Journal of Solid State Electrochemistry

, Volume 6, Issue 2, pp 111–118 | Cite as

Comparative study of electrochemical and thermal oxidation of pyrite

  • C. Almeida
  • B. Giannetti
Original Paper

Abstract

The oxidation of pyrite was studied as a function of grain size, employing voltammetric and thermal analysis. The data obtained with the electrochemical experiments are consistent with the results shown in the thermogravimetry-differential thermogravimetry (TG-DTG) records. The use of both techniques revealed that oxidation of the mineral is affected by the grain size employed. The maximum yield of SO42– was obtained from electrodes constructed with <210 µm-sized particles. The same behavior was observed during thermal decomposition. When the temperature surpasses 490 °C, the small particles (<210 µm) oxidize in a single step which is not affected by changes in the rate of air flow, indicative of their higher reactivity among the ground mineral electrodes. The comparison between the results obtained by the two methods suggests that, below 490 °C or 0.6 V, pyrite oxidation, either in air or in aqueous media, is similar and depends on the semiconducting properties of the mineral.

Voltammetry Thermal analysis Pyrite particles Electrochemical dissolution Surface reactivity 

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Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • C. Almeida
    • 1
  • B. Giannetti
    • 1
  1. 1.LaFTA – Laboratório de Físico-Química Teórica e Aplicada, Instituto de Ciências Exatas e Tecnologia da Universidade Paulista, R. Dr. Bacelar 1212, Cep 04026-002, São PauloBrazil

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