Kinetic of Pyrite thermal degradation under oxidative environment

Abstract

Pyrite is the most common mineral in polymetallic sulphides ores. In order to apply the combustion group theory to the pyrometallurgical processes that occur in the reaction shaft it is necessary to know the kinetic processes that happen in pyrite. In this study a thermogravimetric analysis was carried out under oxidative atmospheric conditions with 100% O2 and a heating ramp of 5, 10, 15 and 20 ºC min-1. The material used was pyrite with a grain size of 63-125 μm. From the thermogravimetric data we got the kinetic parameters of the oxidative reactions of pyrite. The different kinetic methods used in this study have been E1641-16 ASTM, Ozawa-Flynn-Wall, Kissinger-Akahira- Sunose and Friedman. These methods were used for obtaining the kinetic parameters through Regression analysis, Sum of squares, mean residuals between experimental and calculated values and Student coefficient (95%) and to determine which kinetic method is the most suitable to describe the kinetics of pyrite oxidation.