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By J. W. Howland

A demonstration of dozer blades, designed for recontouring area-mined spoil and shown effective at Kansas and East Texas surface mine sites, was conducted at a Northeast Arizona surface coal mine to determine their effectiveness in different climate and soil conditions. The specialized tools were: 48-ft angle blade (on side-by-side tractor), 24-ft grading bar, modified 24-ft "U" blade (on side-by-side tractor), and a 13-ft deep "U" blade. Interest in the increased dirt-handling capacity of a previously built 22-ft blade, resulted in the design of a new Centerflow Blade of good versatility, able to maintain increased flow in otherwise difficult-to-move spoil. The demonstration involved 263 acres and showed a reduction of 50% in reclamation costs and 20% in fuel requirements for this mine site over conventional equipment. This savings resulted from improved technology, trained operators, and rigorous application of supervisory and monitoring techniques. Procedures and results of the demonstration are presented and analyzed here, along with guidelines for application of findings.

Jan 1, 1982

By R. E. Heithecker

In June 1933 the Bureau of Mines, in cooperation with the State of Oklahoma and the Oklahoma City Chamber of Commerce, published a report of the gas at reserves in the Oklahoma City oil field3/ based upon data as of October 1932, at which time there were 43 classified gas wells in the field, The estimates were obtained by the ?porosity-area" method. There are two general methods of estimating natural-gas reserves. The porosity-area method, as used by Hill and Rawlins, is used when a gas field is comparatively new but after enough drilling has been done to determine the average thickness, porosity, and areal extent of the producing horizon. The "pressure-volume? method of estimating gas reserves, the method used in this report, nay be used after a sufficient volume of gas has bean withdrawn from the reservoir to cause an appreciable decline in reservoir pressure.

Jan 1, 1937

By Kevin Connor

During 1986, the Government continued with efforts to ease the country's almost total reliance on coffee exports for trade revenues by allocating 45% of the Government's budget to commerce and industrial projects. The collapse in coffee prices in 1985 continued to exacerbate the country's growing trade deficit, weakened currency, and dwindling reserves of foreign exchange in 1986. Amoco Burundi Petroleum Corp., a subsidiary of Amoco International Oil Co., continued with plans to drill at least two exploration wells in Lake Tanganyika in 1987. Both offshore and onshore drilling exploration was planned by Amoco Burundi. Any oil or gas finds were expected to have substantial impact on the Burundian economy, as a major portion of the country's trade deficit was directly attributable to petroleum and gas imports.

Jan 1, 1988

By Albert W. Deurbrouck

The performance characteristics of five hydrocyclone coal washers were evaluated to determine the sharpness and efficiency of separation that might be anticipated in commercial operation. The hydrocyclone overflows contained generally good clean coal products that would require little re-treating to remove misplaced high-gravity material. The underflows, however, contained from 63.6 to 36.7 percent of misplaced low-gravity material, which would require secondary cleaning to provide acceptable clean coal yields.

Jan 1, 1974

By J. E. Conley

[Available statistics show that the demands of the American chemical industry for sodium sulphate have been increasing slightly in recent years. The supply from domestic sources, particularly in the form of byproduct salt cake from the acid manufacturers, has been tending to decease due to the growing manufacture of synthetic acid. Both hydrochloric and nitric acids are being synthesized from their elements. The natural result has been that a smaller amount of salt cake is available. Simultaneously, the expansion of the Kraft-paper industry, especially in Lie South, has brought about greater demand for sodium sulphate in that section. This demand is being met by domestic byproduct salt cake, by imported German sodium sulphate made from potash waste liquors, and by favorably situated domestic deposits of Glauber salts and tile anhydrous salt, thenardite. No shortage of natural sodium sulphate exists in the United States, but usually such deposits occur in semiarid regions far re¬moved from transportation facilities and from markets. Moreover, the major portion of the natural deposits is Glauber salt or mirabilite (Na2SO4?10H20), which must be dried or dehydrated in order to most consumer requirements. The waters of hydration represents, roughly, 55 percent of tae total weight of the crude salts and therefore has a very important influence on transportation costs. In marry instances the cost of getting even the dehydrated product to market is the deciding economic factor. Therefore, the recovery or production of anhydrous sodium sulphate from plant-waste liquors or from natural brines of suitable composition might be economically feasible.]

Jan 1, 1936

By George L. Gates

[When clays are mixed with water to -.,tee mud fluids for use in trilling wells for nil and --ac b ;l-,e rotary method the liquid mixtures have certain physical characteristics that vary with the quantity and size of their inherent solid particles. All naturally occurring clays contain variable quantities of particles of different sizes ranging from relatively coarse (sands) through -,.tedium (silt) to fine materials of colloidal dimensions. Tie colloid content is extremely important 2.s a desirable _.'ale constituent of mud fl-z to fit well drilling. ';'it:-out colloids the souk?;,' in a mud fluid wouldr rapidly, end ti-c-and. wall-building qualitites of the' fl,-,id would l ..o r re 1 impaired. Mud .fluid.^ with insufficient quantities of colloids also are lacking in "lubricating" g listen, and it is, to ° min casing in, -)re holes drilled with such fluids.]

Jan 1, 1941

By John C. Machisak

STATISTICAL data on injuries and employment pertinent to metal mines and to their mills, and/or processing plants are presented in this Information Circular for the calendar year 1960. The information pertains to metal mines, as well as ore-dressing plants and primary nonferrous smelters, refineries and reduction plants, and their auxiliary works. These data are voluntarily submitted annually to the Bureau of Mines by the operators, and contribute greatly toward the promotion of safety in the mineral industries. The data presented are classified according to the principal mineral produced and include information on copper, iron, lead-zinc, gold-silver lode, gold placer, uranium-vanadium and miscellaneous metals. A breakdown of miscellaneous metals by commodities is shown in table 19, page 41. The data also relate to workers engaged in production, exploration, development, construction, and maintenance and repair work, as well as supervisory personnel and office- workers at the mine or plant site. Injury and employment data at metal mines and metallurgical plants in the United States for 1960 are shown under the following general sections:

Jan 1, 1963

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 P. G. Guest

MANY of the gases and vapors used in anesthesia form explosive mixtures with oxygen or air. Sources of ignition for these mixtures always have existed in operating and anesthetizing areas. When ether was first introduced, candles,5 gaslights, and coal stoves caused fires and mild explosions of the vapor-air mixtures. Today the chief causes of ignition are electrical. Fires and explosions are still much too frequent; and, because many of the mixtures are rich in oxygen, the explosions sometimes are very violent. Obvious sources of ignition, such as electric-power sparks and arcs in open motors, switches, and receptacles, as well as exposed incandescent wires and hot plates, usually are recognized by hospital personnel and corrected. A source of ignition that is not so obvious to many is static electricity. Until quite recently the presence of this hazard in a large majority of anesthetizing areas was not even suspected. However, numerous explosions-many of them fatal to patients-have been attributed, with good reason, to sparks from static electricity.

Jan 1, 1953

By William H. Lewis

Energy Research Corp., under contract to the Bureau of Mines, has developed a new miners' caplamp battery. The new battery is based on nickel-cadmium technology and offers significant improvements in performance with reduced size and weight when compared to the conventional lead-acid battery presently in use. This report describes the design and fabrication of the nickel-cadmium battery, which utilizes a roll-bonded electrode structure. The final battery design has a 15-A-h capacity in a 2-112-lb package, which is over 2 lb lighter than the present lead-acid caplamp battery.

Jan 1, 1983

By William G. Hedling

The operation of electric face equipment in underground coal mines has proven to be extremely hazardous to mining personnel, including equipment operators and others working in the vicinity of active equipment. Recent industrial engineering studies* of accidents and fatalities indicate that a major contributor to this hazardous situation is noncompliance with modern principles of human engineering, particularly lack of standardization of control configurations. Control configurations differ not only among different machine types, but also among the same machine types produced by different manufacturers. This lack of standardization can produce a high incidence of error in the operation of electric face equipment, thus creating a potential source of accidents. Other examples of non-compliance with human engineering principles are the widespread use of identical black, round control knobs (regardless of the function being performed), and the inappropriate location, spacing, and labeling of controls. Any or all of these factors may place the operator in a "negative transfer" situation, which means that control manipulations appropriate for one type of machine are different from (or even the reverse of) the control movements required to produce the same effect on other machine types. This situation increases the accident potential to the operator, as well as to others in the vicinity. Accident potential is further increased by circumstances which do not allow for large error tolerance-specifically, emergency procedures. Reports of accident statistics cite operator inexperience as a primary cause of most accidents involving underground electric face equipment. Several factors contribute to operator inexperience, including: 1. High personnel turnover 2. Employee absenteeism 3. Current union practice of bidding for jobs.

Jan 1, 1974

By Jeffrey Shawn Peterson

The testing procedures of the U.S. Mine Safety and Health Administration specify that intrinsic safety acceptance tests be conducted using a standard tungsten-cadmium electrode configuration in the break- flash apparatus. However, in realistic mining environments, other materials may be more likely sources of sparking. Information defining the probability of spark ignition between common materials such as aluminum, brass, copper, lead, tin, cold-rolled steel, and stainless steel is of more practical value in determining ignition hazards. The U.S. Bureau of Mines has completed an investigation of the influence of material on the ignition probability using the breakflash apparatus. By comparing ignition currents or ignition voltages corresponding to a probability of one ignition per thousand sparks to those found previously for cadmium, a margin of safety may be estimated for each material. This report presents the results of an investigation into the influence of disk electrode material on the probability of ignition.

Jan 1, 2002

By John C. Machisak

STATISTICAL data on injuries and employment pertinent to metal mines and to their mills, and/or processing plants are presented in this Information Circular for the calendar year 1960. The information pertains to metal mines, as well as ore-dressing plants and primary nonferrous smelters, refineries and reduction plants, and their auxiliary works. These data are voluntarily submitted annually to the Bureau of Mines by the operators, and contribute greatly toward the promotion of safety in the mineral industries. The data presented are classified according to the principal mineral produced and include information on copper, iron, lead-zinc, gold-silver lode, gold placer, uranium-vanadium and miscellaneous metals. A breakdown of miscellaneous metals by commodities is shown in table 19, page 41. The data also relate to workers engaged in production, exploration, development, construction, and maintenance and repair work, as well as supervisory personnel and office-workers at the mine or plant site. Injury and employment data at metal mines and metallurgical plants in the United States for 1960 are shown under the following general sections: 1. General injury experience: Tables I-5-Data on injuries, injury-frequency and severity rates and related employment data, work location, and degree of injury.

Jan 1, 1963

By Lee J. Raabe

A specialized loading system for tensile and fatigue testing of wire rope was constructed and installed in the U.S. Bureau of Mine Wire Rope Test Facility in Bruceton, Pennsylvania. The computer-controlled closed-loop servo-hydraulic test system which can apply up to 800,000 pounds of force on the rope while stretching it up to 30 inches will be used in the development and verification of hoist rope retirement criteria for ropes in the 1 to 2 ½ in. diameter range. Characteristics and capabilities of the system are discussed.

Jan 1, 1984

By John S. Ball

[A system of analysis for sulfur groups in petroleum distillates has been developed as one phase of the Bureau-of Mines investigation of the more economic utilization of the so-called "black oils" of Wyoming. This problem is being studied by the Bureau of Mines under a cooperative agreement with the University of Wyoming at the Bureau's Petroleum Experiment Station , Laramie, Wyo. Wyoming black oils have high sulfur and asphalt content and usually yield only small percentages of straight-run gasoline. A more detailed description of the properties of black oils has been given in a previous publication (3)3/. The preparation and properties of asphalts from those oils have been described (1, 2), and the effect of thermal cracking and the use of ordinary methods of treating wore discussed in one Bureau publication (4), Although these studies gave considerable insight into the properties and characteristics of black- oils; it was thought t that a more fundamental attack would assist-materially in, the problem of sulfur removal.]

Jan 1, 1941

By Albert L. Toenges

Early in 1944 the Chilean Government expressed a desire for assistance from the Bureau of Mines in a study of the coal deposits, coal-mining methods, and preparation and benefication of coals in Chile. A Memorandum of Understanding setting forth the purpose of the work was executed by the United States Government and the Government of Chile. Parts of this agreement are quoted: On February 4, 1944, the Ambassador of Chile in Washington expressed the interest of his Government in obtaining the loan of a mission of experts to assist in the conduct of a survey looking toward the utilization of the low-grade coals of Chile and the application of such technology as may be developed for the distillation of these coals and the use of oil shales. The matter has since been the subject of correspondence between the Secretary of State and the United States Department of the Interior, and the latter Department has agreed to cooperate with the Government of Chile, through the Bureau of Mines, subject to the following understanding:

Jan 1, 1948

By John S. Ball

[A system of analysis for sulfur groups in petroleum distillates has been developed as one phase of the Bureau-of Nines investigation of the more economic utilization of the so-called "black oils" of Wyoming,. This problem is being studied by the Bureau of Nines under a cooperative agreement with the University of Wyoming at the Bureau's Petroleum Experiment Station, Laramie, Wyo. Wyoming black oils have high sulfur and asphalt content and usually yield only small percentages of straight-run gasoline. A more detailed description of the properties of black oilshas been given in a previous publication (3)3/. The preparation and properties of asphalts from those oils have been described (1, 2), end the effect of thermal cracking and the use of ordinary methods of treating wore discussed in one Bureau publication (4), Although these studies gave considerable insight into the properties and characteristics of black oil, it was thought t that a more fundamental attack would assist materially in the problem of sulfur removal.]

Jan 1, 1941

This study of underground mine water inflow was initiated by the U. S. Bureau of Mines in March 1980. The objective of this study is to evaluate the hydrologic variables associated with surface water and ground water systems that affect the inflow of ground water into an underground mine. Data collection techniques are reviewed for their applicability for quantifying these hydrologic variables. Innovative techniques are also investigated. Existing analytical and numerical procedures for predicting underground mine water inflow are reviewed and evaluated. Over 300 computer models were reviewed for their applicability to modeling underground mine water inflow. The model UNSAT2 is utilized for modeling inflow to a shaft and tunnel or drift. This model and the techniques developed in this study are applied to two existing mines.

Jan 1, 1982

The Menominee Range of northern Michigan was a major producer of direct shipping iron ore for nearly a century. When the last underground mine on the Range ceased operation in 1978, it marked the end of an era. For since the start of mining in the early 1880's the district has gone through a Lull cycle from the start-up of mining through close-down. During this period over 200 million long tons of iron ore were produced and shipped from nearly 100 mining operations. This development and production spanned the time from when the United States advanced from an essentially rural-agriculatural society through the industrial revolution and into the beginnings of the computer and space age. There are many lessons that can be learned from such a rich history. This report attempts to provide ouch a lesson. Through the use of case histories, deficiencies in past mining practices and mine closure procedures that have resulted in current mine related problems are documented. These problems -an be grouped into three areas; 1) subsidence 2) hydrological or drainage problems and 3) problems related to inadequate mine shaft sealing and capping practices.

Jan 1, 1983

By George L. Gates

[When clays e.re mixe~ "Jith "~later to nake mud fluids f'ol' use in :irilling ','Iells "for oil and gar: h;:r vue :;'0 tary me thee. t 18 liquid mij~ tUl"es have certair.. phypicr..l characteri.",t.ics that vary ",dth t e Qlldlltit.y find]

Jan 1, 1941