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By L. B. Pankratz

The Bureau of Mines conducted heat-content measurements above 298.15° K for dehydrated analcite (NaAISi2O6) to 1,000°K, kaliophilite (KA1Si04) to 1,800° K, and leucite (KAlSi206) to 1,800° K. Heat content and entropy increments were tabulated, and the heat content data, were given in equation form. A first order transition was noted for kaliophilite near 810° K with a heat absorption of 160 cal/mole. Leucite had a second order transition which became complete near 955° K. In this transition a crystal change occurred from tetragonal (low-temperature form) to cubic (high-temperature form).

Jan 1, 1968

By Thomas E. Marshall, Gerald L. Finfinger

The Bureau of Mines has developed a practical methodology for deter- mining occluded gas contents of domal rock salt samples. The method, which is portable and field worthy, provides results in 5 min or less and does not require a laboratory environment or specially trained personnel to obtain meaningful results. The results can be used to identify gas-enriched zones, and thus may aid mine operators in production planning or ventilation design. The test method is based on the relationship between gas content and the acoustic response of salt samples as they are dissolved in water. The relationship is defined by an equation, and the results are repeat- able. The equation was derived by testing a series of rock salt samples collected from domal salt mines in Louisiana.

Jan 1, 1987

By Hendrik Gerritsen

The research to be described is directed to the construction of an instrument that detects methane in air. The principle on which it is based is that methane gas absorbs infrared radiation in the wavelength range of about 3.2 to 3.4 micron. Solid state p-n junctions of composition In, .97Ca.03As emitting radiation in a band centered at 3.3 micron were grown by liquid epitaxy on InAs. Fight separate growth cycles and a total of 200 diodes were measured to determine total power, wavelength peak, spectral. half width and reproducibility of the method. In order to compensate for temperature changes, dual emitter systems (one InGaAs, and one InAs diode) mounted on the same TO-5 header were made. These devices were imaged, using a folded optical path cell, on large area InAs detectors, grown by a planar diffusion technique. In the 0-50°C range the primary temperature sensitivity is in the InAs detector rather than in the emitters. Several methods to reduce the overall temperature sensitivity to within acceptable limits were demonstrated. Humidity was shown to have a negligible effect on the measurements.

Jan 1, 1976

By C. Özgen Karacan

Methane emissions from a longwall ventilation system are an important indicator of how much methane a particular mine is producing and how much air should be provided to keep the methane levels under statutory limits. Knowing the amount of ventilation methane emission is also important for environmental considerations and for identifying opportunities to capture and utilize the methane for energy production. Prediction of methane emissions before mining is difficult since it depends on a number of geological, geographical, and operational factors. This study proposes a principle component analysis (PCA) and artificial neural network (ANN)-based approach to predict the ventilation methane emission rates of U.S. longwall mines. Ventilation emission data obtained from 63 longwall mines in 10 states for the years between 1985 and 2005 were combined with corresponding coalbed properties, geographical information, and longwall operation parameters. The compiled database resulted in 17 parameters that potentially impacted emissions. PCA was used to determine those variables that most influenced ventilation emissions and were considered for further predictive modeling using ANN. Different combinations of variables in the data set and network structures were used for network training and testing to achieve minimum mean square errors and high correlations between measurements and predictions. The resultant ANN model using nine main input variables was superior to multilinear and second-order non-linear models for predicting the new data. The ANN model predicted methane emissions with high accuracy. It is concluded that the model can be used as a predictive tool since it includes those factors that influence longwall ventilation emission rates.

By H. J. Sloman

"INTRODUCTION Industry, including coal mining, has come to realize that to prevent accidents the human element must be given more consideration than was customary in the past. In formulating safety rules and regulations and in the enactment of laws governing mining, too often enforcement is emphasized rather than the means of gaining willing compliance.' The purpose of this paper is to call attention to the human side of accident prevention, and the approach to this important and much-discussed subject will deviate somewhat from the usual discussions.The human being is a complex mechanism, both physically and mentally. It is difficult to establish a common denominator for the actions of humans, except in general. In establishing mining laws, rules, regulations, and standards, the ultimate objective should be to gain the best possible response of workmen, so that optimum results in accident prevention may be obtained. The complexity of human beings is apparent when the many ways 1n which they differ are considered. Some of these differences are manifested in emotional and phlegmatic types, degrees of intellect or native intelligence; and in hopes, desires, aspirations, and philosophies of life. How much simpler ac¬cident prevention would be if the response to laws, rules, regulations, or standards were equivalent to the definite movements of puppets responding to pulls on strings. Each time, the strings are pulled in exactly the same way, the puppets will respond in exactly the same manner. Human beings, although having many similar characteristics, do not respond uniformly to identical ""string-pulling""; therefore, much study is necessary before the desired re¬sponses can be obtained. To achieve the ultimate in accident prevention, it must be ""worked at"" constantly. Regardless of the adequacy of safety laws, rules, regulations, or standards, good accident records will not ""roll in"" if dude consideration is not given to the personal traits of those most likely to be involved in accidents."

May 1, 1948

This Part is concerned with the theoretical study of UHF radio communication in coal mines, with particular reference to the rate of loss of signal strength along a tunnel, and from one tunnel to another around a corner. Of prime interest are the nature of the propagation mechanism and the prediction of the radio frequency which propagates with the smallest loss. Our theoretical results are compared with measurements made by Collins Radio Co. This work was conducted as part of the Pittsburgh Mining and Safety Research Center's investigation of new ways to reach and extend two-way communications to the key individuals that are highly mobile within the sections and haulage ways of coal mines.

Jan 1, 1974

By John M. Gomes

Two methods for electrowinning tungsten from wolframite [(Fe,Mn)W04] were investigated. The first method, direct electrowinning from wolframite concentrate dissolved in molten salt mixtures composed essentially of various combinations of sodium phosphates, sodium borates, and sodium halides, yielded impure products. The second method was electrowinning from a halide-tungstate melt that was obtained from a high-temperature, two-phase extraction of tungstic oxide (W03) from wolframite. Electrolysis in electrolytes prepared from addition of sodium metaphosphate (NaPO3) and boric oxide (B2O3) to the halide-tungstate melt produced tungsten metal of 99.9 percent purity. Tungsten carbide (WC) was electrodeposited from the halide-tungstate melt when the melt was adjusted to contain 82 mole-percent NaCI and 6.0 mole-percent each of W03, sodium metaborate (Na2B204), and caustic soda (NaOH).

Jan 1, 1970

By G. T. Lineberry, W. J. Wiehagen

This paper discusses a practical method for enhancing the performance of mining work crews. The method, described as the Work Crew Performance Model (WCPM), seeks to define performance variability within similar tasks of an underground work crew. Key components of the WCPM include: (I) job definition through task analyses; (2) the ranking of job elements by perceived cost consequence; (3) observational techniques to establish performance baselines; and (4) cost linkages between adherence to task procedures and measures of consequence for noncompliance. The components of this model emphasize a reliance on learning from a veteran work force and using that information to reinvest in strategies to enhance safety and efficiency. These strategies are not limited to technologic efforts but include consideration of the so-called "soft-skill technologies" aimed at reducing variability in individual performance and at effecting a continuous improvement in overall system effectiveness.

Provide mine personnel with a convenient means of determining the optimum installation geometry of roof trusses in bedded roof. Background Mine operators frequently ask the following questions concerning roof truss installations: 1. Where should the bearing plates or brackets be placed or where should the inclined holes be started? 2. At what angle should the holes for the inclined chords or angle holts be drilled? 3. What tension should be put into the inclined chords so as to achieve the most effective results for the effort and expense? Truss hardware manufacturers have responded to these questions with answers based on what seems to work best. While designs based on past experience are frequently reliable, there was a need for a rational approach that could accommodate a variety of conditions. The Bureau has developed a procedure that enables mine operators to optimize roof truss installations in bedded roof.

Jan 1, 1989

Control the release of ground-water into active underground coal workings by short-term pumping from dewatering wells sited on fractures. Approach The sudden release of fracture-stored groundwater into underground coal workings often occurs when mine workings are developed beneath fracture valleys, Pumping from fracture trace-sited dewatering wells, prior to development of the underlying workings, can be an efficient means of intercepting fracture-stored groundwater before it is released into the mine. Dewatering operations are discontinued once the underlying mine workings have been fully developed, and the maximum possible reduction in fracture storage has been achieved through pumping. How It Works An aerial photographic technique known as fracture trace analysis is used to site dewatering wells on rock fractures in a valley bottom. Downhole caliper and temperature logs are used to assess the fracture flow potential of each dewatering well drilled.

Jan 1, 1987

To expediate the transfer of technology from Bureau laboratories into new products and processes that enhance the economic competitiveness of the U.S. mining and minerals industry in world markets. Background The U.S. Bureau of Mines and various members of the industry are concerned about the current technology challenge to the minerals industry in the United States. They arc working together to delineate ways of enhancing the mineral industry's technology base. More emphasis is being placed on collaboration between the government, academia, and industry to formulate the innovative revolutions needed to maintain our technology edge. Through these partnerships, real issues and problems can be identified, the industry's needs as customers can be defined, and research and development activities can be tailored to meet these needs. Now is an especially exciting time in research because some special opportunities exist to encourage private industry to capitalize on Federal laboratory research and development. These opportunities arc called CRADA's. What Is A CRADA? The Congress recently enacted a mechanism that enhances collaboration between industry and government through the Technology Transfer Act of 1986. A key lea lure of this Act is a provision through which Cooperative Research and Development Agreements or CRADA's can be developed to encourage industry and government to work together and stretch their research budgets. By entering into a CRADA, a private, non-Federal company can cost-effectively perform research by sharing the costs of this research with the Federal Government. The agree¬ment involves no transfer of funds from the Government. The Government agrees to provide personnel, services, facilities, equipment or other resources (but nut funds) and the non-Federal party agrees to provide funds, personnel, services, facilities, equipment, or other resources needed to conduct a specific research or development effort.

Jan 1, 1992

By James R. Welty

Heat content values were experimentally determined for yttrium metal between temperatures of 400° and 1,300° K and for iron pentacarbonyl between 301° and 380° K. The drop technique was used; that is, a sample of material sealed in a protective capsule was heated to 3 desired temperature in a furnace and then dropped into an ice calorimeter. A revised technique for determining heat content values from calorimetric data is described. Heat content and corresponding entropy-increment data above a reference temperature of 298.15° K are presented in tabular form. Equations for heat content and heat capacity as functions of temperature were derived for each substance. These equations are [Y (c): HT-H298.15 = 1.2041T 1 3.393 x 10-3T2- 0.4176 x 10' T"1 + 739.9 cal/mole Cp = 1.2041 + 6.786 x 10-3T + 0.4176 x 106-T-2 cal/deg mole Fe (CO) E, (1) : HT - H298.15 = 55.636T - 16,588 cal/mole Cp = 55.636 cal/deg mole]

Jan 1, 1963

By Franklin P. Hall

U.S. supply and demand data for utility electricity by States and regions were tabulated for the years 1960 and 1965. Estimates are provided of State-by-State quantitative data for the utility electricity industry that can be integrated into State and regional energy balances by source, form, and major consuming sectors, and used to determine basic flow-patterns. The difficult problem of compiling interstate and interregional shipments of electricity was resolved by (a) assuming the negligibility of interregional shipments and (b) deriving a theoretical line loss percentage used for determining interstate shipments. The data developed were able to show an estimated total supply of utility electricity available for consumption. The tables also report the distribution of the supply among the major consuming sectors (household and commercial, industrial, and transportation). To compare the various energy sources of utility electricity, quantities were converted to their British thermal unit (Btu) equivalents. The Federal Power Commission, Edison Electric Institute, and Bureau of Mines are the sources of the data used in this study.

Jan 1, 1969

By F. N. Kissell

The Bureau of Mines has successfully used sulfur hexafluoride (SF6) as a tracer gas to measure mine air flows under conditions where conventional methods have failed. SF6 was employed experimentally to measure accurately recirculation of return into intake air caused by leakage through an old stoped area, to check for potential leakage from an adjacent mine, to trace 10,000 cfm of “lost” air from an intake airway, and to measure transit air time through uranium mines. It proved useful as a means of accurately measuring airflow volumes in airways of large cross section and very low flow velocity, and in determining the recirculation resulting from underground cooling plants.

Jan 1, 1974

By E. G. King

Low-temperature heat capacity determinations of the minerals goethite and pyrophyllite were made in the temperature range from 510 to 298° K. The entropies at 298.15° K were evaluated as 14.43 ±0.15 cal/deg mole for goethite and 56.6 ±0.5 cal/deg mole for pyrophyllite. The entropies of formation from the constituent oxides are -4.4 ±0.2 cal/deg mole for goethite and -12.3 ±0.6 cal/deg mole for pyrophyllite. The standard free energy of formation of goethite from its oxides is ?G°298.15 = 0.16 ±0.20 kcal/mole.

Jan 1, 1970

Reduce costs of surface mine reclamation by improving bulldozer operating efficiency. Approach A draft power indicating system helps bulldozer operators adjust blade height and other controls for maximum load movement, by continuously indicating the rate at which work is being done. How It Works This system continuously measures both the push of the blade against the overburden, and the true ground velocity of the bulldozer. It multiplies those quantities to determine the real work rate of the machine. The system consists of a velocity sensor, a blade load sensor, processing circuits, and a work-rate indicator. The processing circuits include an analog multiplier which has an output signal representing the draft power (velocity x load = power). The draft power, or pushing power is a measurement of the work rate at that moment.

Jan 1, 1979

By T. O. Llewellyn

Laboratory batch and semicontinuous studies showed the feasibility of using methylene bromide and trichloroethylene in heavy liquid cyclone concentration of a Nevada brucite ore. Cyclone tests of minus 20- plus 200-mesh material at specific gravities of 2.42 and 2.44 recovered 71.6 to 74.9 percent of the MgO at grades of 95.5 and 95.4, respectively. Neither increasing the feed pulp density from 5 to 25 percent solids, nor varying feed pressures from 25 to 60 psig had any apparent effect on the heavy liquid separation.

Jan 1, 1971

By Eugene V. Cilento, R. Clark Lantz, K. A. DiGregorio

"This laboratory bas developed a sensitive electro-optical method to quantify the initial rate (R) and total amount (MAX) of superoxide (02) produced by single pulmonary alveolar macrophages (PAM). The method uses a microscope-based TV system to visualize PAM in culture, and to video record the images during the time the cells produce 02. MAX and R are calculated from measurement of temporal changes in optical density in the images due to precipitated diformazan formed by the reaction of O2-, produced by each PAM, with nitroblue tetrazolium present in the culture medium. To date, values of Rand MAX, measured due to adherence of PAM to the dish, have been compared to values obtained when quartz, coal mine dust (CMD), and kaolin . were added to the medium (in vitro). Rand MAX have also been calculated for PAM lavaged from animals exposed to quartz and CMD in the WVU Inhalation Facility. Presently, experiments are being done using which will permit PAM to be restirnulated by different dusts to help establish a dose response relation~ p and a means to study the role of lung surfactant on modifying the acute toxicity of inbaled dusts. Ultimately, this methodology should provide useful insight into establishing the role of 02 in PAM dysfunction due to inhalation of dusts, and in lung diseases such as pneumoconioses. INTRODOCTIONPAM are free cells found in the lungs which protect the lungs by removing foreign debris and bacteria. This is accomplished, in part, by the process of phagocytosis, whereby foreign matter is internalized into vesicles known as primary phagosomes. Phagocytosis also involves the chemical breakdown of inhaled dusts and the killing of microbes. Detoxification is aided by the respiratory burst, which is a metabolic response of the cell to foreign substances, that results in the production of highly reactive oxidizing agents from the partial reduction of extracellular oxygen to superoxide (02) at the surface of the plasma membrane. Superoxide undergoes either spontaneous or enzyme catalyzed dismutation reactions to form hydrogen peroxide (H202) and subsequently hydroxyl radical (OH•) and singlet oxygen (02 t ). However, while these oxygen metabolites aid in the killing of microbes they also may destroy endogenous tissue. For example, 02 has been linked to the aging process and to many diseases including emphysema, diabetes, and cancer.'' Therefore, a better understanding of the production of 02 is extremely important since an abnonnally low production could result in damage by inhaled dusts and bacteria while an abnormally high production could result in direct damage to the lung tissue by the phagocytes. Inhalation of respirable sized mineral dusts, such as quartz (silica), coal mine dusts (CMD), and asbestos, results in various pulmonary disorders. PAM are thought to play an important role since evidence suggests that the first step in fibrogenesis is an interaction of dust particles with PAM. Generally, in vivo exposure of animals to mineral dusts results in increased respiratory burst activity, migratory patterns, phagocytic behavior, and secretory potential of PAM, and for this reason these have been implicated to be pivotal events in the pathogenesis of pulmonary diseases.1 In addition to stimulation of resident PAM, an influx of monocytes into the lung and/or production of new macrophages generally occurs in response to fibrogenic dust inhalation. Further, PAM may attract and stimulate fibroblasts, which normally synthesize proteins and collagen during rep~ of tissue, by secreting chemoattractants and enzymes. Thus, PAM may be involved in pulmonary disorders through failure or partial loss of their defensive capability, or indirectly, through release of other mediators."

Jan 1, 1990

1. In 2003, a total of 258 metal mining operations reported employment to the Mine Safety and Health Administration (MSHA). Metal mines were the smallest mining sector, comprising 1.8% of all mining operations.1 • Gold mines comprised 44.2% (n = 114) of all metal mining operations. Other common types of metal mines were iron ore (n = 29; 11.2%), copper ore (n = 28; 10.9%), and lead and/or zinc ore (n = 21; 8.1%). • Nevada had the largest number of metal mines (n = 48; 18.6%) followed by Alaska (n = 29; 11.2%).

Feb 1, 2005

By F. S. Karn

Measurements were made of the flow of helium, methane, ethane, butane, and toluene through thin disks of coal. All measurements were made on a dense layer in the Pittsburgh seam identified as attritus. Flow increased with pressure differential and temperature. At room temperature and a pressure differential of 1 atmosphere flow rates along the bedding plane of Pittsburgh seam coal were helium 881 X 10-10 cm2 sec-1, methane 1.2 X 10 -10 cm2 sec-1, ethane 0.54 X 10-10 cm 2 sec-1, n-butane 0.35 X 10-10 cm2sec-1, and toluene 3.8 X 10-10 cm2sec-1. Flow rates were 50 percent lower across the bedding plane of the coal than along the bedding plane. Activation energies were 3.9 kcal mole-1 for helium and 13.6 kcal mole-1 for methane, with diffusion measured either along or across the bedding plane.

Jan 1, 1970