Search Documents

By W. R. Reed, J. A. Organiscak

Surface mining operations use large off-road haul trucks extensively to move material at mining properties. Past research, using the United States Environmental Protection Agency’s (EPA) emissions factors for unpaved haul roads, has shown that haul trucks generate the majority of dust emissions from surface mining sites, accounting for approximately 78%-97% of total dust emissions. Observations of dust emissions from haul trucks show that if the dust emissions are uncontrolled, they can be a safety hazard by impairing the operator’s visibility. This increases the probability for haul truck accidents (See photos above). However, the greatest long-term health hazard of dust generated from hauling operations is due to inhalation of the respirable dust [median diameter <4 micrometers (µm)] and tho­racic dust, which is equivalent to the EPA’s definition of PM10 [particulate matter with a median diameter <10 µm]. Exposure to respirable dust has long been considered a health hazard at surface mining operations, especially if silica dust is present. There are two legislative acts that regulate the air quality for mining operations: the Federal Coal Mine Health and Safety Act of 1969 and the Clean Air Act of 1970. The Federal Coal Mine Health and Safety Act of 1969 established the limits for dust in the work place for health and safety pur­poses. The Clean Air Act of 1970 regulates air emissions from facilities from an envi­ronmental perspective.

By C. Lorimar Colburn

"The use of helmets during the war has accentuated interest in the advisability of using stiff hats in mines to protect the miners against falling rocks. About forty per cent of the accidents in mines are due to falling rocks or roof. A large number of these accidents could be prevented if the miners wore stiff hats or helmets.The use of head protective devices in minas is not new, for they have been in use for many years in Europe and in the Lake Superior District in the United States. In practically all of the mining districts in Europe stiff hats of some kind are required by the mine management. George S. Rice, chief mining engineer of the Bureau of Mines, reported that in Germany, Belgium, and France stiff hats made of papier mache or felt rosin are in use. Similar hats are generally employed in the Lake Superior District. In building the subways of New York and Philadelphia it was the practice of engineers and workers to let the hair grow very long and to wear a close fitting cap or felt hat. In Germany the hats are high like the military helmets, whereas in France and Belgium they fit more closely to the crown. In England the practice is mixed. As a rule the miners use soft padded caps, but in Yorkshire many of the miners use sole leather, tight-fitting caps of jockey pattern with the seam forting a little ridge down the middle of the cap. These hats are very useful allow thin beds of coal, as in crawling one is very likely to strike his head a sharp piece of rock or on a timber. Of course, such mishaps are more likely to occur to a man not familiar with the mine. It must be admitted such hats do not stick on well, though this is usually due to their not being especially fitted. The German hat is particularly unsuited to an American-shaped head.It is interesting to note that on the continent tight cotton caps are generally worn over the hair and under the hard hat. This is a measure for cleanliness which is excellent. In low beds of coal share much crawling on hands and knees is necessary the dirt and coal dust sift down, making the miner black and dirty. In metal mines stiff hats are of especial use in shaft work; also in raises or high stapes. A small fragment of rock falling some distance either down a shaft or raise would kill a man if it struck him squarely on the head. A stiff hat or helmet may protect him and save his life. At a station in a shaft where men are loading the cage or skip, some kind of adequate head protector should be compulsory. A head-protecting hat or cup which is also a good insulator should be worn where there is danger of striking one's head against a wire carving an electric current."

Jun 1, 1920

By L. C. IlsLey, E. J. Gleim

The extensive use of pulverized coal for fuel in industrial plants has brought to the front again a question that heretofore has been considered only a mining problem, namely, " Can coal dust be ignited by an electric arc ? " If it can be so imited, the next logical query is , "under what conditions can such ignition occur ? " In view of the new problems relating to pulverized coal installations , and because of occasional mine disasters attributed to ignition of coal dust by electric arcs , it seems advisable to review the work done by Thornton and Bowden with electric flashes in coal dust , and to report two preliminary investigations conducted by the Bureau of Mines .

Jun 1, 1922

By Raja V. Rarnani, Robert L. Frantz

"Scientific, engineering, and biomedical research teams synergystically developed major topical research areas in the Respirable Dust Center. Descriptions of their interactions and resulting accomplishments demonstrate how cooperative research within and among these study groups benefits the overall respirable dust research and practical application needs of the mineral industries.The development of a state-of-the-art small animal inhalation exposure facility suitable for studies of fresh and aged coal mine dust, a major goal of this research group, will contribute toward the GTCRD goal of advancing the understanding of causative mechanisms for the occupation-related lung impairments and the airway diseases of mine and mill workers. Such understanding includes improved definition of the role of various aspects of the lung environment (e.g., surfactant and the mucociliary system) in the disposition and toxicity of respirable dust, comprehensive characterization of the role of the pulmonary alveolar macrophage (PAM) and its secretory products on the development of dust-related lung disorders, and an expanded search for methods to reduce the toxicity of respirable dust both before and after it enters the lung. The National Academy of Sciences has recommended, in Measurement and Control of Respirable Dust in Mines, that respirable dust research should include study of the behavioral and constitutional factors affecting individual susceptibility to workers' pneumoconiosis occupational disease and the development of methods for detecting the potential onset of pneumoconiosis earlier and more conclusively than can be done using X-ray methods. These recommendations have guided the research group in its goals of establishing and disseminating a scientific protocol for standardizing the inhalation testing for all research objectives within the Generic Center which involve small animal exposures and implementing the infrastructure necessary to make lung tissues obtained during inhalation studies available to all researchers within the Generic Center."

Jan 1, 1995

By D. Harrington

In general, mining is carried on underground, that is, in confined places where it is difficult to obtain adequate lighting and frequently in rock strata requiring much care to prevent caving. Moreover, explosives must be used in mining with the numerous hazards associated with them, and some mines give off explosive or irrespirable gases; also, ma- chinery must be used, usually under conditions much more hazardous than on the surface. These and many other considerations cause mining to be probably the most hazardous occupation in which large numbers of our fellow countrymen are employed. Prevention of accidents in the mining industry is far more complicated than in surface industrial work, even of the more hazardous types, because the different elements that enter into possible accident occurrence are ascertained more readily above ground and suitable action can be taken against them; moreover, errors in connection with prevention of accidents in surface industrial work usually affect only one or, possibly, a few persons, while in zines one human error may readily cause an explosion or other untoward occurrence resulting in the death of scores or even hundreds of persons. This difficulty in the prevention of accidents in and around mines is well-known, and most countries and States have regulations to guard the safety and, to a much smaller extent, the health of workers in mining and allied industries. In general, the State laws and regu- lations regarding the welfare of mine workers are merely a skeletonized outline of some more or less fundamental minimum requirements and are far too general to do much more than suggest some procedure which may or may not be safe or healthful. Most of them are grotesquely out-of-date as applied to present-day conditions, and none of them is adequate to protect life, limb, health, or property. Unquestionably, there is great need for a closer correlation of the laws and regulations of the various States with regard to safety in the mining and allied industries, and while mining conditions vary far too much for a standardized mine safety law applicable to all of the States, on the other hand there are numerous standard and fairly fundamental safety pro- visions which apply to all mines and which should be embodied in the mining codes of all States. Undoubtedly, these standardized safety requirements would be opposed by a consider- able part of the industry, but the ultimate effect would be beneficial to the owners, work- ers, and the general public. For many years progressive mining companies in the United States have not been satisfied to operate only within the meager safety requirements of the State laws or regulations and have adopted additional and far more effective safety procedure of their own, although com- plying also with the State laws and regulations. As a result of this forward-locking policy, zany of these companies have made astonishing progress in the reduction of accidents.

Dec 1, 1935

By Gloria L. Walker

The Bureau of Mines Information and Analysis Directorate collects worldwide data on virtually every commercially important non fuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. This data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 329), to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Information and Analysis activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress), which strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1990

By Gloria L. Walker

The Bureau of Mines Information and Analysis Directorate collects worldwide data on virtually every commercially important nonfuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. This data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 329), to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Information and Analysis activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress), which strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1990

By M. C. Chapman, E. C. Westman, A. T. Iannacchione

Examination of seismic records during the time interval of the Sago Mine disaster in 2006 revealed a small amplitude signal possibly associated with an event in the mine. More needs to be understood about the seismicity from mine explosions in order to properly interpret critical seismic information. A seismic monitoring system located at NIOSH’s Lake Lynn Experimental Mine has monitored experimental gas and dust based explosions and impact tests. The seismic signatures from these different events were analyzed using standard waveform analysis procedures. The magnitude of seismic energy during a gas and dust explosion was found to be more dependent on mine entry geometry and seal behavior rather than on the amount of explosive fuel present. The results suggest a large explosion that’s not restricted can generate potentially the same magnitude as a small explosion that is restricted.

By Industrial Research Office

"The U.S. Bureau of Mines established on August 15, 1983, the Generic Mineral Technology Center for Respirable Dust within the Mining and Mineral Resources Research Institutes (MRIs) at The Pennsylvania State University and West Virginia University in association with participating MRIs at Massachusetts Institute of Technology and the University of Minnesota. The Center's research program has been developed with recognition of the stated objective of the Federal Mine Safety and Health laws which is to ""... permit each miner the opportunity to work underground during the period of his entire adult working life without incurring any disability from pneumoconiosis or any other occupation-related disease . . . ."" The Center's program is designed to permit an accelerated attack on the fundamental research problems for the control of respirable dust in mines.The primary goal of the Center is to reduce the incidence and severity of respirable dust disease through advancing the fundamental understanding of all aspects of respirable dust associated with mining and milling and the interaction of dust and lungs. The Generic Technology Center's research program explores these concerns with the objective of refining existing strategies and developing new respirable dust control techniques that are consistent with the fundamental dust-lung interaction processes that lead to mine worker disability. The work concentrates on: (1) control of dust generation; (2) dilution, dispersion and collection in mine airways; (3) characterization of dust particles; (4) interaction of dust and lungs; and (5) relationship of mine environment, geology, and seam characteristics to dust generation and mobility. The fundamental aspects of this work are applicable to the control of respirable dust problems in both hard rock mines and coal mines and to other dusts such as diesel-generated. The Center activities involve the training of engineers and scientists, graduate students and undergraduate students through their respective institutions, and the technology transfer to the industry. The Center also serves as the reference center for publications' in the respirable dust area.The Center is composed of faculty from the four universities/institutes listed above. The personnel, facilities and equipment that are available to the Center from these entities are diverse, complementary and comprehensive. More than fifty scientists, engineers; and medical personnel in the Center are engaged in respirable dust research. Additionally, the expertise and facilities of the NIOSH--Division of Respirable Disease Studies are available as a result of the existing relationship between NIOSH and West Virginia University.The breakdown of the dust research program into the five areas mentioned above recognizes the importance of an integrated fundamental research approach to the respirable dust problem compatible and complementary with the existing and ongoing U.S. Bureau of Mines activities. The specific projects in the research areas are a result of a careful evaluation of the past and ongoing research activities, the identification of areas where data and information are scarce, and awareness of the recommendation of the National Academy of Sciences Study on the Measurement and Control of Respirable Dust. Penn State is the administrative unit for the Center. Funding to date is nearly $6.5 million."

Aug 31, 1989

Objective To develop a passive, inexpensive technique for monitoring explosion overpressures within sealed areas in underground coalmines. Background From 1994 to 2000, seven explosions of methane and/or coal dust occurred within the worked-out, sealed areas (gobs) of underground U.S. coal mines. These explosions, believed to have been started by lightning, destroyed many seals and caused much damage external to the sealed area. One gob explosion went undetected until the mine operator reopened the sealed area and discovered the damage. Fortunately, these gob explosions did not cause any fatalities or injuries. Because lightning occurs in just about all mining areas, several questions arise. Could gob gas explosions be occurring in other sealed areas and going undetected? If so, what is the magnitude of the resulting explosion overpressures? The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) undertook a study to identify and evaluate passive measuring devices to monitor and quantify the overpressures associated with such explosions. This work was done in parallel with full-scale explosion experiments for evaluating the strength characteristics of seals used for isolating areas in underground coal mines. Approach Evaluation studies were done in PRL&apos;s 20-liter explosion test chamber and in the full-scale Experimental Mine at Lake Lynn Laboratory to evaluate the response and accuracy of various commercially available automobile tire pressure gauges to overpressures generated from gas and dust explosions. The first series of tests was done in the 20-liter chamber, which is used to study the explosibility and inerting of fuel dusts and gases. Data from the tire pressure gauge tests were compared to the pressure-time data obtained from the 20-liter chamber &apos;s traditional electronic strain gauge pressure transducer recorded on a high-speed data acquisition system. To evaluate the tire pressure gauges, the valved inlet (tip) of the candidate pressure gauge was removed and the body of the gauge was cemented with epoxy into a 0.25-in pipe elbow and attached to the outside of the test chamber. A second series of tire gauge evaluation tests was done at Lake Lynn during explosion-resistance testing of seals used in underground coal mines. Full-scale seals (20 ft wide by 8 ft high)were constructed as one wall of a 2,000-ft3 chamber and exposed to a series of methane explosions. Average overpressures ranged from20 to 80 psi. The seals were built with various strength materials ranging from 7 to 48 in thick. The modified tire gauges are attached on the outside of the chamber to a 0.25-in NPT pipe that extends into the chamber (figure 1). The axis of the gauge is mounted at a right angle to the plane of the seal to minimize the coupling of any seal movement to the stem of the gauge that may cause inaccurate readings. The internal explosion pressure history is recorded with a strain gauge pressure transducer mounted inside the chamber. Methane is injected into the chamber, mixed with air, and ignited with an electric spark located at the geometric center of the chamber. Maximum explosion overpressures are recorded and compared with the tire gauge pressure.

Jun 1, 2001

By S. D. Hudock, C. M. Keran

A review of all upper extremity cumulative trauma disorder (UECTD) injuries was conducted by the U.S. Bureau of Mines for 1985 through 1989. This review was performed by analyzing each injury, as reported by law and maintained on the U.S. Mine Safety and Health Administration&apos;s accident data base. This analysis found that incidence rates in mining were lower than in private sector industry, although the number of reported UECTD injuries increased sevenfold and their percentage of all mining injuries increased fivefold from 1985 through 1989. Metal-nonmetal mines accounted for 80 pct of UECTD injuries, while coal mines accounted for 20 pct. Nearly 63 pct of UECTD injuries were accounted for by only four occupations-mechanics, laborers, boney (crusher) operators, and miners not elsewhere classified (NEC)-with an incidence rate well above the private sector industry rate.

Jan 1, 1992

By McHenry Mosier

The diamond-drill method was tried at the site selected for driving a 5- by 6 -foot air shaft at the east end of the Bellefonte mine . This method of sinking consisted , first , of drilling a 5-3/4 -inch-diameter cut hole from the surface , then drilling parallel 1.5 - inch ( EX ) holes around it at appropriate distances for a balanced blasting round . The cut hole was not charged with explosive but served as a relief chamber for the incipient expansion of the ground broken by. blasting the surrounding 1.5 - inch holes . The length of each hole was 236 feet , which was the finished depth of the shaft . The nature of the work in the air shaft was largely experimental , and many difficulties arising from the lack of special equipment and proper technique for precise alinement of the drill holes caused expensive delays before they could be overcome . Drilling the 5-3 /4 - inch hole , which was impeded by frequent core blocks in the core barrel , required 10 shifts . average advance per shift for an EX hole was about 150 feet . The The holes were charged and fired from the surface . The length of the section blasted in one cycle was 10 feet . Blasting progressed from the bottom of the shaft upward . The broken stone dropped into a chute , from which it was drawn into cars on the haulage level . The Bellefonte mine is an underground limestone mine.3/ The primary objective in undertaking the research on shaft sinking by diamond drilling was to perfect a method for driving connections between levels of the mine .

Oct 1, 1948

By Richard A. Winters

In 1987, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 6,022-acre Spring Basin Wilderness Study Area (OR-005-009) in order to evaluate its mineral resources. The study area is in Wheeler County about 13 miles southwest of Fossil, Oregon. No mineral resources were identified. The area is underlain by volcanic flows, domes and sediments ranging in composition from olivine basalt to rhyolite of the Clarno and John Day Formations. There are three mining claims in the study area, all apparently located for lapidary material. Samples of agate were of poor quality. Four of 13 alluvial samples, two inside and two adjacent to the area, contained gold; content ranged from 0.0000097 to 0.00416 troy ounce per cubic yard. About 23 percent of the Wilderness Study Area is covered by oil and gas lease applications.

Jan 1, 1988

This surveillance report summarizes data on work-related fatal and nonfatal injuries, illnesses, and hazardous exposures in the mining industry for the 10-year period 1986-1995. The term "surveillance," as used in public health, may be new to many readers of this report. With regard to occupational safety and health, the goal of surveillance is to describe the occurrence of work-related injuries, illnesses, and known hazardous exposures; to identify new hazards that may occur due to the introduction of new technology or other factors; and to assess the effects of preventive measures designed to improve worker safety and health. Surveillance provides an overall picture, which can be used to focus resources on areas most in need of prevention programs or further research. Surveillance generally requires the use of multiple sources of data, all of which have their own strengths and limitations. Surveillance in the U. S. mining industry is complicated by the fact that U.S. national data systems that provide information on mining are based on two different definitions of the mining industry. One is established by the Mine Safety and Health Administration (MSHA), the other by the Standard Industrial Classification (SIC) System [Office of Management and Budget 1987] and the 1980 U. S. Bureau of the Census (BOC) Classification System [U.S. Bureau of the Census 1982]. The mining industry as defined by MSHA is based on the regulatory jurisdiction of that agency. Reporting requirements for injuries, illnesses, and workplace exposures are stipulated under the Federal Coal Mine Health and Safety Act of 1969 and the Federal Mine Safety and Health Amendments Act of 1977. Of note is that the oil and gas extraction industry falls outside of MSHA jurisdiction. The Occupational Safety and Health Administration (OSHA) was charged with enforcement in the oil and gas industry under the Occupational Safety and Health Act of 1970. Under the SIC, the definition of mining covers the extraction of naturally occurring minerals, including liquids (petroleum), gases (natural gas) and solids (coal, metal, and nonmetallic minerals). Exploration and development of mineral properties are also included in the SIC definition of the mining industry. The SIC was developed by the Office of Management and Budget for use in classifying establishments based on the type of economic activity in which they are engaged and serves as the industry classification standard for all establishment based Federal economic statistics. This classification is important for occupational safety and health surveillance because it also serves as the industry classification system for all data on work-related injuries and illnesses collected by the U.S. Bureau of Labor Statistics (BLS). The U.S. Bureau of the Census uses an industry coding scheme similar to that used by the SIC. For the mining industry, the categorization is identical in both systems. Death certificate data made available by the National Center for Health Statistics (NCHS) are categorized under this system. Death certificate data are particularly important for surveillance of mortality from work-related illnesses. Key differences between the SIC/BOC categorization system and the MSHA system can be summarized as follows: • MSHA excludes the oil and gas industry, which is classified as part of the mining industry under SIC/BOC. • MSHA excludes work that is done off of mine property; work off of mine property is included under SIC/BOC if it is performed by an establishment falling into one of the SIC/BOC mining industry codes. • MSHA includes mine-associated mills and processing plants; these are classified under the manufacturing industry, rather than mining, according to the SIC/BOC coding structure. Since the data collected by MSHA and the data collected by BLS and NCHS using the SIC/BOC classification system are both important sources of information on the mining industry and in many cases serve different purposes, data from both systems are presented in this report. In general, data using the SIC/BOC system are comparable across U.S. industries and should be used when comparing mining to other U.S. industries. Much of the data in this report are presented in the form of frequencies or rates. A frequency provides only a count of the number of cases without providing any information about the risk of occurrence. Rates provide an estimate of the risk of injury or illness. The reader is cautioned, however, that rates based on small numbers can be unstable; thus, any inferences should be drawn with care. In this report, no rates are presented for groups in which there were fewer than three cases. The incidence of most injury and illness conditions differs by age, sex, and race. For this reason, data in many surveillance reports are adjusted for these demographic factors. It was not possible to do this for most of the rates in this report because information on demographics was not available. With the exception of the proportionate mortality ratios (PMRs), all data presented are unadjusted. A detailed account of the sources of data is in appendix A. The methods used in data selection and analysis are described in appendix B.

Jan 5, 2000

By Mary H. Brown

The heats of formation of oxalic acid and sodium, potassium oxalates, and lithium oxalates were related by solution calorimetry to the heat of formation of (COOH)2.2H20, a value believed to be reliable as reported in the literature. The following heats of formation were determined: (COOH)2(a), -198.1±0.1; (COOH)2(ß), -197.8±0.1; UAW,, -328.7±0.4; Na2C204 -316.2±0.1; K2C204, -321.9±0.2; and K2C204-H20, -393.5±0.2 kcal/mole. The heat of the crystalline transformation (COOH)2(a) ? (COOH)2(ß) was determined to be 0.30±0.02 kcal/mole at 298.15° K.

Jan 1, 1970

By W. E. Miller, John Campbell, W. P. Yant, G. W. Jones

"Because of its interest in accident prevention, the U.S. Bureau of Mines cooperates with city officials and utilities in investigating the causes of explosions in sewers, manholes, and other underground openings and in developing means for preventing such explosions. For several years this Bureau has been cooperating with the Edison Electric Illuminating Co. of Boston and the Boston Consolidated Gas Co. in detecting and eliminating combustibles and physiologically harmful gases in manholes in the city of Boston and adjacent territory.These Bureau of Mines investigations° have shown that combustible gases from the usual sources — leakage from gas—distributing systems and from underground tanks and gasoline wastes — can be located and the dangerous conditions remedied by a well—planned, adequately supervised, systematic, and continuous manhole survey. However, other types of gas, which are termed here ""soil"" gases, also occur in manholes and are more difficult to eliminate because they have no fixed origin and because seasonal and barometric changes affect their production and passage into the manhole space. These gases appear to be produced by bacterial and fermentation or through reactions of entrapped air in the soil. Soil usually abnormally high in carbon dioxide and low in oxygen, and contain varying amounts of methane. They are especially clangorous to men entering manholes because they lack sufficient oxygen to support life. Owing to the difficulty of constructing gastight manholes the most feasible method for eliminating soil gases from manholes is by ventilation. Consequently the Bureau of Mines initiate 4 study of natural ventilation methods for the removal of these gases from manholes and also for taking care of unforeseen accumulations of combustible gases and vapors.The following factors were considered by the Bureau to be important to the natural ventilation of manholes: (1) Relation of area of ventilation opening* to the capacity of the manholes, (2) size and shape of the manhole, (3) design of the ventilation opening (4) and velocity, and (5) weather conditions."

Jun 1, 1936

Analyze variably saturated flow in mining and other environmentally sensitive settings through the use of personal computer (PC) based software. The Problem There is an increasing need for mining companies to quantify water contaminants and their migration in the unsaturated zone. New and innovative computer models are therefore necessary to more accurately assess the potential impact of mining activities on groundwater resources and the environment. Applications for unsaturated flow modeling include (1) assessment of the impact of surface or underground extraction mining on flow conditions; (2) assessment of various hydrologic designs for resource recovery, such as in heap leaching or in situ leach mining; (3) assessment of the transport of conservative nonrcactive constituents in response to migration from spoil piles, or acid mine drainage; and (4) assessment of any combination of the above to facilitate expeditious permitting for mining operations. Since the mid 1970&apos;s there has been a proliferation of mathematical models and procedures for solving unsaturated now problems; however, few of these approaches have been integrated into software for public use. Commercially available unsaturated flow software models typically are limited to a single application and have restricted approaches. For example, computer codes that solve the unsaturated flow problem based on an analytic expression arc restricted to a simple geometric shape, homogeneous and isotropic materials, and provide only information regarding pressure and flow conditions in specified wells. The variably saturated computer codes that take advantage of the finite difference or finite element approach arc often restricted to either steady state or transient solutions; utilize one specific moisture-retention relationship and moisture-dependent permeability function; do not account for hysteresis; and are used with specific hardware such as a mainframe or work station. This restricts their use because they arc hard to interface, and arc often poorly documented, support dependent, and expensive. The mining community needs a flexible, more broadly based, variably saturated fluid flow simulator for the PC-platform to more accurately predict fluid movement in the mining environment.

Jan 1, 1991

By D. Harrington

"A tabulation is printed below showing the accident record of the thirty-two mines of the Anaconda Copper Mining Co., in Montana, for the years 1915, 1916, 1917, 1918, 1919 and 1920, with summation for the six years. The table gives the number of shifts worked by each mine with the serious plus fatal accident rate for each 10,000 shifts worked.It is seen that in a total of 16,460,767.5 shifts worked by employees of the company's mines during this six-year period, there were only 2,005 serious and fatal accidents and of these, 200 were fatalities, leaving 1,805 serious accidents (a serious accident being one in which 14 or more days' time are lost). This is at a rate of 9,120 shifts per serious accident and at a rate of 82,304 shifts per fatality. Hence, if 300 days be adopted as a year's work, there would be one fatality per 274.3 years of work in these mines and one serious accident for every 30.4 years work.According to Bureau of Mines Technical Paper 286, (Metal-mine accidents in U. S. in 1919, by W. W4 Adams), during the years 1916, 1917, 1918, and 1919, the metal mines of the United States worked a total of 210,548,640 shifts and had 39,705 serious accidents. During the same years, according to the following tabulation, the mines of the above-mentioned company worked 11,958,978 shifts and had a serious accident rate of 0.995 accidents per 10,000 shifts worked. If the metal mines of the United States, working these 210,548,640 shifts, had this company's serious accident rate of 0.995 serious accidents per 10,000 shifts, the total number of serious accidents would have been only 21,000 or the country's metal-mine serious accidents would have been reduced nearly one-half, and there would be 18,705 fewer serious accidents than actually occurred."

Jun 10, 1921

By Ronald F. Balazik

The introduction of "high-tech" materials such as new polymer composites presents significant competitive challenges and opportunities in conventional mineral markets. Moreover, rapid advances in materials science are critical to the resolution of important economic and strategic issues, including national competitiveness and import dependence. This Bureau of Mines study examines the displacement of conventional nonfuel mineral materials by certain new materials, specifically advanced plastics and ceramics. Analyses of substitution by plastics are conducted for five major U.S. industrial sectors: motor vehicle manufacturing, aerospace applications, building and construction, packaging, and heavy machinery production. Based on interviews with more than 60 scientists, executives, and other professionals engaged in materials development and sales, forecasts of substitution by plastics during the 1990&apos;s are made for aluminum, steel, and glass. In addition to these forecasts, study findings identify key factors that will influence the emergence of advanced materials in the next decade.

Jan 1, 1987

By Fred Biggs, Walter Utt, Richard Miller

Powered haulage has been, and continues to be, a major source of severe accidents and fatalities at metal/nonmetal surface mines. Between 1986 and 1997, truck drivers accounted for63% of the lost-time injuries in surface haulage. This project was undertaken to reduce the number and severity of lost-time injuries among operators of these trucks. Work involved measuring shock acceleration at a western surface mine during representative work cycles on two types of trucks and collecting data from cab floors using a triaxial accelerometer and from operator seats using a seat pad accelerometer. NIOSH researchers also used the mine’s GPS systems to locate shock events on a mine map in real time. Shock tests were also run at Caterpillar, Inc.’s, proving grounds in Green Valley, AZ, to determine the magnitude of shocks resulting from controlled rock drops onto the bed of a haulage truck.