N_(2)气氛下黄铁矿热分解平衡温度与热力学参数研究

Study on Pyrolysis Equilibrium Temperature and Thermodynamic Parameters of Pyrite in N_(2)Atmosphere

原生黄铁矿在空气中易热分解自燃,影响矿山安全生产。采用同步热分析仪在N_(2)气氛下对原生黄铁矿进行了差热分析,研究黄铁矿热分解行为与热力学参数。借用Semenov热爆炸模型求证黄铁矿热分解TG曲线拐点的临界平衡温度;采用Kissinger函数计算热分解动力学参数,并将其用于求解热力学参数。结果表明:原生黄铁矿热分解会生成结构致密的中间产物,其热分解过程与普通黄铁矿一致;在高温时由于伴生矿热分解产物会与原生黄铁矿热分解产物发生放热反应,导致热分解温度滞后;Semenov热爆炸模型计算的热平衡临界温度与不同升温速率下的拐点温度相近,两者温度相对误差均小于5%。因此,通过联合热分析技术与Semenov热爆炸理论模型可以较准确地预测热分解平衡温度。

Primary pyrite is easy to pyrolyze and self-ignite in the air,which affects mine safety production.In this paper,the differential thermal analysis of primary pyrite in N_(2)atmosphere was carried out by synchronous thermal analyzer,and the pyrolysis behavior and thermodynamic parameters of pyrite were studied.The critical equilibrium temperature of the inflection point of the TG curve of pyrite pyrolysis is verified by Semenov thermal explosion model,the kinetic parameters of pyrolysis were calculated by Kissinger function and used to solve the thermodynamic parameters.The results show that the pyrolysis of primary pyrite produces dense intermediate products,and its pyrolysis process is consistent with that of ordinary pyrite.At high temperature,the pyrolysis temperature lags due to the exothermic reaction between the pyrolysis products of associated ores and the pyrolysis products of primary pyrite.The critical temperature of thermal equilibrium calculated by Semenov thermal explosion model is close to the inflection point temperature at different heating rates,and the proportional errors of both temperatures are less than 5%.Therefore,the pyrolysis equilibrium temperature can be accurately predicted by combining thermal analysis technology and Semenov thermal explosion theoretical model.