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By W. A. Calhoun

The purpose of this investigation was to develop a procedure for removing excess iron from representative samples of bauxite ore from the Quapaw deposit of American Cyanamid Co., Saline County, Ark., in order to produce a beneficiated ore suitable for use in the alum industry, At the request of the sponsoring company, the samples were reduction-roasted at 800° C. and then magnetically separated. Although some rejection of iron was effected under these conditions, the general results were not satisfactory, A much more successful procedure, from the standpoints of both rejection of iron and recovery of alumina, consisted of a short (l5-minute), low-temperature (400° C.) oxidizing roast, followed by a 2-minute interval in a hydrogen atmosphere, then cooling to room temperature, and, finally, high-intensity magnetic separation to remove the iron.

Jan 1, 1957

By Ann G. Kim

Methane in coal constitutes a serious hazard during mining. Draining the methane from large blocks of coal in advance of mining is an effective method of improving the safety and efficiency of coal mining. Because of the similarity of the two gases, drained methane can be recovered and added to pipeline supplies of natural gas. To effectively apply advance drainage techniques and recover drained gas, a gross estimate of the methane content of coal is necessary. Using data from previous investigations, the virgin reserves of the Pittsburgh coal in the central and southwestern parts of Washington County, Pa., are estimated at over 1.5 billion tons, with a methane content of 50 to 100 fts/ton. The Pittsburgh bed in this area of approximately 265 mi2 contains over 130 billion ft3 of methane.

Jan 1, 1974

By L. A. Johnson

The Bureau of Mines analyzed three cores from the south Seep Ridge area of the P. R. Spring tar sand deposit of northeastern Utah. Four tar sand zones are indicated in the area. The zones range in average thickness from 13 to 24 ft. The total net thickness of the tar sand in the three coreholes ranges from 71 to 112 ft. The tar sand occurs between the depths of 27 and 254 ft. It has good porosity, 25.6 pct of bulk volume; high permeability before and after oil extraction, 819 and 2,218 md, respectively; but a relatively low oil saturation, 36.5 pct of pore volume. Gravity of the oil ranges from 8.20 to 16.5° API.

Jan 1, 1975

By Aarne Visnapuu

Pneumatic chipping, scaling, and grinding can expose the tool operator to noise levels in the range 90 to 120 dbA. In most chipping and scaling operations, casting resonance is the primary source of noise, followed by air exhaust, and machine and chisel resonance. In grinding, the air-exhaust noise predominates. The Bureau of Mines has shown that noise from these operations can be reduced by up to 15 dbA. Workpiece resonance was reduced by sand or other damping methods; tool resonance, by internal damping; and chisel resonance, by constrained-layer treatment. Mufflers reduced air-exhaust noise, and an acoustically treated booth was effective in containing noise around the work area without increasing operator exposure.

Jan 1, 1977

By D. J. Bauer

Solvent extraction separation of light group rare-earth elements in a quaternary ammonium compound-chelating agent system was demonstrated in single-stage studies, Typical separation factor values obtained were 93 for lanthanum-praseodymium, 5.4 for praseodymium-neodymium, and 11.6 for neodymium-samarium. These values are significantly higher than those obtained using organophosphate extractants. Further studies in a 20-stage countercurrent mixer-settler resulted in the production of 99 percent lanthanum (oxide basis) at 96-percent recovery. Subsequently, 88 percent of the neodymium with a purity of 92 percent was recovered in the raffinate.

Jan 1, 1971

By H. Carroll

An ozone detector was built and evaluated for its applicability in smog-chamber studies. The detection method is based on the reaction of ozone with ethylene and the measurement of resultant chemiluminescence. In the first phase of evaluation, the detector's response to ozone was studied as a function of several instrument parameters, and optimum conditions were defined for the maximum and most stable responses to ozone. In subsequent evaluations, the method was checked for sensitivity, precision, and interferences and was compared with two alternative methods. Results showed the chemiluminescence method to be acceptably sensitive and precise for smog-chamber studies and superior to the Mast ozone meter and KI (colorimetric 1 percent neutral-potassium iodide method) methods in that it is specific for ozone.

Jan 1, 1972

By Howard E. Parkinson

A brief description is given of various Bureau of Mines research activities that have begun since July 1974 and are not being reported on by others at the Third West Virginia University (WVU) Conference on Coal Mine Electrotechnology. An essential feature of the various projects is that they are pragmatic. The projects are applied research and are carried out both by the Bureau in-house research group and by other research groups through contract research. Projects have been directed toward wired-type communications with a special effort to modify the wired systems so as to be more effectively used. The projects are in three groups: Pager phone systems, trolley line phone systems, and guided-wire wireless communications. Also, a brief sketch is given of research that is essential for further developments in mine communications. From the early results of these various projects, the Bureau has good reason to project that there will be improved performance of existing communication systems and that communications will be extended to other individuals working in areas that are excluded from present mine communication systems.

By L. J. Froisland

An integrated process for recovering metal from nonmagnetic auto-shredder reject scrap was investigated by the Federal Bureau of Mines. The methods used were air classification, water elutriation, screening, magnetic separation, handpicking, and heavy-media separation. Metal recoveries in this process were projected at 39 percent copper and copper alloys, 53 percent aluminum, 96 percent iron, and 98 percent zinc die cast. An economic evaluation of the conceptual process indicated that a facility designed to reclaim the reject scrap from 200 shredded automobiles daily could be profitable. Total investment in this plant was estimated at $321,000; the discounted rate of return before taxes was 53 percent.

Jan 1, 1975

By Willard L. Hunter

The Bureau of Mines smelted samples of chromite ore and concentrate from the General Services Administration (GSA) purchasing depot at Grants Pass, Oreg., in a submerged-arc furnace to establish smelting conditions and the energy requirement to produce high-carbon ferrochromium. Raw material, in the form of ore, flux, and reductant, and electrical energy are available on the Pacific coast to smelt the chromite. The concentrate can be smelted without prior agglomeration by employing hogged wood (wood chips) as a major portion of the reductant. The energy requirement is relatively low, about 3,960 kw.-hr. per ton of alloy. The ferrochromium produced will contain about 60 percent chromium. In addition to the smelting data, a statistical summary of the grade and amount of chromite purchased during the stockpile program and estimated chromite reserves and production volume are given. It is estimated that 632,000 tons of Cr203 contained in chromite of all grades is available in the western coastal States. Of this total there appears to be sufficient metallurgical-grade and beneficiable ore to sustain a smelting operation for 25 years at a consuming rate of 25,000 tons a year, utilizing material comparable to that delivered to the Government stockpile.

Jan 1, 1961

By James C. Cawley

A summary is presented of existing leaky feeder communications systems currently in operation in North America. Background information pertaining to previous use of leaky feeder technology is discussed along with the survey methodology. A review of some pertinent facts concerning propagation in tunnels and specific reference to mine tunnel propagation is presented. A summary of the characteristics of each mine visited is presented in tabular form, and methods of procurement and maintenance are discussed. The role of user training in efficient system use is presented. Seven sites representing eight mines are included in the survey. Economic and technical topics are considered.

Provide an improved, rugged, reliable, cost-effective automatic fire protection for mine haulage trucks. Approach Systems that automatically sense and extinguish fires on haulage trucks were designed, built, and in-mine tested. How It Works Temperature sensors mounted above the engine of the truck detect the heat from a fire while it is still small and controllable. A cab-mounted control panel warns the operator of the fire emergency and then automatically triggers the discharge of 60 pounds of multipurpose dry chemical extinguishing agent (from storage tanks through hoses and nozzles) into the engine compartment. If desired, the control panel can be field-adjusted by changing one resistor to delay the discharge for up to 60 seconds to allow time for the operator to stop the truck and shut down the engine. The system can be assembled with either pressurized storage tanks, or a combination of non-pressurized storage tanks plus separate pressure cartridges. This pressure source option is one of the improvements of this system over the earlier systems described in Technology News No. 11. Other improvements are a simplified control circuit and an improved sensor.

Jan 1, 1980

Improve the safety and comfort of operators of large mining equipment. Approach Develop an improved driver restraint system that is easy to use, reliable, and cost-effective, while providing increased protection in the event of a collision or rollover. The Novel Restraint System There are several problems associated with conventional lap-belt type restraint systems. Among these are: restriction of movement, lack of comfort, and fear of entrapment. Standard seatbelts become dirty and oily from lying on the vehicle cab floor and can ruin a driver's clothes. Some haulage equipment may not even have seatbelts available to drivers since they are sometimes removed during maintenance activities or as a result of vandalism. Recognizing a need to address such problems by providing a more acceptable means of driver restraint, the Bureau of Mines designed and fabricated a novel vest-type restraint system. The vest is designed to be worn during a driver's 8-hour shift and would be issued much like safety glasses, hard hats and safety shoes, thus becoming part of the operator's individual protective equipment and assuring that each vehicle has a restraint system when in operation. The vest-

Jan 1, 1985

Develop a method for mapping planar geologic features in deep underground mines where the presence of metal interferes with compass readings. Background A fundamental problem of mapping planar geologic features in deep underground mines is the presence of metal (water and air pipes, track, equipment, etc.), which affects the accuracy and consistency of compasses. Present geologic mapping methods include use of transits or theodolites, both of which are cumbersome and time consuming to use. To complicate the mapping, process each planar feature must be surveyed, and if that feature is not apparent on the opposite wall, it cannot be mapped. Another method of mapping is to stretch a tape measure between two survey spads and place a string along a planar feature on one wall and out into the opening until it intersects the tape measure. This method, in addition to being time consuming, is also inaccurate. Because detailed mapping of planar geologic features deep underground involves many repetitive measurements, a quick, accurate, and reliable method for making such measurements was necessary. The geolaser was developed to make such measurements in deep underground mines where metal interferes with conventionally used compasses.

Jan 1, 1990

Provide a means through which members of the mining community can easily and readily access information on human factors/ergonomics as it relates to mining. Approach As part of a research study aimed at reducing human error accidents in mining the Bureau of Mines developed a computerized information retrieval system which provides relevant human factors or ergonomics information on 19 mining-related special interest categories.

Jan 1, 1988

By W. D. Ryan

The American public has at all times been prone to discuss important questions that call for consideration and adjustment. Debatable subjects upon which sides may be taken always receive unusual prominence, but other questions equally important may be neglected. The real "paramount issue," calling for remedial action, is the ever-increasing number of deaths caused by preventable accidents. This matter demands the attention of the entire American people; the importance of accident prevention can not be overemphasized, and in many phases of American life, especially among the mining and allied industries, far too little real attention has been given the importance of conserving life and limb by accident prevention. ACCIDENTS COMPARED TO WAR AS A CAUSE OF DEATH Harry T. Hoffman, Wyoming labor commissioner, writes the following: It is one of the peculiar complexes of this rapidly moving age that we all stand aghast at the horrors of war and view with appar- ent indifference the greater havoc of industrial peace. Did you ever stop to think that approximately twice as many people were killed by accidents in the United States in 1929, as there were American soldiers killed in the entire period of the World War? Every employer and every worker should be thoroughly aroused over the tremendous toll levied against industrial forces by accidents which are largely preventable and develop a faith in safety efforts that will fire them with a zeal as pronounced as that of their religion or their patriotism. Let us remember safety-first to the end that the workman shall live to enjoy the fruits of his labor; that his mother shall have the comfort of his arm in her age; that his wife shall not be untimely a widow; that his children shall have a father; that crip- ples and helpless wrecks who were strong men shall no longer be a by-product of industry.

Apr 1, 1931

By John Redington

This paper describing the milling practice at the Coniaurum Mine is one of a series of papers on milling methods, practice, and costs prepared in cooperation with an published by the United States Bureau of Mines. The 500-ton will of the Coniaurum Mines (Ltd.) is located at approximately the center of the company's property and a little more than a mile from the town of Schumacher, Ontario. The main shaft through which all the ore is heisted is adjacent to the mill so that the ore hoisted in a 3-ton skip is dumped directly into a 15-ton bin at the crusher.

Jan 1, 1931

By Dennis R. Dolinar, Eric R. Bauer

Skin failures of roof and rib in underground coal mines continue to be a significant safety hazard for mineworkers. Skin failures do not usually involve failure of the support systems, but result from rock or coal spalling from between the support elements. For instance, in 1997 more than 800 miners were injured by roof and rib falls, of which 98% were the result of skin failures [Bauer et al. 1999]. Also, nearly 80% of the roof and rib failure injuries occurred at or near the working faces in development sections. The face area is a zone where the potential for skin failure accidents and injuries and for roof and rib failures is high because of mining activity, ground readjustment due to changing stress conditions, and the higher exposure of mine workers. In addition, failures occur where the roof and rib are unsupported. This paper reviews the roof and rib accident statistics resulting from skin failure, and highlights the incidences by type, numbers and percentage, in-mine location, supported and unsupported roof, and worker activity at the time of injury. Also discussed are the causes of roof and rib skin failures, current and improved support methods and materials for skin surface control, and machine design modifications for improved roof bolter operator protection. It also reviews the historical literature on skin failures and control methods.

Jan 10, 2000

By Rollien R. Wells

THERE are two recognized methods of recording the state of the metallurgical art. One involves delineation of individual advances reported in the literature. This approach is used effectively in the excellent annual reviews published by some of the leading technical journals and in the technology sections of the individual commodity chapters in this volume. In an effort to more clearly indicate the current trend of metallurgical research and development, the authors of this chapter chose the method of discussing generally selected items of interest brought to their attention during 1959. Since technology cannot be confined by dates on a calendar, most of the items mentioned have been in the process of development for several years. No attempt was made to identify the sources of information used here. Material was drawn from many sources : Nonconfidential correspondence and conversations with authorities of the metallurgical fraternity, papers delivered at technical meetings, and articles noted in the technical press, including particularly Engineering and Mining Journal, Metal Progress, Journal of Metals, Mining Engineering, Industrial and Engineering Chemistry, Chemical Engineering, Chemical and Engineering News, Chemical Week, Materials in Design Engineering, Review of Metal Literature, the Canadian Mining and Metallurgical Bulletin, the Mining Journal (British), and the Journal of the Institute of Metals (British).

Jan 1, 1960

By Roy H. Grau

The National Institute for Occupational Safety and Health (NIOSH) has conducted research to improve the ventilation of large-opening mines whose entries are at least 93m2 (1,000 ft2). The ventilation of large-opening mines is unique compared to other types of mines because (1) it is challenging to keep airflow velocities high enough to effectively remove or dilute airborne contaminants because the entries are so large, (2) large air volumes can be moved through the mines with little static pressure drop, and (3) stoppings that are used to direct ventilation airflows are costly to construct and to maintain. The research results suggest that the ventilation of large-opening mines is improved significantly by incorporating ventilation planning into the mine planning process, using propeller fans to direct airflow, developing new stopping materials and construction methods, and using long pillars to eliminate crosscuts where possible.

Jan 1, 2009

By Dean H. Ambrose

A computer model was created that generates contact data by means of simulation while altering several variables associated with the machine and its operator. These variables include work environment, the operator's anthropometry, work posture, choice of risky work behavior, and the machine's appendage velocity. In the model, a contact means two or more objects intersecting or touching each other, e.g., the appendage colliding with the operator's hand, arm, head, or leg. This report documents the code development of special features of the computer model, random virtual human motions and behaviors, which made it possible for researchers to study hazardous interactions, such as contacts between the operator and machine. The original idea for random virtual human motions began with the need for a model that, when simulated, would experimentally mimic machine and human actions that could cause actual injuries or fatalities in the workplace. Injury incident investigation reports do not usually contain enough information to aid in studying this problem, and lab experiments with human subjects are also not feasible because of safety issues and ethical issues. Early investigation that evaluated the feasibility of random motions resulted in a primary programming structure and building blocks for code expansion. Basic motions and standard derivation data provided random parameters for the operator's movement in the random motion code. Experimenting with basic motions in preliminary models helped researchers devise a random motion technique that worked with xyz motion parameter values from basic motion parameters. Both values were the building blocks used in motion commands that comprised the core of the random motion code. When the code is executed in a three-dimensional computer model, it generates realistic starting positions for the operator's (virtual human) body and body parts and realistic motions mimicking a work sequence with a valid range of variation in movements. Researchers developed several rules for the random motion technique that, when applied, will maintain directional integrity of a virtual human's basic motions. From previous research, researchers formulated the algorithm that determines the behavior during machine operation. The decision algorithm was needed by the random motion code to randomly select what behavior to use for a simulation execution for a realistic representation of the operator's motions and risky behaviors during work tasks. The operator's chance of avoiding the moving appendage was also a concern to ensure that data reflecting a near-miss would not be considered a contact. Therefore, to filter a database obtained from simulations for actual contacts, it was necessary to track the operator's field of view and determine from this information when the appendage is in and out of the operator's view. NIOSH researchers successfully applied random motions and risky behaviors to examine the speed range of a roof bolter machine appendage for different workplace scenarios and compare statistically which is most likely to cause contacts (and possible injuries) to miners. Researchers in this study believe that the use of such simulations, treated with advanced statistical procedures, are extremely useful tools to evaluate the hazards of tasks where it is not possible to perform experiments with human subjects.

Jan 3, 2004