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By Linneas W. Laage

Coal production from underground coal mines has been important to the development of the industrial economy of the United States. Environmental problems have developed from some abandoned operations. These problems include: mine and refuse pile drainage, subsidence, unsafe mine openings and to a lesser extent mine gases, slope stabilities, mine and refuse pile fires and abandoned equipment and structures. Field investigations in three eastern coal mining districts, two in Ohio and one in Illinois, were performed to document the mine closure procedures used and subsequent problems that developed. The purpose was to identify, evaluate, and rank the seriousness of these problems. Based upon this evaluation, the undesirable present day situations could have been avoided or at least minimized by varying certain mining practices or mine closure procedures. It was found that federal regulations address all of these problems during the pre mining, active mining and post mining phases except for abandoned equipment which is the least threatening problem category. Ideally current practice would prevent future problems. However, the extensive and complicated nature of the legislation, environment and mining practices will necessitate adjustments to the law. The investigator recommends the following: 1) Goal oriented legislation encouraging complete resource extraction, standardization and compilation of mining generated hydrological data, periodic review of the coal mining regulations, and improved communication and cooperation between coal interests, regulators and the public. 2) Permitting effluent limitations to accurately reflect natural conditions. 3) Solidly back filling shafts and individual assessment of sealing or capping requirements. 4) Installing shaft vent pipes into the fill material to intercept and vent methane.

Jan 1, 1982

By William K. Tolley

The U.S. Bureau of Mines (USBM) is currently investigating the electrochemistry of mineral flotation. A significant need in this area is greater reliability of sensors. The USBM is testing electrolytic methods to clean and condition redox-sensing electrodes to improve the reliability and extend the service life of these instruments in the harsh physical and chemical environment of mineral processing slurries. A novel method for removing scale from fouled electrodes has been developed that includes anodic polarization to 1.2 V versus the Ag/ AgC1 reference potential, followed by brief potentiodynamic conditioning. Laboratory results show that this technique removes calcarious deposits from gold sensing electrodes and returns the electrodes to useful service within approximately 10 min. Mechanical abrasion to remove the scale is thereby avoided.

Jan 1, 2010

By I. AITKENS

Turquoise is prized solely for its attractive color ; it is dull and opaque , wholly lacking the brilliant luster that is the chief attraction of transparent gems . The best quality of turquoise is blue , of a soft and pleasing tone , like the color of clear sky but distinctive , as indicated by use of the term " turquoise blue . " Often its value is lessened by a greenish cast ; in many stones the green predominates . A large proportion of the turquoise that is mined is utterly worthless , so inferior and unattractive is its color . The finest grade of turquoise comes from Persia , notable from Nishapur . Large quantities have been mined in the Southwestern States of the United States , and less important deposits have been found in a number of the other States .

Sep 1, 1931

By A. A. Cochran

Methods of preparing small heats of steel containing radioisotopes were developed, and the techniques of stripping film autoradiography were used to detect and study the carbide and sulfide phases in titanium-bearing steels. Metallography had revealed areas of titanium sulfide and ferrite or pearlite adjacent to areas of titanium carbide and ferrite, and unidentified, irregular phases at the boundaries between these two areas. Sulfur 35 was used to deter-mine the extent of the titanium sulfide inclusions, and carbon 14 was used to delineate the titanium carbide phase. Individual radioactive areas were located with a resolution of approximately 10 microns. A general background exposure that was not correlated with microscopically visible phases was observed in the carbon 14 autoradiographs. The evidence from both sulfur 35 autoradiographs and carbon 14 autoradiographs indicated that the unidentified inclusions were sulfides rather than carbides. INTRODUCTION The use of radioisotopes to facilitate the work at the Rolla Metallurgy Research Center was expanded in fiscal year 1959 when the Bureau of Mines authorized the installation of an intermediate-level radioactivity laboratory. Before this time, sealed cobalt 60 sources had been employed for radiography, but no tracer work was done. The primary objective of the first experiments conducted in the new laboratory was to supplement physical metallurgy investigations of selected problems in steel research.

Jan 1, 1962

By J. J. McClelland

The face area of a continuous mining section of an underground coal mine is the most dangerous area in the mine. Workers there are at nearly twice the risk of death or disabling injury than those in other parts of the mine. Despite extensive training of miners and improved equipment and mining methods, fatality and injury rates have remained constant during the past few years. It is clear that advanced research is necessary to apply new technologies or modify work procedures to solve the continuing problem of the loss of lives and the numerous injuries at the mine face. A U.S. Bureau of Mines research program is developing a Reduced-Exposure Mining System (REMS) that relocates personnel operating the mining machinery at the face away from the hazards to a nearby haven of relative safety. REMS uses proven technologies of computer automation and robotics to help control the operation of the mining machines at the face, while personnel are moved away to a nearby, safe control room. In this protected, well-ventilated environment, they can supervise or control the operation of the machines while viewing what the machine is doing using video and graphic display monitors.

Jan 1, 1994

By W. J. Fene

It is often desired to obtain samples of air in places where collection by ordinary methods is not feasible, as in shafts amore means of descent or ascent are not provided, in sewer manholes, in gas or water wells, in empty oil tanks, and in sealed areas in mines. Heretofore, when such sampling was required, it was necessary to utilize the aspirating method, which was not always satisfactory; and to obtain samples of air in deep shafts, it was necessary to use long sections of rubber tubing, which was not always available. DESCRIPTION OF NEW DEVICE A new method or "device" employs a common snap-type mousetrap to break the neck of a vacuum tube at the place where it is desired to collect the sample (see fig. 1). A mousetrap is mounted on one end of a block of wood 11-3/4 by 3 by 3/4 inches in such camper that a lead weight attached to the trigger hall spring the trap when the device is given a sharp jerk. A vacuum tube is placed on the other end of the block and held in place by a strong rubber band. A strip of corrugated rubber is placed on each side of the grooved block to prevent the tube from clipping when the sample is taken. An adjustable shoulder, provided with a rubber cap, is pieced se that the neck of the vacuum tube will rest on it. The shoulder is made adjustable to accommodate various sizes of tubas and to keep the neck of the tube from breaking tee far back from the point. A metal handle is fastened to one end of the block, with a hole in the end through which the brass wire used for lowering the device is tied. The device is enclosed by a strong wire-gauge covering, hinged on one side and so arranged that it can be locked shut on the other side. This covering prevent: breaking of the tube while it is being lowered or raised in a shaft or other place. Brass wire of not less than 22 gage should be used for lowering the device. A detailed drawing of the device is shown in figure 2.

Jan 1, 1940

By Richard L. Unger

The U.S. Bureau of Mines has designed, fabricated, and tested a prototype track maintenance vehicle for underground coal mines. The vehicle uses a stiff rotating brush to clean the track so that a visual inspection is possible. It is also equipped to measure track gauge and cross-level. The objective of this report was to describe the track maintenance vehicle and detail the results of investigations into present underground track inspection procedures and cleaning technologies, which led to the development of the prototype. Recommendations are made concerning the integration of components of this prototype vehicle into current track cleaning and inspection systems used in underground mines.

Jan 1, 1984

By R. P. Maloney

The Bureau of Mines conducted a reconnaissance of the less accessible parts of the Beluga River coalfield in August 1957 to determine, if possible, which areas were most favorable for developing large reserves of coal suitable for open-pit mining. Several outcrops of subbituminous coal were observed within an area about 30 miles long and 3 miles wide; neither the length nor the width of the coal-bearing area was delineated by the examination. Coal beds 30 feet thick or more outcrop at two places, and beds 5 to 20 feet thick or more outcrop fairly abundantly along the Beluga River and its tributaries The coal measures appear to occur in a series of folds. The overburden comprises glacial gravels and poorly cemented sandstones and ranges from 20 to 400 feet in depth. Few partings were seen in any of the coal beds. Samples ranged in calorific value from 6,240 to 8,246 B. t. u. on an as-received basis. Adequate water is available for stripping by hydraulic methods.

Jan 1, 1958

By R. V. Higgins

Many contributions to methods of forecasting the performance of waterfloods of a five-spot pattern have been made by investigators. In most of these forecasting methods, a previously selected sweep efficiency is used, and other simplifying assumptions are employed to obtain the objective. In this paper the calculated oil recoveries from several five-spot single- and multiple-layer stratified reservoirs were made with a minimum of assumptions, and because of the techniques used, no previously selected sweep efficiency was required. As a result, the accuracy of the forecast is increased. Permeability curves and continuously changing saturation gradients are used in every section of the pattern. By means of a potentiometric model, the flood pattern is divided into channels, the centers of which are the streamlines. The channels are divided into cells. As flood water enters, the permeability and saturation of each cell change with time. In this study the production from multiple-sand layers of different absolute permeability but with the same relative permeability-saturation relations are combined. The results are shown for a single- and 10-layer reservoir with a permeability variation of 0.60. The oil rate, water-oil ratio, and recovery are shown as functions of time for a 2- and 20-centipoise oil starting in primary phase and after fill-up.

Jan 1, 1962

By T. H. Jeffers

The U.S. Bureau of Mines has developed porous beads containing immobilized biological materials such as sphagnum peat moss for extracting metal contaminants from waste waters. The beads, designated as BIO-FIX beads, have removed toxic metals from over 100 waters in laboratory tests. These waters include acid mine drainage (AMD) water from mining sites, metallurgical and chemical industry waste water, and contaminated ground water. Following the laboratory studies, cooperative field tests were conducted to evaluate the metal adsorption properties of the beads in column and low-maintenance circuits, determine bead stability in varied climatic situations, and demonstrate the beads' potential as a viable waste water treatment technique. Field results indicated that BIO-FIX beads readily adsorbed cadmium, lead, and other toxic metals from dilute waters; effluents frequently met drinking water standards and other discharge criteria. The beads exhibited excellent handling characteristics in both column and low-maintenance circuits, and continued to extract metal ions after repeated loading-elution cycles. Based on laboratory and field data, cost evaluations for using BIO-FIX technology to treat two AMD waters were prepared. Operating costs for BIO-FIX treatment, which ranged from $1.40 to $2.30 per 1,000 gal of water treated, were comparable with chemical precipitation costs.

Jan 1, 2010

By Albert Mendelsohn

This paper, describing the mining practice at the Champion mine of the Copper Range Copper Mining Co., is one of a series of papers on mining methods and costs being prepared by the United States Bureau of Mines. Mining practice at the Champion mine has undergone considerable change during the last four years. Previous to that time the mine was worked by the horizontal out-and-fill method, the stopes starting near the shafts and advancing away from them (fig. 2). The floor pillars were mined by the inclined cut-and-fill method, working en the retreat or toward the shafts (fig. 1). At present the mine is being developed to .tope entirely on the retreat by a sublevel inclined cut-and-fill method.

Jan 1, 1931

By Q. H. Forbes

"The high injury rand fatality rate in coal mining, as compared with other industries, has caused the mining industry to become more and more interested in accident prevention methods.The prevention of accidents in the mining industry is probably not as simple a problem as it is in other industries, but if the experience of coal mining companies who have taken up the work of accident prevention seriously during recent years means anything, there is little doubt that most mining companies car improve their accident records very materially.Such results can be obtained in practically all instances without adding to production costs. In fact, there is little doubt that a well-organized program of accident prevention Will bring about a 'material production cost reduction due to increased efficiency, lower labor turnover, fewer delays due to accidents, better satisfied workmen, and a direct saving in compensation costs as well as many other items of expense.The more closely a. person is connected with the work of accident prevention, the more he becomes a believer in the value of amity in human relationships and the more he is able to exercise a spirit of toleration, fairness, justness, and helpfulness toward the problems of others, whatever those problems may be. Human nature responds to just these expressions of good willAnother great and invaluable effect of working for safety, is the fact that it is building up in the mind an appreciation of that which is constructive and, conversely, in opposition to that which is destructive In other words; the person who is sincerely striving to prevent accidents because they are destructive, costly, tad injurious, is subconsciously training his mind to look on any proposition from a constructive point of view. Working for accident prevention and safety is about the finest social training any person can have. It does not make a Person a financial Wizard or an executive genius, but it does make for the highest type of citizenship.While humanitarian reasons alone should be sufficient to maze accident prevention work an important factor in every mining organization, there are other reasons as well, since it has been proved conclusively that there can be no efficiency and economy without safety, as somebody pays when safety is lacking. Every safety device pays dividends; every safety application evaded is an assessment and a loss. Dangerous conditions are the most expensive and extravagant conditions in or about a coal mine. The economic gains are of considerable interest to all coal mining companies and this is brought about as before stated--through decreased compensation rates, the reduction of labor turnover, etc."

Dec 1, 1930

By G. J. Slavens

The Bureau of Mines has devised technology to recover cobalt, nickel, and byproduct copper from domestic lateritic material using an oxidative, ammoniacal ammonium sulfate leach. Nickel, cobalt, and copper were recovered by solvent extraction and electrowinning. To reduce the cost and complexity of cobalt recovery, an alternate method using lig-nite to extract Co3+ was investigated as reported herein. In the first 25 BV (bed volumes) of solution contacted with lignite, 97 wt pct of the Co3+ was extracted in & downflow column at pH 9.3. After 85 BV, the lignite was loaded to 1.5 wt pct Co3+ and further ex-traction was minimal. The lignite extracted cobaltic ammine complexes rather than cobalt ions and was nonselective as to other -metal cations and ammonium ions. Deleterious cations and 80 wt pct of the nonammine ammonium ions were removed prior to acid elution of the lignite. The removal of the ammines prior to elution to produce an ammonium-ion-freeCo3+ eluate was only partially successful. Thus Co3+ removal from ammoniacal solutions by lignite is technically difficult and economically unfeasible. It was also determined that reduction of Co3+ to Co2+ occurred during the extraction-elution process.

Jan 1, 1984

By David Schlain

This Bureau of Mines report describes a method for electrodepositing titanium diboride from a molten salt bath. Initially, the electrolyte is a mixture of LiBO2, NaB02, Na2 Ti03 , Li2Ti03, and Ti02? The cell is operated at 900° C in a dry, inert atmosphere with consumable anodes of titanium or hot-pressed titanium diboride (TiB2) powder. Agitation of the electrolyte is essential. Current densities may be 6 to 9 amperes per square decimeter (amp/dm2) with titanium anodes and 9 to 30 amp/dm2 with titanium diboride anodes. A current density of 6 amp/dm2 is equivalent to a plating rate of about 35 micrometers per hour. The adherence of the TiB2 deposit varies with the substrate material. It is most adherent on molybdenum and on 4130 steel that has been preplated with copper and nickel, less adherent on nickel, and still less adherent on Inconel and on 4130 steel without the preplate. Cathode and anode reactions are suggested.

Jan 1, 1976

By Charles D. Litton

This U.S. Bureau of Mines report details the results of a series of large-scale experiments where small coal fires were used to ignite the conveyor belt at air velocities ranging from 0.76 to 6.1 m/s. In the tests, electrical strip heaters imbedded within a pile of coal were used to heat the coal to a point of flaming ignition. The flaming coal subsequently ignited the conveyor belt located approximately 5 to 10 cm above the coal pile. During the tests, temperature, CO, and smoke levels were continuously measured in order to determine both alarm time and level as the fire intensity progressed through the stages of smoldering coal, flaming coal, and flaming coal plus flaming belt. Analysis of the data leads to certain conditions of air velocity and sensor alarm levels that are required for early detection of conveyor belt entry fires. Two nomographs are presented, which define sensor alarm levels and sensor spacings as a function of belt entry cross-sectional area and belt entry air velocity.

Jan 1, 2010

By J. B. Cheung

The results of a program to demonstrate the technical feasibility of hydraulic borehole coal mining are presented in this report. The hydraulic borehole method of coal mining involves inserting a hydraulic mining device into a borehole that has been drilled from the surface into the underground coal bed. The borehole mining device issues a jet of water under high pressure, which breaks the coal. These pieces of coal, along with the water, form a slurry, which flows to the base of the borehole where it is pumped to the -surface. Phase I of the program encompassed the design, fabrication and factory-testing of a hydraulic borehole mining device. The program was successfully completed with the field tests being conducted at the Wilkeson-Carbonado Coal Field near Wilkeson, Washington. The technical feasibility of hydraulic borehole coal mining was demonstrated by mining 32 tons of coal at a depth of about 75 ft over a period of 4 hours.

Jan 1, 1976

By Walter R. Storms

This paper, which describes the mining methods of the Potash Co. of America in Eddy County, N. Mex., is one of a series being prepared by the Mining Branch, of the Bureau of Mines on mining practices and methods in various mining districts of the United States. 4, T. The mine and plant of Potash Co. of America are situated in sec. 20 S., R.. 30, E.,. N. M. P. M., about 22 miles by paved road northeast of Carlsbad (fig. 1). A spur line of the Atchison, Topeka & Santa Fe Railroad also connects the mine with Carlsbad.

Apr 1, 1948

By D. Hinton, M. McCawley, R. C. Lantz, F. Pisano, C. Stanley

"INTRODUCTION Aerosols (5 um have not been shown to be consistently generated and characterized in inhalation chambers. Particle deposition in the lungs however may occur with particles as large as 25 um(1). Therefore, in order to closely simulate the atmosphere of an underground coal mine where the distribution is bimodal, with modes at S and 15 um (2), particles much greater than <1 um must be characterized for uniform mixing and size distribution within these chambers. The Hazelton Animal Exposure Chamber has been chosen because it has been best characterized for smaller particles (<1 um) (3), and is the major type used by most inhalation toxicology institutes such as Lovelace Inhalation Toxicology Institute and Battelle Northwest Laboratory.BACKGROUNDPreviously published studies on the inhalation of solid aerosols have attempted to characterize the distrition of particles of <2 um in diameter. There are no published reports of extensive work characterizing either the size distribution of particles <1 um or the concentration throughout the exposure chamber (Table 1).Table 1 shows the variability and sizes of several aerosols <1 um in diameter used in five previous chamber studies.Discussion of Previous StudiesThe study done by Bauermash, Bryan, Dickinson, and Burke (4)stated two major concerns in the development of the 6.5 ft. diameter chamber. The first was that a quantity of animals could be exposed to the same concentration regardless of the location of the animal, and second was that the chamber could be easily cleaned and decontaminated. The solution to the first concern required a circular chamber with the contamination air entering the chamber somewhere along the central axis. The animals could then be changed during exposure time so that each animal was exposed throughout the total volume."

Jun 1, 1988

By Philip C. Good

Unweathered low-grade calcareous phosphate rock of about 20 percent P205 grade was beneficiated by a procedure in which contained carbonates were decomposed by calcination at about 1,000° C. On quenching the hot calcined rock in water, major impurities passed into a slime phase which was mechanically separated from a coarser concentrate fraction. Phosphate rock of two major types was beneficiated in batch-scale studies yielding concentrates containing 31.3 to 38.5 percent P205 at recoveries ranging from 54.8 to 86.0 percent. The samples were from two major deposits in India. Processing information gained was utilized in extending the work to a continuous-flow system, processing phosphate rock at rates up to 157 kilograms per hour. Superphosphate exceeding 16 percent water-soluble P205 was prepared from concentrate derived from continuous-flow processing.

Jan 1, 1976

By H. H. Schrenk

[A colorimetric method5/ for the determination of benzene in amounts as low as 0.001 mg has been developed recently at the U.S. Bureau of Mines Pittsburgh Experiment Station by the authors, with the assistance of chemical personnel fro a 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. The development worth included a study of possible interference by chemicals that be present in those situations in which the method. would be employed. In this study it was found that a specimen of hexane prepared by the Gulf Research Laboratory, Pittsburgh, by fractionation of West Virginia natural gas gave positive result for benzene, whereas a specimen of pentane prepared in the same manner showed only a trace, and specimens of n -heptane and octane (2,2,4 trimethylpentane) supplied by Eastman Kodak Co. save a negative result. According to information obtained from the Eastman Kodak Co. the latter two compounds were highly purified, the n-heptene being prepared from line and the octane synthesized in the laboratory. On nitration of a larger amount of tae natural hexane a visible quantity, of needlelike crystals which resembled those of m-dinitrobenzene was obtained. The hexane from this nitration was recovered by distillation and again nitrated, but no crystals or colorimetric indication of benzene was obtained. This imitated that the specimen of natural hexane contained a substance which at least had the chemical behavior of benzene.]

Jan 1, 1935