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By E. K. Stanek

This report contains the results of an investigation into the feasibility of periodically measuring parameters of the insulation for a mine electrical power system in order to detect incipient faults. The variety of insulation parameters evaluated included insulation resistance, dissipation factor, power factor (vs. applied voltage), current harmonics, leakage current, infrared radiation, as well as certain circuit breaker parameters and tests. In order to augment field tests a program of accelerated life testing was also carried out. Apparent inconsistencies in data were identified as the result of environmental effects, primarily temperature and relative humidity. A series of environmental tests were conducted to develop correction factors that allow one to refer measured parameters to standard conditions. A portable data collector was develop-ed to aid in the accurate collection and analysis of laboratory and field data. The primary conclusion is that insulation deterioration can be measured and failure predicted with reasonable confidence. The secondary conclusion is that most of the tests are impractical in the field although useful in the laboratory. Infrared sensing, insulation resistance and dissipation factor are the best insulation field tests when portability is taken into account.

Jan 1, 1979

By James P. Ulery

In This Chapter [Geologic features associated with anomalous methane emissions Gas outbursts and blowers Methane drainage strategies for mitigating anomalous methane emissions and General considerations for a methane drainage program] This chapter summarizes how certain geologic features may be associated with unexpected increases in gas emissions during coal mining. These unexpected emissions have the potential to create explosive conditions in the underground workplace. Also discussed are the generally used practices to alleviate potential hazards caused by gas emissions associated with these geologic features. INTRODUCTION Unforeseen mine gas emissions in quantities sufficient to create hazardous conditions have been attributed to sources outside the mined coalbed since the first documentation of methane explosions in coal mines [Payman and Statham 1930]. Geologic features such as faults have long been recognized as conduits for gas flow from strata adjacent to mined coalbeds [Moss 1927; Payman and Statham 1930]. Other features such as sandstone paleochannels, clay veins, and localized folding have also been recognized for their impact on gas emissions into mine work-ings [Darton 1915; Price and Headlee 1943; McCulloch et al. 1975; Ulery and Molinda 1984]. The fact that strata adjacent to mined coalbeds can emit large quantities of methane gas into mine workings is not surprising from a theoretical perspective. Many researchers have recognized that during the burial and diagenesis of the organic matter forming today’s minable coalbeds, similar dispersed organic matter in adjacent strata has produced methane in quantities far exceeding the storage capacity of the coal and surrounding rock [Juntgen and Klein 1975]. It is not surprising then that large quantities of methane can remain trapped in these strata. A potential hazard occurs when mining of a nearby coalbed causes pressure differentials and mining-induced fractures conducive to gas flow into the mine workings from these strata. This gas flow may be facilitated or temporarily impeded by the presence of geologic structures or anomalies.

Jan 6, 2006

By G. L. Anderson

The critical importance of wire rope integrity to the mining industry has led to the creation of standards for the retirement of wire rope as well as to the development of electromagnetic devices and procedures that would allow wire ropes to be tested against these standards without destroying them, The U.S. Bureau of Mines (USBM) conducted research to evaluate these devices by measuring loss of metallic cross-sectional area and the number of wire breaks, or local faults. The intent was to define the extent to which the technique can identify degradation within the rope, e.g., broken wires, corrosion, and wear. Experimental results showed that instrument sensitivity depended on a number of factors, including rope diameter, placement of sensors, location and characteristics of flaws, rope speed, and tension on the rope. The experiments also demonstrated the importance of having an elongated recorder trace and a properly trained and experienced operator to interpret overall results. A design of a rope and test procedures for use in laboratory evaluation of instruments have been recommended by the American Society for Testing and Materials Committee E07.07.10, Wire Rope Applications. The USBM is working through this committee to develop standards for an electro-magnetic method of wire rope inspection.

Jan 1, 2010

By G. R. Hopkins, E. W. COCHRANE

The number of completed petroleum refineries in the United States continued to decline in 1937 , but the total capacity to process crude oil continued to increase . These facts were ascertained in the Bureau's annual canvass of refinery capacity as of January 1 , 1938 . Several important changes were made in the census questionnaire for January 1 , 1938 . First , the basis of reckoning cracking capacity was changed from cracking stock charged to cracked gasoline produced . Although this is a definite improvement , in that it is no longer necessary to consider the yield , it is unfortunate that the data for January 1 , 1938 cannot be compared with cracking - capacity statistics since 1925. Other changes or additions included separating capacity at operating plants into that actually operating and that closed down ; collecting data on capacity added or retired during the previous year ; breaking down idle capacity according to physical status ; and separating new capacity into that built for replacement and that built to augment existing capacity . Prior to January 1 , 1938 , the total capacity of an operating plant was listed as " operating " even though some stills might have been closed down ; furthermore , the only capacity reported as being under construction was that of new plants that were being built on January 1. To make the statistics clear , the totals for the United States as of January 1 , 1938 , are given on both the old and the new bases . On January 1 , 1938 , there were 551 completed plants compared with 572 the previous year . Ten new plants were under construction on that date compared with 11 the year before . The greatest number of completed plants recorded was 632 on January 1 , 1936 ; since then , competitive conditions , particularly in the East Texas field , have been instrumental in reducing the number of small independent plants . The total crude- oil capacity of the completed refineries on January 1 , 1938 , was 4,351,151 barrels , of which 3,970 , 196 barrels ( 91 percent ) represented the capacity in actual operation and 380,955 barrels ( 9 percent ) was shut down . The " shut -down " capacity ( 199,875 barrels on the old basis ) was the lowest since pre- depression days , chiefly because numerous idle East Texas plants were removed from the list . The new method of compiling the statistics sheds considerable light on excess crudeoil capacity , which has been the subject of considerable speculation in recent years . The highest daily average crude runs to stills reached in this country was about 3,460,000 barrels in September 1937. At that time , the total crude - oil capacity was about 3,925,000 barrels . This indicates that at peak operation the excess capacity was somewhat less than

Aug 1, 1938

By D. Harrington

Near the close of the nineteenth century electricity was introduced underground, and the mining industry automatically was confronted with another potential source of fatalities and injuries to mine workers. Electricity has become an increasingly vital factor in the production of goal, particularly in recent years, because of the greatly extended mechanization that has taken place underground. The enlarged use of electrical equipment for cutting, loading, and hauling coal unquestionably increased the potentiality of shock and explosion hazards underground. Electricity may be used in coal mines with minimum danger if electric equipment and power-carrying wires are chosen properly and installed and kept protected by proper safeguards; on the other hand, if vigilance is relaxed in the slightest degree accidents may result. Electrical accidents are caused chiefly by direct contact with electrical equipment or power-carrying wires, by ignition of explosive gas or dust, and by fires of electrical origin. Electricity now ranks fourth as a cause of coal-mine fatalities, not including deaths from explosions or fires of electrical origin.

Jan 1, 1936

By L. A. Readdy

Pilot Hole "X" was drilled to test the formations through which the ventilation shaft for the proposed U.S.B.M. demonstration oil shale mine would be drilled. The geologic formations encountered in this hole are discussed. Correlation of the geologic horizons encountered in this hole with those encountered in nearby drill holes was accomplished by the use of geophysical logs. Data on the geophysical interpretations are provided. The anticipated geotechnical characteristics of the geologic units encountered in Pilot Hole "X" are described.

Jan 1, 1977

Commodities statistics and other information are available through the following three systems: Internet Access: To acccess the USBM Gopher server on Internet, connect to: gopher.usbm.gov port 70, using gopher client software. Or contact the Systems Administrator for technical questions: Matt Klevemann, 412-892-6499 (klevemmc@miner.usbm.gov) These USBM materials are available on Internet, with more to come in the future: Publications and other research findings, including this bimonthly publications list, newsletters, tech transfer updates, enviromental technology research, health and safety information. USBM software products Media materials and speeches. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. Mines FaxBack. Return fax service. 1. Use the touch-tone handset attached to your fax machine's telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219-3644. 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone. 4. After completing your selection, press the start button on your fax machine.

Jan 1, 1995

By G. J. Hundman

Control of respirable dust produced by auger type continuous mining machines is normally attempted by water sprays from fixed nozzles mounted on the frame of the machine. In tests conducted under this contract, a 'wet auger' system was used, where the spray nozzles were mounted on the rotating auger itself. The tests were conducted at the Hunter mine of Smith and Stover Coal Company using a Jeffrey 1.00L auger miner. Operating the mining machine in the wet auger mode, it was found to produce 47 pct less respirable dust than when the fixed conventional sprays were used. On section dust levels were reduced too 3.5 mg/m3 which is equivalent to approximately 2.0 mg/m3 for a full shift portal to portal sample. The major difficulty that had to be overcome was the development of a simple reliable water transfer mechanism to get the water into the rotating augers. This was successfully achieved by the development of a water-through-the-shaft water system. This system can be retrofitted to existing machines and is available in kit form.

Jan 1, 1977

By Frank E. Cash

Data on the occident experience of the pebble-phosphate industry in Florida for 1937 and 1938 are combined in this report with statistics for the 7-year period 1930-36, inclusive, which were published in Information Circulars 69174/ and 69685/. The periodic publication of such data enables the pebble-phosphate industry, as well as other industries, to consider relative hazards, compare experience, and thereby help to prevent accidents. ACKNOWLEDGMENTS Accident data ere furnished by the following; operating companies: Amalgamated Phosphate Co., Brewster; American Agricultural Chemical Co., Pierce; Coronet Phosphate Co., Plant City; International Agricultural Corporation, Mulberry; Phosphate Mining Co., Nichols; Southern Phosphate Corporation, Bartow; and Swift & Co. Fertilizer Works, Bartow.

Jan 1, 1940

By Hewitt Wilson

Until recent years the term "whiting" was applied exclusively to the water-ground chalks of certain north European countries. In many industries these are still considered superior to the whiting made from domestic limestone and marble. However, the latter material has replaced much of the European whiting in the American market, largely due to improvements in grinding and classification by American manufacturers.4 To encourage the domestic industry, the Bureau of Mines in 1931 undertook a study of the preparation of whiting from American raw materials and a comparison of the finished products with European whitings.

Jan 1, 1937

An active list of permissible explosives was published in December 1936 as part of Bureau of Mines Report of Investigations 3324, under the title "Active List of Permissible Explosives and Blasting Devices Approved Prior to July 31, 1,936." This list included 170 brand names. Changes in the list that have been authorized to June 30, 1937 placed 35 additional brands of permissible explosives on the active permissible list as a result of tests, changes in brand names, or transfer from the inactive list. Ten permissible explosives were transferred from the active to the inactive list. The present list contains 196 brand names, one explosive having been placed on the list subsequent to June 30, 1937. The brand names of the permissible explosives placed on the active list are as follows: [ ]

Jan 1, 1937

By A. J. Barry

An apparatus and procedure have been developed for testing the anchorage effectiveness of slotted-type bolts. The apparatus consists of: (1) A hydrualic Jack assembly for loading the bolt and (2) a device (extensometer or cathetometer) for measuring displacement of the bolt as it is loaded. This apparatus and procedure permit measurment of anchor slip for loads up to the yield load of the bolt. Two representative makes of slotted-type bolts (a total of 94 bolts) were tested in typical sandstone and shale mine roof. Analysis of the test results showed that (1) anchorage capacities up to the yield load of the bolts can be developed in either rock type; (2) the shape of the slotted end of the bolt affects the ease with which the bolt can be driven; (3) all bolts for which the driving distance was more than 1.25 inches produced satisfactory anchorage in both rock types (thus, driving distance can be used as a criterion for satisfactory anchorage); (4) for the group of bolts that was satisfactorily anchored the anchor slip was unaffected by the type of bolt but was considerably larger in shale than in sandstone; and (5) the bolt expansion, that is, the amount the wedge expands the prongs in excess of the diameter of the hole, can also be employed as a criterion for satisfactory anchorage. Although the bolt-expansion and driving-distance results do not differ appreciably, the latter is recommended because it is easier to determine.

Jan 1, 1954

By S. D. Cramer

Corrosion research is being conducted by the Federal Bureau of Mines to determine suitable construction materials for geothermal resource recovery plants. As part of this research, the corrosion resistance of 31 iron-nickel-, aluminum-, copper-, titanium-, and molybdenum-base alloys was characterized and evaluated in laboratory corrosion studies in low-and high-salinity geobrines representative of those found in the Imperial Valley, Calif. General, crevice, pitting, weld, and stress corrosion were measured at 105° and 232° C in deaerated brines and brines containing dissolved 02, C02, and CH4 General corrosion rates in deaerated brines at 105° and 232° C were usually below 5 mpy for the alloys tested except carbon steel, the low-alloy steels, Monel 400, 70-30 cupronickel, and the aluminum-base alloys. Dissolving carbon dioxide and methane in the brines at 2320 did not markedly alter these results. However, the introduction of oxygen, which can enter the brine during process operations, seriously degraded the corrosion resistance of many alloys by increasing the incidence of stress corrosion cracking, crevice corrosion and, except for the titanium-base alloys, pitting. In deaerated brine at 2320 C, the general corrosion rates for carbon steel and the low-alloy steels were relatively unaffected by pH in the range of 6.1 to 3.0. However, general corrosion rates increased sharply below pH 3.0. In deaerated brine at 232° C, welds in several iron-, nickel-, and titanium-base alloys corroded at rates comparable to the general corrosion rates of the alloys, but the addition of oxygen to the brine increased corrosion rates for welds in Inconel 625 and E-Brite 26-1. Alloys exhibiting good corrosion resistance in the deaerated Salton Sea KGRA-type brine at 232° C were E-Brite 26-1, Inconel 625, Hastelloy S, Hastelloy G, Hastelloy C-276, TiCode-12, Ti-0.2Pd, Ti-2Ni, Ti-1.7W, and TZM. The alloys most resistant to corrosion in oxygenated Salton Sea KGRA-type brine at 232° C were the titanium-base alloys. These alloys appear the most suitable for use in the construction of geothermal resource recovery plants. Carbon steel and the low-alloy steels are unsatisfactory for high-temperature, high-salinity brines and alternative low-cost materials with improved corrosion resistance should be sought.

Jan 1, 1980

By William A. Beck

"In 1912 bauxite was discovered in the Andersonville district, which lies in the 28th and 29th land districts of Georgia and comprises parts of Sumter, Macon, and Schley Counties. Mining was begun in May 1914 by the Republic Mining & Manufacturing Co. Considerable ore has been produced in this region since that time by individual interests and by the American Cyanamid & Chemical Corp., which acquired the property formerly owned by the Republic Co.The area was examined in the fall of 1941 by representatives of the Bureau of Mines and the Geological Survey, after which a prospecting program was begun by the Bureau. Drilling was started on December 26, 1941, and continued until November 18, 1943. A total of 1,192 holes was drilled in the district, and 3,679 samples were taken and analyzed.Mineral exploration agreements were signed by 146 property owners covering 42,128 acres. Holes were drilled on 121 of these properties, which have a total area of 38,778 acres.Drilling under this project disclosed several new deposits, of which four have been completely delimited. Previous prospecting in this area by mining companies did not find bauxite, as it lies under heavy overburden. Work by the Bureau indicates 14,412,000 long tons of ore containing 30 percent or more alumina. The total tonnage is divided as follows:Georgia State Highway Routes 26 and 4-9 traverse the district. The Central of Georgia Railroad passes through the center of the entire district (see fig. 1).The project was initiated by J. R. Thoenen, supervising engineer, Non-metals Mining Section, Mining Division, Bureau of Mines. It was under his general supervision until July 1942, after which it was under the general supervision of E. J. Lintner and Rowe McCrae, district engineers for Georgia, South Carolina, and Flordia, respectively.John C. Feeley, Jr., was project engineer from December 1941 to April 1942. Other engineers who assisted in the work on the project are R. E. Babcock, T. M. Romslo, Don M. Coulter, and Walter T. Lewiecki.Acknowledgment is due the metallurgical staffs at College Park, Md., and Tuscaloosa, Ala., for analyses of samples and beneficiation tests.Acknowledgment is also expressed to Alfred D. Zapp, M. W. Harris, Elmer Kneedler,and Parke D. Snavely, of the United States Geological Survey, for their aid, data, and maps.Bauxite was discovered in the Andersonville district in 1912 on lot 187 of the 28th land district, in Sumter County. This lot is situated about 1.5 miles west of the Flint River, on the south slope of the valley of Sweetwater Creek. Mining was started in May 1914 by the Republic Mining & Manufacturing Co. This and adjacent properties were acquired in 1930 by the American Cyanamid & Chemical Corp., which has been operating there since."

Dec 1, 1949

By Wallace W. Key

This report concerns types, quantities, specifications, and uses of non-metallic minerals as a basis for improving their supply, conservation, and utilization. Supply-demand details concerning mineral fillers, roofing granules, and roofing rock used in asphalt are incorporated in this report, along with highlights on production and sales of roofing, floor tile, and other related asphalt products of California. Comparable data for the United States are included. Although large quantities of commercially prepared mineral fillers are used in asphalt for paving and related applications in other States, addition of commercial fillers for these uses rarely is required in California because of the natural fines available. On the other hand, California manufacturers of asphalt products other than paving utilize about 300,000 tons of asbestos, diatomite, limestone, mica, soapstone, slate, and other nonmetallic minerals as filler, mainly for roofing and flooring. Also, about 500,000 tons of roofing granules is produced in California, most of which goes into roofing manufacture in California. In addition, a significantly large and growing tonnage of relatively coarse mineral aggregates are used on low-angle, built-up, asphalt roofs to produce an attractive surface and offer protection against the elements. Nearly all minerals used in asphalt products manufactured in California come from local sources, except asbestos and mica--and there are indications that local deposits of these commodities could be utilized in some use categories.

Jan 1, 1966

By J. E. Murphy

A method is being developed by the Federal Bureau of Mines for recovering lead metal from galena without the generation of SO2. Lead chloride is obtained by leaching lead concentrate at a temperature of approximately 100° C with FeCl3 solution: PbS + 2FeCl. " PbC1 2 + 2FeC1 2 + S. Electrolysis of the PbCI 2 product in a fused-salt bath results in deposition of molten lead metal at the cathode and evolution of chlorine at the anode. The chlorine can then be absorbed in the spent leach solution to regenerate FeCl3 for recycling. Optimum electrolyte composition was a PbC12-LiCl eutectic containing 7.6 wt-pct LiCl. The PbCl2-NaCl eutectic also proved satisfactory. Electrolysis in the PbCl2-LiCl bath at 450° C yielded 99 pct current efficiency at a current density of 5 amp/in2 with an energy requirement of only 0.24 kW-hr/lb metal produced. This compares with 98 pct current effi¬ciency and 0.26 kW-hr/lb metal produced for the PbCI2-NaCI bath. A typical lead deposit contained less than 100 ppm total detectable metallic impurities. At the low temperature employed for electrolysis, there was essentially no vaporization of Pb or FbC12.

Jan 1, 1974

By Y. H. Cheng, D. M. Lewis, V. Castranova, M. W. Barger, J. K. H. Ma, J. Y. C. Ma, W. F. Xin

Bis-basic ethers off fluorene and fluoren-9-substituted derivatives such as tilorone have been reported to inhibit silica-induced fibrosis in rats. The potential antifibrotic potency of 2,7-bis (diethylamino) ethixy fluorine fluorenone (F-9-H.H), fluorenoxime (F-9-one), and fluorenol (F-9-ol) was F-9-axime > F-9-one ~ F-9-H,H > F-9-ol. Since the release of reactive oxygen species and growth factors from alveolar macrophages (AM) in response to silica exposure has been linked to the development of pulmonary fibrosis, the present study was carried out to determine the inhibitory effects of these compounds on rat AM activity in vitro. The following parameters were monitored: (1) cellular viability; (2) zymosan-induced respiratory burst activity (superoxide and hydrogen peroxide release, chemiluminescence, and oxygen consumption) of AM; (3) drug binding to AM; and (4) lipopolysaccharide (LPS)-stimulated interleukin- I (IL-1) release from AM. The bis-basic ethers, at 40 did not affect cell viability when incubated with AM for 30 min, but significantly inhibited zymosan-induced macrophage respiratory burst activity. The inhibitory effect of these agents was F-9-oxime > F-9-one ~F-9-H,H > F-9-ol. Binding of these drugs to AM was time and dose dependent, and exhibited the following binding affinity: F-9-oxime > F-9-one > F-9-H,H > F-9-ol. F-9- oxime was shown to inhibit LPS-stimulated IL-I release by AM in a dose-dependent manner. This inhibition of IL-1 release by AM cannot be explained as a decrease in viability. In addition, these drugs were also shown to impair human fibroblast proliferation in response to serum stimuli without impairing cell viability. These results indicate a positive correlation between drug binding to AM or other cell types and their inhibitory effects on cellular activities including oxygen consumption, superoxide release, hydrogen peroxide secretion, chemiluminescence, IL-I release, and proliferation. The ability of-these bis-basic ethers to modify AM and fibroblast functions in vitro suggests that further investigation of their reported antifibrotic potency in vivo is warranted.

Dec 1, 1996

By T. C. Shelton

The Bureau of Mines Contract No. H0101706 with Virginia Polytechnic Institute and State University was a part of a broad-scale investigation directed toward applied problems in mine safety and particularly toward preventing accidents and fatalities resulting from falls of roof and ribs in coal mines. Under the auspices of the Chemical Stabilization Program, Bureau of Mines, Spokane Mining Research Center, Spokane, Washington, the broad objective of the Contract was to conduct research for the purpose of studying the behavior of large engineering structures. Contract No. H0101706 consisted of two related but distinct tasks. TASK I was to make "Barodynamic Analysis of Large Mine Models," and TASK II was "Preparation of Undisturbed Rock Specimens.?

Jan 1, 1974

By Robert J. Timko

In early June 1986, an underground fire of unknown origin erupted in one of several entries of a coal mine located in southwestern Colorado. For a time, mine personnel aggressively fought the fire. However, control of the fire was later lost. To prevent further damage and reduce the possibility of an explosion, all portals and shafts to the mine were sealed. The mine operator requested the U.S. Bureau of Mines' assistance in obtaining and analyzing mine fire gases taken from sampling ports placed through the mine seals, as well as down boreholes drilled after the fire. This report recounts activities within the first 2 years of the mine being sealed. It includes a description of gases analyzed and mine atmosphere status equations generated from the analyzed gases. The gases were analyzed by chromatography and included standard atmospheric gases as well as higher hydrocarbons that are found in postfire atmospheres. Nine equations were used to evaluate what was occurring within the sealed mine. Following a description of the rationale behind each equation, the 2-year trend is briefly analyzed.

Jan 1, 2010

By E. H. Denny

In discussing safety in Colorado metal mines there are two important points for metal -mining men to consider , namely , the direct and indirect cost of accidents and the possibility and means of preventing accidents . For statistics on Colorado metal - mine accidents , reference has been made to published reports of the United States Bureau of Mines on metal- mine accidents from 1919 to 1927. This period was considered because only with the year 1919 are complete figures on nonfatal accidents available and because these years represent postwar activities ; 1927 is the last year for which the U. S. Bureau of Mines has published accident statistics . During the nine -year period 1919 to 1927 , inclusive , 153 metal miners were killed by mine accidents in Colorado and 5,035 miners suffered lost - time injuries . The accidentfrequency rate of number killed per 1,000 300- day workers for this nine - year period was 4.68 as compared with the general average of 3.26 for all the metal mines of the United States for the same period . In other words , the fatality rate in the metal mines of Colorado for this nine- year period averaged 40 per cent higher than that of the metal- mining industry in the United States generally . In 1924 and 1926 the Colorado metal mines had a better accident record than the average of those of the United States , but 1927 was a bad accident year and the State Bureau of Mines figures for 1928 and 1929 showing respectively 18 and 23 men killed in and about the metal mines indicate a continuing relatively high death rate from accident . The cost of accidents to the miner for the period 1919 to 1927 can be estimated from the accident figures just given . The United States Bureau of Mines as well as other authorities assess 6,000 days lost time for every fatality and every permanent total disability . These authorities have also agreed that a permanent partial disability costs 800 days lost time to the worker over his working lifetime , that lost time injuries of less than 14 days average about 6 days lost time and lost time injuries not involving permanent disability but having loss of more than 14 days average 32 days lost time . On this basis the Colorado metal miners have suffered in nine years a gross loss of 1,214,146 days , or , at $5 per day , $6,070,730 . The miner receives about one -ninth of this amount in compensation so that the net loss to the metal miner in Colorado for this nine - year period was about $5,400,000 .

May 1, 1930