Semiconductor electrochemistry of coal pyrite. Technical progress report, July--September 1993
Pyrite (FeS{sub 2}) synthesis was studied in aqueous solution at room temperature and atmospheric pressure using ferric chloride (FeCl{sub 3}) and sodium hydrosulfide (NaHS) as reactants, and sodium hexametaphosphate ((NaPO{sub 3}){sub 6}) as dispersant and crystal growth modifier (to control the particle size of pyrite). The effects of the reaction pH and the concentrations of the reactants and the dispersant on the product characteristics were studied. The pH of the reaction system determines the chemical constitution of the products. Elemental sulfur is produced at pH 2.4. As pH increases, the reaction product becomes a mixture of elemental sulfur plus pyrite at pH 2.9. In the pH range of 3.6 to 5.7, pyrite is formed with a pseudospherical shape and a size of 2 {mu}m. With further increase in pH, amorphous iron sulfides are obtained. Lowering the concentrations of the reactants decreases the particle size of pyrite in the earlier stages of the reaction. However the final particles have the same size irrespective of the initial concentrations of the reactants used in the study. Addition of the dispersant can change the properties of the products. The mechanism of the dispersant action is currently under investigation, in an effort to minimize particle aggregation and produce discrete nanosize pyrite particles.
- Research Organization:
- Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG22-91PC91303
- OSTI ID:
- 10133580
- Report Number(s):
- DOE/PC/91303-T8; ON: DE94007998; TRN: 94:003660
- Resource Relation:
- Other Information: PBD: Nov 1993
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
PYRITE
CHEMICAL PREPARATION
ELECTROCHEMISTRY
CRYSTAL GROWTH
PROGRESS REPORT
PH VALUE
AQUEOUS SOLUTIONS
COAL
SEMICONDUCTOR MATERIALS
STRUCTURAL CHEMICAL ANALYSIS
400201
400400
010400
010800
CHEMICAL AND PHYSICOCHEMICAL PROPERTIES
PROCESSING
WASTE MANAGEMENT