Thermal behavior and kinetics of sulfide concentrates

Abstract

Thermal behavior of sulfide concentrates can give rise to many serious problems in its storage and transportation. In order to uncover the thermal behavior of sulfide concentrates, as well as obtain the kinetic parameters, four representative samples were tested using TG-DTG-DSC techniques in the presence of oxygen from 20? to 1000? and with three different heating rates of 5, 10, and 15? per minute. Meanwhile, corresponding activation energies of sulfide concentrates were also determined by the Coats-Redfern method (199.4-234.9 kJmol?1 for Sample 1, 203.6-235.9 kJmol?1 for Sample 2, 234.7-255.6 kJmol?1 for Sample 3, and 199.7-254.9 kJmol?1 for Sample 4). Results indicate that the heating rate is an important factor affecting the thermal behavior of sulfide concentrates. The peak temperature corresponding to the maximum mass loss rate of the ore sample at different heating rates is different and the sulfide concentrates at heating rate of 5? per minute is more prone to spontaneous combustion. Furthermore, this thermodynamic method was demonstrated to be effective for investigating and predicting the thermal behavior of sulfide concentrate and the activation energy index was reasonable for determining its spontaneous combustion tendency.