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By R. H. Sprute

This report describes a feasibility study to consolidate coal waste sludge in a 100-acre pond by applying direct current between floating and buried electrodes. The study was conducted by the Bureau of Mines under a cooperative agreement with Washington Irrigation and Development Co., located near Centralia, Wash. Part 1 covers results of laboratory tests at the Bureau's Spokane Research Center and a small-scale field test at the cooperator's coal preparation plant in western Washington. The process is efficient and cost-effective when power is applied at low current density. A proposed system, fully described in part 2, has electrodes covering 21 acres of pond surface radially arranged around a central power platform. Densification of pond contents would require 2 to 3 years of treatment. Total cost of equipment, labor, and material is approximately $500,000.

Jan 1, 1982

Provide reasonably priced, reliable fire protection for large walking draglines. Approach Fire hazards on large draglines were analyzed, then appropriate automatic fire sensing and suppression systems developed and in-mine tested. How It Works Five fire hazard areas identified for special attention are: electrical control room, high voltage transformer enclosures, circuit breaker rooms, collector ring/roller path area, and the automatic lubrication rooms. Automatic fire sensing and suppression systems were separately designed for each area. The design of each system was tailored to the hazards and equipment protected. Spot thermal sensing and Halon 1301 suppression were specified for the electrical

Jan 1, 1981

By Robert J. Willard

This chapter includes tables from 1983 that were not available in time for publication of the 1983 Minerals Yearbook, but does not include corresponding tables for 1984. The value of raw nonfuel minerals produced in the United States during 1984 was estimated at $23.2 billion, an increase of $2.1 billion over the value for 1983. This is the second consecutive year that the value has increased, and except for a decrease in 1982, the value for each year has increased since 1971, or 12 out of 13 years. In 1984, 16 out of 21 metal commodities increased in output while 5 metals decreased; 14 metals increased in value and 7 decreased. Of 46 nonmetal commodities. 37 increased in output while 7 decreased and 2 remained unchanged; 35 nonmetals increased in value and 11 decreased. These statistics are grounds for continuing the cautious economic optimism expressed in 1983. Despite the note of optimism, however, numerous problems plague the mining industry, weakening its stability and inhibiting its growth potential. The problems are a complex mix of international and domestic factors that have been building in the recent past, but have become even more troublesome in 1984.

Jan 1, 1985

By J. Ankrum, T. Xia1, D. Wilder, K. Spratt

The human lumbar spine is inherently an unstable structure and requires sophisticated neuromuscular control to maintain its stability and for performing physical tasks. As a consequence, it is important to understand the potential health effects on human operators of mechanical stimuli such as shock and vibration.1 Impact applied to a vehicle operator combines the risk of sudden, unexpected load with the mechanical stress of the seated posture.2 Because many work environments contain the potential for multiple, unexpected impacts, it is important to understand how the trunk muscles respond to complex conditions. We believe the results have implications for isolation design and standards development. Methods Muscle activity was recorded during simple and complex impacts, applied randomly and without warning, while subjects sat on an air-suspension truck seat located on a man-rated 6-DOF motion platform (Rexroth-Hydraudyne). Simple (single) impacts consisted of 100 ms quarter-sine jolts in the side-to-side (L and R) and vertical upward (V) directions with peak amplitude at 0.4 g. Complex impacts consisted of combinations of two simple (single) impacts in sequence (LV, RV, VL, VR), separated by 100 ms. Twelve right-handed males (23.7 ± 7.8 years old) were tested without a blindfold under 2 posture conditions (supported while leaning back and unsupported, sitting upright) and 2 seat suspension conditions (present or absent). Each type of impact was repeated three times under each posture and suspension condition, resulting in 84 impacts in total. Surface EMG signals from the left and right erector spinae (ES), rectus abdominis (AR), external obliques (EO) and internal obliques (IO) were recorded and transformed to 25ms RMS values. The response time, defined as the time the muscle activity exceeded the mean + 2 STD of the pre-impact resting period, peak response amplitude, and time were then derived. A mixed-model repeated measures analysis of variance was used to evaluate statistical significance, where type I error rate was set at .05. Results One question we asked of these data was whether there were differences in responses related to simple single strike impacts (L, R, or V) and complex, double-strike impacts (LV, RV, VL, VR). There are 21 possible combinations of comparisons of simple and complex impacts to each other. The differences found are listed in Table 1.

Jan 6, 2006

By Ronald D. Hill, Elmore C. Grim

Sediment is one of America's greatest pollutants. More than a billion tons of sediment reach the major streams of the United States annually(l). Damages are reflected in the reduced carrying capacity of streams, clogged reservoirs, destroyed habitat for fish and other aquatic life, filled navigation channels, increased flood crests, degraded facilities for water-based recreation, increased industrial and domestic water treatment costs, premature aging of lakes by enrichment of the water with silt-carried fertilizer that promotes algae growth, destroy crops, and reduce productivity of flood plain soils. Erosion and sedimentation are natural processes that are usually gentle actions releasing controlled amounts of silt from watersheds to receiving streams. Surface mining activities accelerate these natural processes and short duration, high intensity storms can become a violent force moving thousands of tons of soil in a brief period of time. Cover is a very important factor. With the removal of ground cover, water moves across the denuded area on its own terms picking up soil particles as it flows and leaving gullies behind. The susceptibility of strip-mined land to erosion depends on: 1.Physical characteristics of the overburden 2. Degree of slope 3. Length of slope 4. Climate 5. Amount and rate of rainfall 6. Type and percent of vegetative ground cover. By development of erosion and sedimentation control plans before disturbance of the area, many of the detrimental effects of strip mining can be prevented.

Jan 1, 1974

This Part describes a mine pager phone to public telephone interconnect sys tem that permits mine paging telephones to be selectively interconnected with the public telephone system, as illustrated by Figure 1. This interconnect concept was first conceived and demonstrated in breadboard form by H. E. Parkinson of Industrial Hazards and Communications, PMSRC, as one means for providing improved emergency and off-hours communications. The third-generation prototype unit described in this Part was designed and fabricated by Arthur D. Little, Inc. This unit is a small desk-top or wall-mounted unit that connects directly to both the public telephone line and the mine pager phone line, and requires no modifications to either the public dial telephone or mine pager phones. As part of this task, ADL also built, under a very compressed time schedule, a second-generation prototype unit suitable for reliable demonstration of the interconnect concept during the Bureau's technology transfer seminar on mine communications in March 1973. * A major objective of the design of the third-generation unit described in this Part was that it be compatible with present mine pager phone systems utilizing DC voltage on the mine phone line to activate the phone loudspeakers. Therefore, this unit was designed to operate in a push- to-talk, push-to-listen mode that accommodates the inherent design differences and operation modes of the mine phones of different manufacturers. Though this push- to- talk, push- to-listen mode of operation may seem slightly unusual at first sight, we have found it is easily learned by new users. However, mine phone manufacturers wishing to expand their product lines with such an interconnect system will probably find it to their advantage to customize the design of this system to their particular mine phones, thereby utilizing the unique attributes offered by their individual product lines. This customization should not be difficult, and Section III below suggests some of the features that can be easily added to future designs. Detailed parts lists and circuit schematics for the present third-generation proto- type system can be obtained from the system manual submitted to PMSRC and placed on public file.

Jan 1, 1974

Tax for Toxic Waste Cleanup. - The Superfund Act of 1980 became effective April 1, and provides that producers of certain metals and chemical substances are to be taxed in order to fund toxic waste cleanup. Industry will provide 88% of the 5-year, $1.6 billion fund. The Environmental Protection Agency will administer the Act, but the Internal Revenue Service will be responsible for collection of the industry tax. Under the Act, nickel companies, for example, will be required to pay a tax of 0.225 cents per pound on pure nickel products produced or imported into the United States. Standard for Exposure to Lead. - The Occupational Safety and Health Administration (OSPA) has announced a stricter standard on the test of a worker's exposure to lead. Effective May 15, in all lead intensive occupations with the exception of those at primary and secondary lead smelters, a worker would have to be removed from his work station if the level of lead in his blood tests out at 60 micrograms of lead per 100 grams of blood, instead of the previous standard of 70 micrograms. In the case of primary and secondary lead smelters, the ruling has been stayed until June 1, 1981, to allow time for further study.

Jan 1, 1981

By James H. Russell

The Bureau of Mines, U.S. Department of the Interior, in cooperation with the Department of Energy, has attempted to increase the activity of nickel catalysts for converting synthesis gas, derived from coal, to a substitute natural gas. This report describes the effects of low-level additions of B, Ca, Ce, Co, Mn, Mo, Pd, Re, Ti, Y, Zn, and Zr on the methanation activity of Raney nickel. The methanation rate at 320° C and the resistance to poisoning by 2 ppm H2S were used to compare catalysts. The effects of the additions were small, and the experimental variances were large, necessitating the use of statistical methods to identify significant effects. Co, Ti, Y, and Zn improved the resistance to H2S poisoning, but only Co improved the methanation rate In some individual catalysts containing Ca, Mo, or Mn, both the methanation rate and resistance to H2S poisoning were improved.

Jan 1, 1980

By Kenneth L. Cashddollar, Terry G. Montgomery, Eric S. Weiss, John E. Going

The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted joint research on dust explosions by studying post-explosion dust samples. The samples were collected after full-scale explosions at the PRI, Lake Lynn Experimental Mine and after laboratory explosions in the PRL 20-L chamber and the Fike 1-m3 chamber. The dusts studied included both high and low volatile bituminous coals. Low temperature ashing for 24 hr at 515°C was used to measure the incombustible content of the dust before and after the explosions. The data showed that the post-explosion incombustible content was always as high as or higher than the initial incombustible content. The MSHA alcohol coking test -was used to determine the amount of coked dust in the post-explosion samples. The results showed that almost all coal dust that was suspended within the explosion flame produced significant amounts of coke. Measurements of floor dust concentrations after LLEM explosions were compared to the initial dust loadings to determine the transport distance of dust during an explosion. All of these data will be useful in future forensic investigations of accidental dust explosions in coal mines or elsewhere.

By Ernesto Villaescusa, Andres Brzovic

Rock masses of the primary copper ore at the El Teniente Mine are very competent and massive. The rock mass contains almost no open discontinuities. Nevertheless, there is a high frequency network of small discontinuities coupled with widely spaced faults. A data collection campaign designed to characterize the rock structure was recently implemented. The results show that conventional analysis in terms of discontinuity frequency does not predict differences between two studied sectors. However, when an empirical definition of a weak discontinuity is applied, appreciable differences between the two sectors appear in terms of discontinuity frequency and predicted in situ block size distributions. These differences are in accordance with actual observations at the mine site. Due to the geological features of the primary copper ore, rock mass classification schemes cannot be readily applied to characterize these rock masses.

Jan 5, 2007

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 K. O. Bennington

The thermodynamic properties of synthetic acmite, NaFe3+Si206, were determined by the Bureau of Mines. The enthalpy of formation was determined by hydrofluoric acid solution calorimetry. The values of the standard enthalpy of formation at 298.15 K, ?Hf°298.15, from the elements and from the oxides, ?H°298.15, are ?Hf°298.15 = -615.87 ±0.71 kcal/mole, ?H°298.15 (from oxides) = -32.08 ±0.53 kcal/mole. Various experimental data were combined with other data from the literature to calculate all the related thermodynamic properties in the range of 298 to 1,263 K. The standard Gibbs energy of formation is ?Gf°298.15 = -575.8 kcal/mole.

Jan 1, 1981

By H. F. Weaver

The 18th National First-Aid and Mine Rescue Contest was held in the Memorial Auditorium, Buffalo, New Vork, October 5, 6, and 7, 1959. The meet was sponsored by the Federal Bureau of Mines and the Joseph A. Holmes Safety Association, in cooperation with State mine inspection agencies, management and labor of the mineral extractive industries, and other safety minded groups. The Arrangements Committee, as authorized by the General Committee, made a11 the necessary arrangements for conducting the 1959 contest. Members of the Arrangements Committee were: Harry Gandy, Jr. (chairman), National Coal Association; James B. Benson, Southern Coal Producers' Association; Charles Ferguson, United Mine Workers of America; George C. Trevorrow, Bituminous Coal Operators' Association; and James Westfield, Federal Bureau of Mines.

Jan 1, 1960

By W. T. Abel

The Bureau of Mines tested 48 materials for their ability to absorb H2S from hot simulated producer gas (1,000°-1,500° F). The material found best from the standpoint of absorption capacity, durability, and amenability to regeneration was sintered pellets of 75 percent fly ash-25 percent Fe203. The performance of this absorbent under simulated and actual conditions is described. The effect of absorbent composition, absorbent temperature, steam content of the gas, and tar vapors and dust in producer gas is discussed.

Jan 1, 1974

The Bureau of Mines has conducted considerable research to improve life support technology for underground mining applications. This proceedings volume presents several new developments that may help increase the chances of mine workers in surviving underground disasters. Several papers address the performance of present self-contained self-rescuers (SCSR's) and provide proposed guidelines for the design and testing of a second-generation SCSR. Improvements In the safety and effectiveness of mine rescue and recovery operations are described, including the design of a low-profile rescue breathing apparatus and a rescue team helmet.

Jan 1, 1987

By A. W. Henderson

The growing importance of halide metallurgy for preparing high-purity metals has stimulated research to extend halogenation reactions to the direct extraction of metals from low-grade sources. This Bureau of Mines investigation involves a pioneering study of chlorination reactions in the presence of a fluorine donor. Tin slags containing tantalum and columbium and a zircon concentrate containing a relatively high ratio of hafnium to zirconium were studied. Direct chlorination of these materials at 500° C. yields only a 5-percent conversion of tantalum and columbium or zirconium and hafnium to anhydrous chlorides. This investigation showed that small additions of calcium fluoride to the reaction increased the recovery of tantalum and columbium to 95 percent and the recovery of zirconium and hafnium to 27 percent. These results were achieved with ratios of calcium fluoride to mineral or slag of only 0.2. Silica, the major impurity in the materials studied, was found to be converted to silicon tetrafluoride during chlorination in direct proportion to the quantity calcium fluoride added to the charge. However, large additions of calcium fluoride decreased the volatility of the resulting halides of tantalum, zirconium, and hafnium. Smaller amounts of calcium fluoride also favored recovering minor metal constituents in the zircon concentrate (uranium, thorium, and rare earths).

Jan 1, 1962

By Lloyd A. Morley

This report details the continuation of mine power systems transient research under USBM Grant G0155003. The purpose of the work, which commenced under Grant G0133077, is the elimination of safety hazards created by transients" and the objective is to provide knowledge about transients existing in a-c and d-c coal mine power systems. The report chapters cover theoretical background, instrumentation, and experimental investigations. The instrumentation discussion scans measurement problems and considerations plus the development of a low-cast peak-detector. Transient data from in-mine measurements are presented and include high-voltage distribution and d-c trolley systems. Extremely unique field exercises are described involving actual power equipment connected on the surface to duplicate typical underground coal mine system arrangements. Here, transients on high-voltage distribution resulting from vacuum circuit breaker operations could be observed under controlled conditions, and work centered around how surge capacitors effect transients. Using the in-mine and staged transient data, specific conclusions and recommendations are made with emphasis on high-voltage distribution.

Jan 1, 1977

By Benjamin W. Haynes

Materials from phosphate rock mining and processing were analyzed for fluorine and uranium content as part of the Bureau of Mines program to more effectively recover resources from mining and mineral processing reject materials. The analysis of both feed and waste materials generated in the beneficiation and acidulation of phosphate rock was performed to obtain information on the disposition and concentration of these elements in phosphate rock processing streams. Fluorine was determined by a distillation-titration method and by ion chromatography. Uranium was determined by the dibenzoylmethane (DBM) method, the reliability being confirmed by roundrobin analysis of samples within Bureau of Mines research centers. National Bureau of Standards (NBS) Standard Reference Material (SRM) 120b-Phosphate Rock was also analyzed for fluorine and uranium to verify procedures and results. Fluorine values ranged from 0.3 wt-pct in gypsum filter cake to 3.7 wt-pct in phosphate rock concentrate. Uranium ranged from less than 5 µg/g in gypsum filter cake to 200 µg/g in a dried clay slime.

Jan 1, 1981

By G. E. McElroy

[During the period July, 1923, to April, 1924, we made a large number of careful determinations of the resistance to the passage of air in selected sections of airways in the metal mines of Butte, Mont. The experiments were conducted with the cooperation of the Anaconda Copper Mining Co., Frank D. Cannon, mining engineer of that company, and Fred P. Gaethke, mining engineer of the bureau, assisted in carrying out this work. This paper summarizes the, main group of data obtained in the form of a table, of friction factors, or coefficients of friction that is, values of K in the generally accented formula or air flow of [P = KSV or H = KSV2 ] where, in units customary to mining practice;]

Jan 1, 1925

By William H. Schiffbauer, William D. Mayercheck, August J. Kwitowski

This report summarizes work sponsored by the Bureau of Mines in the development of a remote operating system (ROS) for controllng a thin-seam continuous miner (TSCM) 500 feet or more distant from the extraction face. Detail s are provided on ROS subsystems including the continuous miner, video equipment, controls and displays, the electronic control system, and the operator station.