辉钼矿氧化焙烧动力学研究

Kinetics of Molybdenum in Oxidation Roasting Process

通过热重-差热实验,采用气-固多相反应的未反应收缩核模型研究了辉钼矿氧化焙烧的动力学.结果表明,辉钼矿氧化焙烧是强放热反应,温度越高,辉钼矿氧化速率越快;350~500℃辉钼矿转化率较低,Arrhenius方程计算的表观活化能为80.14k J/mol,反应由内扩散控制;540~630℃时转化率明显增高,表观反应活化能为90.42 kJ/mol,反应由界面化学反应控制;升温速率对辉钼矿氧化焙烧过程影响显著,升温速率越低,辉钼矿氧化越充分、转化率越高,氧化放出的总热量越多.

The gas-solid multiphase reaction did not retract reaction model, the weightlessness of molybdenite curve and differential thermal curve are used to study the roasting molybdenite oxidation kinetics based on large number of experimental studies. The results showed that oxidation roasting of molybdenite is a strong exothermic reaction, the higher the temperature, the faster the oxidation rate of molybdenite is. At 350~500 ℃,the conversion rate of molybdenite is low, and the apparent activation energy calculated by the Arrhenius equation is 80.14 k J/mol while the reaction is controlled by internal diffusion. At 540~630 ℃, the conversion rate of molybdenite become significantly higher, and the apparent activation energy is 90.42 k J/mol while the reaction is controlled by chemical reaction. Heating rate has influence on oxidation roasting process of molybdenite significantly, the lower heating rate, the higher conversion rate of molybdenite is, and the more quantity of heat emitted by oxidation.