Electrochemistry of a semiconductor chalcopyrite concentrate leaching by Thiobacillus ferrooxidans

Conference · Tue Jan 01 00:00:00 EST 1991

OSTI ID:5989409

Torma, A E

Using carbon-paste-CuFeS{sub 2} electrodes and a cyclic voltammetric technique, it was found that a large number of intermediate electrochemical oxidation reactions were associated with the dissolution of chalcopyrite in presence and absence of bacteria. The effects of concentrations of copper, ferrous and ferric ions, as well as of agitation on the peaks of cyclic voltammograms were measured. It was established that chalcopyrite oxidation was solid-state controlled as suggested by the data of chronopotentiometric and chronoamperometric measurements. The activation energy of solid state diffusion of chalcopyrite leaching was determined by the Sand's method to be {triangle}E{sub a} = 20.5 kJ. The leaching mechanism is discussed in terms of solid-state properties (energy bonding) of the n-type semiconductor chalcopyrite and energy density states of redox systems of acidic bacterial leach media. A generalized model for the mechanism of chalcopyrite leaching in presence and absence of bacteria is presented. 23 refs., 10 figs.

• Research Organization: EG and G Idaho, Inc., Idaho Falls, ID (United States)
• Sponsoring Organization: DOI; Department of the Interior, Washington, DC (United States)
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 5989409
• Report Number(s): EGG-M-91059; CONF-9108111-2; ON: DE92003335
• Resource Relation: Conference: 30. annual Canadian Institute of Metalurgist (CIM) conference, Ottawa (Canada), 18-21 Aug 1991
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
59 BASIC BIOLOGICAL SCIENCES
CHALCOPYRITE
MICROBIAL LEACHING
ACTIVATION ENERGY
BAND THEORY
ELECTROCHEMISTRY
PH VALUE
SEMICONDUCTOR MATERIALS
THIOBACILLUS FERROXIDANS
VOLTAMETRY
BACILLUS
BACTERIA
CHEMISTRY
DISSOLUTION
ENERGY
LEACHING
MATERIALS
MICROORGANISMS
MINERALS
SEPARATION PROCESSES
SULFIDE MINERALS
SULFUR-OXIDIZING BACTERIA
400400* - Electrochemistry
550700 - Microbiology