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By F. J. Gallagher

The purpose of this circular is to present information on the construction and use of reinforced rubber-jacketed tubing and insulating air-line couplings in coal mines where Airdox is used for breaking coal in order to eliminate, insofar as possible, arcing at the face between Airdox tubing and the track or other face equipment.

Sep 1, 1949

By Bernard Porter

The rate of the heterogeneous reaction between high-purity uranium metal and uranium tetrafluoride in molten lithium fluoride was measured. The apparent heat of activation for the reaction is 16.91 kilocalories per mole of UF4. A surface-controlled mechanism is suggested in which UF4 is adsorbed on the uranium metal surface. Additional UF4 reacts with the adsorbed species and the metal site to form an activated complex that decomposes to the product UF3. The reaction is an important source of metal loss in the electrowinning of uranium metal.

Jan 1, 1966

By Walter R. Storms, Jerry W. FAUST

This paper, which describes mining methods and costs at the Kearney zinc-lead mine, is one of a series being prepared by the Mining Division of the Bureau of Mines on mining practices, methods, and costs in varicus mining districts of the United States. The Kearney mine, which is owned by the New Mexico Consolidated Mining Co., a subsidiary of the Peru Mining Co. (Illinois Zinc), is situated a few miles southeast of the town of Hanover, in the northwest corner of sec. 27, T. 17 S., R. 12 W., in the Central Mining District, Grant County, N. Mex. (Figs. 1 and 2.) This report presents a brief history of the district, describes the geology, and outlines methods of prospecting and exploration, including eampling and estimation of tonnages and values. Development and mining methods are explained, and transportation, ventilation, drainage, safety measures, and organizatich are described. The wage scale and mining costs comprise the concluding sections of the report.

Jun 1, 1949

By P. L. Loyselle, B. D. Comilsen, D. H. Carlson, J. H. Johnson

"In-mine airborne particulate samples have been successfully collected and the relative amounts of diesel and coal determined using the Laser Raman Quantitative Analysis (LRQA) method. This method allows analysis of filters which have been collected by a method similar to that used to determine the airborne respirable dust concentration in us underground coal mines. Samples were taken near the feeder-breaker, on haulage vehicles, and in the returns. Sampling methodologies were developed for coal-only and diesel-only particulate reference samples with sufficient filter loading for the LRQA method. A statistical analysis of reproducibility has been carried out. Samples have been collected simultaneously at two locations using the LRQA and the size-selective sampling methods. Good agreement between the two methods has been found.INTRODUCTIONThe goal of this research has been to develop the Laser Raman Quantitative Analysis (LRQA) method to measure the composition of respirable particulate, i.e. the fractions of coal and of diesel particulate, in the mine ambient air. In earlier Bureau of Mines sponsored research, we successfully demonstrated that the LRQA method could be used to measure the fraction of Diesel Particulate Matter (DPM) in coal/diesel particulate mixtures which were prepared in the laboratory.(I) 'The immediate objective was to test and refine this LRQA method on samples collected in a diesel underground coal mine.Specific objectives required to meet this goal include:I) Develop in-mine sample collection methods which will insure sufficient particulate loading on filters for LRQA. ,2) Develop methodology for in-mine collection of reference samples (""coal-only"" and ""diesel-only"" filters) which arc required for quantitative LRQA. 3) Analyze precision and accuracy of the LRQA method. 4) Compare composition measurements with another analytical method, i.e. the University of Minnesota/Bureau of Mines size selective sampling Micro-Orifice Uniform Deposit Impactor (MOUDI) method.An advantage of the LRQA method is that it allows analysis of filters which have been collected by a method similar to that used to determine the respirable dust concentration in US underground coal mines. No new sampling instruments and techniques are required. Transfer of sample from collection substrate to analysis substrate is not necessary. Furthermore, other analyses can be made on the same sample since the technique is nondestructive."

Jan 1, 1988

By Je M. Oh

The Bureau of Mines is conducting research to determine the high temperature oxidation resistance of substitute stainless steels (SS) containing two less strategic elements, Al and Si, instead of Cr. Chromium is considered to be a critical and strategic metal. Although the Cr content was reduced to 8 wt pct, the alloys showed better oxidation resistance than did 304 SS containing 18 wt pct Cr. Specifically, the alloys that contained Fe-8Cr-16Ni with combinations of Al and Si showed excellent oxidation resistance even at temperatures up to 1,000° C. In this study, the effects of the alloying elements on oxidation kinetics and morphology of oxides were investigated using a Cahn Rg electrobalance, scanning electron microscopy, an energy-dispersive X-ray analyzer, X-ray diffraction, and an electron microprobe. Aluminum and silicon additions in combinatin were more effective in providing oxidation resistance than either element was alone.

Jan 1, 1986

By Michael A. Trevits

The National Institute for Occupational Safety and Health (NIOSH) in partnership with Strata Products tested the sealing capability of Ventstop®? as part of an ongoing mine fire control and suppression research program. Ventstop®? is a multi-purpose, inflatable device that is produced by Minvent Solutions and is available world wide for use in the metal and nonmetal mining industry. Ventstop®? is also used in the Australian coal industry as a temporary ventilation control device. The device can be quickly deployed, is reusable and can be placed in horizontal and vertical mine voids to control dust, fumes and smoke. Deployment, multi-day inflation and air leakage tests were conducted at the NIOSH Lake Lynn Laboratory to determine the capability and limitations of Ventstop®? in a simulated coal mine setting. During the tests, Ventstop®? was also subjected to low level forces of a nearby methane gas ignition. It is thought that Ventstop®? could be used by the US coal mining industry to temporarily close an underground mine area in response to a fire or spontaneous combustion heating event, to temporarily redirect mine ventilation during longwall equipment moves or during stopping construction. This paper describes this inflatable temporary mine sealing technology and presents the results of the NIOSH tests. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of NIOSH.

Jan 1, 2009

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Jan 1, 1997

By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

APPENDIX D DEVELOPMENT AND EXPERIMENTAL VERIFICATION OF ACOUSTIC SEAL CHECKER THEORY 1. Introduction In Section 7 of the report the acoustic seal checker concept was described in a general manner and the parameters which affect the signal level at the microphone were discussed briefly. In this appendix the theoretical basis will be presented and the experimental program described which permitted the extension of the theory into practice. The basic goal of the acoustic seal checker is to relate the reduction in sound pressure level to the size of the residual hole in the fly ash barrier. The smallest hole size that may be measured is determined by the signal to noise ratio, where the noise in this case includes the ambient noise in the mine, the internal microphone noise and the sound transmitted from the acoustic source via the flanking paths through corridors adjacent to the one being sealed. The latter source of noise can be discriminated against, at the expense of increased complexity of the acoustic system, by employing a pulsed source and pulse gating of the microphone signal set to accept sound via the barrier path and to reject the delayed flanking path signals. In order that the acoustic system be insensitive to precise source and microphone location and to permit assessment of system performance on an acoustic power flow basis, a broad frequency band of pseudo-random noise is emitted by the loudspeaker source. The preferred frequency range must be determined, the advantage of a directive source must be assessed, and the necessity

Jan 1, 1973

By Oliver Bowles

Calcareous rocks, of which the principal varieties are marble and lime¬stone, are used extensively for building and ornamental purposes. Onyx and travertine, subdivisions of these groups, are sufficiently distinctive in origin and use to merit separate classification. The purpose of this paper is to define the terms "onyx" and "travertine" and to describe the occurrences and uses of the materials bearing these names. ORIGIN AND CHARACTER Confusion exists in the use of the word "onyx." True onyx is a banded chalcedony, a form of silicon dioxide related to jasper, agate, and flint. Calcium carbonate is commonly deposited from solution in successive layers of varying color closely resembling onyx, and for this reason such calcareous rock is also called "onyx." To distinguish the calcareous from the siliceous

Jan 1, 1940

By H. H. Schrenk

[A calorimetric method3/ for the determination of benzene in amounts as low as 0.001 m has been developed recently at the U.S. Bureau of Mines Pittsburgh Experiment Station by the authors, with the assistance of chemical personnel from the Allegheny County (Pa.) Relief Works Division. The method is based on the direct nitration of either liquid or gas - phase benzene, followed by neutralization, extraction with butanone, and final treatment with sodium hydroxide which produces a violet color. The color is matched with color standards of known values. Although the method is adaptable to many conditions the primary objective was a procedure that would be suitable for hygienic investigations.]

Jan 1, 1935

By Todd M. Ruff

Researchers at the National Institute for Occupational Safety and Health (NIOSH) are studying methods to prevent workers from being entangled in machinery used at mining operations. An analysis of mining accidents in the United States that resulted in a fatality or permanent disability from 2000 through 2005 showed 438 severe incidents that involved contact with machinery or equipment, an average of 73 per year. Researchers determined that the most common machinery involved in these severe accidents was conveyors. Also, a significant portion of the accidents occurred during machine maintenance and repair. Researchers are focusing on improved methods to prevent unintentional machine startup during maintenance activity and methods to detect workers near moving machine components. One new technology that shows promise for this application is intelligent video. Popular in the surveillance and security industries, these systems use cameras and computerized video analysis techniques to automatically detect the presence of people in preset zones within the camera?s field of view. A preliminary study has been initiated to determine if this technology could reliably detect the presence of workers in hazardous locations near machinery. Possible advantages of the use of this technology include improved detection zone demarcation and improved ability to distinguish between hazardous and non-hazardous proximity, compared to conventional proximity sensor techniques. Initial tests to detect a person near a conveyor system in daylight conditions showed promising results. A description of the technology, test procedures and results, implementation challenges, and future research needs are discussed.

Jan 1, 2008

By C. D. McMaster, John C. Hartley

Three systems that monitor ventilating fans are described . These electronic monitoring systems automatically perform most of the operations required to conform with the provisions of the Federal Mine Safety Code in the event of fan failure or slowdown .

Jan 1, 1964

By H. R. Beard

The Bureau of Mines investigated the absorption of radium and thorium from waste uranium leach liquor by clays and other materials. This work was conducted in support of the Bureau's goal of minimizing the environmental conflicts, impacts, and occupational hazards associated with mining and milling operations. Tailing and soil samples from New Mexico were evaluated for their potential to absorb radium and thorium from tailing liquors. Absorption ranged from 0 to 97 pct for radium and 0 to 60 pct for thorium. Some samples that readily absorbed radium were contacted with various salt solutions that could be present in tailing solutions to determine whether desorption would be a potential problem. The desorption of radium ranged from 0 to 75 pct. An alpha spectrometric method was used to determine the radium and thorium concentrations in the solutions and solids.

Jan 1, 1980

By J. H. East

The occurrence of hydrogen sulfide in the gas in solution in the oil produced from the Tensleep sandstone in the Elk Basin oil field in Wyoming constitutes a serious hazard to persons working in, that field. Aware of the general conditions because of petroleum reservoir studies being conducted in that field by its engineers, the Bureau of Mine's willingly agreed to a request of the Petroleum Administration for War to publicize the hazard and the measures for overcoming it. In October 1943 and November 1944, the Bureau of Mines investigated the method's used in handling the oil and in disposing of the hydro¬gen sulfide that occurs with it. This circular reports the results of these observations. HYDROGEN SULFIDE OCCURRENCE IN THE. ELK BASIN OIL FIELD The Elk Basin oil field is in Park County, Wyo., and Carbon County, Mont. It is about 18 miles north of Powell and 12 miles west of Frannie, Wyo. The original Elk Basin oil and gas field was situated in an eroded depression surrounded by an inner rimrock about 200 feet high with a bordering higher plateau about 500 feet above the basin floor.

Jan 1, 1945

By P. A. Wasson, M. M. Fine

Roasting research involving small , batch experiments was conducted to explore the use of solid reductants for converting nonmagnetic iron ore to a magnetic type . Three typical Minnesota ores were tested with one or more of the following reductants : Lignite , lignite chars , anthracite , bituminous coal , petroleum coke , peat , and pyrite . Reductive roasting was accomplished in a 3- by 4- inch externally heated rotating drum . Ore and reductant were placed in the drum and heated to a desired temperature , which was maintained for a predetermined period . Recoveries of over 90 percent of the iron in magnetic concentrates were achieved at 650 ° C , using lignite , some lignite chars , a high- volatile bituminous coal , peat , and pyrite . Pyrite is a novel reductant , which is superior to carbonaceous materials other than lignite and some chars .

Jan 1, 1963

By M. B. Shirts

Bench-scale studies were made on a reductive hydrometallurgical procedure to convert chalcopyrite flotation concentrate to copper metal or a readily leachable sulfide. Reductive conversion of chalcopyrite and dissolution of iron and sulfur were accomplished in hydrochloric or sulfuric acid solution by the addition of metallic copper, iron, or lead. Use of metallic copper as the reductant enabled extraction of 95 and 46 percent of the iron and sulfur, respectively. The products were ferrous iron, hydrogen sulfide, and a copper sulfide. Use of metallic iron or lead as the reductant enabled extraction of 95 percent of both the iron and sulfur. The products obtained with metallic iron or lead were ferrous iron, hydrogen sulfide, and metallic copper.

Jan 1, 1974

By Oliver Bowles

The United States Bureau of Mines has within its ranks a group of engi- neers who are engaged in working out quarry problems, the solution of which will be of general benefit to the industries involved. The problems undertaken are approached in a systematic and thorough manner, all the evidence for and against any proposed change or new development being collected as carefully as an attor- ney would prepare his data on an important case. Unlike the attorney, however, the Bureau engineer does not take sides; his judgment is based entirely and in- partially on the array of facts presented. In order to gain the desired infor- mation he visits many plants, consults with the leaders in the industry, works out experiments in his laboratory, and supplements this information with a stu- dy of all available literature already published on the subject in any part of the world. As an engineer who has for eight years conducted such inquiries in the stone industry, I propose to discuss the Bureau of Mines viewpoint; and it may be of interest to consider with me in a brief and general way the engineer's method of looking at quarry problems, and some of the results attained through past and present labors. While the Bureau has conducted no investigation directly for the crushed- st one industries, two years of investigative work at cement-plant quarries, and work now being conducted at lire-plant quarries, has a very direct bearing on the problems of the crushed-stone industry, since stripping, drilling, blasting, loading, and transportation are similar in many respects in all stone quarries. The results of cement-plant quarry investigations are to be found in Bureau of Mines Bulletin #160. (b) Two short papers on lime-plant quarry problems have been issued in mimeographed form as Serial #01 (c) and Serial 3 (d).

Jan 1, 1923

By Charles A. Kumke, GROVER J. DUFF

This paper describes mining and milling practices at the San Xavier mine of the Eagle- Picher Mining & Smelting Co. in Pima County , Ariz . It is one of a series being prepared by the Bureau of Mines on mining methods in various mining districts of the United States . The mine and the mine surface buildings are situated in sec . 11 , T. 17 S. , R. 12 E. , in the Sierrita Mountains in Pima County , 20 miles south by southwest from Tucson via the San Xavier Mission and Twin Buttes road ( fig . 1). A well-maintained dirt road continues southward toward Twin Buttes for 4 miles and then branches off northeasterly for 5-1/2 miles to Sahuarita , where the concentrator of the Eagle - Picher Mining & Smelting Co. is situated on the west slope of the Santa Cruz River Valley . Tho mill is connected by a railroad branch to the main line of the Southorn Pacific Railroad between Tucson and Nogales . It is generally assumed that the San Xavier silver - lead deposits became known to the Jesuits and Spaniards in the early part of the eighteenth century . However , no extensive mining operations were conducted by the Jesuits in what is now Arizona before the middle of the eighteenth century . The completion of the Southern Pacific Railroad from Los Angeles to El Paso in 1881 marked the beginning of intense activity in mining throughout the southern part of the State . The San Xavier mine produced 6,000,000 pounds of lead , considerable zinc ( exact figures not available ) and $200,000 in silver from 1897 to 1918 . The Eagle- Picher Mining & Smolting Co. re- opened the San Xavier mine in 1943 and built a 175-ton concentrator at Sahuarita . The capacity of the plant was increased in 1944 to 500 tons in order to take in custom ore . The surface rocks at the San Xavier mine are , in great part , of sedimentary origin . Limestones of various ages comprise most of the exposed sedimentaries , some quartzites and shales also being present . The sedimentaries rest upon coarse - textured , intrusive , igneous rocks comprised mainly of granite and granodiorite . The San Xavier deposit is composed of galena , sphalerite , chalcopyrite , and pyrite . Generally the individual ore bodies are small , discontinuous , and occur as irregularly spaced shoots or lenses . The present mine workings extend horizontally a distance of 2,700 feet and vertically 900 feet . Owing to ground weight, all mine openings are timbered on the levels and all stopes are square- setted and waste -filled .

Sep 1, 1950

By L. B. Berger, W. P. Yant, George W. Jones

Improper combustion of natural gas is the cause of low efficiency in heating appliances , also the liberation of carbon monoxide , an insidious and deadly gas . Carbon monoxide is produced during the incomplete combustion of any carbonaceous material , and quantities as low as 0.2 per cent may product death in a very short time . For healthy atmospheric conditions in the home , in which the occupants are continuously exposed , carbon monoxide should not be present in amount greater than 0.01 per cent , which value is taken as the safety limit in this report . The tests herein reported give the conditions which produce carbon monoxide when radiant -fire heaters burning natural gas are used . The conclusions drawn are based on tests made on one type of radiant heater only , but the general conclusions should apply to other types of radiant heaters of similar construction . The gas consumption , gas pressure , orifice pressure , size of orifice , and heater adjustments were changed so as to obtain as many different operating conditions as possible . In a general way the tests were carried out under the same conditions that the heater might be operated in the home .

Feb 1, 1923

By A. L. Engel

As a part of the program of the Rare and. Precious Metals Experiment Station, Reno, Nev., in connection with investigations of treatment methods for precious and precious-base metal ores, to further conservation and recovery of precious and base metals, tests Were made on samples from the Buzzard Mine, located in the vicinity of Placerville, Calif. These samples represented ore exposed during previous development work, in tunnels and a shaft on the property, including highly oxidized material from the surface zone and sulfide ores from depths of 150 to 300 feet. The surface samples contained little base metal and only enough gold 80 that economic exploitation of them would depend on development of a large tonnage of ore, low-cost mining methods, and satisfactory treatment methods. The sulfide samples were valuable enough to warrant further exploration and development and, if present in suitable tonnage, the installation of a treatment plant for recovery of both precious and base metals. The oxidized surface-zone samples carried 0.11 to 0.14 ounce gold per ton. Standard amalgamation and flotation tests of these samples gave low recoveries. Standard cyanidation tests indicated high consumption of lime and cyanide and gold extraction of 79.4 and 82.7 percent. Water-leaching the ore after crushing to minus 10-mesh improved cyanidation considerably. Ex-tractions of 82.7 to 85.8 percent were obtainec1 with lime consumption of 6 to 7 pounds per ton of ore and cyanide consumptions of 1 to 4 pounds. Grinding the samples to minus 200-mesh followed by water-leaching and cyanidation gave improved extractions of 91-92 percent of the gold, but with slightly increased consumptions of lime and cyanide.

Jan 1, 1949