Evaluation on Spontaneous Combustion Tendency of Sulfide Ores by Activation Energy

摘要

Spontaneous combustion of sulfide ores is one of the more severe safety problems in metal mines. Three representative sulfide ore samples (denoted as 1-2, 2-2, and LB4) were obtained from a typical metal mine in China. The chemical reaction processes were analyzed by thermo-gravimetric analysis (TG) and differential scanning calorimetry analysis (DSC) at the heating rates of 5, 10, and 15°C/min in air flow from ambient temperature to 800 °C. The corresponding curves of TG and DSC for each sample under different conditions were gained, and their combustion characteristic parameters were also presented. Based on the Flynn-Wall-Ozawa method, the reaction activation energy for 1-2, 2-2, and LB4 samples was calculated, which is 427.242, 116.835, and 56.225kJ·mol-1 respectively. It can be concluded that LB4 sample is the most susceptible one to cause spontaneous combustion for its lowest activation energy value, whereas 1-2 sample is difficult to arouse spontaneous combustion. This explana- tion is in accordance with the factual situation in mines. Therefore, activation energy value can be used as the standard for evaluating spontaneous combustion tendency of sulfide ores.