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By Robert F. Chaiken

More than 500 fires are now burning in abandoned coal waste banks and coal deposits in the United States. Once established, such fires can burn for decades, and extinguishing them by conventional methods such as surface sealing to exclude air, excavation to remove fuel, or flushing to cool the fire zone is usually difficult and always expensive. Burnout Control, a technique developed by the Bureau of Mines for the control of abandoned coal fires, involves the accelerated combustion of coal in place with total management of the heat and fumes produced. A burning waste bank or mine is placed under negative pressure relative to the atmosphere, and heat and combustion products are drawn from the combustion zone through an exhaust ventilation system. Heat produced appears as sensible heat in the exhaust, at temperatures as high as 1,000° C (1,832° F), and could be recovered for the production of steam, hot water, process heat, or electricity. The Bureau's first field demonstration of Burnout Control was at Calamity Hollow in Allegheny County, PA (near Pittsburgh). Calamity Hollow was the site of an underground mine in the. 1900's and was surface mined in the 1940's. In the winter of 1961~62, a fire of undetermined origin was discovered in the exposed coal. In 1963, the Bureau constructed a trench barrier around the fire and a surface seal over the affected area. The fire was isolated but, not completely extinguished. In 1979, when the Bureau began work on the Calamity Hollow Mine Fire Project to demonstrate controlled burnout, the fire was still smoldering on the hot side of the trench barrier. The project, which was begun in December 1979 and ended in July 1982, consisted of the design, construction, operation, and subsequent dismantling of a Burnout Control ventilation system. This report, although considered part 2, is actually the last of a five-part series that describes the Calamity Hollow Mine Fire Project. It was written last because it involved the analysis of a substantial body of data describing in detail the results of a continuous 4-month burnout operation. The first report, part 1, describes the design and construction of the field installation. Part 3 describes the instrumentation used to control and monitor the progress of the burnout operation. Parts 4 and 5 deal with the closeout phase of the field demonstration. Part 4 describes the procedure used to quench the fire, and part 5 describes the final excavation and backfilling of the heated zones. The reports in this series document the Calamity Hollow controlled burnout demonstration, which showed that (1) controlled in situ combustion is a feasible method for controlling underground fires in abandoned mines, (2) the resultant thermal exhaust output is suffIcient for energy utilization, and (3) water injection-fume exhaustion is a potentially effective method for cooling large underground fire zones. Further investigations of both Burnout Control and the water injection-fume exhaustion quenching procedure are planned.

Jan 1, 1989

Objective: To improve the effectiveness of dust collector capture on surface mine drills.

Oct 1, 2005

Develop a simple and economical technique for determining the absolute stresses and the change of stress on the surface of roofs, floors, or walls in miners. Approach Use a commercially-available, permissible, Whittemore-type gage to determine the stress at the surface of a mine opening and to monitor any stress changes that might take place. How It Works The following equipment is used: ? One steel templet (for laying out a 60° rosette on the: rock surface). See first photograph. ? One 3/8-inch rock drill bit for drilling holes for the rosette pins. ? Six stainless-steel rosette pins. ? One Whittemore-type mechanical strain gage. ? One drill (not shown). ? Epoxy for cementing the rosette pins. ? Tape to hold the pins while the epoxy sets. The following procedure is used to determine the absolute stress on the rock surface. 1) Spot the location of the rosette pins with the templet. 2) Drill the pin holes and set the pins with epoxy cement. 3) Measure and record the distance between the pins across three diameters of the rosette with a 10-inch Whittemore-type gage. See diagram. 4) Drill a 1 1/2-inch diameter hole in the center of the

Jan 1, 1981

By Stephen D. Cramer

The solubility of methane, carbon dioxide, and oxygen was measured in brines at temperatures from 0° to 300° as part of Federal Bureau of Mines research on the corrosion of metals in high-temperature geothermal and mineral processing environments. Solubilities were measured by the technique of extracting pure gas, dissolved at pressures where Henry's law was applicable, from known volumes of brine. The results were smoothed with respect to temperature. The solubility, expressed in terms of the Henry's law constant, reaches a maximum at temperatures ranging from 60° to 100° C for methane and oxygen, and from 160° to 170° C for carbon dioxide. The Henry's law constant increases, that is, gases are salted out of the brines, in the presence of dissolved salts. Salting-out coefficients are strongly dependent upon temperature. The temperature dependence of the Henry's law constant for geothermal brines is different from that for sodium chloride brines owing to the more complex chemistry of the geothermal brines. The solubility of oxygen and carbon dioxide in brines exposed to air saturated with water vapor and at a total pressure of 760 mm Hg is reported for temperatures from 0° C to the normal boiling point.

Jan 1, 1982

By Larry A. Haas

The U.S. Bureau of Mines investigated the use of organic binders as substitutes for bentonite in agglomerating iron ore concentrate. Over 30 organic binders were evaluated at several dosage levels in laboratory tests. The binder groups producing the greatest green pellet strengths were natural gums (guars carboxyl methyl celluloses) and gelled starches. The nongelled and alkalized starches, starch acrylic copolymers) wood-related products, and dairy products were less effective but better than bentonite. The highest wet pellet drop numbers were obtained with binders that had a medium plate water absorption value (>500 and <10)000) in distilled water and a high slurry viscosity (>75 cP) at 6 pet solids. The highest dry compressive strengths were obtained with binders that gave the highest adhesive tensile strength (>4 kg/ cm2) on iron oxide lap-joint substrates. Pellets with 0.1 pct organic binder had lower compressive strengths and reduction disintegration indices than those with 1 pct bentonite, but higher reduction rates. Pellets with carboxyl methyl cellulose and gelled starch had higher softening temperatures than those with bentonite. Overall, the most promising binder is gelled starch. Its price makes it more cost effective than carboxyl methyl cellulose, and its pellets have metallurgical properties superior to those of bentonite pellets.

Jan 1, 1989

By J. M. Kuchta

Ignition and flammability test methods were developed by the Bureau of Mines for use in the classification of flammable solids by the Department of Transportation. A rotating disk ignition apparatus and a flame-spread-rate apparatus are proposed for determining the ignitability and flammability, respectively, of most flammable solids. Extremely flammable solids, such as pyrophoric materials, are evaluated by determining their ease of spontaneous ignition in an environmental chamber at high-humidity conditions. Data are presented for various representative solids to show the reliability of the test methods for classifying the materials. A classification system is also proposed for use in government transportation regulations.

Jan 1, 1972

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

NIOSH continues to conduct respirable dust control research for surface mine blasthole drilling operations. Research areas have included testing variables (shroud leakage area, drill deck cross-sectional area, shroud height, collector-to-bailing airflow ratio, etc.) that have the most impact on respirable dust control, development of a dust collector inlet hood, development of a dust collector dump point shroud, and testing of a small diameter water separating sub. This paper summarizes the results of the aforementioned research that has been completed. Additionally, past dust control research for drilling operations of both underground and surface mines completed by the U.S. Bureau of Mines, created in 1910 and incorporated into NIOSH in 1997, is reviewed.

By F. P. Miknis

Previous studies at the Bureau of Mines have shown that broad-line nuclear magnetic resonance (NMR) techniques have potential applications for rapid evaluation of oil-shale deposits. In a continuation of this study the techniques of pulsed NMR have been applied in a similar manner. The basis for the pulsed NMR oil-shale assay method lies in the assumption that the free induction decay (FID) amplitude following a 90° pulse is proportional to the potential oil yield. This assumption was tested on two groups of oil-shale samples, numbering 141 and 263 samples, from two different oil-shale cores. For both groups of samples a small number were selected as calibration samples. Free induction decay amplitude measurements were made on the 141 and 263 samples. The best least-squares regression line was obtained for the calibration samples, and the oil yields of the remaining samples were calculated using the slopes and intercepts obtained in the regression analyses. The agreement between measured and calculated oil yields was good, the indexes of determination being 0.93 and 0.89 for the groups of 141 and 263 samples, respectively.

Jan 1, 1974

By Lawrence W. Scott

The performance of RETIMET metal foam as a flame arrester on explosion-proof enclosures was investigated by the U.S. Bureau of Mines both in laboratory tests and at the U.S. Mine Safety and Health Administration&apos;s (MSHA&apos;s) Approval and Certification Center, Triadelphia, WV. The objective of this research was to develop a permissible pressure vent for use on lightweight, vented, explosion-proof enclosures. In laboratory tests, four grades of RETIMET, a stainless steel foam material, were evaluated: (1) 45 NC-7, (2) 45 NC-13, (3) 80 NC-7, and (4) 80 NC-13. Explosive gas mixtures were prepared by a dynamic flow system. Ignition was by a low-voltage arc. Each grade of RETIMET metal foam successfully arrested the flame front in all methane-air tests. To evaluate RETIMET metal foam on large, commercial size enclosures,a multi compartmented enclosure was designed and tested in MSHA&apos;s explosion gallery in Triadelphia, WV. Extensive explosion testing revealed that a minimum vent-area-to-enclosure-volume ratio of 11.33 in2/ft3 is required to keep internal pressure rises below 3 psig. The RETIMET metal foam functioned satisfactorily in all tests as evidenced by the absence of external ignitions.

Jan 1, 2010

By H. William Zeller

The Bureau of Mines performed laboratory research to determine the effects of a barium-based fuel additive on diesel particulate emissions. The test engine was typical of types used to power underground coal min-ing equipment. Test parameters consisted of baseline measurements without additive, three fuel additive concentrations, and five steady-state engine loads, all at 1,200 r/min. Additive effects on soot mass concen-tration, opacity, particle size distribution, volatile fraction, and NOx emissions were determined. Important findings are as follows: Using the manufacturer&apos;s recom-mended additive concentration increased the gravimetrically measured mass of particulate by 30 to 80 pct at four of the five steady-state load conditions. Soot measurements by optical methods did not agree with those by gravimetric techniques, for additive-treated fuels. The additive reduced volatile hydrocarbons adsorbed on filter deposits by up to 50 pet. At most engine loads, carbon particulate was also reduced. About 40 pet of the barium added to the fuel was accounted for in the exhaust. The health implications for miners were considered, but no firm conclusions were drawn or recommendations made because the results are for steady-state conditions, which may not be representative of real-world operation of diesel-powered equipment underground.

Jan 1, 1987

By Bill M. Stewart, Philip W. Patton, Curtis C. Clark

Handling materials in underground mines continues to be a major safety problem. To help reduce materials-handling injuries, researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health are investigating those materials-handling tasks in underground mines that appear to generate a high number of injuries. Data from the Mine Safety and Health Administration for the years 1989-1999 were studied to find out if there were any trends in materials-handling accidents and if so, to determine what tasks were involved and the sources of injuries. Several underground coal and metal mines we revisited to document innovative materials-handling technologies. Considerations for safety training and mechanization needs for continued reduction in materials-handling injuries are described.

By F. N. Kissell

The applicability of the "direct method" for determining the methane content of virgin coalbeds was tested. Preliminary results indicate that the direct method, when applied to exploration cores, can be successfully used to estimate coalbed gas content and also approximately predict the total gas emission from a prospective mine located in the coalbed at the exploration site.

Jan 1, 1973

By A. J. Kraemer

The Bureau of Mines for a number of years has been carrying on an investigation of properties of crude oils from producing fields in the United States and has published a series of reports on different fields, including oil fields of Texas3. Production Data The Spindletop field was discovered in 1901 when the pay sand was found at deaths of about 800 feet. During the following twenty-five years a number of attempts were made to find a deep productive sand. All attempts sere failures until a roll drilled by the Yount Lee Oil Company found oil late in 1925. An intensive drilling campaign began at once, and the production of the Spindletop field increased to a daily average of 93,217 barrels in September, 1926; the present production is estimated at 66,000 barrels doily. Tile following table taken from the Oil and Gas Journal for February 10, 1927, shows the daily average and the total production by ninths for 1926.

Jan 1, 1927

By Lloyd A. Morley, Robert Stefanko

1 Abaibanel, S , "Deflection of Confining Walls by Explosive Loads," Israel Jour. Technology, vol. 4, n. 1, Feb 1966. 2 Albertoni, S and others, "Numerical Computation Methods for Implosion Processes," EURATOM Proc. of the Conf. on Megagauss Magnetic Field Generation by Explosives and Related Experiments, Milan (Italy), July, 1966. 3 Alexander, S. J , and Hambly, E. C., "Design of Structures to Withstand Gaseous Explosions," Concrete, vol. 4, n 2, Feb. and March, 1970. 4 Anonymous (Belgium Institute of Extractive Industries), "Report for 1968 (covering approved equipment for Belgiums gassy coal mines)," (in French and Flemish), Amales des Mines de Belgigue, n. 6, June, 1969. 5. Anonymous (Ghent Univ., Belgium), "The Welding of Very Thick Steels. Margin of Uncertainty of the Robertson Test," EURATOM Contract 042-61-9-RDB, May 20, 1965. 6. Anonymous, "Inportance of the Nature and Size of Weld Defects with Regard to the Mechanical Strength of Pressure Vessels, (in Flemish), A. Sys. Rev. Soudure, vol. 27, n. 3, 1971. 7. Anonymous (Raentgen Technische Dienst N V., Rotterdam), "Non¬Destructive Welding," Quarterly Report No 13, EURAEC - 1342, March 30, 1965. 8. Anonymous (Staff, USBM Safety Research Center), "Research and Technologic Work on Explosives, Explosions, and Flames: Fiscal year 1969," USBM IC8492, 1970. 9. Anonymous, "Symposium on Flameproofing Intrinsic Safety and Other Safeguards in Electrical Instrument Practice, April 27, 1962," IEEE Conf. Report Ser. 3, 1963. 10. Anonymous, "Unfired Pressure Vessels," ASME Pressure Vessel Code, Sec. 8, 1965. 11. Anonymous, "Unusual Pressure Relief Devices," Industrial and Engineering Chemistry, vol 54, n. 1, Jan., 1962. 12. Archer, G. L., "Design to Avoid Brittle Fracture in Welded Structures," Paper No. 4, Improving Welded Prod Design, vol. 1, Welding Inst., Cambridge, England, 1971. 13. Bailey, F. C., "Buckling and Failure Strength of Plating Panels Loaded in Shear," Final Report NASA Contract NObs-72290, Lessels and Assoc., Inc., Waltham, Mass., Sept. 20, 1963.

Jan 1, 1974

By Manuel Gomez

Dehydrogenation factors, proximate analysis, and ultimate analysis were examined as predictors of the low-temperature -carbonization properties of coals varying in rank from lignite through anthracite. All factors studied contributed to reduction in variance of the sample populations investigated. Response surface regression models based on variables from proximate and ultimate analyses of coal were constructed for eight low-temperature carbonization assay product and gas component Fields. These models were tested with independent samples that included drill cores, sized fractions, petrographic fractions, and run-of-mine coal. The models developed were used to predict low-temperature carbonization yields or coals from major fields of Wyoming. This information was cast in the form of contour plots describing the potential low-temperature carbonization product yields of Wyoming coals and the properties of the resultant char or coke. The variables used as input v the models may be measured and collected during exploration; thus, the carbonization properties of a seam can be determined in advance of mining. The information presented in this report is useful in that it broadens the deciionmaking base for management when either mine locations or coal conversicl plant sites, or both, are being considered.

Jan 1, 1971

By I. D. Shah

The copper-nickel ore of the Duluth Gabbro Complex in northeastern Minnesota is a large potential domestic resource of cobalt and platinum-group metals. However, because of the low grade of the primary metal values (0.5 pct Cu, 0.15 pct Ni), the private sector has assigned a relatively low priority to the development of technology for processing this ore, anticipating that mining probably would not begin until the mid-1990&apos;s. Furthermore, preliminary processing flowsheets considered by the mining companies centered on the primary metal values. As part of an effort to help provide the basis for technology to recover critical and strategic minerals from domestic resources the Bureau of Mines is investigating methods to recover all of the mineral values, in the Duluth Gabbro material, with particular attention to the byproduct critical minerals. A key step in this process is the removal of a relatively large amount of iron present in the bulk sulfide flotation concentrate to permit subsequent extraction of mineral values. This report describes a direct smelting method that removes most of the iron and produces a copper-nickel-cobalt matte, an intermediate product from which the metal values subsequently are separated. Copper, nickel, and cobalt grade and recovery data are presented for the direct smelting method. Test results showed that under certain conditions some of the mineral values reported to the slag, requiring slag cleaning to recover them.

Jan 1, 1983

By D. E. Hirsch

The Bureau of Mines has developed a systematic procedure for separation, characterization, and semiquantitative analysis of high-boiling (350° to 550° C) distillates of crude oils. Isothermal and molecular distillation were used to prepare the 370° to 530° C distillate of Recluse, Wyo., crude oil. The distillate was separated into fractions by chemical treatment, silica-alumina gel adsorption, and gel permeation chromatography (GPC). The fractions were analyzed by use of GPC correlations and mass and nuclear magnetic resonance (NMR) spectrometry. The increased knowledge of petroleum composition obtained from the data will contribute to improved petroleum processing and utilization and energy conservation.

Jan 1, 1974

Etching solutions containing hexavalent chromium ions (e.g., chromic acid) are used in brass finishing, printed circuit board etching, preparation of plastic for plating, anodizing, and various other industrial surface treatment operations. As the solutions are used, hexavalent chromium ions are reduced to their trivalent state, contaminants accumulate in the solution, and the effective acid concentration is reduced. When the etching rate becomes unsatisfactory for the particular operation, the solutions are discarded. This is a problem because the discarded solutions are pollutants, and because replacing the etching solution is expensive. The Bureau of Mines has developed a process for regenerating these spent solutions and returning them to the surface treatment operation without interrupting the etching process. An electrolysis cell containing anode and cathode compartments that are separated by permeable membranes, is used for regenerating the spent solutions. The spent chromic acid solution is fed to the anode compartment and sui (uric acid is circulated in the cathode compartment. Application of a steady electrical potential of a few volts dc across the electrodes causes the copper ions and other contaminants in the spent solution to migrate through the membrane to the cathode compartment where copper is plated onto the cathode. Zinc and the other contaminants remain in the sulfuric acid. At the same time, the complex, trivalent chromium ions in the spent solution are attracted to the anode where they are oxidized to their original hexavalent state. The regenerated solution in the anode compartment is then recycled back to the plant?s etching operation for reuse.

Jan 1, 1980

By B. Z. Zhong, T. Ong, W. E. Wallace, W. Z. Whong, Z. W. Gu, M. J. Keane

"Abstract-Diesel emission particles (DEP) from an engine operating on the Federal Test Procedure VDC were dispersed in an aqueous mixture of dipalmitoyl lecithin (DPL). a major component of pulmonary surfactant and saline and were tested for genotoxicity using the unscheduled DNA synthesis (UDS) assay with autoradiography techniques in cultured Chinese hamster lung cells. A DEP sample from the same source was dispersed in dimethyl sulphoxide (DMSO) and subjected to the same assay. Both dispersions (in DPL and DMSO) were found to induce UDS in a dose-related manner. After separation of the sample into supernatant and sediment fractions. the activity of the DEP sample was found to reside in the supernatant fraction for the DMSO-dispersed sample; and in the sedimentary fraction for the surfactant-dispersed sample. These findings further indicate that genotoxic activity associated with DEP inhaled into the lung may become bioavailable through the dispersion properties of pulmonary surfactant components.INTRODUCTIONTHE mutagenicity of diesel emission particles (DEP) has been studied intensively (LEWTAS and WILLIAMS, 1986). Carcinogenic effects of diesel exhaust in exposed animals have been reviewed (NIOSH, 1988) and an evaluation of carcinogenic risks to humans from diesel engine exhausts has been published (IARC, 1989). Using components of pulmonary surfactant such as dipalmitoyl lecithin (D PL), dipalmitoyl phosphatidylethanolamine (DPPE) or dipalmitoyl phosphatidic acid (DPPA) dispersed in physiological saline, we have previously shown that diesel soots express mutagenic activities in the Salmonella histidine reversion assay system and in the sister chromatid exchange assay using the cultured Chinese hamster lung (V79) cells. Mutagenic activity of diesel soots dispersed in DPL, DPPE and DPPA was quantitatively comparable to and in some cases greater than, the activity expressed by an equal mass of soot extracted by dichloromethane-dimethyl sulphoxide (DCM-DMSO) (WALLACE et al., 1989).Unscheduled DNA synthesis (UDS) is accepted and frequently included, as one of the tests in the battery of assays used to assess carcinogenic-mutagenic potential -of chemicals (MITCHELL et al., 1983). In this study, induction of UDS in V79 cells by DEP, dispersed in the major component of pulmonary surfactant DPL, was carried out. The purpose of this study is to validate the suggestion generated from our previous work that mutagens associated with inhaled particles may be dispersed or solubilized in the phospholipid component of pulmonary surfactant and become active in such a phase (WALLACE er al., 1989) and to test the fractionated DEP sample using UDS assay for a more complete evaluation of its genotoxicity."

Dec 1, 1995

By H. A. Tucker

This Bureau of Mines investigation was conducted to determine the appropriate quantities of rare-earth methals (REM) in the form of silicides to add to an alloy steel for the purpose of increasing toughness and ductility. The work was conducted in a vacuum induction furnace with the rare-earth additions required to deoxidize and desulfurize a simulated basic oxygen furnace (BOF) vacuum-degassed steel initially containing 0.013 to 0.016 percent sulfur. The product proved to be as good or better than the best basic electric furnace steel of the same composition made by the steel industry. Twenty-three experimental heats of 5 Ni-Cr-Mo-V steel were made, cast into 50-1b ingots, and hot-worked in a press and a rolling mill to ½ inch plates which were then heat-treated to 130/150 ksi4 yield strength. Impact and tension tests showed that the addition of 0.025 to 0.100 percent, or ½ to 2 lb per ton, respectively, of rare-earth metals when compounded with silicon were appropriate for increasing toughness and ductility. These quantities resulted in retained cerium contents between 0.014 to 0.025 percent, and increased the Charpy V-notch energy absorption and the percent reduction of area significantly as compared with base heats at the same sulfur content levels. All the test heats, including those with additions of REH of as much as 4 lb/ton, had greater Charpy V-notch energy absorption values than the base composition could have developed at the starting sulfur range of 0.013-0.016 wt pct.

Jan 1, 1968