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Electrochemistry of Thiobacillus ferrooxidans reactions with pyrite

Description: The objective of this project is to provide the fundamental information on the mechanisms of bacterial leaching of pyrite. The knowledge of how bacterial leaching of pyrite functions is essential for design and development of a technology for coal cleaning with bacteria. The features of major electrochemical techniques will be examined to find out if any of them can provide a diagnostic information on the mechanisms of related reactions.
Date: January 1, 1992
Creator: Pesic, B.
Partner: UNT Libraries Government Documents Department
open access

Phosphate-bonded glass cements for geothermal wells. Final report

Description: Calcium aluminosilicate glasses were found to react with phosphoric acid in three ways depending upon silica content. Above 55% SiO/sub 2/ they are insoluble while below 50% they dissolve readily. The transition compositions release calcium and aluminum ions and a silica gel phase replaces the glass. Activation energies in the order of 10 kcal/mole are associated with the dissolution. Equilibrium studies in the systems CaO-P/sub 2/O/sub 5/-H/sub 2/O, Al/sub 2/O/sub 3/-P/sub 2/O/sub 5/-H/sub 2/O… more
Date: September 1, 1979
Creator: Rockett, T.J.
Partner: UNT Libraries Government Documents Department
open access

Optical properties of flyash

Description: The general aims of this research are to provide a fundamental scientific basis for the physical understanding and reliable calculation of heat transfer in coal combustion systems, particularly as it is influenced by the presence of inorganic constituents deriving from mineral matter in coal. (VC)
Date: April 1, 1992
Creator: Self, S.A.
Partner: UNT Libraries Government Documents Department
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Waste Treatment and Disposal Progress Report for June and July 1961

Description: 7 7 6 4 : 9 8 9 6 5 : 9 aluminum nitrate waste was calcined in the close-coupled continuous evaporator-pot calciner unit. Waste oxides from TBP-25 waste were incorporated into glassy materials after the addition of phosphate and borate fluxing agents. Melts formed at 850 to 950 deg C were glassy solids when cooled and had densities from 2.41 to 2.47 g/ml. Waste volurne reduction factors were from 7.6 to 9.3. Low-Level Waste Treatment. A demonstration run was completed in the 60 liters/hr scaven… more
Date: October 24, 1961
Creator: Blanco, R. E. & Struxness, E. G.
Partner: UNT Libraries Government Documents Department
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Oxidation/gasification of carbon residue on retorted oil shale. Final report

Description: Studies of the oxidation and gasification of oil shale char were extended to an investigation of the effects of mineral catalysis. Six shales with differing mineral compositions were studied, including samples from the saline zone in the Western Colorado and from the Antrim shales of Michigan. Oxidation kinetics data, corrected for mass transfer effects, were compared for all six samples. A high assay shale from Utah and a sample from the saline zone were found to have the highest oxidation rat… more
Date: January 16, 1984
Creator: Thomson, W. J.
Partner: UNT Libraries Government Documents Department
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Control of pyrite surface chemistry in physical coal cleaning

Description: The successful separation of pyrite from coal by flotation is dependent to a large extent upon the selectivity of the process, and the use of a pyrite depressant is one of the most important and cost-effective techniques for achieving this. This report evaluates the effects of three factors on the floatability of pyrite. These are (1) the superficial oxidation of pyrite, (2) the contamination of pyrite surfaces by carbonaceous matter, and (3) pulp redox potentials. XPS (x-ray photoelectron spec… more
Date: June 24, 1992
Creator: Luttrell, G. H.; Yoon, R. H. & Ou, Z. S.
Partner: UNT Libraries Government Documents Department
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Exploratory research on solvent refined coal liquefaction. Annual technical progress report, January 1-December 31, 1979

Description: This report summarizes the progress of the Exploratory Research on Solvent Refined Coal Liquefaction project by The Pittsburg and Midway Coal Mining Co.'s Merriam Laboratory during 1979. In a series of experiments with varying feed gas composition, low levels (5 to 10 mole %) of carbon monoxide had little effect on the SRC II processing of Pittsburgh Seam coal (Powhatan No. 5 Mine) while higher levels (20 to 40 mole %) resulted in a general degradation of operability and reduced oil yields. Add… more
Date: September 1, 1980
Partner: UNT Libraries Government Documents Department
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Multielement analysis of geologic materials by inductively coupled plasma-atomic emission spectroscopy

Description: Atomic emission spectroscopy using an inductively coupled plasma (ICP) source permits the rapid acquisition of multielement geochemical data from a wide variety of geologic materials. Rocks or other solid samples are taken into solution with a four acid digestion procedure and introduced directly into the plasma; fluid samples are acidified or analyzed directly. The entire process is computer-controlled, fully-automated, and requires less than five minutes per sample for quantitative determinat… more
Date: March 1, 1980
Creator: Christensen, O.D.; Kroneman, R.L. & Capuano, R.M.
Partner: UNT Libraries Government Documents Department
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Investigations of the Natural Fission Reactor Program. Progress report, October 1976--September 1977

Description: During Fiscal Year 1977, efforts of the Natural Fission Reactor Program have been directed toward (1) further measurements and predictions of reactor product migration at Oklo, (2) uraninite solubility studies, (3) radiogenic equilibria studies of natural Pu, Ra, and Th in U ores, (4) search for evidence of other natural fission reactors, and (5) supportive analytical measurements and procedures development.
Date: November 1, 1977
Creator: Apt, K.E. (ed.)
Partner: UNT Libraries Government Documents Department
open access

Removal of silica from Raft River geothermal water

Description: Lack of sufficient quantities of clean surface or near-surface water at Raft River for cooling purposes dictates that cooled geothermal fluid, effluent from the Raft River 5 MW(e) Pilot Power Plant, must also be used as condenser coolant. Prior testing revealed that a water-treatment system would be required to reduce silica and calcium concentrations of the cooling fluid. The water-treatment system specified was to use dolomitic lime for both pH adjustment and source of magnesium. The dolomiti… more
Date: June 1, 1980
Creator: Suciu, D. F. & Miller, R. L.
Partner: UNT Libraries Government Documents Department
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Theoretical study of the structure, energetics, and dynamics of silicon and carbon systems using tight-binding approaches

Description: Semiempirical interatomic potentials are developed for silicon and carbon by modeling the total energy of the system using tight-binding approaches. The parameters of the models were obtained by fitting to results from accurate first-principles Local Density Functional calculations. Applications to the computation of phonons as a function of volume for diamond-structured silicon and carbon and the thermal expansions for silicon and diamond yields results which agree well with experiment. The ph… more
Date: October 25, 1991
Creator: Xu, Chunhui.
Partner: UNT Libraries Government Documents Department
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Studies in Coal Liquefaction with Application to the SRC and Related Processes. Final Report, November 1978-September 1983

Description: The objective of this research program is to systematically investigate, characterize, and delineate the effects of changes in process operating conditions, equipment configuration, and nature of raw materials upon the kinetics, mechanism, and extent of coal dissolution, heteroatom removal, and hydrogenation in the SRC and closely related processes, for the purpose of providing an increased fundamental understanding of SRC process chemistry as well as guidelines and recommendations leading to e… more
Date: January 1, 1983
Creator: Tarrer, A. R.; Guin, J. A. & Curtis, C. W.
Partner: UNT Libraries Government Documents Department
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Studies on transition metals and alloy Fischer-Tropsch catalysts, their electronic and bulk properties. (I: Fe/MnO; II: Fe/TiO/sub 2/; III: Fe/Mord. ). Final report, July 1, 1982-September 30, 1983

Description: The objectives were: (1) to characterize samples D1, 10% FeO/90% MnO, and D2, 48% FeO/52% MnO, under varying conditions of reduction (at 250/sup 0/C or 350/sup 0/C in H/sub 2/) and of syngas reaction 1:1 of CO:H/sub 2/ at 290/sup 0/C) and in some cases use CO only for reduction and to identify species by Moessbauer Spectroscopy and Magnetization (sigma/sub s) measurement; (2) similarly, to see if there is any metal (oxide)/support (Mordenite) interaction by the same techniques. The characteriza… more
Date: November 1, 1983
Creator: Mulay, L.N.
Partner: UNT Libraries Government Documents Department
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Alternate materials of construction for geothermal applications. Progress report No. 14, July--September 1977

Description: A program to determine if non-metallic materials such as polymers, concrete polymer composites, and refractory cements can be utilized as materials of construction in geothermal processes is in progress. To date, several high temperature polymer concrete systems have been formulated, laboratory and field tests performed in brine, flashing brine, and steam at temperatures up to 260/sup 0/C (500/sup 0/F), and economic studies started. Laboratory data for exposure times > 2 years are available. Re… more
Date: September 1, 1977
Creator: Kukacka, L. E.; Fontana, J.; Zeldin, A.; Sugama, T.; Horn, W.; Carciello, N. et al.
Partner: UNT Libraries Government Documents Department
open access

Study of rock-water-nuclear waste interactions in the Pasco Basin, Washington: Part II. Preliminary equilibrium-step simulations of basalt diagenesis

Description: Interactions between a large number of complex chemical and physical processes have resulted in significant changes in the Pasco Basin hydrochemical system since emplacement of the first basalt flow. In order to perform preliminary simulations of the chemical evolution of this system, certain simplifying assumptions and procedures were adopted and a computer model which operates on the principal of local equilibrium was used for the mass transfer calculations. Significant uncertainties exist in… more
Date: August 1, 1980
Creator: Benson, L. V.; Carnahan, C. L. & Che, M.
Partner: UNT Libraries Government Documents Department
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Physical characterization of magmatic liquids. [Ultrasonic and Brillouin Scattering Studies of Natural and Synthetic Silicates and Oxides]

Description: This report describes a research project that was conducted from August 15, 1985 to February 28, 1992. The project was based on the ultrasonic studies of natural and synthetic silicate melts, and the study of Brillouin scattering of synthetic silicates and oxides. Measurements of the compressional wave velocity and attenuation can be established using the ultrasonic methods. Temperature dependences of silicates can be established by the Brillouin scattering. (MB)
Date: June 5, 1992
Creator: Manghnani, M.H.
Partner: UNT Libraries Government Documents Department
open access

Silicon ingot casting: Heat Exchanger Method (HEM)/multi-wire slicing: Fixed Abrasive Slicing Technique (FAST), Phase IV. Quarterly progress report No. 2, April 1, 1980-June 30, 1980

Description: Silicon ingot size cast by HEM has been extended to 34 cm x 34 cm x 10 cm. A 20 kg ingot has been solidified at 3 kg/hr with no crucible attachment or ingot cracking problems. Another ingot of 26 kg weight has also been solidified. The heat treatment used to develop a graded structure caused cracking on the inside surface of the first large crucibles. The thermal conditions were altered to minimize high gradients and the cracking was eliminated. A high degree of single crystallinity has been ma… more
Date: August 1, 1980
Creator: Schmid, F.; Khattak, C.P. & Basaran, M.
Partner: UNT Libraries Government Documents Department
open access

Evaluation of an optical microscope method for coal-pyrite/marcasite differentiation

Description: A reflected-polarized light microscope technique for coal marcasite-pyrite differentiation is detailed. Presence of the two minerals was verified by x-ray diffraction analysis. The optical technique produced marcasite content values that were consistently lower than those measured by x-ray diffraction. Although the optical technique produces data that are at best semi-quantitative, it can be used to approximate (+-20%) marcasite concentration in coal without a heavy mineral concentration step.
Date: May 1, 1980
Creator: Sanner, Jr, W. S. & Meteney, D. L.
Partner: UNT Libraries Government Documents Department
open access

Effects of temperature on the absolute permeability of consolidated sandstone

Description: The effect of temperature on absolute permeability has been a point of disagreement in the petroleum literature for many years. Recent work at Stanford University has shown no dependence on temperature of the absolute permeability to water of unconsolidated sand cores. The objective of this report is to extend the investigation to consolidated sandstone by following similar experimental procedures and observing whether any temperature effects exist. Fontainebleau sandstone was chosen as the cor… more
Date: April 1, 1984
Creator: McKay, W.I. & Brigham, W.E.
Partner: UNT Libraries Government Documents Department
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Effect of cation exchange on the subsequent reactivity of lignite chars to steam. [108 references]

Description: The purpose of this investigation is to determine the role which cations in coal play in the subsequent reactivity of chars. It is hoped that this investigation will aid in an understanding of the catalytic nature of inorganic constituents in coal during its gasification. It was found that increased heat treatment temperature decreased reactivity. The decrease in reactivity was shown to be due, at least in part, to the changes in the nature of the cation with increased heat treatment temperatur… more
Date: March 1, 1977
Creator: Hippo, E. J. & Walker, Jr., P. L.
Partner: UNT Libraries Government Documents Department
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