Pyrite surface characterization and control for advanced fine coal desulfurization technologies

Technical Report · Wed Jan 01 00:00:00 EST 1992

DOI:https://doi.org/10.2172/6649718· OSTI ID:6649718

Wang, X H; Leonard, J W; Parekh, B K; Jiang, C L

This is the 9th quarterly technical progress report for the project entitled Pyrite surface characterization and control for advanced fine coal desulfurization technologies'', DE-FG22-90PC90295. The work presented in this report was performed from September 1, 1992 to November 31, 1992. The objective of the project is to conduct extensive fundamental studies on the surface chemistry of pyrite oxidation and flotation and to understand how the alteration of the coal-pyrite surface affects the efficiency of pyrite rejection in coal flotation. During this reporting period, the surface oxidation of pyrite in various electrolytes was investigated. It has been demonstrated, for the first time, that borate, a pH buffer and electrolyte used by many previous investigators in studying sulfide mineral oxidation, actively participates in the surface oxidation of pyrite. In borate solutions, the surface oxidation of pyrite is tronly enhanced. The anodic oxidation potential of pyrite is lowered by more than 0.4 volts. The initial reaction of the borate enhanced pyrite oxidation can be described by:FeS[sub 2] + B(OH)[sub 4][sup =] ------> [S[sub 2]Fe-B(OH)[sub 4]][sub surf] + e. This reaction is irreversible and is controlled by the mass-transfer of borate species from the solution to the surface. It has been shown that the above reaction inhibits the adsorption of xanthate on pyrite. Comparative studies have been made with other sulfide minerals. The solution chemistry of the iron-borate systems have been studied to understand the electrochemical results.

• Research Organization: Kentucky Univ., Lexington, KY (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG22-90PC90295
• OSTI ID: 6649718
• Report Number(s): DOE/PC/90295-T9; ON: DE93011633
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL
DESULFURIZATION
COAL PREPARATION
FLOTATION
PYRITE
OXIDATION
REMOVAL
ELECTROLYTES
PROGRESS REPORT
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
DOCUMENT TYPES
ENERGY SOURCES
FOSSIL FUELS
FUELS
MATERIALS
MINERALS
SEPARATION PROCESSES
SULFIDE MINERALS
010300* - Coal
Lignite
& Peat- Preparation- (1987-)
010402 - Coal
Lignite
& Peat- Purification & Upgrading