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By S. M. Shelton

Tests employing various ore-dressing methods were made on a manganese wad ore from the W. A. Chinn property in the Batesville-Cushman district of Arkansas in an effort to develop a practicable procedure for the production of ferromanganese-grade concentrates. The ore body occurs as a bed approximately 7 feet thick in the residual clay of the Ferndale limestone formation5/. The crude wad ores are soft aggregates of various oxides of manganese, which are loosely bonded together. Hard lumps of high-grade ore are disseminated throughout the wad. Hausmannite, pyrolusite, and psilomelane are the principal minerals. Some clay is present, but most of the gangue consists of leached fragments of the original siliceous and calcareous rocks in which the manganese occurred. In addition, hydrated oxides of iron, which axe present, also must be considered as gangue. Definite phosphate minerals have not been identified.

Jan 1, 1942

By J. McCoy

Charged sprays and fog have been evaluated for reducing respirable dust concen¬trations. Charged spray technology was reviewed for effectiveness, equipment and theoretical considerations. A mathematical model was developed for predicting dust reduction effects. Laboratory tests were made showing charged spray is considerably more effective at reducing dust on a unit water basis than hydraulic spray. Positive and negative sprays are equally effective. Combined polarity sprays are considerably less effective than either polarity alone. Little difference in effectiveness by dust type was observed. The charged cloud can present a spark hazard in explosive atmospheres. Due to this spark hazard from the charged droplet cloud this technique must not be used in gassy mines. Predictions were made for field test conditions but confirmation was impossible due to particles resulting from dissolved solides in the spray water. Dissolved or suspended solids in atomizing sprays can result in an increase of the respirable dust burden. Charged sprays are an available dust control technique best suited to applications where water usage must be limited and long contact time between spray and dust is possible.

Jan 1, 1983

The objective of this research was to evaluate the technical and economic constraints on the extraction and utilization of anthracite coal and to determine the research and development needed in order to make anthracite coal more fully utilized as a premium energy resource. In the report the contractor examines in detail the anthracite industry both past and present and evaluates market possibilities. Anthracite reserves and resources are analyzed and tabulated, and the problem of pumping and drainage from the flooded anthracite fields is covered. Current technology is considered in detail with a discussion of production techniques with potential for improvement. The contractor concludes the report with a summary of constraints on the anthracite industry and the contractor's recommendations for effecting a revitalization of that industry. An estimated production of 17 million tons annually by 1990 can be anticipated if adequate planning, research, and development to overcome present constraints are initiated in the near future.

Jan 1, 1975

By M. K. McCarter

Previous investigations suggest the possibility of determining shear strength of geologic materials by measuring the force necessary to rupture the web between two closely-spaced, parallel holes using a borehole jack. Current research using finite element modeling and laboratory testing of intact rock indicates that web failure initiates by tensile fracturing induced by a complex stress field. Based on these results, a theoretical justification for relating web strength with shear strength appears unlikely for holes of equal diameter spaced two diameters apart. Empirical results, however, show a strong correlation between average web strength and average unconfined compressive strength for some rock materials under laboratory conditions. A good correlation also exists between residual web strength and the residual angle of friction under the same conditions. This research project involves the construction and field testing of a large borehole jack. The jack is designed to operate within a conventional 12-1/4 inch rotary blasthole common to open pit mining. The system is capable of exerting approximately 800,000 pounds on curved platen measuring roughly 4x24 inches. Field tests indicate that the system will operate in a mining environment, and preliminary results suggest the possibility of using the force-displacement data generated by the jack to rank the competency of material within a mine bench.

Jan 1, 1982

By R. W. Stahl

The use of continuous mining machines has greatly minimized the necessity for blasting in coal mines, even during pillar recovery; however, explosives are still used to blast stumps. The use of improper blasting materials, improper procedures, or both has caused mine explosions and fires, with loss of life and property damage. Researchers and manufacturers are continuously improving explosives and blasting accessories; use of the more recently developed materials will make the blasting operation safer. Extreme caution is mandatory when blasting stumps, as the ignition of methane or coal dust may trigger an explosion or cause a fire. Since the blasting of stumps will no doubt continue, although often unnecessarily, this paper summarizes recent findings published by the Bureau of Mines and recommends safer methods.

Jan 1, 1962

By Thomas V. Falkie

The purpose of this work was to investigate the rate at which coal is delivered from the underground working face by gathering arm type loaders as employed on continuous mining machines, to identify the factors -- geometrical, geological, mechanical, or procedural which affect the delivery rate, and to develop quantitative rate descriptive equations for the loading function. The mathematical techniques employed were factor analysis and multiple linear regression. It was determined that the coal-cutting function of the continuous mining machine is the factor that primarily influences the loading function. The geometrical factors -- the dimensions of the work area in relation to the dimensions of the mining machine - were the factors of secondary influence. Fifty-five percent of the experimental variation in the loading function was explained in terms of the six most prominent independent variables. It is expected that this work will be useful in operations-research studies as applied to underground coal mining, and with refinement will enable mine planners to select equipment based on the operating characteristics of the equipment and the mining conditions.

Jan 1, 1972

By Michael Horn

[An economic trading region made up of 22 eastern Washington, northern Idaho, and western Montana counties, with Spokane, Washington as the central place, was defined for this study. modeling system with the, 1985 county database was to create an Input/Output based model of the regional economy. The leading ice, with respect to income, employment, value of exports, and total industry output are shown for each county and the region. The value of total industry output from natural resource based industries is also shown for each county and the region. Interindustry transactions, final demand, and value added components for the region are shown in the Regional Gross Flows Table. The total gross output for the region is valued at $36.7 billion. Total industry output for the region is $18.1 billion. The region provides $5.4 billion in income to a work force of 286,000. Spokane County, Washington accounts for about 50 percent of the regional total industry output, income, and employment. Both Spokane County and then as a whole produce about 80 percent of the total industry output for final demand with remaining 20 percent going to intermediate inputs for further production. Spokane County exports about 43 percent of its total output while 35 of the regional output is exported. Exports account for more 50 percent of the total in 18 of the 22 counties within the region. About 9 percent of the total industry output from Spokane County and 19 of the total output from resource f: .t *III For counties Spokane a industry ? N from nafural resource based represents 18 percent ?.{1 to 71 s. ?-{ and averages 39 r. ?-11 of total county +' ' 7:. FS.-f.?) If t. Natural resource it us -t for more than 50 coutny 1 s ? sass in seven counties within region.]

Jan 1, 1992

By W. P. Diamond, F. Garcia, J. K. Marshall

Many longwall mines rely on methane drainage to supplement traditional fan-based ventilation systems. However, the surface production facilities for methane drainage systems, including gob gas ventholes, are commonly located in remote locations, sometimes without convenient access to electrical power, and they may be monitored infrequently. The first evidence that a methane drainage system may not be operating efficiently, or not operating at all, can be an increase in methane concentrations at a return air shaft or underground where the workforce is exposed to the risk of a methane explosion. A solar powered, remote gob gas venthole monitoring and cellular telephone-based real-time data transmission system has been developed and successfully field tested by the National Institute for Occupational Safety and Health (NIOSH) to address this problem. With this system, individual methane drainage boreholes can be monitored from the mine office to determine current operational performance parameters, as well as review past data to anticipate maintenance needs and troubleshoot operational problems.

This appendix contains the list of equipment selected for the capitol cost estimate, with the respective quotations from their vendors/manufacturers. A vendor response report along with a separate equipment and motor list has been included in the first part of this appendix.

Jan 1, 1979

By R. J. Matetic

The Bureau of Mines, as part of a program to improve mine planning and development, is currently investigating the effects of pillar load transfer, which can impact mining operations wi.thin a multiple-seam configuration. At two mine sites where such ground interactions were present, the Bureau performed a complete geological analysis and installed and monitored instrumentation to gather pertinent data on rock mechanics. Overburden depth varied dramatically in the vicinity of the study area and reached a maximum at the study site; innerburden thick-ness was less than a pillar width (40 to 4S ft); heaving was experienced in both mines where sandstone and/or shale floor units were observed; overlays of the mine layouts show pillars were not totally superpositioned; a maximum of S in of roof to floor convergence was measured; and pressure readings indicated pillar core loading only and increased to a maximum of 7,000 psig over instrument setting pressure.

Jan 1, 1987

By Gregory M. Molinda

The Coal Mine Roof Rating (CMRR) was developed 10 years ago to fill the gap between geologic characterization and engineering design. It combines many years of geologic studies in underground coal mines with world-wide experience with rock mass classification systems. Like other classification systems, the CMRR begins with the premise that the structural competence of mine roof rock is determined mainly by the discontinuities that weaken the rock fabric. However, the CMRR is specifically designed for bedded coal measure rock. Since its introduction, the CMRR has been incorporated into many aspects of mine planning, including longwall pillar design, roof support selection, feasibility studies, extended-cut evaluation, and others. It has also become truly inter-national, with involvement in mine designs and funded research projects in South Africa, Canada, and Australia. This paper discusses the sources used in developing the CMRR, describes the CMRR data collection and calculation procedures, and briefly presents a number of practical mining applications in which the CMRR has played a prominent role.

Jan 5, 2007

By David Schlain

The Bureau of Mines investigated methods for electrodepositing platinum-group metals from molten cyanide baths. The preparation of thick, protective coatings on molybdenum, Inconel, graphite, stainless steel, copper, and other structural metals were studied, as well as the electroforming of platinum and iridium crucibles. Iridium, rhodium, and ruthenium can be electrodeposited under an inert atmosphere, while platinum and palladium require the presence of air. Electrolytes may be prepared by direct-current electrolysis in NaCN or mixtures of NaCN and KCN using anodes of the particular platinum-group metal. When the concentration of metal increases to about 0.3 or 0.4 percent, the deposits become bright, adherent, and coherent. Current densities may be 10 to 25 ma/cm2, and plating rates are often 0.5 mil/hr. Platinum and palladium baths deteriorate because of the oxidation of cyanide to cyanate and carbonate, and the precipitation of metal. Changes in the platinum cyanide bath are relatively slow. The protection against oxidation afforded by the platinum-group metal coatings is evaluated by testing encapsulated specimens in a thermogravimetric balance. Surface pretreatment and the use of undercoats are discussed.

Jan 1, 1977

By Kyle W. Charlton

The Bureau of Mines utilizes special testing methods for the analysis of underground mine atmospheres for use during or after mine disasters and fires. These methods depend upon drawing sample gas to the surface through multiple tube bundles with the subsequent analysis of grab samples or the automatic analysis by often remotely located instruments on a continuous, 24-hour basis. During cold weather, low ambient temperature causes condensation and freezing of condensable vapors in the sample which can result in delayed response times or complete blockage of the sample line. This report covers research and resulting development conducted by the Bureau of Mines to produce a reliable method to selectively remove condensable vapors and particulate in the sample gas stream under worst-case field conditions. The effort resulted in two prototype systems which have greater field utility than originally anticipated. The innovative project resulted in two patent applications submitted through the Bureau of Mines.

Jan 1, 1981

By Stephen C. Tadolini, Thomas E. Marshall, Cecil Banta, L. J. Prosser, Anthony T. Iannacchione

The Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) endeavors to provide national and world leadership in the prevention of work-related illness, injury, and death. This is accomplished by using a scientific approach to gather information, assemble and create knowledge, then translate the knowledge and results into products and services. These products and services are then delivered to all personnel who can effect prevention. Obviously, the development and use of instruments to monitor mine roof conditions provides an opportunity to execute that mission. In the late 1990’s, based on observations at a number of underground limestone mines, only a few used roof monitors. Subsequently, NIOSH introduced the Roof Monitoring Safety System (RMSS) as an aid to roof inspection beyond traditional visual and sounding techniques. Initial expectations were that by gaining roof movement information, ultimately roof sag rates could provide indications of eventual failure. During this investigation, RMSSs were installed in 13 underground limestone mines in six states and this paper analyzes the data obtained at three of these mines. This paper also provides an overview of the system, data, analysis, and applications relevant to the RMSS.

By Jr. Gabler

The U.S. Bureau of Mines (USBM) has developed a computerized commodity flow model for strategic and critical materials This flow model is generic and applicable to most commodities and amenable to updating supply, demand, and/or production data change. The original model, with slight modifications, was used to track the flow of chromium. This report follows the flow of chromium through its metallurgical, chemical, and refractory applications, and highlights areas where significant losses occur because of downgrading, export, or disposal. The study indicates that materials containing 451,769 mt of chromium were consumed, including 99,221 mt of chromium from recycling, Chromium losses from all causes in 1989 were estimated to be 345,347 mt from a variety of areas. These areas and their chromium losses are as follows: processing losses, 38,825 mt; processing-downgraded scrap, 18,227 mt; manufacturing losses, 18,128 mt; manufacturing-downgraded scrap, 56,595 mt; prompt scrap exported, 1,531 mt; obsolete scrap exported, 43,443 mt; recovery losses, 155,529 mt; and recycling losses, 13,069 mt. Recycled chromium-containing material accounted for 22 pct of the apparent consumption of chromium in 1989.

Jan 1, 1994

By NEFE AEWFW

Changes in the 1980 quantity and value of the sales of various natural abrasives, compared with the data for 1979, were of a mixed nature. Output of garnet and special silica stone products increased in both tonnage and value during the year, while emery and tripoli-type materials production decreased in both tonnage and value. The reported quantity and value of sales of manufactured abrasive material-fused alumina and alumina-zirconia, silicon car-bidet and metallic iron and steel shot and grit-also decreased for 1980. [ ]

Jan 1, 1981

By H. H. Fields

The Bureau of Mines is in the process of degasifying a virgin area in northern West Virginia from the base of an 839-foot-deep vertical borehole¬. An in situ gas pressure hole 199 feet long, and seven degasification holes ranging in depth from 500 to 850 feet (average 618 feet) were drilled in an 8-foot-thick virgin Pittsburgh coalbed from the enlarged (14-foot-diameter) bottom of this borehole. The in situ pressure at the back end of the hole and the range of gas and water flows from degasification holes as they were completed and closed off were 203 psi, 79,000 to 257,000 cfd (average 160,000 cfd), and 5 to 8 gpm per hole (average 6.8 gpm), respectively. Twenty-four hours after the seven holes were connected through individual water traps to a common collector for natural venting of the gas through pipes to the atmos¬phere, the total gas and water flows and the in situ pressure dropped, respec¬tively, to 971,000 cfd, 1.3 gpm, and 18 psi. Eighty days later the correspond¬ing values dropped to 529,000 cfd, 0.50 gpm, and 13 psi. After 180 days of degasification, 91 million cubic feet of gas had been removed from the affected virgin area. This represents 60 to 70 percent of the gas calculated to be contained in the area of coal affected by the holes.

Jan 1, 1973

A preliminary study was conducted by the Bureau of Mines to determine the effect of humidity on salt mine airborne dust levels. Results showed less dust where the humidity was elevated. Dust reductions appeared to be dependent on the equilibrium between humidity and salt.

Jan 1, 1980

To mine uraniferous sand-stone in an economically feasible and environmentally compatible manner without placing men underground. Approach Uraniferous sand is remotely extracted through a single borehole by cutting Into the are around the borehole with a high pressure water Jet, and pumping the resulting slurry to the surface. How It Works A 16-inch-diameter borehole Is drilled from the surface down into the burled mineral deposit, and the mining tool Is installed. High pressure water Is released as a jet from a nozzle In the mining tool to erode the are, forming a slurry that flows to the bottom of the cavity. The slurry Is drawn Into Inlets located near the bottom of the drill string. See drawing. After being pumped to the surface, the slurry is weighed, metered, and checked for radioactivity. It is then deposited Into one of a pair of sumps. Water collecting in the sumps drains Into an adjoining pond for reuse. Thickened are In the sumps is removed and placed In piles.

Jan 1, 1978

By Carlie E. Banks

Tasks during Phase I of this contract effort were performed in four principal functional areas. These were geology, hydrology, reclamation and mining. Data were gathered from literature reviews, mine visits, survey of manufacturers, consultation with government agencies, and unpublished or private communications with contractors and consultants. The data collected were analyzed for omissions or inaccuracies, then organized into tables, graphs and flow charts to provide a concise body of technical and cost data suitable for the engineering analyses required in Phase II of this contract. Maps illustrating estimated grade and thickness of the oil shale were prepared, some of which are included as exhibits to this report. A preliminary mine layout was performed to test the completeness of the collected data.

Jan 1, 1975