Thermodynamic Simulation of Sulphide Mineral Leaching

Abstract:

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Geochemical modeling program PHREEQC was used to simulate generic bioleaching processes. Carbonate minerals (e.g., calcite) dissolve in acid solution, increasing the solution pH and Ca concentration while the concentration of CO2 may be controlled by the equilibrium with the atmospheric CO2. Non-oxidative dissolution of Fe-monosulphides was demonstrated to release H2S and increase the pH. In the absence of ferric iron precipitation (goethite), the oxidation of pyrite decreased the solution pH from 2 to ~1.4, while the oxidation of Fe-monosulphide and chalcopyrite increased the solution pH to ~3.2-3.4. Assuming equilibrium precipitation of goethite, oxidative leaching decreased the solution pH for all three minerals from pH ~2 to ~0.9-1.2. Adjustment of the solution pH to 1.8 or 2.0 with KOH with concurrent equilibrium precipitation of K-jarosite resulted in low dissolved iron concentrations.

Info:

Periodical:

Advanced Materials Research (Volumes 71-73)

Edited by:

Edgardo R. Donati, Marisa R. Viera, Eduardo L. Tavani, María A. Giaveno, Teresa L. Lavalle, Patricia A. Chiacchiarini

Pages:

437-440

DOI:

10.4028/www.scientific.net/AMR.71-73.437

Citation:

L. Ahonen et al., "Thermodynamic Simulation of Sulphide Mineral Leaching", Advanced Materials Research, Vols. 71-73, pp. 437-440, 2009

Online since:

May 2009

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Price:

$35.00

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