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By Neal M. Muir, Robert S. Sanford, Bruce I. Thomas

"INTRODUCTION The presence of the zinc-lead-copper deposits an the north slope of Mount Eielson, Mount McKinley National Park, Alaska, has been known for many years. The deposits were examined by J. C. Reed, a geologist of the United States Geological Survey during the summer of 1931. In the summer of 1943 the authors and Clyde Wahrhaftig, a geologist of the Geological Survey, examined the deposits.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the and that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual investigative work, and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiation tests.Particular acknowledgment is due to Heine Kenworthy, who conducted the beneficiation tests under the supervision of C. Travis Anderson; to Clyde Wahrahaftig of the Geological Survey, who completed the Geologic and topographic maps, to Grant Pearson of the National Park Service; and to O. M. Grant and Mrs. Frank McGarvoy for their assistance during the examination."

Nov 1, 1947

By A. B. Hooker, L. C. IlsLey

"Observation of the use of trailing cables in ""mines shows that the chief limiting factor in the life of the cables and their safe use is the smashing or crushing of the cables in service, together with the effects of consequent splicing.Trailing cables are crushed when run over by cars, mining machines; and locomotives or when hit by falls of roof. Crushing damages the insulation and may cause failure at once or in later use. Failure may be either by short circuit between the conductors or by grounding to the track. The failure of a live cable causes electric arcs capable of igniting explosive mixtures of methane and air. Every cable failure in a gassy or dusty mine is, therefore, a real or potential hazard.Some mine operators do not allow the splicing of trailing cables for use in gassy mines, bet require that a damaged cable be immediately replaced and if repaired that it be used only in nongassy mines. Other operators allow the making of temporary splices to permit completion of the shift but require that such splices be remade and vulcanized before the cable is used again.Still other operators allow the continued use of temporary splices, which in general means that a cable is used until the splices give trouble in reeling, or overheat, or pull apart. Then the spliced sections are either cut out or the whole cable is replaced.Splices often determine the useful life of a cable. A splice poorly made may pull apart ueder mechanical strain and cause arcing that burn* the surrounding cable or ignites as or coal-dust. If it has lower conductivity a splice is the first part of the cable to heat; it may become so hot under load that it will burn apart and damage other parts of the cable, or, if it be a soldered splice, the solder may melt and allow parting of the cable. A poorly made splice often has insufficient insulation which may alloy short-circuiting between conductors or permit external contacts capable of giving an electric shock to one handling the cable. The splice is sometimes bulky from too much insulation and takes up too much room on the reel, causing uneven reeling; also by catching on the spooling device the oversized splice may receive expressive pulls and wear. Splicing is therefore a very important factor in the use of trailing cables."

Mar 1, 1932

By Robert A. Cummings

A rock mass classification system has been developed for support estimation in mines using caving methods. The developed system (MBR System) accepts readily-obtainable geotechnical properties, and mining geometry, to develop a rating that permits recommendations for drift support in block caving mines. The data base includes major active United States caving mines. The method is intended to be used for planning and estimating purposes and for preliminary support design. The Manual explains the organization and nature of the MBR System, its derivations, details of required input data, methods for assessing the data and for developing rock mass ratings, and techniques for selecting the most appropriate mine support recognizing mine requirements and desired stability. A worked example is provided.

Jan 1, 1984

By Susanne Hering, Brent Kirby, Charles D. Litton, Tracy Allen, Kirk R. Smith, Rufus Edwards

In developing countries, high levels of particle pollution from the use of coal and biomass fuels for household cooking and heating are a major cause of ill health and premature mortality. The cost and complexity of existing monitoring equipment, combined with the need to sample many locations, make routine quantification of household particle pollution levels difficult. Recent advances in technology, however, have enabled the development of a small, portable, data-logging particle monitor modified from commercial smoke alarm technology that can meet the needs of surveys in the developing world at reasonable cost. Laboratory comparisons of a prototype particle monitor developed at the University of California at Berkeley (UCB) with gravimetric filters, a tapered element oscillating microbalance, and a TSI DustTrak to quantify the UCB particle monitor response as a function of both concentration and particle size and to examine sensor response in relation to changes in temperature, relative humidity, and elevation are presented here. UCB particle monitors showed good linearity in response to different concentrations of laboratory-generated oleic acid aerosols with a coarse (mass median diameter, 2.1 µm) and fine (mass median diameter, 0.27-0.42 µm) size distributions (average r2 = 0.997 ± 0.005). The photoelectric and ionization chamber showed a wide range of responses based on particle size and, thus, require calibration with the aerosol of interest. The ionization chamber was five times more sensitive to fine rather than coarse particles, whereas the photoelectric chamber was five times more sensitive to coarse than fine. The ratio of the response between the two sensors has the potential for mass calibration of individual data points based on estimated parameters of the size distribution. The results demonstrate the significant potential of this monitor, which will facilitate the evaluation of interventions (improved fuels, stoves, and ventilation) on indoor air pollution levels and research on the impacts of indoor particle levels on health in developing countries.

By M. W. Von Bernewitz, W. J. Sharwood

So far as is known , there is no complete bibliography on sampling, therefore , this one should be of value . In it are nearly eleven hundred references , some dating back 30 years , on sampling at mines , mills , smelters , power plants , pumping stations and refineries . For convenience , there are included a few references to methods for sampling such materials as leather belting in mills , salt impregnated soils , and mine waters . All the important technical journals , - including some in foreign countries- and engineering society publications , also mining and metallurgical text - books , have been studied for anything concerning sampling , and while it is not claimed that every important reference has been listed , the bibliography is fairly complete . The arrangement is alphabetical by authors ' names , and the references are numbered serially in the crder that they appear in the bibliography . Anonyous references are listed under the name of the journal in which they appear , and are numbered like the references bearing an author's name . Patents are grouped in their numerical order , without index nu.bers . Under the heading , " U.S. Bureau of Mines Publications " , are listed all publications of the bureau that deal with sampling . While the serial number is omitted , these same references , of course , have serial numbers where they appear in the list arranged alphabetically by authors .

Mar 1, 1922

By John A. Kiefer

Ground fault and overcurrent protection criteria for coal mine a.c. distribution systems were examined under a Bureau of Mines funded investigation. The report begins with a literature review which discusses relaying topics including instrument transformers, ground-fault pickup methods, static relaying, and comparison of relaying techniques. A chapter on ground-fault relaying provides recommendations for maximum and minimum pickup levels as a function of maximum ground current and power system line-to-ground capacitance. Research in the area of phase overcurrent protection has resulted in a complete set of procedural recommendations for the selection and setting of overcurrent relays and current transformers, molded-case circuit breakers, and distribution system fuses in coal mine power systems. The final chapter, which discusses relay system maintenance, introduces a unique test set which was developed by KETRON and used to test the performance of relaying systems in coal mines.

Jan 1, 1980

Capture airborne respirable dust generated by an auger-type continuous mining machine to reduce workers' dust exposure. Approach Install a water-powered scrubber system, operating at 1,400 psi, on the sides of the conveyor. The scrubber draws the dusty air from the face area and discharges cleaned air into the face return. How It Works Auger-type continuous miners pose unique ventilation and dust control problems. To protect face workers from the dust, the end of the brattice is usually maintained close to the face to increase ventilation effectiveness. However, it is taken down as the machine cuts toward the exhaust side to allow the machine to complete its cut. Often, the brattice is not reinstalled in a position to most effectively control

Jan 1, 1989

By G. L. Oldwright, Virgil Miller

"The data presented in this paper were collected at the smelter of the Consolidated Mining & Smelting Co. of Canada Limited, Trail (Tadanac), Brithish Columbia. The authors are greatly indicated to S.G. Blayrock, vice president and general manager; James Buchman, smelter superintendent; and the staff members mentioned in Report of Investigation 3243. The authors are exceedingly grateful to George Murray, assistant smelter superintendent, for his keen interest, suggestions, and help in carrying out this investigation.INTRODUCTIONThe methods of charign the blast furnaces at Toole and Kelloggs were noted in Report of Investigations 2957 and 3094 respectively. Report of Investigations 2957 cited (4 to 9 inclusive) Hofman's Metallurgy of Lead (p. 226) and the work of A.S. Dwight, Thompson and Sicka, the staff of the Engineering and Mining Journal, and L.D. Anderson, N.F. Collins, in The Metallurgy of Lead (Chas. Griffin, London, 1910) also gives (pp. 247 254) the principles that he believes govern the successful charging of the blast furnace."

Dec 1, 1934

By D. Randolph Berry

The objective of this program was to develop a system to extinguish coal mine fires by remote sealing of the underground passageways. The system developed had to be versatile enough to function under a wide range of operating conditions, including large variations in passageway geometry, depth of mine, water conditions, both in the mine and at the surface, and rubble in the mine passage. The system developed had to include instrumentation for the remote probing of the passageway prior to sealing, a system for sealing the mine passages, and instrumentation for remote monitoring of the quality of the seal during and after construction. These objectives were successfully achieved during this program. The remote mine sealing capability of the system was satisfactorily demonstrated in a field test conducted at the Eastern Associated Coal Corporation Federal No, 1 Mine in Grant Town, West Virginia.

Jan 1, 1973

By L. W. Higley

It is estimated that well over 20 million lb of chromium and 8 million lb of nickel, plus other metal values, are diverted annually to furnace dusts, mill scale, and contaminated swarfs in the domestic stainless and other specialty steelmaking industry. Little inroad has been made toward the in-plant recycling of these wastes to reclaim the metal values. The Bureau of Mines has devised a process for recovering about 90 pct of the chromium and molybdenum and well over 90 pct of the nickel and iron from stainless steelmaking furnace dusts, swarf, and mill scale. Other metals such as manganese are also recovered. Initial laboratory results were confirmed and expanded to include a wide variation of stainless steelmaking waste mixtures. Later experiments have included specialty steelmaking wastes other than from stainless steelmaking. Significantly, the ease of technology transfer has been demonstrated by a number of industrial-sized (19-ton) commercial electric furnace heats, in which the pelletized wastes represented some 10 to 20 pct of the furnace charge, replacing part of the normal scrap charge. Results of these successful large-scale trials are presented. Some information is also presented on incorporation into the pellets of chromium-bearing particulate wastes originating from other than steelmaking production. Cost evaluation indicates the process is economically attractive.

Jan 1, 1982

The 1969 Lignite Symposium was held at Grand Forks, N. Dak., on May 1-2, 1969. Cosponsored by the University of North Dakota and the Department of the Interior, Bureau of Mines, the meeting was the fifth in this series. Registrants from many States and Canadian Provinces attended the meeting representing many segments of energy-oriented companies, State and Federal Government, and universities. At 2-year intervals, these symposia provide a common meeting place where recent research and developments in technology and utilization of energy resources with emphasis on solid fuels (lignite) are presented. Proceedings3 of the previous symposia including a Forum held in 1958 have been published.4

Jan 1, 1970

By E. M. Cohn

The literature dealing with the electrical conductivity of solid dielectrics, including all its aspects and its relationships to other physical properties of these materials, is extensive and scattered in many books, phamphlets, and periodicals. It is believed that most of the important contributions to this field up to October 1943 have been listed and abstracted in this circular. Also included are some general references on static electricity. Methods of removing static charges are described; methods of and conditions for measurements of resistivity are discussed; equations for the calculation of resistivity are given; and methods of resistance measurements in Situ are reviewed. Data on the variations of resistivity with changing conditions as well as explanations for them have been collected, and three tables showing the resistivity of various dielectrics at different humidities are included. The appendix contains a short development of the mathematical formulation of the charging and discharging currents due to interfacial polarisation. INTRODUCTION Methods for Removing Static Electricity Of the various means employed for preventing or removing accumulations of static electricity in industrial processes, grounding is the most common and most generally effective. It is a precaution readily applied to stationary machines anti may often be utilized to good advantage to rid persons and portable equipment of an acquired charge. There are many situations, however, in which direct low-resistance grounding cannot be used, either because the charged bodies are insulators or are inaccessible, or because contact to a ground lead might give rise to a hazardous spark. If the charged body is a conductor, contact made to a neighboring conductor, even though the latter be insulated from ground and of relatively small capacitance, may also result in the occurrence of an incendive spark. In such instances, static electricity can sometimes be removed most satisfactorily by means of strong atmospheric ionization produced by radioactive material, X-rays, ultraviolet light, or A. C. high-voltage brush discharge. Where no danger exists from flammable

Jan 1, 1944

By J. R. Thoenen

[Before 1914 Germany held virtual monopoly on the world supply of potash for fertilizer purposes. During the world War, potash shipments to the United States ceased, and recourse was had to domestic supplies. High war-time prices stimulated interest n various sources, and domestic production increased rapidly. At the close of the war, resumption of shipments from Germany and other sources reduced prices to below pre-war levels, and, as a result, most of the domestic producers ceased operational.]

Jan 1, 1941

Rock property tests were performed on NX-size diamond drill core from the roof, floor, and coal from the longwall mining section of Federal No. 2 mine, West Virginia. The purpose of these tests was to determine the engineering properties of the various strata as part of a ground control study of the longwall operation. The following tests were performed: 1. Uniaxial compressive strength, Young's modulus, and Poisson's ratio 2. Triaxial compressive strength 3. Brazilian tensile strength 4. Modulus of rupture 5. Specific gravity Thirteen boxes of core delivered to the University on April 1, 1974 were identified as follows: 2 PTR 1 -2 boxes of roof rock 2 PTF 1 -2 boxes of floor rock 2 PTR 2 -2 boxes of roof rock 2 PTF 2 -2 boxes of floor rock with approximately 3 ft of coal in Box 2 (designated 2 PTC 2) 2 PTR 3 -2 boxes of roof rock 2 PTF 3 -2 boxes of floor rock 1 PC 5 -1 box of coal

Jan 1, 1976

By H. M. Lawrence, E. Roca

"INTRODUCTION Of the phosphate rock deposits of the United States that are being exploited actively at present, the land-pebble area in Florida is the largest producer. In recent years the land-pebble district, in Polk and Hillsborough Counties, has produced about 80 per cent of the raw phosphate rock that has supplied the requirements of the several national industries based on this essential commodity.In the land-pebble deposits sizes finer than 16 to 22 mesh are below the commercial limit in phosphate content, and washing-plant practice has been directed to the recovery of the coarser material. Recently, more extensive control of the washery plan has resulted in the saving of additional amounts of phosphate, the loss of which had been considered unavoidable. However, strict requirements of the trade regarding the lowest acceptable grade of phosphate rock prevent the inclusion of more than a very small proportion of the low-grade phosphatic sands with the washery output of phosphate roe:. Further advances in practice resulting in larger recoveries of phosphate can only be effected by the application of processes that are based on other principles than merely a difference of particle size. Research is be conducted actively along these lines by the industry and by cooperating agencies.Flotation has been studied for several years by the International Agricultural Corporation and its allied company, the Phosphate Recovery Corporation. J. T. Burrows, vice-president of the International Agricultural Corporation, in a letter dated July 10, 1929, states:"

Aug 1, 1931

By G. L. Oldright, J. D. Sullivan, W. E. Keck

"An apparatus and procedure developed in the laboratory of the South-west Experiment Station of the Bureau of Mines are capable not only of determining the rate and volume of penetration of solutions into porous materials but also of determining the total volume of voids within particles of porous material, and the density. The method is applicable to ores, bricks, concretes, tiles, filter bottoms, or other porous materials of this nature. As will be made clear in the descriptive matter to follow, the method measures (a) the volume of voids within the porous materials and is not concerned with the interstitial space between the particles.Porous materials usually contain some large voids and also pores that are capillary in nature. To measure the total volume of voids in a sample it is necessary to replace the gas or gases within the voids with some liquid of known density. The large cavities can be filled quite readily, but under ordinary conditions a long time may be required to fill capillary pores. As many porous materials are of a decomposable nature it is necessary to evacuate the porous materials and then submerge them in a liquid of known density to bring about saturation in a short time. Then by the use of a hydrostatic balance the volume of porous material (solid itself) can be determined. To determine the volume of porous material plus voids it is necessary to coat the sample with some material, such s paraffin, which will prevent solution from entering the voids; then, by means of a hydrostatic balance, the volume of porous material plus voids is determined and by subtracting that of the porous material from this the volume of voids is ascertained. The rate of penetration of solutions can be determined either (a) by measuring the change in weight as the sample becomes saturated when immersed ni a liquid of know density, or (b) by measuring the volume of liquid penetrating with a dilatometer. In either instance, due to the fact that some penetration takes place as soon as the sample comes in contact with solution and before a reading can be taken, the sample must be paraffined to determine the total volume of penetration. Since many porous materials partly decompose and disintegrate in liquids the rate and volume of penetration can better be measured by dilatometer than by the change in weight, as saturation takes place when immersed in a liquid. The details of procedure for determining (a) total volume of voids, and (b) rate and volume of penetration are given in this paper."

Oct 1, 1930

By James A. Brierley

Wastewater from uranium mines in the Ambrosia Lake district near. Grants, New Mexico, U.S.A., contains uranium, selenium, radium, and molybdenum. The Kerr-McGee Corporation has a novel treatment process for waters from two mines, sections 35 and 36, to reduce the concentrations of the trace contaminants. Particulates are settled by ponding, and the waters are passed through an ion exchange resin to remove uranium; barium chloride is added to precipitate sulfate and radium from the mine waters. The mine waters are subsequently passed through three consecutive algae ponds prior to discharge. Water, sediment and biological samples were collected over a 4-year period and analyzed to assess the role of biological agents in removal of inorganic trace contaminants from the mine waters.

Jan 1, 1981

By R. H. Oitto

To determine whether reflectors could substitute for the trip lights referred to in the Federal Mine Safety Code, the Bureau of Mines studied trip safety devices under simulated haulageway conditions. The noticeability of reflectors compared with trip lights and fluorescent panels was evaluated from distances of up to 850 feet with light source intensities of up to 1-6 foot-candles (ft c). Reflectors tested consisted of a reflective lens in a holder secured to a frame that can be attached to a trip. Reflectors were found to be suitable for use as a trip safety device. In fact, for the conditions in many underground haulageways some reflectors would be more effective than a permissible trip light.

Jan 1, 1968

By Lowell Stroud

This report is the third in a series presenting equilibrium vapor-liquid data for helium-bearing natural gases. The first two reports contained phase data for the gases processed for helium at the Bureau of Mines Amarillo and Exell, Tex., helium plants. The present report offers similar information for a lower-helium-content (0.75 mole-percent) natural gas to be processed in the Department of the Interior's long-range helium-conservation program. A windowed-cell apparatus was used to obtain 218 samples of equilibrium vapor and liquid phases at 73 experimental conditions ranging in temperature from -100° F to -275° F and in pressure from 100 to 500 psi. From the phase data, the condensation characteristics, helium solubility, and equilibrium-vaporization-coefficient data for helium, nitrogen, and methane were evaluated. The effect of using a. preliminary hydrocarbon trap upon the subsequent vapor-liquid compositions is reported. A brief comment regarding the composition effect of passing the gas through a gasoline-removal unit is also included.

Jan 1, 1963

By Donald E. Ralston

The Huntsville study area in northeastern Alabama consists of Jackson, Limestone, Madison, and Marshall Counties. Major emphasis was placed on the Huntsville urban area in Madison County to analyze the relationship of urban growth and the minerals industry. Huntsville was delineated into its component urban, suburban, and rural parts for 1964, and the primary area of growth was predicted for 1990. Population estimates were made for the four-county area as a unit and Madison County separately, and projected to 1990. Demand estimates for crushed stone and sand and gravel were made for the same area units and projected to 1990. Analysis of quarry sites in the Huntsville area was made for the present and for the future. The mineral operations of the study area are all located in rural areas; in the case of Huntsville, the mineral sites are located in areas defined as "rural" in the component urban-suburban-rural system. The operations outside Madison County can expect to have minor problems with urban encroachment, while those operations in Madison County can expect major problems associated with urban growth and development. Some of the problems associated with limes tone production can be reduced if producers invest in capital equipment that will reduce the nuisances inherent in this activity. Although urban expansion endangers some quarry operations in Huntsville, topographic and political restrictions which prevent urban expansion can effectively shield quarry operations for some time.

Jan 1, 1970