Semiconductor electrochemistry of coal pyrite. Technical progress report, October--December 1992
This project seeks to advance the fundamental understanding of the physics-chemical processes occurring at the pyrite/aqueous interface, in the context of coal cleaning, coal desulfurization, and acid minedrainage. A novel approach to the study of pyrite aqueous electrochemistry is proposed, based on the use of both synthetic and natural ( i.e. coal-derived) pyrite specimens, the utilization of.pyrite both in the form of micro (i.e. colloidal and subcolloidal) and macro (i.e. rotating ring disk) electrodes, and the application of in-situ direct electroanalytical and spectroelectrochemical characterization techniques. The kinetic study of the reaction between sulfide and ferrous ions in solution suggested that the black species formed initially is FeHS{sup +} intermediate. To farther confirm this mechanism, the experiments aimed at establishing the stoichiometry for the intermediate were carried out thermodynamically with a stopped-flow spectrophotometric technique. The results showed that the mole ratio of H{sup {minus}}/Fe{sup 2+} is 1 to 1 for the intermediate product, which is in good agreement with the kinetic results previously obtained. Furthermore, the equilibrium constant for the reaction Fe{sup 2+} + H{sup {minus}} = FeHS{sup +} was determined as K = 10{sup 4.34}. The forward rate constant is 10{sup 3.81}(mol/l){sup {minus}1}sec{sup {minus}1} and the backward rate constant is 10{sup {minus}0.53} (mol/l){sup {minus}1} sec{sup {minus}1}.
- 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:
- 10143649
- Report Number(s):
- DOE/PC/91303-T5; ON: DE93012461
- Resource Relation:
- Other Information: PBD: Feb 1993
- Country of Publication:
- United States
- Language:
- English
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Semiconductor electrochemistry of coal pyrite. Technical progress report, January--March 1993
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
PYRITE
ELECTROCHEMISTRY
COAL
DESULFURIZATION
IRON COMPOUNDS
CHEMICAL REACTION KINETICS
SULFIDES
CLEANING
REACTION INTERMEDIATES
CATIONS
SPECTROPHOTOMETRY
PROGRESS REPORT
EXPERIMENTAL DATA
010300
400400
400201
PREPARATION
CHEMICAL AND PHYSICOCHEMICAL PROPERTIES