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By L. M. Demers, D. C. Kuhn

The alveolar macrophage (AM) responds to stimuli such as coal mine dust by releasing inflammatory mediators such as cytokines, growth factors. reactive oxygen species. and eicosanoids. Eicosanoids are synthesized by°AM through the action of cyclooxygenase and lipoxygenase enzymes and serve to modulate the proinflammatory function of this cell as part of the lungs' host defense mechanism. Reactive oxygen species can be generated by AM as a by-product in the biosynthetic pathway of the prostaglandins. AM produces primarily prostaglandin E2, thromboxane A2, and leukotriene B4 as part of the cellular response to an inflammatory stimulus. There is evidence to suggest that eicosanoid production by AM is functionally linked to both surface interaction with mine dust particles like silica and by the phagocytosis of the dust particle itself. In this report, we examined the effects of an antioxidant, vitamin E. on dust-induced synthesis of PGE2 and TXB2 in vitro and in vivo by AM obtained by bronchoalveolar lavage from rats. We also looked at the effects of the surface of silica particles on AM eicosanoid biosynthesis under conditions of calcination, a process that removes exposed hydroxyl groups from the surface of silica particles, thus reducing the likelihood of soluble hydroxyl radical formation. Treatment of AM with vitamin E in vivo and in vitro reduced the augmentation in eicosanoid production usually observed when AM are exposed to mine dusts. These results suggest that vitamin E may effectively reduce the inflammatory and fibrotic response produced by inhalation of mineral dust through an antioxidant mechanism. Silica that has been chemically altered by calcination was unable to activate AM eicosanoid production in vitro when compared to untreated, freshly fractured silica. These findings suggest that the mechanism by which dust particles can activate AM eicosanoid release may involve interaction of surface and/or soluble factors with the cell membrane. Taken together, these studies point to the involvement of AM eicosanoid production as part of the proinflammatory response of this cell to occupational inhalation of mineral dust. - Environ Health Perspect 102(Suppl 10):97-100 (1994)

Dec 1, 1995

By C. L. Brown

Coal has been transported by belt conveyors in mines for many years; however, only since the beginning of the general mechanization period have complete transportation system of this type been employed. Aside from my complete belt-conveyor transportation systems, belt conveyors are frequently used in conjunction with other transportation. Many early installations, for the most part, were made without standards as a guide. As a result, some States have outlined certain requirements based more or less on experience following mine fires. Correlation of these regulations should result in more uniformity in connection with standardization of regulations. The National Electrical manufacturers Association has published standards for mining-belt-conveyor installations2/ that should be helpful to the coal-mining industry generally. Bureau of Mines Schedule 2F3/ requires certain controls for permissible-belt- conveyor drives, and similar requirements are listed in Bureau of Mines bulletin 514.4/ Committees of the American Mining Congress have prepared much valuable information concerning operation of belt conveyors, and a subcommittee on fire-resistant belting has been active. 5/

Jan 1, 1956

By N. A. C. Smith

During the past, six, years, the Bureau of Mines has made and. published several hundred analyses of typical crude oils and 'has developed a system of interpreting the analyses and of classifying crudes. This system is presented here with. It is apparently equate for classifying crude oils into four main groups and has also been found very convenient in studying the geological relationships between crude oils, and the probable refinery yields of valuable products from them. Crude petroleum is morn to be a very complex substance. An analytical statement of its properties must, therefore, consist of two distinct parts, - first, the report of the results of the determinations made by the analyst in the laboratory, - second, the proper arrangement, classification and interpretation of these results so that the analysis, as a mole, will indicate the meaning- and the relative- importance of the essential characteristics of the oil.

Jan 1, 1927

By M. J. Beus, M. K. Larson, J. K. Whyatt

U.S. Bureau of Mines researchers reviewed an in situ stress estimate developed from measurements of overcore strain taken at test sites on the 7300 and 7500 levels of the Star Mine near Mullan, ID. Although the field measurements of overcoring strain were found to be useful, significant deficiencies were found in the stress estimation procedure. A new stress estimate was developed incorporating statistical methods and an improved understanding of stress concentration factors for interpreting overcore strains recorded by doorstopper cells. Spatial variability of overcore strains and the implications for stress field variability were explored.

Jan 1, 1995

By G. Dale Cor, Will H. Coghill, M. F. Williams, I. L. Feld

"INTRODUCTION During the past several years the Southern Experiment Station of the Bureau of Mines, with the cooperation of the University of Alabama, has given attention to hydraulic classification. One of the things this work has revealed is a variability not generally recognized in the conditions of teeter at different depths. This report depicts the passage of material through a teeter column and its emergence as a classified product.The work was made possible through the development of a classifier for several hundred pounds per hour permitting a small quantity of coarse spigot material to be discharged without the usual interruptions caused by stop-pages. Previous designs of small classifiers have been unsatisfactory because the,orifice used to control the quantity of spigot product as subjectto stoppages, particularly when attempting to discharge a small quantity of although the classifier used in this work has been described in detail in a previous publication 6/ its principal features will be discussed briefly herein. The main subject matter of the paper is based upon the three figures that illustrate in panorama the conditions that exist in a classifier during the continuous classification of bituminous coal, anthracite coal, and an iron ore trailing."

Jan 1, 1946

By R. W. Watson

This Bureau of Mines report summarizes some recent results on the sensitivity of various experimental explosive systems using ammonium nitrate (AN) as the oxidizing agent. The sensitivity survey included drop-weight and friction testing and sensitivity to initiation by projectile impact and a No.8 blasting cap. It was found that certain types of AN prills can result in cap-sensitive mixtures when combined with No.2 diesel fuel (Fa); prilled AN mixed with nitromethane also result in cap-sensitive mixtures. Mixtures of AN prills and neat 1-and 2-nitropropane were not cap-sensitive, and the use of powdered or grained aluminum in AN-FO did not adversely affect the sensitivity except possibly to increase its sensitivity to friction.

Jan 1, 1974

By G. W. Grove, G. L. FreAS

One of the chief hazards in mining bituminous coal is the accumulation of coal dust in the mines . When coal dust is thrown into suspension , it can be ignited and exploded by electricity through short -circuiting of mining machinery and trolley wires , or by arcs and sparks . The Bureau of Mines has endeavored to assist the coal -mining industry in preventing disasters from this cause by urging that all bituminous -coal mines be rock -dusted . As it has been difficult to convince some mining men of the danger of ignition of coal dust and of the effectiveness of rock dusting in preventing widespread explosions , a small , portable , coal -dust - explosion gallery has been designed to demonstrate the explosibility of bituminouscoal dust . Such galleries are furnished to Bureau engineers , inspectors , and safety instructors to illustrate visually and impressively the Bureau's accident -prevention educational work on the causes and prevention of dust explosions in bituminous -coal mines .

Jun 1, 1949

By Raymond F. Farrell

A goal of the U.S. Department of the Interior, Bureau of Mines, is the advancement of minerals technology through the development of improved metals and minerals processing. In support of this goal, the Albany Metallurgy Research Center has developed atomic absorption spectrographic methods for the rapid analysis of A1203, CaO, Fe203, MgO, MnO, and Si02 in steelmaking slags. The application of these methods is discussed using an inexpensive pressure dissolution system. The overall coefficient of variation is 5 pct. The accuracy is the same as the reproducibility.

Jan 1, 1979

By Murray Jacobson

The Federal Coal Mine Health and Safety Act of 1969 established mandatory dust sampling of coal mines according to procedures prescribed in the Mandatory Health Standards, title 30, Code of Federal Regulations, part 70, published in the Federal Register on April 3, 1970. A laboratory was established in the Pittsburgh Field Health Group of the Bureau of Mines to process the coal mine dust samples collected by the mine operators. This paper describes the laboratory and presents the equipment and procedures used in processing these samples.

Jan 1, 1971

By Eric E. Cather

A mineral investigation by the U.S. Bureau of Mines revealed no mines or prospects and no past or present mining claims in the Agua Tibia Wilderness Study Area (WSA). The area is underlain mainly by weakly foliated gabbro similar to rock that has hosted gem- and lithium-bearing pegmatites in the Pala district about 6 mi to the south. However, no gem- or lithium-bearing pegmatites have been discovered in the WSA. Nearby quarries in the gabbro have yielded rock for facing and dimension stone. No sand, gravel, or energy (oil, gas, coal, or geothermal) resources were identified.

Jan 1, 1984

By B. D. Hanson

The U.S. Bureau of Mines has developed an interactive computer program which enables the user to identify the effect of cutting system changes on relative dust generation and forces for continuous miner drums. The program simultaneously evaluates machine and coal seam parameters, and those parameters which the user can control. One or more of these parameters may be changed to determine their individual or collective effect on relative dust generation and cutting forces. The program is written in the BASIC programming language. A complete program listing is included along with user instructions and sample outputs.

Jan 1, 1989

By Eric Cather

A mineral investigation of prospects in the Sawtooth Mountains B Wilderness Study Area (WSA) by the U. S. Bureau of Mines in 1983 revealed none had mineral production, resources, or development potential. The area is underlain by tonalite and smaller amounts of schist, One developed prospect and one prospect pit are in the WSA. They are in schist similar to host rock which has yielded gold in nearby mining districts, Sand and gravel deposits in the WSA are large but too far from markets to be considered resources. No energy (oil, gas, coal, or geothemal) resources were identified in the USA.

Jan 1, 1984

By W. C. McBee

Over the past several years the Bureau of Mines has developed a sulfur concrete (SC) technology in which chemically modified sulfur is mixed with suitable mineral aggregates to produce construction materials that are resistant to corrosion by acids and salts. Modified SC materials have been tested in actual operating conditions in 50 corrosive process environments at 40 commercial plants. SC components ranging from small test coupons to 4-ton acid sump tanks were fabricated and installed at plant locations where chemical corrosion was destroying conventional concrete materials. Through cooperative agreements with several companies, floors, retaining walls, and foundations were cast in place us-ing SC materials, then monitored for resistance to corrosion and retention of strength properties.

Jan 1, 1983

By R. V. Mrazek

The heat of formation of vanadium trichloride was determined at 298.15° K. Measurements were made in a solution calorimeter in which an aqueous hydrochloric acid-potassium dichromate solvent was employed. Data are presented for the heats of solution of vanadium trichloride and the vanadium trioxide "backup" compound, and for appropriate dilution reactions needed to preserve stoichiometry. The resulting heat of formation of vanadium trichioride (VCI3) at 298.15° K was found to be ?H°298.15° K = -138.89 ±0.37 kcal/g mole.

Jan 1, 1968

The title of this book, The Phoenix of Natural Disasters: Community Resilience is aptly chosen. ?The Phoenix is a mythical bird that never dies; the phoenix flies far ahead to the front, always scanning the landscape and distant space. It represents our capacity for vision, for collecting sensory information about our environment and the events unfolding within it.? (source: The Feng Shui Handbook, feng shui Master Lam Kam Chuen.) There are Chinese, Japanese, Russian, Egyptian, and Native American counterparts of the phoenix. All of these birds are identified with the sun and depicted as rising from the ashes ? living again. This is the essence of a community after a natural disaster ? they live again. The Phoenix of Natural Disasters: Community Resilience is edited by Kathryn Gow and Douglas Paton who have done an excellent job of creating a relatively seamless transition between chapters with different authors. The content is organized well with the first chapter providing an excellent overview of what is to come and each chapter including an abstract clarifying the focus of the chapter.

Jan 1, 2009

By Fred N. Kissell, Jay F. Colinet

The two major lung diseases of miners are "blacklung" and silicosis. Blacklung, or pneumoconiosis, was first recognized as a disease of British coal miners in the 1600s. However, investigations into the cause of blacklung disease did not begin until the 1900s. The causative agent of pneumoconiosis in coal miners was thought to be silica until studies in the United Kingdom provided evidence that expo- sure to coal dust containing minimal silica could also cause pneumoconiosis. In the Federal Coal Mine Health and Safety Act of 1969, coal workers pneumoconiosis (CWP) was defined as "a chronic dust disease of the lung arising out of employment in an underground coal mine." Diagnosis of CWP is generally based on chest x-ray findings and a patient's history of working in coal mines, usually for 10 or more years. In its early stages, CWP is called "simple CWP." Miners with simple CWP are at increased risk of developing an advanced stage of the disease, called "progressive massive fibrosis" pMF) or "complicated CWP." PMF (complicated CWP) is associated with significant decreases in lung function and oxygen- diffusing capacity. PMF is also associated with breathlessness, chronic bronchitis, recurrent chest illness, and episodes of heart failure. Coal miners with silicotic lesions or PMF have an increased risk of tuberculosis and other mycobacterial infections. PMF may progress even in the absence of further dust exposure. This disease is also associated with increased mortality (National Institute of Occupational Safety and Health [NIOSH] 1995). The most recent study to determine the prevalence of CWP in coal workers was in the mid- 1990s. The average prevalence of CWP was 2.8%, but for those with 30 or more years in the industry it was 14%. For the 10-year period from 1987 to 1996, 18,245 deaths were attributed to CWP. The most frequently recorded occupation on the death certificate (70%) was mining machine operator (NIOSH 1999). Silicosis may develop when inhaled respirable crystalline silica (quartz) is deposited in the lungs. The clinical diagnosis of silicosis is based on (1) recognition by the physician that the level of silica exposure is adequate to cause the disease, (2) the presence of chest radiographic abnormalities consistent with silicosis, and (3) the absence of other illnesses (e.g., tuberculosis or pulmonary fungal infection) that may mimic silicosis. The radiographic patterns are often the same for CWP and silicosis; thus, these diseases are sometimes distinguishable only by work history or pathological examination. Chronic silicosis commonly involves 15 or more years of exposure to silica. The characteristic microscopic feature is the silicotic nodule. Chronic silicosis is often asymptomatic and may manifest itself as a radiographic abnormality with small, rounded opacities of less than 10 mm in diameter, predominantly in the upper lobes. Lung function may be normal or show mild restriction. Chronic silicosis is also associated with a predisposition to tuberculosis and other mycobacterial infections and with progression to complicated silicosis.

By S. F. Ravitz, T. M. Romslo

During 1940 and 1941, the Bureau of Mines examined a large number of silver mines in Arizona for their potential as producers of manganese ores. Although very little manganese ore had been produced from these mines, it was generally known that manganese oxides in appreciable amounts were associated with the silver ore. Following the examinations, the Bureau further investigated some of the ore deposits by diamond drilling and other types of sampling. The results of these investigations, from the viewpoint of manganese, were discouraging. However, the investigations did indicate that appreciable tonnages of manganese-silver ores had been left in some of the mines by earlier operators. Most of these ores were too low-grade for direct shipping as ores of manganese or silver, and their beneficiation by ordinary processes was not economic. Exploitation of the ores appeared to be dependent upon the development of a low-cost milling method, which would yield a marketable manganese product and recover a high percentage of the silver. Later, the Bureau of Mines constructed an experimental mill at Salt Lake City, Utah, for the treatment of manganiferous ores by the dithionate process, designed to recover manganese as a high-grade product. The dithionate residues can be treated by other processes for the recovery of additional values that may be present in the ore. This development focused attention on the manganese-silver ores of Arizona and led to setting up Bureau project No. 370, which is the subject of this report.

Jun 1, 1947

Lower the respirable dust expo-sure of longwall mine workers by reducing the amount of air-borne respirable dust generated during coal extraction. Approach Increase the moisture content of the coal seam through water infusion before the coal is mined. How Water Infusion Works Increasing the moisture content in coal tends to prevent respirable dust from becoming air-borne during mining and transport. The moisture content of the coal seam can be increased by infusing water into the seam. Water under pressure is forced into the cracks (cleats) of the coal seam through sealed bore-holes. The effectiveness of water infusion is a function of the amount of water the coal seam accepts (its infusibility), which depends on the cleat density (cleat spacing) and cleat size (crack diameter). Thus the effect of water infusion on dust control depends mainly on coal seam characteristics. Water infusion techniques are generally used to restrict the flow of methane gas to the working face; however, the technique provides an alternative dust control method in mines with severe dust problems which limit production.

Jan 1, 1987

By McHenry Mosier

The application of diamond drills for blast holes is limited to the special Job of extracting floor and stope pillars, and therefore their operation is intermittent. The zinc ore drilled occurs in metamorphosed dolomitic limestone. The mining method is sublevel open-stoping on 200- foot lifts. Ample fresh air is provided by mechanical ventilation. Diamond drilling blast holes began in August 1944. Drills were mount- ed on a 3-inch quarry bar. The contract price for labor for operating equipment owned by the company was $0.23 per foot. The diamond bits were cast-set at the factory in a sintered tungsten matrix. Bit replacement costs were $0.15 to $0.20 per foot drilled. The feet drilled per bit ranged from 87 to 258. The feet drilled per diamond-drill shift ranged from 121 to 129. Holes were loaded with 60-percent special gelatin dyna- mite and fired electrically. In percussion drilling, the estimated feet drilled por machine shift with hand-held sinkers was 65. The tons broken per machine shift averaged 40 throughout the mine. Detachable bits have been adopted recently. The principal advantage of diamond-drilling blast holes at the Balmat mino is the extraction in a safe manner of ore not minable by short-hole drilling. The principal disadvantago is the greater cost per foot of holo in comparison with percussion drilling.

Jun 1, 1947

By V. P. Bhavanandan

The mucus secreted in the respiratory tract provides the first barrier against inhaled particulate and gaseous toxicants. Trachea removed from pathogen-free rats were maintained as organ cultures and used to study the effects of coal dust exposure on the synthesis of mucin. The high molecular weight isotopically labeled (3H-glucosamine, 14Cleucine or 35S-sulfate) mucin could be purified by gel filtration, treatment with testicular hyaluronidase, ion exchange chromatography, delipidation and CsBr density gradient centrifugation. To examine effect of coal dust on mucin production, groups of explant cultures were exposed to media containing coal dust at 100 µg per ml every 2 days for 2 weeks while control cultures were treated with media without dust. Analysis of the spent culture media showed that treatment with dust markedly decreased the production of nondialysable glycoproteins as well as hyaluronidase-resistant acid-precipitable fraction consisting mainly of mucin. Since the synthesis of protein was not affected to the same extent the decrease in mucin production is not entirely due to cell death. In separate experiments rats were subjected to in vivo coal dust exposure in inhalation chambers and tracheae of these and control rats were removed for explant cultures. The incorporation of precursor isotopes into mucin by these explant cultures are being examined. (Supported by U.S. Bureau of Mines through the Generic Mineral Technology Center for Respirable Dust under grant G1135142, project 4210).

Jan 1, 1988