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By Herbert H. Fields

The Bureau of Mines has been promoting health and safety in mining since its establishment in 1910. One area of research covers methane control in coalbeds; this report describes a multipurpose borehole used for both degasification and the production of commercial-quality gas. The multipurpose borehole was drilled into a barrier pillar, and seven horizontal degasification holes and one pressure point hole were drilled radially out from its perimeter. On January 28, 1974, after 505 days of degasification, a compressor was installed to the exhaust stack of the multipurpose borehole (1), and pipeline--quality gas was introduced into a commercial pipe-line. As of February 4, 1975, over 171 million cubic feet of gas had been purchased by the gas company. The in situ pressure at a depth of 200 feet into the coalbed and the average gas flow and water flow from the degasification holes as they were completed and closed off were 203 psig, 1,200,000 cfd, and 6.8 gpm, respectively. Twenty-four hours after the seven holes were connected through individual pipes to the atmosphere, the total gas and water flows and the in situ pressure dropped, respectively, to 971,000 cfd, 1.3 gpm, and 18 psig. Five hundred days later, the corresponding values were 620,000 cfd, 0.15 gpm, and 10.5 psig. Daily flows have been as high as 800,000 cfd, and as low as 360,000 cfd, during the last 500 days. On February 4, 1975, after 882 days of degasification, 576 million cubic feet of gas had been removed from the Pittsburgh coalbed; apparently a much larger area of virgin coal is being degasified than is defined by the holes. This study indicates that horizontal boreholes drilled into a coalbed from the bottom of any shaft will effectively remove gas from the Pittsburgh coalbed,

Jan 1, 1975

By Ivette E. Torres

The estimated value of world crude mineral production in 1992 was $1,633.3 billion in terms of current (1992) dollars, or $1,178.0 billion in terms of constant 1983 dollars. This latter figure was 4.8% above the 1992 level but was 2.4% below the record-high level of $1,207.1 billion 1983 dollars set in 1980. Table 1 provides the latest available revised time series of the estimated value of world crude mineral production both in terms of 1983 constant dollars and in terms of current dollars. The statistical base for this estimation is derived from the data on the value of production of a group of key commodities that was published in the authoritative French language mineral industry periodical, Annales des Mines, for selected years up to 1983. The aforementioned values and those presented in the table are for crude minerals only and only begin to suggest the impact that the mineral industry has on the world economy. These figures represent only the value of mineral materials as they are mined or otherwise extracted from the Earth. They do not reflect the value added to these materials through downstream processing within the facilities commonly accepted as mineral industry plants. That is, value added through beneficiation of ores, smelting, refining, and similar processing is not included in these figures. Comprehensive world data on the value added by such processing are not available; however, a conservative estimate of the total value of processed output from mineral industry plants derived wholly from primary (newly mined) materials would be on the order of about $2,800 billion constant 1983 dollars or $3,900 billion in terms of 1992 dollars.

Jan 1, 1994

By Maurice Deul, Herbert H. Fields, John H. Perry

The Bureau of Mines has been promoting health and safety in mining since its establishment in 1910. One area of research covers methane control in coalbeds; this report describes a multipurpose borehole used for both degasification and the production of commercial-quality gas. The multipurpose borehole was drilled into a barrier pillar, and seven horizontal degasification holes and one pressure point hole were drilled radially out from its perimeter. On January 28, 1974, after 505 days of degasification, a compressor was installed to the exhaust stack of the multipurpose borehole (2), and pipeline--quality gas was introduced into a commercial pipeline. As of February 4, 1975, over 171 million cubic feet of gas had been purchased by the gas company. The in situ pressure at a depth of 200 feet into the coalbed and the average gas flow and water flow from the degasification holes as they were completed and closed off were 203 psig, 1,200,000 cfd, and 6.8 gpm, respectively. Twenty-four hours after the seven holes were connected through individual pipes to the atmosphere, the total gas and water flows and the in situ pressure dropped, respectively, to 971,000 cfd, 1.3 gpm, and 18 psig. Five hundred days later, the corresponding values were 620,000 cfd, 0.15 gpm, and 10.5 psig. Daily flows have been as high as 800,000 cfd, and as low as 360,000 cfd, during the last 500 days. On February 4, 1975, after 882 days of degasification, 576 million cubic feet of gas had been removed from the Pittsburgh coalbed; apparently a much larger area of virgin coal is being degasified than is defined by the holes. This study indicates that horizontal boreholes drilled into a coalbed from the bottom of any shaft will effectively remove gas from the Pittsburgh coalbed.

Jan 1, 1975

By Thomas V. Falkie, R. Venkataramani

Anderson, L. B., 1963, "Multiple Regression Techniques Correlate Experimental Data," Chemical Engineering, V. 70, N. 12, pp. 223-228. Aubert, E. J., Lund, I. A., and Thomasell, A. J., 1959, "Some Objective Six-Hour Predictions Prepared by Statistical Methods," Journal of Meteorology, V. 16, pp. 436-46. Barrett, A. L., 1958, "Alternating Current in Continuous Mining," Mechanization, V. 22, N. 9, pp. 83-86. Bower, A. B., Jr., 1970, "Bit Design: Key to Coal Cutting," Coal Age, V. 75, N. 7, pp. 70-72. Bower, A. B., Jr., 1971, Personal Communication dated April 29, 1971; General Electric Company, Mining and Metallurgical Products Department, Detroit, Michigan. Burt, C., 1950, "Group Factor Analysis", British Journal of Statistical Psychology, V. 3, pp. 40-75. Cady, L., Gertler, M., Gottsch, L., and Woodbury, M., 1961, "The Factor Structure of Variables Concerned with Coronary Artery Disease", Behavioral Science, V. 6, pp. 37-41. Cattell, R. B., 1965, "Factor Analysis: An Introduction to Essentials I. The Purpose and Underlying Models," Biometrics, V. 21, N. 1, pp. 190-215. Christensen, R. W., Heins, R. W., Babcock, W., and Tonn, R., 1971, "The Effect of Material Properties on Materials Handling Processes," Six Month Technical Report, (August 1971) to Advanced Research Projects Agency, U. S. Department of Defense; The University of Wisconsin. Collins, G., 1961, "Factor Analysis," Journal of Advertising Research, V. 1, N. 5, pp. 28-37. Cooley, W. W., and Lohnes, P. R., 1962, Multivariate Procedures for the Behavioral Sciences, New York: John Wiley and Sons, Inc. Cree, J. 0., 1956, "Power for Continuous Mining," Mining Congress Journal, V. 42, N. 10, pp. 49-52. Draper, N. R., and Smith, H., 1966, Applied Regression Analysis, New York, John Wiley & Sons, Inc. Griffiths, J. C., 1966, "A Genetic Model for the Interpretive Petrology of Detrital Sediments," The Journal of Geology, V. 74, N. 5, pp. 655-672.

Jan 1, 1972

By D. B. Starkey

Investigation into the expressions of the field produced by a loop over a conducting half space or in an infinite conducting half space are well documented. Reasonably complex descriptions of the effects of stratification also are reported. However, a model which must contain all of these complexities because of transmission to depths of 15,000 feet and also include the pertibation of the field by a verticle cylindrical steel casing loses its facility in the field or for quick, accurate approximation to field magnitudes and phase. This paper describes the results of two field tests to determine the attenuation and phase versus depth and frequency of an electromagnetic wave (induction field). A simple two-layer model is postulated to predict the magnitude and phase of the induced field which does not require sophisticated computing tools. Correlation of the model with experimental results show agreement of most amplitude measurements to within 3 db and most phase measurements to within five degrees. The tests were conducted in a 7400 foot deep well in Nevada and an 11,000 foot deep well in Wyoming which had conductivities ranging from .0025 mhos/m to .25 mhos/m. The surface transmitting dipole had an area of ~ 10 6 feet squared and constant frequency signals of 1.5 Hz to 20 Hz were transmitted through the earth utilizing less than 65 watts of power. Model Description The magnetic field intensity components generated by a magnetic dipole immersed in an infinite homogeneous medium can be expressed in spherical coordinates as: [ ] where N, I, and (p a ) are the transmitting antenna turns, current, and effective area, respectively, and r is the range from the loops circumference to the measurement point. The case of interest for these experiments, however, is the special case of coaxial dipoles, i.e., ? = 180° . For this case H?= 0 and H reduces to: [ ]

Jan 1, 1973

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

Ahmed, M.,• "Development of an Integrated Control System for Mine Ventila¬tion and Firedamp Drainage," Mining Engineer, Vol. 127, No. 91, April, 1968, pp. 382-392. Andrews, J. W., "U. S. Mine Ventilation Standards," Paper presented at the International Mine Ventilation Congress, Sept., 1975. Boyle, J. A., and Conn, 0. S., "The Control of Mine Ventilation Utilizing Multiple Main Fans," Paper presented at the Seventy-second Annual CMIA Meeting, Pittsburgh, December 1958. Collinson, P. L., and Vance, W. E., "Mine Ventilation Planning," The Mining Engineer, Volume 121, No. 14, 1961, pp. 141-156. Committee on Industrial Ventilation, Industrial Ventilation, 12th Edition, 1972. Grever, R. E., "Automatic Monitoring of Ventilation Conditions in European Coal Mines," Symposium on Engineering Systems Design for Mine Safety, Michigan Technological University, August 1973. Hall, C. J., Airflow in Mines - Thermodynamic and Motive Column Analyses, The Book Concern, Printers, Inc., Hancock, Mich., 1967, 263 pages. Hargraves, A. J., "Planning and Operation of Gaseous Mines," Canadian Mining and Metallurgical Bulletin, Vol. 66, No. 731, March 1973, pp. 119-128. Harris, E. J., "The Fluid Network Analyzer as an Aid in Solving Mine Ventilation Distribution Problems," SME-AIME Transactions, Vol. 228, 1963, pp. 391-395 Higgins, J., and Shuttleworth, S. E. H., "A Tracer Gas Technique for the Measurement of Airflow in Headings," Colliery Engineering, November 1958, Vol. 35, pp. 483-487. Kaiser, K. M., and Bhowmick, B. C., "Recent Developments in Mine Ventila¬tion Instrumentation," Journal of Mines, Metals & Fuels (INDIA), June 1974, pp. 155-162. Kalasky, J. D., and Krickovic, S., "Ventilation of Pillared Areas by Bleeder Entries, Bleeder Systems, or Equivalent Means," Trans¬actions AIME, Volume 254, December 1973, pp. 284-291. Mahajan, J. K., "Ventilation Planning for a Deep Metal Mine," Min. Geol. Met. Inst. India, Volume 69, 1972, pp. 31-38.

Jan 1, 1977

By B. K. Cantrell, K. L. Rubow

"Quantifying exposure to diesel exhaust aerosol in an underground coal mine depends on the ability to measure this component of respirable mine aerosol separately from coal dust. Such measurement is complicated by the carbonaceous nature of both the diesel and coal dust particulate that make up the respirable aerosol. Hence, special sampling and analytical techniques must be used to distinguish between these two aerosol components.As part of a continuing study of diesel exhaust aerosol characteristics, the U.S. Bureau of Mines has applied size selective sampling together with gravimetric analysis to separate and measure respirable diesel exhaust and coal dust aerosol concentrations in diesel-equipped underground coal mines. This technique is based on the premise that the diesel portion of the aerosol is predominantly submicrometer and the mineral dust portion is mostly greater than 1 µm in size. In the study, chemical mass balance (CMB) modeling, based on the distribution of chemical elements in aerosol and aerosol source material samples, is used to referee the analysis of diesel exhaust and mineral dust aerosol concentrations from the size selective sampling results.Based on the results of the study, the Bureau, in cooperation with the University of Minnesota and the U.S. Mine Safety and Health Administration (MSHA), have developed a prototype personal diesel exhaust aerosol sampler for underground coal mines. The sampler has three stages: a preclassifier stage to select for respirable aerosol, an inertial impaction stage with an aerodynamic diameter(d) size cut at 0.8 µm to separate diesel aerosol from mineral dust and collect the mineral dust, and a final filtration stage to collect the diesel fraction of the sample. The sampler has been evaluated in both laboratory and field experiments conducted by the Bureau, MSHA, and the Generic Minerals Technology Center for Respirable Dust (GMTC-RD)."

Mar 1, 1992

By Charles Vaught, Belinda Sue Mills, Henry P. Cole, William J. Wiehagen

This study reports the results of a survey of organizations that used problem-solving simulation exercises to support mine health and safety training. The exercises are designed to teach judgment and decision-making skills within two broad domains: (1) how miners respond to mine emergencies (e.g., first aid, self-rescue, and escape) and (2) how miners integrate safety concepts within the context and performance of routine production work. The simulation exercises were distributed by the Mine Safety and Health Administration's National Mine Health and Safety Academy near Beckley, WV. The present study focused on those organizations that ordered the exercises from the Academy over a 2-year period (1995-96). Researchers assessed how the materials were used and trainer perceptions of the impact of these materials on annual mine health and safety training . A total of 147 organizations ordered the exercises over the 2-year period. Survey responses were obtained from 52 of these organizations. Sixty percent of the respondents rated the exercises as more useful than traditional instructional materials, 40% as equally useful, and 0% as less useful. Most trainers (79%) felt that the exercises help them to make better use of workers’ knowledge and experience during training. Many (71%)also reported that the simulations helped to improve the effectiveness of their instruction and promoted a problem-solving approach to their training. Fifty of the fifty-two respondents reported that they would like to have new simulations developed. A large majority showed a proactive interest in helping to develop and field test new exercises. Ninety-four percent of the trainers judged the exercises as a good value; 92% planned to order more simulations in the future. Based on this study, recommendations are offered for the continuation and expansion of simulation exercises as one method for occupational health and safety training.

Jan 1, 2001

By R. E. Head, Virgil Miller

"Under existing conditions in the treatment of oxidized lead ores containing small quantities of molybdenum no provision is made for the recovery of the molybdenum. Considerable quantities of this important element are lost in the slags of the lead smelters and constitute an economic waste. There is little or no probability that slag dumps containing molybdenum in small quantities could be economically treated for the recovery of the element, and steps for the prevention of waste in this respect must be taken prior to smelter treatment.Wulfenite, lead molybdate (PbMo04), and molybdite, molybdic ocher (Mo03), are the molybdenum minerals most abundantly found in deposits of oxidized lead ores. Wulfenite contains 39.3 per cent molybdenum trioxide and 60.7 per cent lead oxide; molybdite contains 66.7 per cent molybdenum and 33.3 per cent oxygen. Plumbojarosite, argentojarosite, cerussite, and occasionally anglesite are commonly associated with wulfenite ores, and the oxidized iron content is usually fairly high.The recent discovery and development of a body of wulfenite ore in the Star district near Milford led to a cursory microscopic examination of samples of the ore, followed by a few preliminary tests which had for their object the separation and recovery of the lead and molybdenum in separate products.The microscopic examination showed that the samples used in the work were composed of wulfenite, plumbojarosite, and a small quantity of cerussite, and indicated that the iron content was quite high. The ore was porous and yellowish-brown; crystals of wulfenite appeared to be quite uniformly distributed through it, and this mineral and plumbojarosite (Pb0.3Fe203.4S03.6H20) apparently accounted for the major part of the lead content, although lead"

Sep 1, 1928

Only limited work has been reported in the literature about the use of latex in soil. Unisol 91 2,3 (a 9:l oil-latex emulsion made b International Synthetic Rubber Company) and Phil1ips Petroset4 geotechnic emulsions are surface soil stabilizers which penetrate a maximum of two inches, but do not reduce permeability. Diamond Alkali 5 found that styrene-butadiene rubber latex as a one percent latex-soil mixture reduced permeability to 0.7 from 21 feet per year under a head of twenty feet of brine. We have found no literature reference for use of latex as sealant at depth in the soil, although asphalt has been applied at depth using civil engineering methods6,7. Most of the materials investigated as soil sealants in the present work were latexes, although some studies were also conducted with a variety of inorganic and organic chemicals. Of the latexes tested, most were rubber but a few were plastic, e.g. polyvinyl chloride. Sealants examined in this investigation are listed individually in Table I with supplier, code number, and other pertinent information. The materials consisted of the following general classes with additional details as indicated: 1.Anionic latexes: a. styrene-butadiene copolymers and terpolymers (SBR) b. butadiene-acrylonitrile copolymer (Paracrils®) c. polyvinyl chloride homopolymers and copolymers (WC) d. ethylene-propylene terpolymer e. vinyl acetate homopolymers and copolymers (VA) f. acrylics (acrylate copolymers) g. 2-chlorobutadiene homopolymer (chloroprene) (prepared specially as cationic material coagulated by soil). 2. Water Soluble polymers: a. polyvinyl ether b. methylcellulose c. polyethyleneimines d. polyacrylic acid homopolymer e. copolymers and terpolymers with acrylic acid types (water soluble as sodium or ammonium salts) f. alginates g. monomers (for polymerization in soil, e.g. acrylamide)

Jan 1, 1972

By John C. Edwards, Gene F. Friel, John J. Opferman, Robert A. Franks

As the use of deep -rut mining increases, there - expected to be a greater demand for methane (CH,) measurement devices capable of scanning working faces al depths in excess of 10 m to alert mine personnel of hazardous concentrations of CH and to satisfy regulatory requirements. Remote optical devices offer the most promise to satisfy these objectives while the operator remains safely under supported roof. A second¬-generation remote Optical methanomeor (ROM) bas been designed and Is undergoing laboratory evaluation at the National Institute for Occupational Safety and Health. It operates on the principle of differential absorption of the "u;' fundamental absorption band of CH, centered at 3.31 um in the infrared region of the spectrum. The new instrument differs from the previous prototypes by the replacement of the two hand pass differential absorption technique of measurement with a single filter gas correlation technique and a refinement of the amplifier and gating circuitry used within the unit. This results in a more accurate isolation of the CH, spectral absorption band centered at 3.31 um. A specially designed 0.4m-diam variable-length gas mixing tunnel was constructed and instrumented with CH4 sampling capability to calibrate the ROM. Experiments have demonstrated the ability of the detector to respond to various conditions of CH, (pn•m) at distances as great as 12 m. Thermal radiation generated within the instrument is the controlling factor in the drift of the output signal nod, therefore the reliability of the instrument. Several approaches to reduce this extraneous radiation interfering moth the infrared detector, described, such as the installation of a fan in the instrument and thermoelectric coolers on the detector's beat sink. Implementation of this technology will significantly improve the safely of miners.

Jan 5, 1997

By W. W. Adams, E. E. Getzin, T. D. Lawrence

"The thirteenth annual accident-prevention competition conducted by the Bureau of Mines during the calendar year 1937 was completed with 318 mines and quarries participating. This contest, known as the National Safety Competition, is open to all minas and, quarries employing 25 or more men underground or in the quarry or open pit. The entries are divided into five groups to obtain as nearly as possible uniformity of operating conditions and hazards. The five divisions are: (1) Underground anthracite mines, (2) underground bituminous-coal mines, (3) underground metal mines, (4) underground nonmetal mines, (5) quarries and open-pit mines. A bronze trophy, known as Sentinels of Safety, provided by the Explosives Engineer magazine, is awarded to the winner of each group. The trophy is kept by the winning company 1 year and then transferred to the winner of the succeeding year's contest. Certificates of Honorable Mention are given to plants ranking second, third, fourth, and fifth in each group and to all plants operating without a lost-time accident provided the period of exposure to hazard was not less than 30,000 man-hours. Relative standing in the contest is determined by the contestant's accident-severity rate, which represents the total number of days of employee disability from accidents per thousand man-hours worked by all employees.The 1937 contest was outstanding in that the accident-frequency rate for the contest group as a, whole was the lowest on record. Moreover, with one exception 1934, the accident-severity rate was the lowest ever attained: For frequency, 3S.0 accidents per million man-hours worked; and for severity, 8.2 days lost from accidents per thousand man-hours worked. The rates represent a decline of 62 percent in accident frequency since 1925, the first year of the contest, a remarkable accomplishment both for the contest group and for the purpose of the contest because a majority of the contestants have not only participated during the past year but have been enrolled several years, some enrollments even dating back to 1925."

Aug 1, 1938

By Ronald D. Hill, Elmore C. Grim

1.In 1972 over 595 million tons (51+0 million metric tons) of bituminous coal were mined; 49% of this tonnage was obtained by surface mining methods. Authorities have predicted that the tonnage of surface mined coal will increase in the future, especially since oil and gas resources are becoming limited. 2. Demands for clean air have increased mining activities in the low-sulfur coal deposits in the West. Pollution problems arising from these operations will be considerably different than those found in the East. The deposits are located in arid to semi-arid regions. Coal seams are generally aquifers and are a principle source of fresh water. Therefore mining may result in alteration of groundwater distribution patterns by aquifer disruption. In general, pollution problems associated with western mining are not well characterized. 3.Since any disturbance of the surface will alter the environment in the vicinity of the disturbance, pre-mining planning is a prerequisite to any environmentally successful surface mining operation. If properly carried out, the adverse social, economic, and environmental effects of coal surface mining will be minimized. Certain land areas will be unsuitable for surface mining where: a.Reclamation is not physically or economically possible. b.Mining is incompatible with existing land use plans. c.The proposed mining area is of critical environmental concern. Core drilling is the most satisfactory method of obtaining accurate information for pre-mining planning. 4. Unaccountable strip mining in the past has created problems that are still present today. Contour mining methods that involve the indiscriminate dumping of overburden on the downslope is one of the largest single sources of sediment from strip mining. However, land disturbed by strip mining can be reclaimed. Techniques have been and are being developed by which mining and reclamation are integrated into a single operation. Mountain top removal, head-of-hollow fill, and block cutting are examples in contour surface mining. These methods drastically reduce pollution problems associated with contour stripping.

Jan 1, 1974

By Richard Mainiero, James H. Rowland

For many years there have been small scale tests available for evaluating the toxic fumes production by cap-sensitive explosives (DOT Class 1.1), but these could not be used with blasting agents due to the large charge sizes and heavy confinement required for proper detonation. Considering the extensive use of blasting agent in construction and mining, there is a need to determine the quantities of toxic fumes generated by blasting agents. At the International Society of Explosive Engineers Twenty Third Annual Conference on Explosives and Blasting Technique in 1997, the authors reported on a facility for detonating large (4.54 kg), confined blasting agent charges in a controlled volume that had been constructed at the National Institute for Occupational Safety and Health’s Pittsburgh Research Lab’s Experimental Mine. Since 1997, this facility has been used to collect data on toxic fumes produced by the detonation of various ammonium nitrate/fuel oil (ANFO) mixtures and several cap-sensitive explosives. ANFO composition ranging from 1 to 10 percent (pct) fuel oil have been studied. As expected from previous studies, with an increase in fuel oil content the carbon monoxide production increases, while nitric oxide and nitrogen dioxide production decrease. The detonation velocity varies from 3,000 to 4,000 m/sec for the 1to 10 pct range of fuel oil content, suggesting that ANFO mixes with improper fuel oil content may appear to detonate properly, while their fume production differs significantly from optimum. The study also considers such factors as degree of confinement, water contamination, and aluminum content on blasting agent fume production. Results indicate that water contamination of the ANFO has little effect on carbon monoxide production, but causes significant increase in nitric oxide and nitrogen dioxide production. Decreasing confinement from Schedule 80 steel pipe to 0.4-mm thick sheet metal also has little effect on carbon monoxide production, but significantly increases nitric oxide and nitrogen dioxide production. Adding5 and 10 pct aluminum to the ANFO had no clear effect on carbon monoxide, nitric oxide, or nitrogen dioxide production.

By Donald P. Tuchman, Robert P. Vinson, Steven J. Page, Linda J. McWilliams, Gerald J. Joy, Steven E. Mischler, Jon C. Volkwein

The United States National Institute for Occupational Safety and Health, through an informal partnership with industry, labor, and the United States Mine Safety and Health Administration, has developed and tested a new instrument known as the Personal Dust Monitor (PDM). The new dust monitor is an integral part of the cap lamp that coal miners normally carry to work and provides continuous information about the concentration of respirable coal mine dust within the breathing zone of that individual. Previous laboratory testing demonstrated that there is a 95% con?dence that greater than 95% of individual PDM measurements fall within ±25% of reference measurements. The work presented in this paper focuses on the relationship between the PDM and respirable dust concentrations currently measured by a coal mine dust personal sampler unit utilizing a 10 mm Dorr Oliver nylon cyclone. The United Kingdom Mining Research Establishment instrument, used as the basis for coal mine respirable dust standards, had been designed speci?cally to match the United Kingdom British Medical Research Council (BMRC) criterion. The personal sampler is used with a 1.38 multiplier to convert readings to the BMRC criterion. A strati?ed random sampling design incorporating a proportionate allocation strategy was used to select a sample of mechanized mining units representative of all US underground coal mines. A sample of 180 mechanized mining units was chosen, representing approximately 20% of the mechanized mining units in production at the time the sample was selected. A total of 129 valid PDM/personal sampler dust sample sets were obtained. A weighted linear regression analysis of this data base shows that, in comparison with the personal sampler, the PDM requires a mass equivalency conversion multiplier of 1.05 [95% C.I. (1.03, 1.08)] when the small intercept term is removed from the analysis. Removal of the intercept term results in a personal sampler equivalent concentration increase of 2.9% at a PDM measurement of 2.0 mg m-3.

By Arnold J. Farstad

The Location Group conversed in the Petroleum Room of the Green Center with the purpose of addressing the following list of topics in light of the Bureau of Mines' requirements for detecting and locating trapped miners by electromagnetic methods. These topics include: Noise, Sources, Antennas (transmit and receive), the Propagation Medium, Signal Processing, Optimum Frequency, Receivers, Pulse vs. CW Techniques, Passive Location Techniques, and Obstacles. Practical constraints such as equipment size, weight and power requirements, cost and intrinsic safety were kept in mind during these discussions. It was emphasized that in-mine equipment must be inexpensive, rugged, simple and lightweight. Otherwise, the mine operators probably would not buy it nor would the miners be able to effectively use it. Present techniques for experimentally detecting and locating trapped miners were discussed, along with techniques to improve their location accuracy. Analytical, numerical, and scale modelling methods were considered as a means of giving further insight into measurement, anomalies caused by terrain variations, conductivity contrasts, and obstacles. After discussion of these topics, conclusions were drawn and existing problem areas were identified. These problem areas were addressed in developing guidelines for future efforts. Following the discussion period, the Chairman gave a summary of the Location Group report and comments were solicited from the entire group. 2.0 GROUP DISCUSSION HIGHLIGHTS 2.1 Noise W. Bensema asked the group whether the noise data provided by NBS was adequate. It was determined that for location systems analysis, the most important form of noise data was the frequency spectra of vertical and horizontal magnetic fields on the surface, and the answer to his question was affirmative. Drs. Wait and Frischknecht pointed out the difficulty in accurately measuring the true vertical magnetic field since these measurements are heavily influenced by the loop setting and the local geology. Nevertheless, these measurements are important since the same perturbations would also affect a receiving loop oriented to receive the vertical magnetic field. Dr. Rankin pointed

Jan 1, 1973

By W. P. Yant, R. R. Sayers, G. W. Jones

In the treatment of any illness the early diagnosis is of very great importance . This is especially true in cases of carbon monoxide poisoning , whether acute or sub-acute in character. A diagnosis of CO poisoning is usually made from a correlation of the history , the possible place of exposure , and the symptoms produced . This , however, is not positive evidence because CO often is present in unsuspected places and can be absent in suspected places . Also , the symptoms of this type of poisoning are common to other causes . In many such cases the correct diagnosis may be very difficult , if not impossible by this method and as a result little or no treatment is given . Sub- acute cases , those in which the subject is exposed to concentration sufficient to cause only headaches , malaise , feeling of weakness and dizziness , may be incorrectly diagnosed and as a result , improperly treated . Probably the best method of diagnosis is by examination of the subject's blood . Many methods for the detection of CO in the blood have been developed , but owing to their various individual disadvantages have never come into common usage . Some of the quantitative methods are satisfactory with regard to accuracy but require elaborate and expensive apparatus , special technique and training, or are too delicate and cumbersome for field use . It is of vital importance in all industrial and domestic accidents occuring at places where CO might be suspected or where the symptoms are typical of CO poisoning that a qualitative and preferably a quantitative determination be made the extent of poisoning being of importance in deciding whether CO was the direct or contributary cause) to show the presence or absence of 0. This is indeed essential from a medical standpoint as it aids in prescribing treatment and from a legal standpoint to insure justice in the claims that are often unjustly decided for want of positive evidence.

Jun 1, 1923

By E. D. Regad, W. E. Wallace, V. Vallythan, V. Castranova, P. Hathaway, F. H. Y. Green, M. J. Keane

"Abstract—Inhaled particle contact with pulmonary surfactant in the hypophase lining pulmonary alveoli was modelled in vitro by exposing two respirable sized dusts, kaolin and silica quartz, to lecithin, a major component of pulmonary surfactant, emulsified in physiological saline. Lecithin adsorbs to the dusts upon incubation at 3TC and suppresses their cytotoxicity as measured by pulmonary macrophage and erythrocyte assays, suggesting that pulmonary surfactant provides a defence system against prompt cell membrane lysis by inhaled dusts. Subsequent pulmonary macrophage phagocytosis and lysosomal enzyme digestion of the coated dusts was modelled in vitro by incubation with phospholipase A2 for one hour. With increasing lipase activity, silica haemolytic potential was restored to native silica levels. Kaolin was retoxified to levels far in excess of native kaolin haemolytic potential. Elution, thin layer chromatography and phosphate assay of treated dusts indicate that most lecithin on silica is digested to lysolecithin and desorbed, silica retoxification being due to surface and adherent lysolecithin effects. Most lecithin on kaolin is not digested in the same time; that which is. results in adherent lysolecithin which is responsible for the kaolin retoxification. Digestion with phospholipases A2 and C together produces only weakly retoxified kaolin. Results suggest that surface adsorption properties which control the adherence of prophylactic surfactant distinguish the pathogenic potentials of quartz, kaolin and mixed dust.INTRODUCTIONERYTHROCYTE HAEMOLYSIS and pulmonary macrophage enzyme release assays show quantitatively comparable high cytotoxicities for both silica quartz and kaolin respirable sized dusts (BROWN, et al., 1980; DANIEL and LE BOUFFANT, 1980.) This contrasts with the strong potential for respirable quartz dust to induce pulmonary fibrosis and the much more limited potential of kaolin dust to do the same (MORGAN and SEATON, 1975).In an attempt to understand this anomalous situation, assays were performed on quartz and kaolin dusts incubated with dipalmitoyl lecithin emulsified in physiological saline, to simulate the initial contact of a respired dust with the pulmonary alveolar hypophase. The ability of kaolin dust to adsorb dipalmitoyl lecithin from physiological saline has been quantified (WALLACE, et al., 1975). Such lecithin treatment suppresses the cytotoxicity of both silica and kaolin to background levels (WALLACE, et a1.,1984).Surfactant coated detoxified dusts should then be phagocytised by pulmonary macrophages, incorporated into a macrophage secondary lysosome and exposed to hydrolytic lysosomal enzymes. Among these is phospholipase A2, which hydrolyses diacyl lecithin to lysolecithin. This was modelled by incubating lecithin treated dusts with phospholipase A2 in vitro to determine if the enzyme can digest the dust-adsorbed lecithin, and if the retoxification differs between the two dusts in a manner which might distinguish their pathogenicity."

Jan 1, 1988

"In sum, significant benefits to mine worker health have resulted and should continue to result from the synergistic scientific, engineering, and medical research in respirable dust. As always, an important objective is the rapid dissemination of the results of this research to industry. Video tapes and the Technology News series published by the United States Bureau of Mines (USBM) have been a very effective means of technology transfer. Individual no-cost subscriptions to the Technological News series are available from the Bureau of Mines, Branch of Technology Transfer, 2401 E St., N.W. Washington, DC, 20241.Two respirable dust conferences have been jointly sponsored by the Center, USBM, NIOSH, and MSHA. The proceedings from these conferences are titled:1. Coal Mine Dust Conference held in Morgantown, West Virginia on October 8-10, 1984 and2. Respirable Dust in the Mineral Industries: Health Effects, Characterization and Control held in University Park, Pa. on October 14-16, 1986.Copies of the proceedings from the first conference are available from the National Technical Information Service (NTIS):National Technical Information Service5285 Port Royal RoadSpringfield, VA 22161NTIS # PB86-169380Telephone Number: (703)487-4650Copies of the second conference proceedings, ISBN: 0-936712-76-7 (publication #3010), are available from ACGIH by writing toWilliam D. KelleyExecutive Director, A.C.G.I.H.6500 Glenway Avenue, Building D-FCincinnati, Ohio 45211Telephone Number: (513)661-7881During the period 1984-1987 more than sixty-four (64) papers and publications have been produced by the Center researchers. These publications have appeared in scientific journals and have been presented at national and international symposiums and meetings. A list of these papers, organized by topical headings, has been included in this publication.The generic center maintains a reference center that serves as a clearinghouse for technical information for the generic area and supplies reports on generic center accomplishments."

Nov 1, 1988

By Thomas C. Ruhe

The Bureau of Mines conducted research to determine the safe operating conditions for using recycled (used) lubricating oil from mining equipment as a partial replacement for diesel fuel to make ANFO-type blasting agents. The use of recycled oil (RO) saves energy, reduces oil imports, and reduces mining costs. Low ambient temperatures may cause these recycled oils to become too viscous for proper absorption by ammonium nitrate (AN) prills and result in poor blast performance, safety hazards, and environmental problems. To help quantify and resolve these issues, viscosity, mixing, and performance tests were conducted at various temperatures. Diesel fuels No. 1 and No. 2 were studied separately and in blends with 25,50, and 75% RO. Good quality ANFO mixes (94-6) were produced with dry absorbent prills and blended fuel (No. 1 diesel plus RO) at temperatures as low as -40° F (-40°C) with 75% No. 1125% RO, and at -20°F (-29°C) with 50/50. Diesel fuel No. 2 also made good mixes as low as -30" F (-34" C) with 75% No. 2/25% RO, and at 0° F(-18° C)with 50/50. Reference detonation velocity tests were conducted in 1.4" (3.6 cm) diameter steel pipe at 70°F (21°C) on No. 1 diesel ANFO (94-6), giving an average value of 9722 ft/s (2964 m/s). Comparison tests showed good ANFO performance at low temperatures. Blended fuel ANFO (75% No. 1/25% RO) mixed, loaded, and tested at -40°F (-40°C), produced an average velocity of 9247 Ws (281 8 m/s). A 50/50 blend gave a velocity of 8083 Ws (2464 ds) at -20°F (-29°C). Based on these results, a practical field method has been developed to help evaluate whether a specific oil blend will mix properly with AN at a low ambient temperature. This method will help to promote the safe and reliable use of RO ANFO at low temperatures, with adequate performance.

Jan 1, 2008