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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

By B. Dimitriades

Data on smog-forming reactivities of exhaust aldehydes are scarce. Such data were obtained by irradiating in a smog chamber typical exhaust aldehydes, individually and in exhaustlike mixtures. Observed reactivity manifestations were rate of nitrogen dioxide formation (RNO2) and yields of oxidant, peroxyacetyl nitrate, and formaldehyde. Results showed that exhaust aldehydes vary widely in reactivity. Formaldehyde showed high RNO2 reactivity but low oxidant yield; benzaldehyde, [m]-, and [p]-tolualdehyde were totally unreactive when irradiated individually; [o]-tolualdehyde was reactive. In mixtures, benzaldehyde manifested reactivity in terms of peroxybenzoyl nitrate yield. Exhaust aldehydes as a group are judged to be as reactive as the exhaust olefin group. The importance of the aldehyde contribution to exhaust reactivity and methods for assessing such contribution are discussed.

Jan 1, 1971

By Kenneth J. Miner

Pittsburgh bed and Lower Freeport bed coals were tested in the U.S. Bureau of Mines two-stage froth flotation pilot plant, which utilizes a new flotation process to remove pyritic sulfur. The process consists of a first-stage coal flotation step to remove coarse, free pyrite and other refuse in the tailings. The clean coal froth concentrate is then repulped and treated with a coal depressant, a pyrite collector, and a frother to selectively float the remaining pyrite in a second stage. Results in the pilot plant were excellent, comparing well with those obtained in laboratory batch tests. That is, about 70 percent of the pyrite present in the Pittsburgh bed coal and about 90 percent of the pyrite present in the Lower Freeport bed coal were removed with excellent final clean coal recoveries.

Jan 1, 1973

By Mark R. Stephenson

Everyone knows that mining is a noisy job, but did you know that you are nine times more likely to lose your hearing than someone who works in a quieter job? If unprotected from noise on the job, by age 50, you will probably need hearing aids. Obviously, the best solution is to engineer out the noise, but that isn?t always im­mediately possible. Until mines are quieter, one way you can help save your vital sense of hearing is to use hearing protectors whenever the noise around you is hazardous. Even if you already have some hearing loss, you can use hearing protectors to prevent your hearing from getting worse. When loud noise is present, proper use of hearing protectors will help miners pre-vent most or all noise-induced hearing loss.

Jan 1, 1998

By Edward L. McHugh, Charles Sabine, Louis J. Denes, Jami M. Girard, Peter Metes

The Spokane Research Laboratory, National Institute for Occupational Safety and Health, is investigating various remote sensing technologies as possible tools to detect, monitor, and mitigate hazardous situations in surface mines that could lead to catastrophic slope failure. Promising technologies include a field-portable spectro-polarimetric imager and a stationary interferometric radar device. Field tests were conducted of a prototype visible and near-infrared spectro-polarimetric imager (SPI) built at the Carnegie Mellon Research Institute. The SPI employs anacousto-optical tunable filter (AOTF) to control wavelength, a phase retarder to measure polarization signatures, and a digital camera and computer to capture data. Images obtained at the Mountain Pass and Castle Mountain mines in southeastern California showed that the instrument is capable of obtaining hyperspectral images of highwalls, outcrops, hand samples and drill core in the field. We have retrieved spectra from Mountain Pass images that closely match those of bastnaesite and have had some success in classifying images. Although radio frequency noise in the data limited spectral classification of imagery, we project that careful alignment of the AOTF should minimize the noise and greatly improve classification.

By S. R. B. Cooke, F. D. DeVaney

"INTRODUCTION The potash mineral receiving the most attention in the newly discovered. New Mexico-Texas potash district near Carlsbad, N. M. is sylvite (potassium chloride). Sylvite contains more potassium than any other mineral. Merchantable high-grade deposits have been found, and those of lower grade may be enriched to a high degree of purity by refining methods. Deposits containing sylvite were the first to be developed and axe the only ones being mined.However, many other minerals that contain potash occur in the salt beds of the Carlsbad District. Of these the more important are polyhalite, carnallite, langbeinite, leonite, and kainite. The nature of the deposits and their mineralogy have been described in detail by members of the United States Geological Survey. 4/Langbeinite, although not so abundant in these deposits as carnallite and has particular interest because the potash is in the form of the sulphate and as such commands a premium in terms of K20 unit. This is explained by Fox and Turrentine 5/, who state:"

Feb 1, 1936

By Harvard Eng

An industrial survey was made for the Missouri Basin Field Committee of the Department of the Interior to determine the type and quantity of water-borne mineral wastes and the water requirements of metal-processing industries in the basin in Kansas and western Missouri. Data are presented on metal-processing plants visited through June 30, 1959. Most of the plants were in the greater Kansas City area. This report is to be supplemented with a similar publication on other industries, including those producing sand and gravel, coal, petroleum, and chemicals. In 1958, 19 million pounds of waste materials was discharged from metal processing industries. Approximately 14 million pounds of this waste was in the form of ferrous sulfate, and 2 million pounds was ferric phosphate. Galvanizing, other hot dipping, and automotive industries contributed the greater part of iron compounds wasted; some of this waste occurred as sludge that was not discharged to water courses but was hauled to refuse dumps, podium was present in nearly all industrial wastes, and the total of more than 900,000 pounds constituted one of the larger material losses. Although small in quantity, electroplating and allied coating wastes contained metals that were expensive when originally purchased.

Jan 1, 1961

By P. R. Tisot

The structural response of propped oil shale fractures was determined for each of two different grades of Green River oil shales (38.0 and 29.0 gpt) as they were heated in an inert atmosphere from ambient to subretorting temperatures (below those required for rapid pyrolysis of the organic matter). Small oil shale cores were propped apart by 3-mm glass beads to simulate a small cross section of a propped oil shale fracture between an injection and a producing well. These specimens were then heated at a uniform bate up to 800° F in a specially designed test cell under stress levels from 100 to 1,000 psi in biaxial and in triaxial confinement. Under the conditions of heat and compressive stress utilized in this study, all of the propped fractures in the two oil shales underwent structural deformation ranging from partial to complete collapse, as evidenced by proppant embedment. Structural collapse of induced fractures would in turn result in serious impairment or complete loss of the fracture flow capacities of the specimens. Results from this Bureau of Mines study indicate that underground retorting of Green River oil shale may be seriously impaired by loss of permeability when utilizing propped fractures in oil shales assaying more than 28 gpt.

Jan 1, 1975

By G. M. Potter, F. S. Wartman, M. D. Schmid

"In matte smelting of copper it has been established that the sulphpr present will combine with copper as long as the latter is present, and that thereafter it will combine with iron. The Cu-Fe ratio in the matte is determined by the Cu-S ratio, presumably owing to the much greater affinity of copper for sulphur or, expressed thermodynamically, the greater stability of copper sulphide in contact with silicate slag. Now, the work of Fournet and of Schütz, which is quoted in many elementary metallurgical texts, indicates that manganese ranks ahead of copper in its affinity for sulphur. Hence, we might expect that manganese could be concentrated from its admixture with iron. Compounds by matte smelting, and Rotts / has patented such a process. This greater affinity of manganese or sulphur is used to advantage in iron metallurgy, also, in which it is well-known that sulphur will combine with manganese and separate from metallic iron as manganese sulphide. Manganese sulphide,however, is quite soluble in silicate slags. 5/ The loss of manganese in slag in any attempted matte smelting is therefore great.If this solubility of manganese sulphide is slag is a physical one and the reaction MnO + FeS MnS + FeOIs substantially complete, then it might be expected that the addition of copper sulphide, which is almost entirety insoluble in slag, would serve to extract the manganese sulphide with the formation of a manganese-copper matte on the other hand, if an equilibrium exists in the above reaction, a copper sulphide layer would displace that equilibrium in one direction or the other, according to whether iron sulphide or manganese sulphide were more soluble in the matter layer."

May 1, 1937

By K. Robert Dorman

This Bureau of Mines report describes laboratory and field experimentation in building mine ventilation stoppings, air-door frames, and fan bulkheads with a civil construction technique. Shotcrete is applied to a free-standing, three-dimensional wire-truss panel, which is easily cut and rapidly erected. In mines where shotcrete equipment is available, this technique should be faster and cheaper than conventional block-and-mortar or monolithic concrete construction.

Jan 1, 1980

By M. L. Whisman

Radiotracer techniques were developed for stoichiometric studies of photochemical reactions associated with atmospheric smog formation. Stock blends of separate hydrocarbon and oxygenated compounds were prepared and calibrated. 14C-labeled reactants and products in reaction systems involving hydrocarbons and nitrogen oxides at the ppm level were analyzed for qualitative and quantitative data. Precision and accuracy of these methods developed by the Bureau were determined by replication and statistical treatment of data, and these methods are described.

Jan 1, 1969

In this Part, we have included copies of the flip charts and overhead projector viewgraphs used in the two briefings we conducted as part of this seismic detection and location task. The first one was an overview and problem definition briefing given to the seismic consultants on September 7, 1972. The second was a formal oral presentation of study results to technical staff members of the Pittsburgh Mining and Safety Research Center on November 21, 1972.

Jan 1, 1974

By R. W. Stahl, H. E. Sanford, J. B. Benson

"As movement or transportation of coal is second only in importance to actual mining, and as the latter is wholly dependent on the former, the efficiency of the haulage system often determines the efficiency of the entire plant. Safe or accident-free transportation is essential, also, because no attempt is made to divorce safety and efficiency, it being realized that they are inseparable.Most of the Ruhr mines were opened decades ago, and many features that were considered up-to-date then are now obsolete. Progress in developing haulage systems has been slow, chiefly because it would be very costly to change many to accomodate more modern equipment. These systems are being altered or modernized slowly, as capital permits. The only revolutionary changes that have been made in mine haulage are the use of larger locomo¬tives and cars, in the movement of shuttle cars, and in the adoption of skip hoisting. Most Ruhr shafts, however, will not accomodate large cars, the secondary roadways are too narrow for large locomotives, and the coal is too soft to permit skip hoisting because degradation would be too great. Therefore, notable advances have been made only at newer plants, where allowances have been made for modern equipment.The shafts are deep (average 2,300 feet) and of comparatively small diameter. The small bore was designed to reduce costs of sinking and lining. Generally, the shafts are lined throughout with masonry; however, most of the buntons and guides are wooden.The hoisting engines arc installed in masonry structures, and where more than one hoist is used they are placed on opposite sides of the shaft to eliminate as much noise as possible (fig. 1). This arrangement also prevents an engineer from acting on any signals except those transmitted to him. A few hoisting engines are mounted in the headframes (fig. 2). The hoisting engines are equipped with overwind, overspeed, and auxiliary braking devices, which are tested frequently and kept operative at all times. The signal code is displayed in view of the engineer, and a light or dial indicator informs him of the cage's position in the shaft. Many hoists are equipped with re¬cording devices, which show on a continuous chart the speed of hoisting as well as any delays throughout the 24-hour period.A Koepe system of winding is in general use because of the depth of shafts (fig. 3). With this system, a single rope passes over a single-groove, large-diameter sheave attached to the motive power, and the ends of the rope, after passing over the head sheaves, are attached to the cages. A flat tail rope suspended in the shaft and connected to the bottom of the cages serves to balance the system. Both steam and electric engines are used to activate the hoisting system, end the engines are capable of moving at least a 50-percent overload.The ropes are necessarily of large diameter (2-1/2 inches and greater), and flexibility decreases as rope diameter increases. To overcome the unwieldiness .of large-diameter ropes as shafts become deeper, a four-rope system is being tried at one mine (fig.4). In this system the load is equalized between four ropes which permits much smaller ropes to be used. All hoist ropes are inspected daily and discarded after 2 years service unless special permission for longer service is granted by the Mine Inspectorate, and then only after thorough visual and electromagnetic inspection."

Jan 1, 1950

By Anthony T. Iannacchione

The Bureau of Mines developed data on the methane content of the Hartshorne coalbed, Haskell and Le Flore Counties, Okla. The methane content is calculated to be between 1.1 and 1.5 trillion cubic feet, based on an estimate of total coal in place of 2.4 to 3.2 billion short tons. Methane increases with depth, but the rate of increase decreases with greater depths. Degasification in advance of mining is recommended for all mines operating at depths greater than 500 feet to reduce hazards and methane explosions, decrease mine ventilation costs, and conserve the natural gas that would be otherwise wasted.

Jan 1, 1979

By Steven R. Davis

Dear Interested Party: Subject: Notice of Intent to Solicit Outside Opinions Regarding Amendments to the Rules Concerning the Leasing of State Owned Lands for the Mining of Metallic Minerals The Department of Natural Resources, Division of Minerals, is seeking outside opinions concerning the leasing of state owned lands far the mining of metallic minerals. Enclosed for your information in a copy of the Notice of Intent to Solicit Outside Opinions Regarding Amendments to the Rules Concerning the Leasing of State Owned Lands for the Mining of Metallic Minerals.

Jan 1, 1994

By Charles L. Kimbell

Comprehensive data on market prices for crude minerals and mineral products for the world as a whole do not exist, and even the data that are available are not necessarily compatible between countries, particularly between the market economy countries and the centrally planned economy countries. Further, it should be evident that the actual delivered price for a small quantity of any specific commodity at some point substantially removed from a production facility or a seacoast port will differ appreciably from that for a large volume of the same product at or near its production source or a major import center. Nevertheless, the regularly published prices of selected major mineral commodities in key market areas can be regarded as indicative of general world price trends.

Jan 1, 1992

By R. B. Stroud

Bureau of Mines studies of copper-bearing Permian red beds, which extend from north-central Texas through western Oklahoma to southwestern Kansas, indicate heretofore undefined commercial possibilities for low-grade, medium-volume, strip-mining operations. Potential ore bodies are indicated containing 0.5 to 1.5 percent copper in zones 6 to 12 inches thick. Cost analysis studies indicate a commercial operation is feasible for a hypothecated 1,000-ton-per-day ore mining and milling complex where a maximum of 60 feet of overburden can be stripped in mining a seam of shale 12 inches thick containing 1.2 percent copper

Jan 1, 1970

By G. P. Sturm

This work was undertaken by the Bureau of Mines in cooperation with the Environmental Protection Agency to determine photochemical specific reactivities of emissions from automobiles using leaded-premium-and regular-grade fuels and prototype lead-free fuels of comparable octane quality. Emissions were photoirradiated in a 100-ft3 environmental (smog) chamber constructed of aluminum and Pyrex glass at three sets of initial hydrocarbon (HC) and oxides of nitrogen (NOx) concentrations. Reactivity was measured and expressed in terms of rate-of-NO formation (RNo2) and dosages of oxidant, peroxyacetyl nitrate (PAN), peroiypropionyl nitrate (PPN), and formaldehyde (HCHO). The results indicate that the evaporative emission samples and the evaporative plus exhaust emissions samples from the lead-free fuels have, in general, higher reactivities per gram than those from the leaded fuels. For the samples containing only exhaust emissions, the only trend observed was the lower specific reactivity exhibited by the leaded premium fuel exhaust. These differences in specific reactivity are taken to reflect the differences in hydro-carbon composition of the fuels and their evaporative and exhaust emissions rather than any difference in lead content per se.

Jan 1, 1973

By R. M. Ray

The Bureau of Mines evaluated five commercial badge-type carbon monoxide dosimeters. Color changes in the badge reagent indicated the presence of carbon, monoxide. Possible effects of ambient conditions on dosimeter response to CO during or after coal mine fires or explosions were studied. Temperature and humidity changes did not change dosimeter sensitivity to CO. Contaminant gases such as CO2, N02, S02, and H2S had effects that varied with brands of dosimeters ranging from no effect to increased sensitivity to CO. Dosimeters tested after 6 months of storage showed an increase in failure rate as high as 25 percent. Tests were conducted to determine the effects on dosimeter time-for-color change caused by observer's sight (colorblind); lighting, and coal dust on dosimeters. No significant effects were observed. Observer variance was the most pronounced factor observed in all tests.

Jan 1, 1975

By R. R. Backer

The Bureau of Mines investigated the typical physical and chemical properties of coal waste materials from the western part of the United States. The results are compared, in so far as possible, with the properties of waste materials from eastern coal operations. The authors found a disparity of mines and preparation plants among western U.S. coal operations and dissimilarities with typical operations in the East. The relatively cleaner product from the predominance of surface mining and the occurrence of thicker seams in the West reduces the amount of coal preparation required and the size of the waste piles. Because of the abundance of land available for waste disposal, many of the piles are low and extended over large areas. New concepts relating statistical shear strength data to liquifaction potential are presented. The somewhat limited data indicates that western coal sludge is coarser with higher permeabilities and shear strengths than the eastern deposits.

Jan 1, 1977