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By Irvin Mayes, Maher E. Tadros

The effects of particle properties and dispersion on the filtration behavior of magnesiumhydroxide, silica, and polystyrene suspensions in aqueous media were examined. It was found that effective separation of particles can be achieved using filter media with larger pore diameters than the size of the particles. The addition of electrolytes, at concentrations lower than the critical coagulation concentration, to suspensions of polystyrene or silica resulted in an increase of the cake resistance. This result was interpreted in terms of a decrease in the effective particle size due to the increase in ionic strength. For magnesium hydroxide, an increase in the absolute value of the surface charge was associated with an increase in cake resistance and a decrease in cake compressibility. Low cake resistance values were obtained with suspensions of large particles with low surface charge and blocky morphology.

Jan 1, 1980

By W. E. Newberry

The Aspen Mining District is situated at the eastern edge of the system of stratified rocks of western Colorado, where this edge meets the ridge of metamorphic granite which divides the State into two unequal parts. In following the valley of the Roaring Fork westward from the continental divide towards Aspen, one passes through a country of granite and gneiss, with no sedimentary rocks until the town is nearly reached. At this point the Cambrian quartzites first make their appearance, lying on the granites, with a dip of from 30' to 45 to the northwest. Beyond these quartzites and conformably upon them lie dolomites, limestones, shales, porphyries and sandstones, gradually flattening in general dip as one proceeds westward, but much disturbed by local foldings and faultings.

Jan 1, 1890

By Raymond Brandon, Marshall Pease

A pattern for providing a large utility, The Detroit Edison Co., with an adequate fuel supply is outlined. From the standpoint of both fuel procurement and utilization, consideration has been given competition relationships, fuel properties as well as operating conditions that must be met to provide dependable service and reliable plant operation.

Jan 2, 1951

I SHALL proceed in this chapter to tell you about lead. Because this metal is overabundant in wateriness, and also because it has its other substances in poor elemental mixture, it is highly impure. It is called an imperfect, leprous, and little-fixed metal, which it clearly shows itself to be because of the ease of liquefying it and because it is easily converted largely into a dross that is almost earthy and also because of the stain that it leaves when it rubs against anything. Nevertheless, when we consider its effects, we judge it to be a metal that we are greatly indebted to. Even though Nature in creating us has put into our souls such a thirst and desire

Jan 1, 1942

By S. C. Lee

An uncoupled thermoviscoelastic finite element formulation with an application to Underground Coal Conversion (UCC) is presented. An incremental solution procedure with an implicit time stepping scheme is used under the thermorheologically simple material (TSM) postulate. The presented formulation, for a homogeneous and isotropic medium, is employed in the simulation of the UCC post-burn phase. Temperature, displacement, stress, and failure responses under thermomechanical loading are predicted. The solutions for the selected field problem indicate potential roof collapse, stress relaxation, and modest surface subsidence with a progressive thermal and failure front. The corresponding thermoelastic responses with temperature- dependent elastic properties are also presented and compared with the thermoviscoelastic results.

Jan 1, 1984

By John C. LaScola, David M. Hyman, William P. Diamond

The U.S. Department of the Interior, Bureau of Mines, has established a computer-implemented coalbed methane data base containing data representing over 2,000 coal samples from approximately 250 coalbeds located in 17 States and one Canadian Province. Space for approximately 130 sample characteristics is reserved for each sample record and is divided for access efficiency into three separate physical files. A software package was written to provide a user-friendly environment in which the three files can be manipulated simultaneously. These files can be used interactively in DATATRIEVE 11, a commercially available sorting, retrieval, and report-writing software package or in any FORTRAN-compatible system for statistical analysis. The data base has been established for coalbed methane research in response to the health and safety needs of the mining industry. Possible applications of the data base include mine planning related to the occurrence of gas, as well as delineating areas of resource recovery and utilization.

Jan 1, 1983

By Branko Ladanyi

In reviewing the current issues in rock mechanics, the author puts an' emphasis on problems related with the needs of extrapolation in scale and time, and of establishing proper conceptual models, especially in connection with the most recent large-scale and long-term projects such as underground disposal of nuclear waste. In such projects, where valid case histories will not be available for many years to come, the observational method can only be successful if combined with a proper framework approach, such as general rock mass classification systems and behavioral models.

Jan 1, 1982

By M. M. Fine

THE results of a research and development lab- oratory and pilot-plant mineral-dressing investigation by the Bureau of Mines of the complex copper-lead-cobalt-nickel ores of southeast Missouri are reported in this paper. This investigation, in cooperation with the National Lead Co., showed that separate concentrates of lead, copper, and cobalt-nickel could be made by fine grinding and flotation. An industrial plant built subsequently by the St. Louis Smelting and Refining Div. near Fredericktown, Madison County, Mo., produced such concentrates during the war years. Present commercial production at the mill is limited to lead and copper concentrates, but research to permit economic utilization of the cobalt and nickel values is continuing.

Jan 7, 1951

By I. E. Rosenzweig

GeophyGical prospecting by earth-resistivity methods is frequently applied to investigation of structural problems in geology. Fig. 1 indicates a scheme of the general arrangement used in these methods of measurements. The battery (or generator) E is connected with two "current electrodes" I1 and I2. The current of intensity J, supplied by this battery, passes through the earth between these elcc- trodes. A potential difference U will be measured between two other electrodes V1 and Vz, called "potential electrodes." According to the configuration of electrodes (Fig. I), the resistivity of a homogeneous soil results from the formula p — 2rca-j [1] where 1 C = -------------------------------------- a a 1 a a [2]

Jan 1, 1940

By Harry Huntington Miller

In spite of its recognized irregularities, the cyanide-assay for copper has always been popular among volumetric methods, being easy and rapid, and reasonably accurate when the solution tested contains nothing but pure copper and ammonium salts. In order to secure this condition, however, especially in operati~ig on low-grade ores, tailings and slags of complex composition, it is the practice to precipitate the copper from the ore-solution,—usually by means of metallic zinc or aluminum. The copper thus precipitated in the metallic form must be dissolved again; and the separa tion is never, in practice, complete, since an appreciable amount of the copper remains behind in the first solution, and the second solution always contains some of the other metals of the gangue; so that the result is at best but partially satisfactory. On the other hand, if this course is not pursued, but (as is

Jan 1, 1902

By H. T. Wyatt, A. S. Baptie

The Ten Section field is approximately 10 miles southwest of Bakers-field, Kern County, Calif. (Fig. 1). There is no surface evidence of the existence of the Ten Section structure, which subsurface exploration has shown to be a gently folded, anticlinal dome. Regionally, this field occurs as a fold in the deeper beds of the gently rolling floor of the San Joaquin Valley. It is on the easterly slope of the valley, its position with relation to the axis of this syncline not having been determined. The field was discovered by Shell Oil Co. with the completion of well Stevens A-l, on June 2, 1936, at a depth of 7888 ft. The location for this

Jan 1, 1938

By H. C. Juvkam-Wold

The aquifer depressurization system uses a number of wells surrounding a mine shaft to reduce the aquifer pressure in the vicinity of the shaft. The effect of various parameters such as number of wells, wellbore diameter, time, and well location is discussed. It is concluded that, with a properly designed depressurization system, the aquifer pressure and the water inflow rate to the shaft may be reduced to less than 15% of their potential values in the absence of wells.

Jan 1, 1983

Feb. 5. Society for Applied Spectroscopy, 6 pm, supper, Tosca's; 8 pm, meeting, Socony-Vacuum Training Center, 63 Park Row, New York. Feb. 6, AIME, Chicago Section, Chicago Bar Assn., 29 S. La Salle St., Chicago. Feb. 18-21, AIME, annual meeting, Hotel Statler, New York. Feb. 19, Michigan College of Mining and Technology, alumni reunion, Skytop Room, Hotel Statler, New York. Feb. 21, AIME, Utah Section, Newhouse Hotel, Salt Lake City. Feb. 28, Bituminous Coal Research, Inc., annual meeting, Edgewater Beach Hotel, Chicago. Mar. 3-7, ASTM, spring meeting and committee week, Hotel Statler, Cleveland. Mar. 5, AIME, Chicago Section, Ladies' Night, Chicago.

Jan 1, 1952

Elected Died 1895 *ABBOTT, AI ATTHUR 1908 1882 *ABBOTT, ARTHUR V 1906 1903 * ADAMS, CHARLES C. 1905 1905 * ADAMS, WILLAMS 1909 1884 *ADDY, MATTHEW 1896 1889 * AKERS, WILLIAMS 1906 1894 *ALLEN R B 1896 1905 * ALLEN, R. SCOTT 1906 1874 *AMIOT, H 1892 1886 *AMSLER, CARL 1894 1895 *ÅNGSTROM, CARL 1901 1900 * ARLETT, GEORGE H 1906 1895 *ARMSTRONG, JOHN F 1898 1882 *ARNOLDS, HUGO 1886 1875 *ASHBURNER, CHARLES A 1889 1872 *ASIIBURNER, WILLIAM 1887 1883 *ATKINS, C M , JR 1885 1905 * AUSTEN, PETER T 1907

Jan 1, 1910

By Kenneth W. Kolthammer

Fundamentals of drying and the equipment used are reviewed. Dryers employed in the mineral industry include rotary dryers, fluid bed dryers, spray dryers, hearth dryers and rotary tray dryers. Concentrate characteristics, corresponding problems and handling methods are likewise discussed. Important factors include weighing and sampling, moisture content, market timetables, transportation availability and climatic conditions.

Jan 1, 1978

By H. Conrad, K. Janowski, G. Stone

The available data on the dynamics of plastic flow of sapphire indicate that the deformation rate in the temperature range .from 900° to 1700°C can be expressed either as A number of investigators1-10 have established that sapphire deforms plastically above 900°C, the most common mode of deformation being slip on the basal plane in the [1120] direction. Under certain conditions and at temperatures above 1500°C, slip

Jan 1, 1965

By S. R. Rao

Interaction of potassium amyl xanthate with pyrrhotite has been studied thermochemically. Heats of adsorption of xanthate on unactivated mineral and the mineral activated with cupric ions have been compared with heats of reactions between potassium amyl xanthate and ferrous and cupric salts. It is shown that xanthate is consumed by stoichiometric exchange with anions present at the mineral surface. The floatability of the unactivated mineral is poor since xanthate is precipitated in bulk without creating a hydrophobic surface on the mineral. At the activated mineral surface, xanthate is adsorbed in certain isolated patches (active spots) and thereby creates a hydrophobic surface. The hydrophobicity of the mineral is greatly improved by lowering the pH to 4.5.

Jan 1, 1972

By F. Windolph

There are no hard and fast rules for building tailing dams, and each case has to be analyzed individually because of special conditions encountered at each location. Certain criteria are used for building dams at Climax, Colo., where they must be placed in rather steep mountain valleys on foundations that are practically impermeable. The tailing is relatively coarse, and a coarse fraction stays near the berm where it is deposited, while most of the fines flow with the water to the pool. Thirty years experience has led to certain design for toe dams, decanter lines and towers and tailing dams. A new tailing disposal area, started at Climax in 1958, will ultimately have a height of 495 ft and impound about 300 million tons. The following applies to the construction of this new tailing area.

Jan 11, 1961

By Howard N. Hall

The compressibility of reservoir rock is a factor which is generally neglected in reservoir engineering calculations. This is due in part to the fact that there is little published information on rock compressibility values for limestones and sandstones. Omission of rock compressibility is undoubtedly justified in calculations for saturated reservoirs; however, in under-saturated reservoirs,* expansion of the rock accompanying decline in the reservoir pressure may be of such magnitude as to affect materially the prediction of reservoir performance. The effect of rock compressibility will be of most importance in: (1) calculation of oil in place by pressure decline data in undersaturated volumetric reservoirs when the limits of the field are unknown or indefinite, and (2) studies of natural water drive performance. To estimate its importance in such cases, a series of laboratory tests were made to obtain usable values for reservoir rock compressibility. The total, or effective, compressibility of any reservoir rock is a result of two separate factors, namely, expansion of the individual rock grains, as the surrounding fluid pressure de-

Jan 1, 1953

By Alvin L. Langstaff, Harold D. Raymond

The design of entry systems and mining panels in room-and-pillar oil shale mines seeks to optimize extraction while ensuring both short- and long-term stability of mine openings. Important criteria for optimization include the definition of allowable roof spans and minimum pillar dimensions. Factors considered pertinent to the design of roof spans and pillars are discussed in this paper. They include, but are not limited to, physical properties and grade of the oil shale, depth of burial, presence and frequency of partings and joints and adverse effects of blasting. Also discussed briefly are some of the ventilation and production considerations in mine design.

Jan 1, 1984