Mechanism and kinetics of pyrite transformation at elevated temperatures

• Autorzy: Aracena Alvaro , Jerez Oscar

Identyfikatory

DOI

10.37190/ppmp/143124

• Języki publikacji: EN

Abstrakty

EN

Pyrite (FeS2) is known as a sulfide that provides energy for various pyrometallurgical processes (fusion and conversion). There are several studies related to the evaluation of pyrite oxidation mechanisms at high temperatures, obtaining discrepancies in the products generated. In our work, the novelty of our research would be to obtain the thermochemical oxidation mechanism of FeS2 by using conventional thermogravimetric methods. The oxidative roasting of pyrite from 550 to 800°C was analyzed for an oxygen concentration of 5.07 to 28.06 kPa of oxygen and particle size between 12.3 to 33.8 microns. The results showed that the pyrite proceeded by sequential roasting: first, it produced an intermediate compound, pyrrhotite (Fe7S8), which was later oxidized to generate hematite (Fe2O3), both stages validated by weight loss of the sample as well as by analysis by DRX. Each stage had a different roasting speed as it was also influenced differently by different parameters. The temperature and particle size favored the rate of pyrrhotite generation, and the oxygen concentration favored the rate of hematite formation. The first-order kinetic equation ln (1-XPy) represented the roasting of the first stage (FeS2 → Fe7S8), with a calculated activation energy of 70.1 kJ/mol. The order of reaction was 0.5 concerning the partial pressure of oxygen and inversely proportional to the initial particle radius.

Słowa kluczowe

EN

pyrite; pyrrhotite; roasting; kinetics

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Physicochemical Problems of Mineral Processing
• Rocznik: 2021
• Tom: Vol. 57, iss. 6
• Strony: 127--139
• Opis fizyczny: Bibliogr. 22 poz., rys. kolor., tab., wykr.

Twórcy

autor

Aracena Alvaro

• Escuela de Ingeniería Química, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2162, Valparaíso 2362854, Chile

autor

Jerez Oscar

• Instituto de Geología Económica Aplicada (GEA), Universidad de Concepción, Casilla 160-C, Concepción, Chile

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