particularly for electrical switch boards, and the deposits have been worked for the manufacture of such products for many years. Open-pit quarrying is the method most commonly employed in obtaining slate. Underground methods have been used in the Peaon Bottom district near Delta, Pennsylvania, but the quarries that were thus operated are now abandoned. Underground methods have been used more extensively in foreign countries, the most famous example being the slate mines at Angers in France, where an over-head stoping method has been employed successfully for many it is only under special conditions that underground methods can be successfully used. If the deposit is wide and relatively thin, or if the material is too unsound to constitute a safe roof, open-pit methods must be used, for slate is too low-priced a commodity to justify the heavy expense of any timbering methods. It is only where the deposit is relatively narrow, of great depth, and sufficiently sound to afford a strong roof that ordinary mining may be employed.The best slate beds in two of the three quarries operated at Monson are no worked by underground methods. The chief bed worked by the Portland Monson Slate Co. is 10 feet thick, stands vertical and strikes N. 63º F. The slaty cleavage is vertical and crosses the strike of the beds at an angle of 5 to 10°. The grain or second direction of splitting is vertical and perpendicular to the cleavage. In addition to the 10-foot bed, to 2-foot beds and one 5-foot bed are available but are not now utilized. In the Monson Maine Slate Co. quarry (the old Pond quarry),a greater number of beds available, but at present quarrying is confined to a single bed about 9 feet thick which dips 30º S.E. and strikes N. 47ºF. The slaty cleavage is vertical and strides N. 45º F., while the grain strikes N. 45-50º W. and is also vertical."

Nov 1, 1920

By Richard F. Link, George S. Koch

Through the use of statistical methods, estimates of metal content and tonnage of an ore body made by using data from 18 diamond-drill holes are compared with actual values established with data from 1,829 drift samples. The reliability of the estimates made from the drill holes is assessed in several ways. The relationship of metal content (assay-width product) to grade is explained. It is concluded that useful estimates can be made from 18 drill holes provided that reasonable assumptions are made and certain risks accepted. The ore body investigated is the Don Tomas vein of the Frisco mine, San Francisco del Oro, Chihuahua, Mexico.

Jan 1, 1964

By Forrest T. Moyer

The safety record of the coal-mining industry, both anthracite and bituminous, in 1966 was improved over that of 1965 in all general measures of injury experience. The improvement was more pronounced in the anthracite industry. The total of 10,679 disabling work injuries comprised 233 fatal and 10,466 nonfatal injuries, 26 and 692 fewer, respectively, than in 1965. The number of fatalities in 1966 was the lowest annual total since complete records were started in 1910. Similarly, the number of nonfatal injuries in 1966 was lower than in any year since 1930 when such data were first collected.

Jan 1, 1969

By M. R. Yenchek

The U.S. Bureau of Mines designed and constructed sensitive and coordination-free ground-fault relays (GFR's) for use on mine power systems. First, a list of GFR attributes for mine ac utilization applications was compiled. These practical guidelines specified design, construction, transient immunity, reliability, and operating criteria. The time-current characteristics of the ac and dc units, subsequently fabricated, were designed to be below the human electrocution threshold. The significant and highly variable capacitance of high-voltage distribution cables was found to preclude the sensing of ground currents in the milliampere range. However, the coordination-free system developed for high-voltage distribution should enhance safety by significantly decreasing response time to ground faults. Implementation of the sensitive GFR technology in the mining industry has the potential to eliminate the majority of injuries and nearly all the deaths resulting from contact with energized components.

Jan 1, 1990

By D. E. Welcome, T. W. McDowell, R. G. Dong, S. F. Wiker

Workers using vibrating hand tools have the potential for developing health problems associated with repeated forceful actions and exposures to hand-transmitted vibration. Hand-arm vibration syndrome (HAVS) and other hand-arm system disorders have been associated with such exposures.1-2 To better assess health risks, comprehensive evaluations of these exposures must include quantitative assessments of hand-tool coupling forces; unfortunately, no standardized method for quantifying hand forces exists. Handle instrumentation may be ill-suited for some field environments. Psychophysical force-recall techniques may provide alternatives to handle instrumentation. A thorough understanding of the effects of vibration and other factors on force-recall accuracy and reliability is important before such methods are applied in risk assessments. Methods In this study, the effects of vibration and other factors on the accuracy of psychophysical force-recall were explored in two experiments. Twelve male subjects participated in the first experiment. The second experiment employed 20 participants (10 female, 10 male). In each experiment, participants applied specific grip and push forces to an instrumented handle mounted on a shaker system. Participants were exposed to sinusoidal vibration at frequencies that ranged from 0 Hz to 250 Hz. Three levels of applied force (low: grip = 15 N/push = 25 N, medium: grip = 30 N/push = 50 N, and high: grip = 45 N/push = 75 N ) and two levels of vibration magnitude (low: ANSI 4-8-hr limit and high: ANSI <0.5-hr limit)3 were examined. During the vibration exposure period, participants were provided with visual feedback while they attempted to “memorize” the applied grip and push forces. At the conclusion of the vibration exposure/force memorization period and a controlled rest period, the participants tried to duplicate the grip and push forces on a non-vibrating handle without the aid of visual feedback. The effects of different vibration frequencies, vibration magnitudes, and grip and push force levels were tested in a random order from trial to trial. Results Participants tended to overestimate grip and push forces. Depending on exposure conditions, error means ranged from 2 N to 10 N. The ANOVA revealed that force-recall errors for exposures between 31.5 Hz and 63 Hz were significantly higher than those at other vibration frequencies (p < 0.05). The frequency effect is depicted in Figure 1. Error means were greater when participants were exposed to the higher vibration magnitude (mean = 9.1 N, 95% CI = 8.2-10.1 N) when compared with the lower vibration magnitude (mean = 4.9 N, 95% CI = 3.9-5.8 N) (p < 0.05). The effect of vibration magnitude is shown in Figure 2. The average error for

Jan 6, 2006

The Bibliographic Data Base contained in the present volume is the result of a literature search conducted as one task of the Bureau of Mines project concerned with research in borehole assay technology. The data base includes articles, symposia, books, corporate and government reports, patents, and other literature concerned with some aspect of borehole logging, from January 1969 through December 1975. Occasional updating to keep the data base current is anticipated. The remainder of the intro¬duction will be devoted to the explanation of the organization of each entry, along with the translation of terms and abbreviations used in the text. Each entry contains six sections. These include an ID code, a title, an author section, a source section, an abstract, and a descriptor section. The first item listed in an entry is the ID code. This serves to identify an entry. It consists of the first six characters of the first author&apos;s (or editor if no authors are involved) last name, along with the last two digits of the year of publication. A letter sometimes follows the year of publication to assure a unique alphanumeric code. For example, if an author named Wilson writes more than one piece of literature in a given year (for example, 1972), the ID code for the entries identifying these pieces of literature would be identical. Therefore, to allow for unique ID codes, the first piece would he identified as "WILSON 72,&apos;, the second piece as "WILSON 72A", the third "WILSON 72B", and so on.

Jan 1, 1976

By Jon C. Volkwein

In This Chapter [Instruments for measuring dust How to calculate the amount of dust from a source How to get a valid concentration measurement Sampling to assess control technology effectiveness] When there is more than one source of dust, sampling may be required to find which dust sources are most significant. Then, efforts to reduce dust can be concentrated where they will have the most impact. This chapter explains how to perform dust source sampling. It describes two kinds of instruments that are available and discusses their limitations. It explains how environmental variables such as concentration gradients, dust dilution, and production changes can impact dust measurements. It also suggests practical ways to improve the validity of dust source measurements under adverse conditions, such as high-velocity airflow or the presence of water mist in the air. [Dust source sampling at coal mine longwalls and at tunnels is more complicated. Chapters 3 and 7 have more information on sampling in those circumstances.] TWO KINDS OF INSTRUMENTS FOR MEASURING DUST Gravimetric samplers. The conventional gravimetric sampler is a good device for measuring dust because it is the instrument used for compliance measurements. This dust sampler consists of an air pump, a small cyclone that separates out the respirable size fraction of the dust cloud, and a filter to collect the respirable dust. In coal mines, the Mine Safety and Health Administration (MSHA)-approved gravimetric sampler uses a 10-mm Dorr-Oliver cyclone operating at an airflow of 2.0 L/min [30 CFR78 74 (2002)]. A correction factor of 1.38 is applied to make the results consistent with the U.K. MRE sampler, the instrument on which the 2.0 mg/m3 coal dust standard is based.

Jan 6, 2003

By B. M. O'Harra

The residues resulting from the retort distillation of zinc ores have from 40 to 75 per cent of the weight of the original ore and contain from 5 to 15 per cent zinc . A rough estimate indicates that approximately 450,000 tons of residues are produced annually in the United States , containing about 36,000 tons of zinc . Besides the current production of residues there are at many smelter sites large accumulations from past operations which are available for treatment if this can be done profitably . In addition to their zinc content the residues contain much unconsumed coal , which has been carbonized during the distillation process , and those from most western ores also contain lead and silver . In this paper is summarized the information obtained in a survey , recently made by the Bureau of Mines , in cooperation with the Missouri School of Mines and Metallurgy , of processes which are in use or which have been suggested for the treatment of retort residues . The complete report of the survey is to be published as a Technical Paper of the Bureau of Mines .

Apr 1, 1923

By Donald O. Capstick

A mineral resource evaluation of the Coyote-Southeast RARE II area (No. 5033) was performed jointly by the U.S. Bureau of Mines and the U.S. Geological Survey in 1981 for the U.S. Forest Service RARE II program. Bureau of Mines personnel conducted a mineral resource inventory of the study area&apos;s mines, prospects, claims, and mineralized outcrops. The study area&apos;s boundaries encompass 51,700 acres on the east flank of the Sierra Nevada and are within Inyo National Forest southeast of the city of Bishop in east-central California. Cretaceous granite underlies most of the area; the remainder of the rocks are metasedimentary. At the contact of the two, tactites formed at many places where carbonate rocks were present; replacement processes produced local scheelite (calcium tungstate) occurrences.

Jan 1, 1983