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By Leonard P. Vitt

This report details the work done to provide the U.S. Bureau of Mines with a customized Wireless Ground Monitor Wireless Ground Monitor was modified as follows: 1. A voltage regulator was added to prevent false trips with line voltage variations. 2. A Ground Wire Trap was designed to eliminate problems with parallel paths and provide spark suppression. 3. A three phase filter was designed to reduce 60 Hz leakage current. 4. A portable tester was designed to permit complete test of installed systems. 5. The design was modified to insure trip with an open ground wire in the event of a failure of any one semi-conductor component.

Jan 1, 1976

By J. H. Field

Capital and operating costs have been estimated for removing sulfur dioxide from flue gases of a powerplant of 12,000-kw. capacity by liquid-purification processes, using limestone, ammonia, or sodium sulfite as the reactant. The annnonia and sodium sulfite processes yield end products that may be marketable. Coals containing about 1.5 and 5.0 percent sulfure have been considered. The sulfur dioxide content of the gases to be treated is 0.083 and 0.30 percent, respectively. Estimates have been made for 90-percent removal of the sulfur dioxide from both gases. A third instance has been considered in which 70 percent of the sulfur dioxide is removed from the flue gas of 0.30-percent concentration. The scrubbed gas would contain 0.09 percent sulfur dioxide, which might be within the permissible limit for discharge to the atmosphere in most areas. Although it is unlikely that flue gases with sulfur dioxide concentrations of less than 0.10 percent would require purification, a cost estimate for such a gas is included because an estimate is available for a British plant employing the limestone process at these conditions. Capital investment and operating costs, with no credit for products, are lowest for the limestone process for gases of both concentrations. Crediting the ammonium sulfate and sulfur produced in the ammonia process at their market prices at the end of 1956 of $32 and $28 per ton, respectively, the operating costs of the ammonia process become the lowest for purification of the gas containing 0.30 percent sulfur dioxide. The operating costs of the sodium sulfite process for purifying gas of high sulfur dioxide content approach those of the limestone process when the byproduct sulfur dioxide is credited at $14 per ton. Even if credit for products is allowed for the ammonia and sodium sulfite processes, the operating costs are higher than those of the limestone process for the gas of low sulfur dioxide content. Because of the large quantity of materials that would be produced by removing sulfur dioxide from a relatively small number of plants, credit for products should be allowed with extreme caution.

Jan 1, 1959

By Robert W. Ageton

The Bureau of Mines investigated the in situ vertical component of the rock stress in the rib of the haulage drift on the 6100-level of the Star mine, Burke, Idaho, using the flatjack and borehole deformation methods. The estimate of the vertical component of stress about 2 feet into the rib at a station along the haulage drift on the 6100-level of the Star mine by the flatjack method is approximately 5,875 psi, whereas the borehole deformation procedure at this station yielded a value of 5,500 psi for the same depth into the rib. The test zone is approximately 5,625 feet below the surface.No attempt was made to extrapolate stress estimates beyond the depth of the flatjack installation.

Jan 1, 1967

By C. F. Wingquist

As part of an ongoing study to determine how the wear of mining tools affects dust generation, the Bureau of Mines has measured bit tempera-ture rise during cutting of abrasive rock. Radial bit wear-flat tem-peratures generated by linear cutting in Berea Sandstone were measured as a function of cutting depth and speed. Depths of cut (DOC) were 1/8, 1/4, and 1/2 in, and cutting speeds were 10, 40, and 80 in/s, respectively. Temperature sensing was accomplished by emplacement of a miniature thermocouple into the center of the wear flat. Temperatures observed ranged from 2000 to 5000 C. Correlation between depth and temperature was weak. Temperature increased linearly with speed at 1/2-in DOC, but data taken at 1/8-and 1/4-in DOC produced inconclusive results. The results indicated that at least for deeper cuts (1/2 in), bit temperature, and therefore wear, can be reduced by lowering the cutting speed.

Jan 1, 1987

By Graham W. Marks

This report is the fourth of a series concerning the development of spectrochemical methods for the analysis of ore samples and related Metallurgical materials by the total-energy method. In this report, the application of this method to the determination of thallium is discussed. This element lies in group III of the periodic tale; one other Clement of this group; indium, has already been investigated.

Jan 1, 1949

By Wing G. Agnew

[This report presents the results of tests made by the Mining Division, Bureau of Mines, on the relative durability of manganese-steel drill rods and carbon-steel drill rods for use with the detachable bolts]

Jan 1, 1941

By Wing G. Agnew

[This report presents the results of tests made by the Mining Division, Bureau of Mines, on the relative durability of manganese-steel drill rods and carbon-steel drill rods for use with detachable bits.]

Jan 1, 1941

By J. A. Lamonica

The Bureau of Mines studied a pulsation damping device designed to smooth pulsating flow in personal respirable dust samplers. The effect on the pulsation dampener efficiency of six parameters was investigated, as follows: Volume, diaphragm elasticity, diaphragm area, center orifice area, inlet-outlet orifice area, and geometry (LID ratio). The results indicate that volume pre-dominates in determining snubber efficiency, while the other parameters become important at small volumes. Geometry has no effect on snubber efficiency. Criteria for an efficient pulsation dampener construction were obtained.

Jan 1, 1971

By P. R. Tisot

The structural response of propped oil shale fractures was determined for each of two different grades of Green River oil shales (38.0 and 29.0 gpt) as they were heated in an inert atmosphere from ambient to subretorting temperatures (below those required for rapid pyrolysis of the organic matter). Small oil shale cores were propped apart by 3-mm glass beads to simulate a small cross section of a propped oil shale fracture between an injection and a producing well. These specimens were then heated at a uniform bate up to 800° F in a specially designed test cell under stress levels from 100 to 1,000 psi in biaxial and in triaxial confinement. Under the conditions of heat and compressive stress utilized in this study, all of the propped fractures in the two oil shales underwent structural deformation ranging from partial to complete collapse, as evidenced by proppant embedment. Structural collapse of induced fractures would in turn result in serious impairment or complete loss of the fracture flow capacities of the specimens. Results from this Bureau of Mines study indicate that underground retorting of Green River oil shale may be seriously impaired by loss of permeability when utilizing propped fractures in oil shales assaying more than 28 gpt.

Jan 1, 1975

By George C. Branner

This study was planned to present salient facts of the California and Nevada sulfur industries and to indicate existing opportunities for increased economic utilization of California and Nevada sulfur resources. Numerous publications on sulfur have been issued by the Federal Bureau of Mines, including Information Circular 6329, Sulfur, by Robert H. Ridgway (1930); annual Minerals Yearbook chapters on Sulfur and Pyrites, by various authors; and a chapter on Sulfur by G. W. Josephson in Bureau of Mines Bulletin 556, Mineral Pacts and Problems (1956). This literature, however, deals primarily with the national and international sulfur situation and does not attempt to analyze the possibilities for increased economic development of sulfur resources by individual States. The present study attempts to analyze these possibilities in California and Nevada and to (1) evaluate factors that have influenced production and consumption in California and Nevada and (2) indicate apparent trends in production, consumption, and prices in these States.

Jan 1, 1959

By M. E. Volin

The Buckeye manganese deposits are in Stanislaus County, Calif., about 33 miles south of Tracy. From 1917 to 1919 the deposits produced 13,370 tons of ore reported to average 46 percent manganese and 14 percent silica. The deposits are confined to two areas of' development, known as the north mine workings and the south mine workings, about 700 feet apart horizontally. Mineralization occurs chiefly as rhodochrosite and psilomelane interbedded in cherts of the Franciscan formation. As a part of the Bureau of Mines program of investigation and development of domestic mineral deposits, a development project was started November 25, 1940, and completed June 27, 1941. The Federal Geological Survey cooperated by mapping the topography and geology and logging the drill cores. The program included road and. trail building, trenching, underground excavation, diamond drilling, and sampling. The following pages mention the location, brief the history, and note the physical .features of' the district. Mine workings are sketched, the deposit is described, and the plan of the project is noted. The work performed by the Bureau of Mines is explained in the concluding pages with a summary of the drill-hole logs.

Jan 1, 1949

By D. W. Bridges, S. R. Borrowman

Thorium and yttrium oxides were recovered from siliceous ores of the Powderhorn , Colo . , area . Processing comprised ( 1 ) acid curing and subsequent ( 2 ) acid baking , ( 3 ) leaching , and ( 4) solvent extraction of thorium , using a primary alkylamine , and yttrium , using di - 2 - ethylhexyl phosphoric acid . About 95 pct of the contained thorium and yttrium was recovered from ore containing 1.2 pct Th02 and 0.5 pct Y₂ 03. The thoria product was 99 pct Tho ; the yttria product was 77 pct Y₂ 03. A 150 - to - 1 concentration ratio was effected on the latter , but some contaminating lanthanon - group oxides remained .

Jan 1, 1964

By J. A. Organiscak

The U.S. Bureau of Mines investigated the relationship of bituminous coal seam parameters and the amount of airborne respirable dust generated at longwalls. Dust and coal samples were obtained from 20 longwalls operating in geographically representative coalfields throughout the United States. Statistical analyses of coal seam parameters and airborne respirable dust measurements indicate a likely causal relationship between seam type and respirable dust. Low-ash, high-volatile coal seams were associated with higher airborne respirable dust levels. A negative linear correlation (significant at the 95-pct confidence level) was observed between the seam's ash content and airborne respirable dust, explaining up to 18 pct (R2 = 0.18) of headgate dust level variation and up to 15 pct of tailgate dust level variation. Volatile matter was found to have a positive linear correlation with tailgate dust level, explaining 16 pct of the variation. Further data examination indicates that these relationships with dust are most likely nonlinear, because of improved R2 values over the linear correlations. However, a notable portion of longwall dust production is influenced by other operational parameters, so additional research under more controlled conditions is needed to determine the seam's causative functions.

Jan 1, 2010

By Laxman S. Sundae

The Bureau of Mines designed, fabricated, and is using an in-seam tester (1ST) for in situ determination of coal cutting forces. This re-port describes the results of field tests conducted in the Pocahontas No. 3 and Upper Freeport seams to obtain peak and mean cutting forces during coal cutting with several bit geometries, including radial and point attack bits currently used on drum-type machines. Comparisons were also made between new and worn bits, and using data obtained from a Bureau-modified chisel bit. The test results show that longwall plough cutting (horizontal cuts) in bony coal bands (shale) requires >3 times the cutting force for the same cuts in a vertical direction. When no bony coal is present, the cutting forces required to make horizontal and vertical cuts are equal. Worn bits require 4 to 5 times more cutting and normal force than new or undamaged bits. Normal force increased drastically for the worn chisel bit. Peak force encountered in making independent cuts was found to be ~3 times higher than that required to make interactive cuts using a spacing-to-depth-of-cut ratio of 2. Both rake and clearance angles were found to have a significant effect on normal and cutting force.

Jan 1, 1986

Introduction The NIOSH Office of Mining and Construction Safety and Health Research has redesigned its Mining Safety and Health Web topic page. The updated page incorporates a significant amount of new safety and health information, plus an improved layout to better serve stakeholder needs. It also provides back-ground information about the NIOSH Mining Research Program, including research awards, core competencies, unique labs, community and educational outreach, and a brief discussion of how the research program is structured. The new Web topic page can be found at www.cdc.gov/niosh/mining. "Search" Feature The redesigned Web topic page features improved search capabilities. The "Search Mining" feature on each page lets you search only the NIOSH Mining Safety and Health Web topic page. The user can still search the entire NIOSH Web page by using the "Search NIOSH" option. New Safety and Health Topics Developers expanded the "Safety and Health Topics" and reorganized the site to make it easier to find information. Each topic link now has a significant amount of new and updated information, as well as links to related topics of interest. Safety and health topics include dusts, diesel exhaust, hearing loss, contact with electric current, fires, explosives, ventilation, emergency management, new and older workers, and education and training. All topics can be accessed from the home page (Figure 1). Publications Although the Web topic page highlights many of the most requested publications on the safety and health topic links, you can find a complete list of downloadable publications as well. More than 600 mine safety and health publications are now downloadable from the page. Short summaries let the user quickly identify publications of interest. Products The updated Web topic page offers more than 120 NIOSH mine safety and health products, including training exercises, toolbox talks, videos, computer software, guides, and checklists, many of which are downloadable. If not, instructions are given on how to obtain copies. Some of our products include: • Software to analyze horizontal stress, design pillars for longwall mines, and select roof bolts for ground control. • Educational software including the Hearing Loss Simulator, which simulates the effects of noise and aging; and Coal Country, which teaches children about coal formation, mining techniques, and everyday uses of coal. • Utility software including the HazCom Helper software to assist individuals in writing a HazCOM plan, as required by the Mine Safety and Health Administration (MSHA), to track hazardous chemicals at their mine sites. • Guides for troubleshooting roof support systems, under-ground workstation design, and seating design. • Training exercises and videos that can be used for safety training. Data and Statistics General mining statistics are used by a wide variety of stakeholders. The NIOSH Mining Web topic page offers statistical graphs, tables, maps, fact sheets, and other publications that document the mining population, injuries, fatalities, diseases, and occupational exposures for all mining commodities. If users prefer to analyze data themselves, downloadable files of MSHA data are available. These cover employment, production, injuries, fatalities, and accident data from 1983 to the present and are available in both SPSS® and dBASE® formats.

Jan 11, 2005

By David C. Byrne

From an engineering perspective an ideal industrial noise control solution focuses directly on the actual source of the poise. Eliminating the noise-generating mechanism altogether obviates the need for other noise contra l treatments or hearing protection devices. However, in cases where attenuating the source is not feasible engineering controls must be oriented toward blocking the path that the sound waves travel toward employees. Acoustical enclosures are commonly used as sound path treatments to contain the noise from a machine: alternatively a control room/booth or equipment operator's cab may be used to isolate the worker from the noise. Anyone who has successfully used acoustical enclosures knows that the design procurement, and installation process is deceptively simple. Alt too often First-time efforts fait to account for many of the constraints that can render the enclosure essentially useless. Things that cannot be overlooked include: providing convenient worker access (physical and visual): allowing for proper machine operation/product flow; and supplying fresh air or preventing undue heat or contaminate build-up inside the enclosure. All of these factors must be given careful consideration, otherwise the enclosure will not perform adequately.

By John T. Metcalf

The assembly procedures for nine different wire rope terminations used in the mining industry are presented in a format and manner to facilitate training and to provide points where inspection of the termination should be performed. The nine terminations addressed are: Flemish Loop with Steel Sleeve & Thimble, Flemish Loop with Steel Sleeve, Wedge Socket, Swaged Socket, Turn Back Loop with Sleeve & Thimble, Thimble Splice with Four Tucks, U-Bolt Clip & Thimble, Zinc Poured Socket, and Epoxy Resin Poured Socket. The manual was prepared to be used primarily for field type mining operations or training where high capacity machinery is quite limited. It is nut the intent of this manual to suggest that the procedures presented are those to be used by manufacturers or other commercial enterprizes. A different set of procedures may be more appropriate where ideal space and equipment resources are available. The assembly procedures were derived from standard industrial practice, manufacturer's recommendations, and the open literature on the subject. These same procedures were used to prapare test specimens for an extensive series of pull and axial fatigue tests. The results of these tests indicate that these procedures are satisfactory in all respects. This manual is to be used as part of a complete training program. Although a brief glossary is included, there has been no attempt to make this a primer on wire rope. The selection of wire rope termination hardware, like the selection of the wire rope, is a subject not covered by this manual. The reader is cautioned that there are various sources for such hardware and this selection must be done carefully.

Jan 1, 1978

By C. H. Elder

Coal degasification boreholes drilled from the surface have been success-fully hydraulically stimulated to increase the flow of gas from the coal. This Bureau of Mines report describes the hydraulic stimulation procedure for a coalbed, the equipment required, and design criteria for the treatment. Three examples of stimulation treatment show from fivefold to twentyfold increases in gas production. The tests were conducted in the Pocahontas No. 3 coalbed, Buchanan County, Va., the Pittsburgh coalbed, Washington County, Pa., and the Mary Lee coalbed, Jefferson County, Ala. Two sites where the coal was hydraulically stimulated and exposed by subsequent mining show no adverse effect on mining operations through the treated zones. The induced vertical partings were confined to the coalbed and did not in any way affect either roof or floor rock.

Jan 1, 1975

By G. M. Potter

During investigation of the occurrence of manganese deposits in the western United States, the Bureau of Mines collected 2-ton samples of 4 ores from 3 properties in northeastern Nevada. Laboratory tests were made to determine the amenability of these ores to ore-dressing methods of concentration. The Caviglia-Vietti property is situated 11 miles southeast of Ely, White Pine County, Nev. The ore deposits are lenticular veins and irregular masses found in limestone fracture zones and along the contact of limestone and underlying shale. Two samples, of the ore were tested: Lot A, from the Vietti shaft, and lot B, from the. Caviglia shaft.

Jan 1, 1954

By A. Sainato, S. J. Kravits, G. L. Finfinger

This Bureau of Mines report describes and compares the procedures, capital investments, and operating costs of rotary and in-hole motor drilling techniques used to drain methane gas from the Pittsburgh Coal- bed in an underground mine located in southwestern Pennsylvania. A timestudy was conducted during the drilling of each of two boreholes, and the data were collated to serve as a base for comparing drilling procedures and operating costs. Findings indicate that drilling with an in-hole motor offers four advantages over rotary drilling; namely, an increase in drilling productivity, fewer worker-hours required, ease of maintaining vertical and horizontal bit trajectory, and less expensive drilling cost per foot of borehole.

Jan 1, 1985