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By D. B. Taliaferro

[Recovery of core specimens from subsurface formations and their subsequent analysis are important aids in efficient development and operation of oil and gas fields. Core specimen first were obtained mainly for the geologic information they revealed; now they are on analyzed to determine many of the physical characteristics and conditions of the subsurface formations as well. Cores recovered from the producing formations may be analyzed for porosity, permeability, oil content, "connate" water content, and other physical and chemical properties of the formation, all to the end of furnishing enough data for making reliable estimates of the quantity and availability of oil and gas within reservoir and in devising efficient means for their withdrawal.]

Jan 1, 1939

By Harry Vivian

This paper deals principally with the retreating method of mining as applied in the Calumet & Hecla Consolidated Copper Co.'s deep Conglomerate mine, pointing cut some of the difficulties encountered in deep mining and describing the particular methods used at Calumet to carry on a large-scale operation at great depth with a minimum hazard factor. The circular is one of a series dealing with mining methods and costs which is being prepared for and published by the United States Bureau of Mines. ACKNOWLEDGMENTS Acknowledgment is due to those officials and operating heads of the Calumet & Hecla Cc. whose years of familiarity with the conditions developing at the Conglomerate mine as great depth was attained have enabled them to contribute valuable information to the subject of deep-mining problems.

Jan 1, 1931

By Theodore Christos

The Bureau of Mines sponsored an investigation of the thermal oxidative degradation characteristics of certain solvents and hydraulic fluids used in underground mining operations. The following halogenated solvents were studied in view of their usefulness and their flame retardant property: tetrachloroethylene, C12C = CC12; 1, 1, 2-trichloroethane, CIH2CCHC12: and trichloroethylene, C12C = CHC1. The hydraulic fluids studied were representative of five groups approved by the Mine Safety and Health Administration for underground operation, namely: glycol-water solutions, mineral oil-water emulsions, synthetics other than phosphate esters, synthetic phosphate esters, and mixtures of phosphate esters with mineral oils and other ingredients. It was observed that the partially halogenated solvents present a greater potential toxic hazard than the fully halogenated materials, due not only to the easy production of hydrogen chloride but also to their ease of oxidation leading to the formation of phosgene and carbon monoxide. The pure phosphate esters exhibited the best thermal oxidative stability of the five groups of hydraulic fluids tested. A fluid containing phosphate esters mixed with mineral oils and other unidentified ingredients appeared to be the most hazardous On the basis that it produced very toxic acrolein and phosphine.

Jan 1, 1980

By G. W. Jones

In cooperation with the Edison Electric Illuminating Co. of Boston, Mass., and the-Boston Consolidated Gas Co., the Bureau of Mines, United States Department of the Interior, has conducted a survey continuously since 1929 to determine the general hazards of combustible gases and vapors in manholes of the Edison Electric Illuminating Co.

Jan 1, 1942

By Walford S. Wright, NORMAN EBBLEY

During the past decade (1937 to 1947), including the war years of heavy demand for metals, the United States realized about one-eighth of its antimony requirements from domestic production, chiefly in Alaska. In World War II, our foreign supply sources became endangered; and uncertainty in our Far Eastern supply made this nation focus on Alaska’s mineral resources with a Production Gear that centered in the Bureau of Mines experimental station at College (Alaska). The development work known as District or central deposits. The strategic mining districts included that of central Alaska was reorganized at Ketchikan Mining Districts. Mines were located here had produced considerable quantities since 1901; but methods for exploration had come from 1936 to spring 1942, some $4 million produced in gold alone. Statistics relating to available ores are those selected by type and exploitation periods with wide variety applied. During the summer of 1941, as part of an extensive Geological Survey program continuing through funds provided by U.S., geological surveys spent six weeks mapping an area approximately two square miles surrounding mines. The mines working both surface & underground work employed these men in mapping exercises.

Jan 1, 1948

By Patrick D. Plumb

The Juneau Office of the U.S. Bureau of Mines has undertaken a study of the environmental permitting process for major mines in Alaska to identify the effects ecosystem management has had or could have on the permitting process. To date, ecosystem management affects major mine permitting in Alaska primarily through the NEPA environmental assessment process. In Alaska, only the Forest Service has instituted ecosystem management in an overt and organized manner, while other agencies are doing so less directly. In recent Bureau of Mines publications, the mine permitting process has been described using case studies of several recently permitted mines in Alaska. The insights into the permitting process and the conclusions of these reports are reviewed and summarized. Several ecosystem management issues were identified in the case studies, including the need for: effective communication between agencies; standardization and coordination of NEPA environmental impact assessment and environmental monitoring programs among agencies, and assessment and selection of alternatives based on risks to ecosystems regardless of jurisdictional boundaries or environmental media-specific regulations. Ecosystem management could be used as a way to systematize, organize, standardize, and coordinate permitting and monitoring requirements and management perspectives among government agencies and project proponents.

Jan 1, 1993

By G. W. Jones

In cooperation with the Edison Electric Illuminating Co. of Boston, Mass., and the-Boston Consolidated Gas Co., the Bureau of Mines, United States Department of the Interior, has conducted a survey continuously since 1929 to determine the general hazards of combustible gases and vapors in manholes of the Edison Electric Illuminating Co.

Jan 1, 1942

By B. S. Covino

The Bureau of Mines has conducted a laboratory and field corrosion test¬ing program to determine materials of construction for the leaching and gas-sparging crystallization environments of the clay-HC1 process in order to more fully utilize the alumina from domestically available kaolinitic clays. Laboratory tests were used to determine the corrosion rates of 22 metals and alloys by weight-loss measurements in these two environments of the process. The results of this laboratory study were used both to suggest metals and alloys for field testing and to determine the effect of the individual solution components on the corrosion behavior of the metals and alloys. Results from the field tests were used to recommend Ta, Ta-2.5W, and Ta-10W for con¬struction of the agitators for the leaching process. The metals and alloys recommended for construction of the gas-sparging crystallizer heat exchangers were Ta, Ta-2.5W, Ta-10W, Nb, Nb-1Zr, Nb-3Zr, Nb-28Ta-10W-1Zr, Nb-10Hf-1Ti, and Zr for the first stage and Ta, Ta-2.5W, Ta-10W, Nb-28Ta-10W-1Zr, Nb, Nb-10Hf-1Ti, and Zr for the second stage.

Jan 1, 1981

By M. F. Dunn

The objective of this work was to define jet fan performance in d variety of large cross-section underground mine applications and to develop guidelines for thin performance in open airways, dead headings, and multiple face areas. Measurements include common ventilation instruments, continuous recording remote electronic anemometers to measure air velocity, and sulfur hexaflouride tracer gas with chromatograph analysis to determine dilution rates and air recirculation. For open airways the following were determined: Large jet fans are leas efficient in smaller airways, but quite effective in larger open airways for achieving both uniformity end greater air entrainment, when inclined about 10° or elevated. For dead headings the following were determined: The jet fan must be placed against the rib of the heeding closest to the incoming airstream from the crosscut or recirculation will increase. The fan should be placed at the pillar corner to increase airflow. As the fan is moved closer inby, recirculation increases. Larger fans promote recirculation. Inclining fans about 12° improves airflow in large headings. For face areas the following were found: For panels having uncontrolled airflow, the fan should be placed in the incoming airflow, about one pillar inby, and directed diagonally across the faces. For panels having narrower rooms and controlled airflow, the fan should be placed alongside the panel side in the first room so as to direct or intersect the incoming airflow at the next entry or crosscut.

Jan 1, 1983

By R. W. Courtney

The objective of this study is to make a critical evaluation of the magnitude and extent of electrostatic hazards in typical U.S. mining operations and to assess the adequacy of techniques, materials, and equipment for detecting and minimizing these hazards. This was accomplished with an incident/accident survey, mine visits, literature search, and engineering analysis. It was concluded that it would be desirable to (1) utilize ground fault interrupters to minimize stray current from electrical utilities, (2) decrease the current and electrostatic sensitivity of electric detonators used in areas with a high incidence of lightning strikes or troublesome stray currents, (3) institute quality control and test standards for blasting material and protective devices, (4) establish an electrostatic monitoring program for loading ANFO in plastic lined holes, and (5) establish a risk criteria for operator exposure in mines.

Jan 1, 1982

By E. P. Carman

This: report gives data on the installation and operation of a packaged-unit heat-pump installation in a residence in McLean, Va., a suburb of Washington, D. C. The original equipment, installed in January 1947, was one of the first of 50 experimental Marvair units manufactured by the Muncie Gear Works, Inc., Muncie, Ind. The compressor unit of this installation was replaced by the company in September 1947, with a modified commercial model. The commercial unit and the original pump and fan accessories have been used as the sole means of heating (and cooling in summer! the. residence for the subsequent five winters and summers. The conclusions and data given herein, therefore, cover 6 winters sad 6 summers of heat pump operation, including 1 winter when temperatures averaged below normal for 2 months and the following summer when temperatures were above normal.

Jan 1, 1953

By J. Ritchey

This report describes the engineering feasibility and economic advantages of using a mobile bridge-type cross-pit belt conveyor system in conjunction with a large dragline to excavate and transport spoils in a typical Western surface coal mine. The studies show that such a system could be built to survive operational and climatic mining conditions, and that its implementation would offer a reduction in both acquisition and operating costs versus conventional mining units of comparable rapacity. Reclamation costs can also be significantly reduced, and the total reclamation process accelerated, making the cross-pit conveyor system attractive to mine Owners and environmentalists alike.

Jan 1, 1976

By J. R. Thoenen

In Progress Report 1,4/ a number of facto mere demonstrated and conclusions drawn from experimental tests and records made during commercial blasting operations at a number of quarries. For example, the tests showed (1) that vibrations received on outcrops were of comparatively

Jan 1, 1938

By Roger E. Burleigh

In June, 1989, the U.S. Bureau of Mines, undertook a 9-day evaluation of the tin resource potential of the Sleitat Mountain tin deposit. Significant tin-tungsten mineralization is associated with quartz-topaz-white mica-tourmaline greisen alteration of a multi-unit, 57 Ma, peraluminous, granite stock which intrudes Cretaceous Kuskokwim Group flysch deposits. The granite comprises marginal biotite-, intermediate biotite-muscovite-, and central zinnwaldite-granite units, interpreted as a zoned alteration system. Major vein mineralization is confined to two east-west-trending zones of steeply oriented tabular lenses of greisen interleaved with mildly altered granite. Cassiterite is the dominant ore mineral while arsenopyrite, loellingite, wolframite, pyrite, sphalerite, chalcopyrite, and bismuth-oxides are present in minor to trace amounts. The north and south greisen zones are estimated to contain an inferred resource of 128 to 212 million lbs Sn in 28.6 million st of mineralized rock. An 1,800-lb representative bulk sample contained 0.37% Sn, 0.04% W and 17 ppm Ag and is considered an average grade estimate for the deposit. Drill testing by Cominco Alaska Exploration indicates that substantial widths of high-grade tin mineralization are included within the lower grade disseminated mineralization. Depth of deposit erosion is substantial and there exists a high probability for placer tin deposits.

Jan 1, 1991

By Paul McIlroy

Costs of producing lead from various known resources in the United States are developed by the Bureau of Mines to define the future availability of domestic lead at various price levels. It is estimated that 60 million tons of primary lead (75 percent of the total resource) is available at $0.20 or less per pound; 72 million tons (90 percent of the total) is available at $0.50 or less per pound; and the 79 mil- lion ton total estimated resource can be obtained at a price or $1.82 or less per pound. The supply available at $0.20 per pound or less will meet demand for over 78 years at the 1970 annual consumption rate of 763,000 tons.

Jan 1, 1974

By Donald J. Ninteman

This Bureau of Mines publication is a literature study of the problem of spontaneous oxidation and combustion of sulfides in underground mines. It summarizes the present-day hazards, process mechanisms, and prevention and control techniques of this growing problem in underground mines. The iron sulfides generally have the greatest tendency to oxidize, particularly pyrrhotite. The presence of moisture and oxygen is essential for the oxidation reaction. Highly fractured sulfides, when found with timber or combustible refuse in slowly circulating air, pose the most serious fire hazard. Quenching with water is effective in quickly dealing with local hot spots, but ventilation at high flaw rates is the most effective and economical means for long-term prevention and control.

Jan 1, 1978

By J. P. Schmid

Results of a comprehensive investigation of the impact of underground mine waste disposal on the health and safety of miners are presented. Information was gathered through an extensive search of American and foreign literature and personal communication with professionals in private industry and government. All conceivable health and safety hazards directly or indirectly related to underground mine waste disposal are analyzed, catagorized, and ranked on an industry-wide basis. Positive health and safety effects are analyzed and ranked in a similar way. Both potential and known hazards and positive impacts are included. Recommendations on abatement techniques for the various hazards are presented. Case histories of a fill-related accident in a metal mine and a health hazard associated wtih coal waste backfilling are included and causes and possible abatement procedures are discussed. The rule of management in the promotion of health and safety in backfilling operation is discussed.

Jan 1, 1982

By R. Stefanko

This Final Report covers the work performed for Contract No. H0377043, "Cables for Face Equipment" from August 1, 1977 to April 1, 1981. It reports the findings in three areas of research: cable protection, circuit-breakers, and high-voltage cable couplers. Laboratory and analytical studies have been conducted in the three areas to determine proper circuit-breaker settings, cable sizes, and coupler performance. Also, an extensive field-monitoring program was established to relate in-mine epxerience to laboratory findings. Further, various pieces of equipment was designed for laboratory testing, particularly in the area of cable reeling and unreeling.

Jan 1, 1981

By T. M. Klemetti, G. M. Molinda, D. M. Pappas

Some of the most difficult coal mine roof in the U.S. can be found in the Illinois Basin. Factors contributing to the high roof fall rate include: weak moisture-sensitive roof rock, high horizontal stress, and limited longwall mining. The depth of cover ranges from 90-1,000 ft and roof damage from horizontal stress can be severe. Moisture sensitive-roof rock is common above the Springfield-Harrisburg Herrin #5 and #6 seams in the Illinois Basin, and contributes to roof skin deterioration. The roof fall rate increases significantly in the humid summer months. The National Institute for Occupational Safety and Health (NIOSH) has shown, using lab and field studies, that highly moisture-sensitive roof rock can be directly correlated to poor roof conditions. Controlling the skin is the key to reducing rock fall injuries, and roof screening is, by far, the best remedy. Illinois Basin coal operators have been successful in reducing the number of rock fall injuries in recent years. NIOSH has documented best practices for screen installation which has resulted in safe, efficient operations. Other solutions to skin failure include: the use of denser five bolts per row patterns to reduce spans between bolts, systematic supplemental support in intersections, straps and large pans protecting operators, and air conditioning to remove moisture from the intake air.

By R. C. Ellman

Since successful industrial lignite-burning equipment was developed in 1925, the commercial use of lignite as a fuel for power plants has increased. It has proved an entirely satisfactory fuel for generating power and can be burned efficiently by various methods.4/ Equipment to fire pulverized lignite was installed and used successfully at the Trinidad Station of the Texas Power & Light Co. as early as 1926. The lignite was predried in steam-heated grid driers before pulverizing.5/ This method of firing was used later in the Comal Station of the San Antonio Public Service Commission.6/ Both stations, however, have since been converted to use other fuels. Units for pulverizing and drying lignite are relatively new in the lignite-consuming region of North Dakota. The air which sweeps the pulverizer and transports the pulverized product to the burners is preheated to dry the lignite during pulverization. The first unit was installed in 1948 in one of the two boiler units of the Crookston Station, Otter Tail Power Co., Crookston, Minn.7/ In 1951 the 30,000-kw. W. J. Neal Station, Central Power Electric Cooperative, Inc., Voltaire, N. Oak., was designed and constructed for firing pulverized lignite exclusively. It is the largest lignite-fired, power-generating station in North Dakota. The 44,000-kw. Lewis and Clark Station of the Montana-Dakota Utilities Co., Sidney, Mont., is fired by a similar pulverizing system. Operation of this plant was begun in October 1958. At Fergus Falls, Minn., the 53,500-kw. Hoot Lake Station of the Otter Tail Power Co., also using a pulverized lignite-firing system, began operating in September 1959.

Jan 1, 1961