Search Documents

By David G. Chedgy

The Meadow River No. 1 preparation plant, owned by Sewell Coal Co. which is a subsidiary of the Pittston Co., was commissioned in the spring of 1974. A survey of the environmental noise levels was conducted, and the dominant noise sources identified. An engineering program was initiated to reduce the prevailing levels to a point that the operator's exposure would be within compliance with the MESA regulation for ear protection. The program was continued until compliance was achieved and the attenuation factors for each abatement device recorded. The highlights of this program will be presented with a discussion of the practicality of the devices utilized.

Jan 1, 1977

By Stanley M. Miller

For rock or soil materials assumed to be generally isotropic and homogeneous, seepage theory and analytic geometry can be used to develop a mathematical technique for estimating the steady state, pie-zometric drawdown to a slope face. The resulting parabolic drawdown curve is a function of slope angle and the height of the original water table above the slope toe. When the slope is cut at a rate faster than that which allows a steady state to be attained, a non- steady state analysis approximates the transient drawdown. Monte Carlo simulation provides realizations of possible drawdown curves that can be included in slope stability risk analyses.

Jan 1, 1983

By David L. Pentz

ABSTRACT A critical summary is given of the analytical procedures available to the engineer for the analysis of slope stability. The emphasis is on the various types of behaviour that have been measured in different rock types. A method of assessing the possibility of failure of simple three dimensional wedges is provided in an attempt to demonstrate how structural features can be included in a meaningful manner. An outline for theoretical design is provided that stresses the importance of carrying out a 'Back Analysis' of large and small instrumented failures so that realistic parameters of the rock mass forming the pit slopes can be obtained.

Jan 1, 1971

By R. M. Schuller, J. J. Suloway, W. F. Childers, R. A. Griffin, S. J. Russell

Seven solid wastes from coal conversion processes were characterized chemically and mineralogically. The wastes included three Lurgi gasification ashes, two liquefaction residues (SRC and H-coal), a fly ash, and a water-quenched slag. Leachates generated from the solid wastes at various pH levels over the range 2.5 to 11.0 were analyzed for over 40 constituents. Results of the leachate analyses demonstrate the wide variation in constituent solubility for the solid wastes. To help assess the environmental impact of the disposal of these wastes, the leachates were also employed in soil attenuation studies and acute 96-hr static bioassays using young fathead minnows.

Jan 1, 1981

By John Birkinbine

Forty years ago, when the first shipments of iron-ore were made from the Lake Superior region, the supply for the blastfurnaces active at that date was in most cases a local consideration ; the majority of the smelting-plants being close to the oremines. Of those which depended in whole or in part upon ores brought from distances greater than an economical wagonhaul, few obtained supplies by canal or railroad from points 50 miles removed. At the present time the ore-supply is a local consideration for but a small proportion of American blast-furnaces, and 700 miles or more separate a greater num-

Jan 1, 1898

By R. S. Dean

AMONG naturally occurring inorganic compounds, magnetite has many unusual and interesting properties, and it is the purpose of this paper to call attention to these properties and review possible uses of magnetite that might be based on them; in other words, to see what uses may be found for magnetite as a physical rather than as a chemical entity, as a mineral rather than as an iron ore. The Mineral Physics Studies initiated in the Metallurgical Division of the U. S. Bureau of Mines a few years ago gathered together much information on mineral properties, and they are therefore the principal source of material for this paper.

Jan 1, 1937

By H. A. Hamza, N. E. Andersen

Emulsions have long occupied an important position in many industries. In the petroleum industry, where enhanced oil recovery techniques such as steam stimulation, flooding, etc. are being increasingly practiced, emulsions are very frequently produced. Characterization of these emulsions are an important prerequisite for monitoring and evaluation of the recovery processes. Emulsion properties will also determine the type of treatment required to separate and recover the oil phase. A variety of laboratory, pilot-scale and field-generated emulsions were characterized. Coulter technique results for size analysis are compared with microscopy (image analysis) and laser light scattering methods; Coulter determined oil contents are compared with gravimetric and volumetric methods of analysis.

Jan 1, 1980

By J. A. Herbst, D. W. Fuerstenau

The effect of mill speed and ball load on the dry ball milling of dolomite is examined in the context of the batch grinding model. Observed changes in the parameters of the model are interpreted, as far as possible, in terms of the mechanics of particle motion in the mill. A parameter estimation scheme previously proposed by the authors is shown to provide the basis for a successful simulation of grinding behavior over a wide range of mill speeds and ball loads. Finally, a combination of experimental and simulated results is used to determine the optimum mill speedball load for closed circuit grinding in this mill-material system.

Jan 1, 1973

Welfare endeavor in connection with both the metal and the coal mines of Utah has shown gratifying progress during recent years and both the operators and their employees are deserving of much credit for the efforts put forth to better living, working, educational and receational conditions in most of the mining camps of the state. In the older metal mining camps of Utah, where the towns are incorporated and independent of the mining properties operating in the vicinity, less opportunity is presented for the companies to exercise efforts looking towards improved welfare conditions than is the case of camps located on company ground and under the full control of operators.

Jan 1, 1925

By James W. Baxter

Underground mining of limestone is becoming increasingly practicable in Illinois. Most quarries are near rivers on the western and southern borders where competition for land use is intensive. Increasing demands for stone can be met by expanded mining with access by adits in existing quarries and by inclines and shafts at downdip sites. Geologic, hydrologic, and engineering conditions indicate that deep mines in the Ste. Genevieve, Salem, Ullin, and basal Burlington limestones of Mississippian age and in the Moredock member of the Dunleith formation of Ordovician age are particularly feasible, but development will require prudent exploration and planning to ensure that the product will be of good quality.

Jan 1, 1981

By Walter von der Linden

A description is presented of the mining conditions of four longwall shield type support installations in the Pittsburgh seam in northern West Virginia and southwestern Pennsylvania. Details of roof control and operating procedures, production and performance data, and equipment description and basic engineering specifications are given for these four longwall installations. The range of mining heights was between 150 and 250 cm (60 and 95 in.). The major accomplishment of the shield supports in all four faces was the provision of an almost 100% availability for coal cutting; i.e., the face-down time due to roof control problems and support maintenance requirements was minimal.

Jan 1, 1978

By J. C. Draper, R. J. Houston, R. E. Pepperman

Duquesne Light Co. and CAI Consultants, Inc. conducted a demonstration program to establish permanent vegetative cover directly on acidic, deep coal mine refuse. Several plots were treated with formulas varying in soil amendment application rates and plant speak. Periodic monitoring of refuse chemistry indicated when maintenance applications of seed and soil amendments were required. To establish drainage control, the site had to be regraded. The most successful experimental formula was used as the bank for the formula applied to regraded portions of the site. Specific treatment for acidic spots has been initiated. Results of the program indicate that adequate permanent vegetation has been established.

Jan 1, 1985

By Fred K. Stieler

The largest updraft sinter machine built has a roasting area of 132 sq.m. Sinter machines with an area of over 200 sq.m. are under consideration. These large machines require new techniques with regard to drive thrust and sealing mechanism. To optimize the results of sinter plants, the charge preparation systems and the return fines circuits were improved. Special crushers were developed for crushing return sinter of up to 800 ºC to a size of minus 6 mm. Strand cooling of Pb-sinter was investigated. Different methods for plant ventilation were compared. New processes, which might replace sintering in the future, are in the stage of large - scale testing.

Jan 1, 1977

By Peter B. Nalle

Over a period of years the Crestmore plant of the Riverside Cement Co. has been supplied with limestone from the Chino limestone bed. The limestone bed dips about 40º and extends 1500 ft along the strike. Thickness of the bed is such that horizontal distance from footwall to hanging wall varies from 400 to 1200 ft. When the new room and pillar mining system was instituted the haulage units used for development were model C Tournarockers. Four of these diesel units were purchased with the idea of using them solely for development work since it was realized that they would have to be supplemented by additional, and perhaps larger haulers.

Jan 4, 1959

By Victor M. Braschi

The railroad history of Mexico began with the first presidential term of General Diaz. Concessions for the building of railroads had been granted in former years; indeed, an exclusive privilege was granted, August 22, 1837, to Francisco de Arrillaga for the construction of a railroad from Mexico to Vera Cruz, with a branch to Puebla, and other concessions were granted from then on at various periods; but the year 1877 was the real beginning of the regular and constant decelopment of the railways of Mexico. The programme laid out at that time by the new government, and responded to by the nation, was to develop its natural ele-

Jan 1, 1902

By Tell Ertl

THE term oil shale is defined. Foreign oil-shale developments are outlined briefly, The richest and most extensive oil-shale deposits in the United States lie in Western Colorado. The Bureau of Mines is opening two adjacent areas for underground mining in Western Colorado. From the first area the oil shale is mined selectively as required by the retorting plant. The second area is being developed as a unit of a full scale oil-shale mine to ascertain the most practical methods of mining oil shale and to determine costs. In both of these mining areas, research will be carried on to develop new and improved practices for mining oil shale.

Jan 1, 1947

By M. T. Simnad, G. Derge, Ling Yang

A method is described for using radioactive tracer for the direct determination of ionic mobility in a molten electrolyte. The ionic mobility of Fe" in silica-saturated iron silicate is found to be 0.0009 (*0.0002) cm2 sec ' volt L at 1250°C. eLECTROCHEMICAL studies', ' of molten iron eE oxide and iron silicates have shown some ionic conductivity at all compositions. The current efficiency in electrolysis increases with the concentration of silica to a maximum of 90 pct at about 34 pet SiO,. In the silica-saturated melts the transport number of ferrous ions is near unity, indicating that

Jan 1, 1957

By J. Marshall Downey

The most fortunately situated U. S. potash producer-whether in New Mexico, California, or Utah--once simply took from the ground a mixture of sodium chloride and potassium chloride, crushed it to a maximum of 10 mesh, and separated the two salts by physical methods. He piled the sodium chloride on the desert and sold the potassium chloride to fertilizer mixing companies. Seven companies in the Carlsbad basin of New Mexico now use at least three basic processes for making the separation and at least three more processes have been or are under investigation. In addition, two companies outside the basin use two methods for taking KC1 from natural brines

Jan 12, 1958

By Herbert Haas

1. INTRODUCTION COPPER matte is now converted into blister copper at a cost of only $5 per ton of copper, or, based on a 40 per cent. matte, $2 per ton of matte, which is the record of at least one large smelting Works; and it seems hardly likely that a further reduction, large enough to warrant, a change in existing practice, could be made in bessemerizing costs. But the new type of converter here described and the new practice proposed are intended, not so much for the treatment of mattes, as for the extension of, the process to the direct reduction in the copper-converter of pyrite ores

Jan 6, 1914

By Bruno V. Nordberg

The high cost of coal in Butte and the development of large amounts of cheap electric power from the Missouri river caused the Anaconda Copper Mining Co. in 1908 to make an investigation as to the possibility of adapt- ing this cheap electric power for the operation of their many large hoisting plants. At this time electric power had already been adopted for practically all other power purposes around the mines, such as pumping, compressing air, etc. The map (Fig. 1) shows the location of the mines of the Butte mining district. These mines are located within a circle of approximately a 1-mile

Jan 1, 1914