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in subjects: "Sulfide Minerals"

open access

Electrochemistry of Thiobacillus ferrooxidans reactions with pyrite

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.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Massive sulfide deposits and hydrothermal solutions: incremental reaction modeling of mineral precipitation and sulfur isotopic evolution

Incremental reaction path modeling of chemical and sulfur isotopic reactions occurring in active hydrothermal vents on the seafloor, in combination with chemical and petrographic data from sulfide samples from the seafloor and massive sulfide ore deposits, allows a detailed examination of the processes involved. This paper presents theoretical models of reactions of two types: (1) adiabatic mixing between hydrothermal solution and seawater, and (2) reaction of hydrothermal solution with sulfide… more

Date: January 1, 1986

Creator: Janecky, D.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

CaO interaction in the staged combustion of coal

The LIMB (limestone injection multi-stage burner) process offers special potential for reducing NO/sub x/ and SO/sub x/ by at least 50 percent in coal combustion. This is to be accomplished by adding limestone with fuel and/or air in a low NO/sub x/ burner. This program has been directed to defining the chemistry and kinetics necessary to optimize sulfur capture in LIMB combustion. More specifically, this program has attempted to clarify the role of calcium sulfide in LIMB chemistry. When limes… more

Date: December 19, 1983

Creator: Levy, Arthur; Merryman, Earl L. & Rising, Bruce W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Surface electrochemical control for fine coal and pyrite separation

This technical progress report, prepared in accordance with the reporting requirements of DOE Project No. DE-AC22-89PC89758, covers the work performed from April 1, 1991 to June 30, 1991. The ongoing work includes the characterization of coal pyrites, the floatability evaluation of three typical US coal samples, the flotation behavior of coal pyrites, the electrochemical measurement of the surface properties of coal pyrites, and the characterization of species produced at pyrite surfaces. 6 ref… more

Date: January 1, 1991

Creator: Hu, Weibai; Huang, Qinping; Riley, A.; Zhu, Ximeng; Bodily, D. M.; Liang, Jun et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced coal liquefaction research. Quarterly technical progress report, July 1, 1983-September 30, 1983

Work this quarter focused on staged liquefaction. The effect of residence time on conversion in single pass experiments was found to be quite different for the subbituminous Belle Ayr Mine and bituminous Illinois No. 6 coals studied. With bituminous coal, conversion to soluble material is quite high and the limit of conversion is approached in only a few minutes. With a subbituminous coal, however, conversion is much lower and the limit of conversion is approached much more slowly. Short contac… more

Date: April 1, 1984

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Separations innovative concepts: Project summary

This project summary includes the results of 10 innovations that were funded under the US Department's Innovative Concept Programs. The concepts address innovations that can substantially reduce the energy used in industrial separations. Each paper describes the proposed concept, and discusses the concept's potential energy savings, market applications, technical feasibility, prior work and state of the art, and future development needs.

Date: May 1, 1988

Creator: Lee, V.E. (ed.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Mild coal gasification: Product separation, pilot-unit support, twin screw heat transfer, and H sub 2 S evolution

Our general objective is to further the development of efficient continuous mild coal gasification processes. Our efforts this year have been in four main areas. A new thrust has been to identify and develop efficient processes to separate the vapor product stream into particulate-free liquid and mist-free gas. We continued work aimed at predicting heat transfer rates (hence throughput) in externally-heated twin-screw pyrolyzers. We sought to provide technical support for the design, installati… more

Date: August 9, 1991

Creator: Camp, D. W.; Wallman, P. H. & Coburn, T. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Perform research in process development for hydroretorting of Eastern oil shales: Volume 2, Expansion of the Moving-Bed Hydroretorting Data Base for Eastern oil shales

An extensive data base was developed for six Eastern oil shales: Alabama Chattanooga, Indiana New Albany, Kentucky Sunbury, Michigan Antrim, Ohio Cleveland, and Tennessee Chattanooga shales. The data base included the hydroretorting characteristics of the six shales, as well as the retorting characteristics in the presence of synthesis gas and ionized gas. Shale gasification was also successfully demonstrated. Shale fines (20%) can produce enough hydrogen for the hydroretorting of the remaining… more

Date: November 1, 1989

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Coal surface control for advanced physical fine coal cleaning technologies

The overall objective of the project is to develop techniques for coal surface control prior to the advanced physical fine coal cleaning process of selective agglomeration in order to achieve 90% pyrite sulfur rejection at an energy recovery greater than 90% based on run-of-mine coal. The surface control is meant to encompass surface modification during grinding and laboratory beneficiation testing. The project includes the following tasks: Project planning, method for analysis of samples, deve… more

Date: January 1, 1991

Creator: Morsi, B. I.; Chiang, S. H.; Sharkey, A.; Blachere, J.; Klinzing, G.; Araujo, G. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Volume 2

This report presents the results of further research on the groundwater geochemistry of 96 well waters in two uraniferous aquifers in Texas and Wyoming, and is a continuation of the work presented by Chatham et al. (1981). In this study variations in concentrations of U, As, Mo, Se and V were compared with the saturation state of the groundwater with respect to mineral phases of these elements known or expected to occur in each area. The non-radiogenic trace elements exhibited strong redox depe… more

Date: August 1981

Creator: Wanty, R. B.; Langmuir, D. & Chatham, J. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Characteristics of American coals in relation to their conversion into clean-energy fuels. Final report. [1150 samples of US coals]

To further characterize the Nation's coals, the Penn State Coal Sample Bank and Data Base were expanded to include a total of 1150 coal samples. The Sample Bank includes full-seam channel samples as well as samples of lithotypes, seam benches, and sub-seam sections. To the extent feasible and appropriate basic compositional data were generated for each sample and validated and computerized. These data include: proximate analysis, ultimate analysis, sulfur forms analysis, calorific value, macera… more

Date: June 1, 1982

Creator: Spackman, W.; Davis, A.; Walker, P. L.; Lovell, H. L.; Vastola, F. J.; Given, P. H. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Fine particle clay catalysts for coal liquefaction

The efficient production of environmentally acceptable distillate fuels requires catalysts for hydrogenation and cleavage of the coal macromolecules and removal of oxygen, nitrogen, and sulfur heteroatoms. The goal of the proposed research is to develop new catalysts for the direct liquefaction of coal. This type of catalyst consists of fine clay particles that have been treated with reagents which form pillaring structures between the aluminosilicate layers of the clay. The pillars not only ho… more

Date: January 1, 1991

Creator: Olson, E.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Control of pyrite surface chemistry in physical coal cleaning

To better understand the flotation behavior of coal pyrite, studies have been initiated to characterize the floatability of coal pyrite and mineral pyrite. The hydrophobicity of coal material pyrite was examined over a range of pH and oxidation times. The results indicate that surface oxidation plays an important role in coal and mineral pyrite hydrophobicity. The hydrophobicity of mineral pyrite decreases with increasing oxidation time (20 min. to 5 hr.) and increasing pH (pH 4.6 to 9.2), with… more

Date: January 17, 1990

Creator: Luttrell, G. H.; Yoon, R. H.; Zachwieja, J. & Lagno, M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Influence of chemical characterization of oil shale solids on understanding water quality impacts

Synfuels technologies will yield products and effluents that are a function of the raw material being processed and the process variables. Chemical and mineralogic characterization of solids generated in synfuels production provide valuable insight into health and environmental impacts associated with synfuels processing (coal liquefaction or gasification and shale oil extraction). This report deals with considerations relating to leachate generation from solid wastes, but the suggested researc… more

Date: January 1, 1981

Creator: Peterson, E. J. & Wagner, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Sulfur and ash reduction potential and selected chemical and physical properties of United States coals. [Contains glossary]

This report presents the washability and comprehensive characterization results of 184 raw coal channel samples, including anthracite, bituminous and lignite coals, collected from the Central Region of the United States. This is the second of a three volume report on the coals of the United States. All the data are presented in six appendices. Statistical techniques and definitions are presented in Appendix A, and a glossary of terms is presented in Appendix B. The complete washability data and… more

Date: February 1, 1991

Creator: Cavallaro, J.A.; Deurbrouck, A.W.; Killmeyer, R.P.; Fuchs, W. (USDOE Pittsburgh Energy Technology Center, PA (USA). Coal Preparation Div.) & Jacobsen, P.S. (Burns and Roe Services Corp., Pittsburgh, PA (USA))

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Exploratory research on solvent refined coal liquefaction. Quarterly technical progress report, January 1, 1980-March 31, 1980

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 for the period January 1, 1980 through March 31, 1980. A series of experiments was conducted with three western coals to study the relationship between coal properties and liquefaction behavior. All three coals were low in iron (0.2 to 0.4%, dry coal basis) and processing in both the SRC I and SRC II modes does not appear t… more

Date: January 1, 1982

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Engineering development of selective agglomeration: Task 7, Evaluation of bench-scale and component tests

This report presents the Task 7 findings of the project entitled Engineering Development of Selective Agglomeration'' to develop selective agglomeration technology to a commercially acceptable level by 1992. The objectives of this report are to summarize the work completed as a part of Task 7, which includes engineering analysis of process deficiencies, analysis of all project test results, and evaluation and selection of an agglomeration process for further development in Phase II. Other objec… more

Date: November 1, 1991

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion

The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important ope… more

Date: October 1, 1991

Creator: Akan-Etuk, A.; Diaz, R. & Niksa, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Fine particle clay catalysts for coal liquefaction

Date: January 1, 1991

Creator: Olson, E.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Investigation of pyrite as a contributor to slagging in Eastern bituminous coals. Quarterly progress report, October 1, 1981-February 28, 1982

Slagging by bituminous eastern US coals in industrial furnaces results primarily from pyritic iron in the coal ash. Since it has been learned that coals of similar pyritic levels fired in furnaces of similar design do not always produce the same slagging conditions, and since segregation of pyrites from other minerals does occur when slagging is encountered, slagging must be attributed to the size and orientation of the pyrites in the coal, in addition to their concentration level. A program is… more

Date: March 1, 1982

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Relationship Between Pyrite Formation and Organic Sulfur Content of Coal as Revealed by Electron Microscopy

There are a large number of questions concerning the mode of occurrence of organic sulfur in peat, and what, if anything, alters its occurrence during and after coalification. The formation of pyrite during periods of peatification and coalification has been hypothesized to have a great effect on the organic sulfur content of organic material surrounding the pyrite. Measurement of organic sulfur contents at different distances from pyrite particles would serve as direct experimental proof for o… more

Date: January 1, 1982

Creator: Raymond, Robert Jr. & Hagan, Roland C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pyrite oxidation in saturated and Unsaturated Porous Media Flow: AComparison of alternative mathematical modeling approaches

Pyrite (FeS{sub 2}) is one of the most common naturally occurring minerals that is present in many subsurface environments. It plays an important role in the genesis of enriched ore deposits through weathering reactions, is the most abundant sulfide mineral in many mine tailings, and is the primary source of acid drainage from mines and waste rock piles. The pyrite oxidation reaction serves as a prototype for oxidative weathering processes with broad significance for geoscientific, engineering,… more

Date: February 15, 1998

Creator: Xu, Tianfu; White, Stephen P. & Pruess, Karsten

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Coal surface control for advanced physical fine coal cleaning technologies

Research continued on surface control of coal. This report describes Task 7 of the program. The following topics are discussed: quantitative distribution of iron species; surface functional groups; comparison of wet and dry ground samples; study of Illinois No. 6 coal wet ground using additives; study of wet grinding using tall oil; elemental distribution of coal samples wet ground without additives; elemental distribution of coal samples wet ground with tall oil; direct determination of pyrite… more

Date: January 1, 1990

Creator: Morsi, B.I.; Chiang, S-H.; Sharkey, A.; Blachere, J.; Klinzing, G.; Araujo, G. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Electrochemistry of Thiobacillus ferrooxidans reactions with pyrite

Date: January 1, 1990

Creator: Pesic, B. & Oliver, D. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department