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Native asphalt was produced in 1977 by six companies in four States. Leading States were Texas and Utah. Output declined 39% to 1,237,000 tons valued at $18,874,000. Bituminous limestone was produced by Whites Uvalde Mines and by Uvalde Rock Asphalt Co. in Uvalde County, Tex.; by Southern Stone Co. in Colbert. Ala.; and by Barton County Rock Asphalt Co. in Barton County, Mo. Gilsonite was produced by American Gilsanite Co. in Uinta County. Utah, and by Ziegler Chemical and Mineral Corp. in Weber County. Utah. The asphalt was used for streets and roads, and for other purposes.

Jan 1, 1980

To increase awareness of float coal dust explosion hazards in the mining industry.

Jan 4, 2006

By A. L. Engel

This publication describes further research by the Federal Bureau of Mines in beneficiating domestic manganese ores. The ores selected for treatment were typical of many manganese deposits in California and Nevada in that they have not been economical to mine because they are low grade or contaminated with siliceous minerals and are not amenable to physical concentration.3 4/ It would be desirable to develop a simple treatment method resulting in nearly complete extraction of manganese from these ores and applicable to small-scale operations. Sulfation reduction appeared to be such a method. The studies reported in this publication were directed toward sawdust or lignin-sulfonates as reducing agents. Sawdust, as waste from lumbering, and lignin-sulfonates, byproducts of woodpulp papermaking, are comparatively cheap and may be available in areas where manganese ores are found. Sugar, oils, and coal were also tried as reducing agents.

Jan 1, 1960

By Thomas O. Llewellyn

Laboratory semicontinuous and continuous heavy liquid cyclone separation pilot plant tests were made to determine the feasibility of producing a high-grade kyanite concentrate from a kyanite-quartz rock sample from Graves Mountain, Ga. Use of a three-stage heavy liquid cyclone circuit demonstrated that a 96.4-to 99.0-percent kyanite concentrate could be obtained with recoveries of 95.5 to 96.7 percent. The test work showed that by steam stripping with 6.9 tons of steam per ton of ore and two stages of detergent scrubbing the residual TBE content of kyanite cyclone products was 0.22 pound per ton of ore.

Jan 1, 1971

By H. E. Powell

The mineral dressing research here reported is part of a continuing program by the Bureau of Mines to develop new or improved concentration processes for oxidized or partly oxidized lead and zinc ores. A sample of low-grade sulfide-oxide, lead-zinc ore from Jasper County, Mo., containing galena, cerussite, pyromorphite, hemimorphite, smithsonite, and sphalerite was concentrated by froth flotation and tabling to a grade of 66 percent lead. Because of the presence of a high content of slime-size values, the overall recovery of lead was limited to 64 percent at this grade. Tests to recover the zinc by froth flotation and by gravity concentration did not give satisfactory results. INTRODUCTION Since its establishment, the Rolla Metallurgy Research Center has con-ducted studies of base metals as a part of its overall program (1, 2, 3, 4, 5,6,7).3/ This research has been, and is, directed to beneficiating complex and submarginal ores, to retreating rejects from commercial installations, and to developing fundamental data.

Jan 1, 1960

By Launa Mallett, PhD, Charles Vaught, PhD

This training material focuses on the content of emergency warning messages. Research has shown that when an emergency occurs, people often do not get the information they need for the purpose of taking appropriate action. This safety talk presents a procedure, using mental cues that can be used by senders and receivers of emergency warnings.

By Lloyd A. Morley

A concept is presented to improve underground coal mine electrical system safety and availability. This proposed technique is based upon the ability to predict incipient failures in the mine power system. Prediction is made possible by a new method, developed during this research, which uses a minicomputer to implement pattern recognition algorithms. The theoretical basis of the prediction system is discussed, along with synthesis of the hardware and software sections. The deterioration modes which could be detected are examined, and an evaluation of the system's ability to predict incipient failure is presented. Typical results of the system's performance during laboratory simulation of power system deterioration are given.

Jan 1, 1977

By Causey J. Douglas

In 1988, at the request of the Bureau of land Management, the U.S. Bureau of Mines studied part of the 13,460-acre Owyhee Breaks Wilderness Study Area (OR-003-059) in order to evaluate its identified mineral resources. The study area is in Malheur County, OR, about 27 miles northwest of Jordan Valley. No mineral resources were identified in the study area during this investigation. There is an occurrence of jasper along Birch Creek and an associated occurrence of zeolite in some tuffs. In the northern part of the study area is an occurrence of bentonitic clay containing less than 40,000 tons. Much of the area is covered by landslide blocks, colluvium, earthflow deposits, and talus, composed of Tertiary-age volcanic rocks. The upper plateaus are capped by Tertiary-age basalt.

Jan 1, 1989

Improve the strength and other properties of steel alloys. Approach Research by the U.S. Bureau of Mines indicates that steels melted and solidified under high nitrogen pressure acquire yield and tensile strengths that are up to four times the strengths of comparable stainless steel alloys without nitrogen. Fatigue strength, creep strength, and other mechanical properties are also improved. Strengthening occurs by two mechanisms: (1) increasing dissolved nitrogen in the lattice and (2) formation of dispersed metal nitride phases. Nitrogen Alloying Nitrogen alloying of a steel is generally done by introducing metal nitrides during melting of the steel. The concentration of nitrogen is limited to its equilibrium solubility at 1 atmosphere. For face-centered-cubic (fee) iron, that solubility is approximately 0.4 weight percent (wt%). For body-centered-cubic (bee) iron, solubility is 0.05 wt%. This solubility limitation can be overcome by melting the metal in a pressurized vessel. European steelmakers currently have metal-processing systems that can melt and pour tons of steel under nitrogen pressures exceeding 4 megapascals (MPa) (40 atmospheres). They have achieved nitrogen concentrations as high as 1.0 wt% in these (stainless) steels. The tensile strength is approximately twice the tensile strength of similar steels without nitrogen.

Jan 1, 1992

Provide sound battery safety guidelines for mine workers who maintain mobile surface mining equipment. Approach Battery-related accidents account for about 5 percent of all nonfatal disabling injuries in coal and metal nonmetal surface mines. These accidents occur despite the fact that appropriate battery safety technology (maintenance-free batteries, cable removers, fault detectors, hot-jumping systems, etc.) exists. Mine operators are not always aware of the safety measures that could be taken because this safety information is widely scattered in numerous unrelated technical reports, vendor brochures, and journal articles. A literature search of these reports and a review of relevant industry standards, handbooks, and references on battery safety, followed by discussions with mining company and MSHA personnel, provided the Bureau of Mines with the background necessary to develop procedures for proper and safe battery usage. These procedures were condensed and written in nontechnical language to serve as guidelines in assuring battery safety during maintenance of mining equipment.

Jan 1, 1986

By J. B. Gayle

The removal of coal particles from a slurry by flotation is made possible by the formation of stable aggregates with air bubbles of suitable sizes. The formation of such aggregates is theoretically possible only for certain favorable combinations of the solid-liquid-gas interfacial tensions. Because interfacial tensions involving solid phases are not conveniently measurable, a related variable, the contact angle, frequently is used as a measure of the floatability of various materials. Zero angles indicate nonfloatable substances, and large angles indicate substances having a high degree of floatability. During a study of contact angles for coal and substances related to coal in their similarity of response to various physical and chemical treatments, particularly flotation, carbonization, and oxidation, the reproducibility of replicate determinations taken within a 4-hour period was found to be much better than that for comparable results taken over a longer period of time. Consideration of possible causes for these differences led to an investigation of the effects of temperature variations on contact angles. References to literature revealed only a small amount of information, some of it apparently conflicting. Specifically, Sutherland and Wark4/ found that temperature variations "within limits" did not appreciably influence the angles measured for galena conditioned with potassium ethyl xanthate. On the other hand, McGlashan and McLeod5/ presented preliminary data showing that for sphalerite conditioned with potassium ethyl xanthate the angle is maximum at 25° to 35° C., depending on the pH of the system.

Jan 1, 1960

By Hylton R. Brown

This publication, an abstract of a progress report covering an investigation of hazards in thermal coal-drying plants has been prepared according to the suggestions and recommendations of a committee6/ appointed by J. J. Forbes, Director of the Bureau of Mines, when the original report was reviewed at a meeting of representatives of the mining industry, operators of coal-drying plants, coal-mine workers, and the Bureau in Washington on May 6, 1955. The investigation on which the report is based was made in accordance with action taken at a previous conference in Washington on May 19, 1954, called by Director Forbes to consider what should be done to prevent explosions and fires in coal-drying plants. Scope of Investigation The investigation was planned to obtain information considered essential for properly appraising fire and explosion hazards in different types of coal driers. A questionnaire sent to Bureau personnel provided preliminary information on coal-drying facilities at more than 270 preparation plants. Information on methods used in operating different types of driers, with their furnaces, fans, cyclones, and other auxiliary equipment, was obtained by personal visits or conferences with the operators at 13 plants. Factual data on operating temperatures, composition of the drying gases, air flow, dust loading of the air or gas currents, use of water sprays, auxiliary air controls, and other factors were obtained by conducting full-scale tests at six different plants and making laboratory investigations with samples of dust and gas collected during the tests.

Jan 1, 1956

By M. A. Reyes

This experiment investigated the effects of different machine mounted area lighting technologies on visual performance. The primary objective was to conduct a comparative evaluation of the lighting technologies based on the visual performance of thirty-six human subjects in a simulated underground mine environment. Incandescent (Incand), fluorescent (Fluor), and light-emitting diode (LED) technologies were used to create four lighting combinations. Visual performance was quantified for the detection of movement in the peripheral field of view and the identification of ground hazards. Measurements were made of the speed [response time measured in milliseconds (ms)], the accuracy (the number of targets and objects missed), and the subjective discomfort rating of the glare experienced for each lighting combination. A secondary objective explored the effects of aging on visual performance. The results indicate that lighting combinations which consisted of LED area lights significantly improved visual performance for the detection of hazards found in the peripheral field of view, as well as those found on the ground. They furthermore, indicate that age plays a significant role in visual performance.

Jan 1, 2009

By M. J. Ankeny

All bituminous-coal mines, by the nature of their product and inherent gassy tendencies, are subject to explosions or mine fires. The evolution from large, hand-loading sections employing numerous men and containing open-type equipment, lights, and nonpermissible explosives to small, concentrated mechanical sections with but few well-supervised men utilizing modern preventive equipment has not altered this premise. Mine catastrophes such as Centralia and New Orient No. 2, as well as recent disasters of less magnitude, have refuted the trend of thinking that modern equipment, will prevent or localize explosions and prevent widespread or loss of life.

Jan 1, 1952

By Donald P. Schlick

This report presents a representative cross section of methods successfully used to ventilate continuous-miner places as well as various factors that should be considered when selecting auxiliary ventilating equipment. Line brattice can direct fresh air to the active face reasonably well, provided that adequate area for installation is available. Continuous mining equipment, however, often restricts clearances to such an extent that proper installation of line brattice is impossible. Consequently, in many instances face ventilation is inadequate; therefore, many methods of auxiliary ventilation for continuous-mining equipment have been developed and have been discussed in this study.

Jan 1, 1963

By Dennis R. Dolinar

Screen material in the form of welded wire mesh and geogrids are used in underground coal mines to prevent the fall of small pieces of rock from the roof between roof bolts. Further, if the screen is installed during the production cycle, roof fall injuries can be reduced significantly. Therefore, the National Institute for Occupational Safety and Health (NIOSH), because of the safety implications, conducted an evaluation of screen materials commonly used in U.S. coal mines to determine their support characteristics and identify the parameters that could affect their performance with respect to controlling the fall of rock from the roof surface. To evaluate the load and stiffness characteristics of the screen, a test frame was designed and installed in the Mine Roof Simulator (MRS) at the NIOSH Pittsburgh Research Laboratory (PRL). With this test set up, the screen is bolted at four corners of the frame and a center load is applied. The test set up allows for up to 20 in of screen deflection while the load and screen defection are continuously recorded. A series of tests were conducted to evaluate the effects of various parameters such as bolt tension, the type of load bearing surface and the size of bearing plates on welded screen performance. The most common screen material used in U. S. coal mines is an 8-gauge wire welded in a 4-by-4-in spacing or aperture. The peak screen load was normally limited by wire breakage. The conditions at the bearing plate influence the nature of the wire breakage. However, the screen stiffness was controlled by slippage at the bearing plates, and by weld and wire failure. The size of the bearing plate had a significant effect on the performance of the welded screen. Therefore, the design capacity of the 8-gauge screen is evaluated based on plate size. For a 6-by-6-in bearing plate the average peak load is 2,900 lb with a stiffness of 250 lb/in. For an 8-by-8-in bearing plate, the average peak load is 4,500 lb with a stiffness of 430 lb/in. These test results are based on a 4-by-4-ft bolt spacing. A geogrid mesh was also tested.

By H. B. Brunot

One of the many difficult problems that confront the present day coal-mine operator is the safeguarding of his employees and property from disasters such as fires, explosions, squeezes, and inundations. Those operators having gaseous or ev en dusty mines have a double responsibility resting upon them in this respect. The introduction of electrical machinery and appera tus in mining operations has been very rapid, and at the present time it is difficult to mention any kind of mining work in which electrical machinery is not used. This extended introduc- tion of electrical equipment has added not a little to the mine operators' safety problem, and it is the desire of the United States Bureau of Mines to aid the mine operator, and the inspection departments having jurisdiction, in solving their electrical safety problems. With this idea in mind, the Bureau has prepared and published schedules setting forth the qualities it considers essential to the safety of various classes of mining equipment, and the conditions under which it will test and give the stamp of its approval to satisfactory designs. Portable electric lamps of the permissible* type are almost universally used in gaseous mines, but the use of permissible electrical machinery has not been so widespread. Until recently the Bureau had issued approvals for only one class. of machinery involving the use of electric motors that is, permissible coal- cutting machines. However, the day is undoubtedly not far distant when the operator, who so desires, will be able to obtain a permissible room hoist, pump, or coal- loading outfit. During the year 1921 the first of a growing list of storage-battery locomotive approvals was granted by the Bureau, and it is with considerable satis- faction that the Bureau how announces the approval of a third class of motor equip- "merit- namely, slectric drills.

Jan 1, 1923

By L. E. Schultze

As part of the Bureau of Mines research program on recovering alumina from domestic resources, methods for extracting iron from aluminum sulfate solutions (obtained by leaching kaolinitic clay with dilute sulfuric ,acid) were investigated. In countercurrent extraction experiments at a l-gal/hr flow rate of aluminum sulfate leach liquor, the iron concentration 'was decreased from 1.4 g/l to 0.01 g/l after four stages of using a primary amine extractant. The iron-loaded amine solution was regenerated in five stages using 3[N] sulfuric acid or in four stages using 6[N] sulfuric acid. The aluminum sulfate solution obtained was suitable for the preparation of alumina meeting cell-grade standards of less than 0.01 pct iron.

Jan 1, 1979

By B. W. Gandrud

In the summer of 1950, Bureau of Mines engineers visited a number of coal-preparation plants in western Europe and Great Britain to obtain information on European and British coal-cleaning and froth-flotation practices. In view of the growing importance of froth flotation as a process for cleaning fine sizes of coal, it was felt that such data and information would be of value in this country, for, although froth flotation has been adopted for use in a few of our plants, it has not as yet been employed as extensively as in British and European preparation plants. Many of the important coal beds in western Europe, especially in the Ruhr Valley of Germany and in the Dutch coal-mining region of Limburg, Netherlands, are very friable, with the result that the run-of-mine product contains a large proportion of the sizes too fine to be treated successfully by any other method than froth flotation. Furthermore, the relatively high cost of producing coal from these beds has for many years made it economically feasible and desirable to treat the fines by froth flotation, especially in the coking-coal fields.

Jan 1, 1951

By T. C. Phalen

"Necessary Qualities There mines are located in out of the way places, where timber is scarce and its price high, the problem of protecting it from fire risk is of considerable practical importance. Scarcity of timber for mining purposes is commonly met with in the more arid parts of the country, where, also, mine timbers are most likely to become dry, and inflammable, and where, therefore, the risk from fire is accentuated. Any effective and cheap method of securing adequate protection of such timber at the lowest possible cost is worthy of careful investigation. The use of magnesite cement has been suggested in this connection.The necessary qualities for any substance for the use suggested above may be summarized as follows: It should be resistant to abrasion, and to impact and structural stresses. It should be durable when subjected to the action of the ele¬ments, and stable to any minor derangements of the base on which it is placed. It must be relatively unaffected by changes in temperature, by the action of water, and should adhere to the material on which it is placed, and it should also be free from shrinkage cracks due to setting up the material, Magnesite cement appears to fulfill the various conditions outlined above.The elasticity of such cement is the outstanding quality which makes it desirable for exterior work. It also possesses the ability to adhere to all materials in a marked degree. Its freedom from expansion and contraction after setting is one of the principal reasons for its adhesive quality. It may be applied to old brick or stone walls, even tho they have been repeatedly covered with paint, and the quality of ad-hearing to wood makes it possible to secure a weather-proof protection to the wooden casings and trim of exterior openings. The quality of adhesion and elasticity is easily proved by applying a 1/2"" layer to a 1"" board which has been first covered with metal lath. Such a board, about 8 feet long, may be repeatedly deflected about 3"" in the center without breaking the bond to the board, or causing any cracks to appear in the magnesia cement. The ability to resist fire as well as the possession of insulating qualities are also desirable characteristics of magnesia cement stucco."

Dec 1, 1919