Technical Note

Pyrite oxidation by hydrogen peroxide in phosphoric acid solutions

P. Chirită

Department of Inorganic and Analytical Chemistry, University of Craiova, 1100, Craiova, Romania

Received 18 February 2003; accepted 20 July 2004


Oxidation characteristics of natural pyrite were investigated in phosphoric acid solutions. Using hydrogen peroxide as an oxidant, the effect of particle size, reaction temperature, and hydrogen peroxide concentration were examined. The oxidation process can be described by the heterogeneous kinetic model in which the surface decomposition reaction is the rate-determining step. An activation energy of 49 kJ mol-1 for pyrite oxidation is estimated. It was found that the smaller the particle size or the higher the reaction temperature, the faster the oxidation proceeds, as anticipated.

Keywords: Pyrite; Hydrogen peroxide; Oxidation; Surface reactivity

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   E-mail : pchirita@chimie.ucv.ro