钼精矿氧化焙烧机理研究

STUDY ON MECHANISM OF MOLYBDENUM CONCENTRATE ROASTING

利用热重分析仪研究了钼精矿氧化焙烧时的热失重特性和析热特性,应用双外推法推断了钼精矿氧化焙烧的反应机理,采用Costs-Redfern积分法和Flynn-Wall-Ozawa积分法对实验数据拟合计算,求得了焙烧反应的动力学参数。结果表明,焙烧反应失重过程主要分为4个阶段,分别为预热干燥段、扩散段、快速反应段和深度氧化段。整个氧化反应放出的热量大部分集中在快速反应段,此阶段主要产物为MoO2,反应活化能为227.7 kJ/mol。深度氧化段的主要产物是MoO3,当温度在600℃左右时,生成MoO3反应的速率最大,此阶段放出热量较少,反应活化能为163.2 kJ/mol。

Simultaneous thermogravimetry analyzer was used to investigate the thermal cracking behaviour and the exothermicity of molybdenum concentrate roasting and roasting reaction mechanism of molybdenum concentrate was concluded on the double extrapolated method.Data processing and fitting was constructed on the basis of Costs-Redfern and the Flynn-Wall-Ozawa integral methods,and roasting reaction kinetic parameters was proposed.The results show that roasting reaction process of weight loss is divided into four stages,namely preheated drying section,diffuser,rapid response and deep oxidation paragraph,respectively.The heat released by the oxidation of the majority concentrated in the rapid response section,main product of this stage is MoO2,and the activation energy of this stage is 227.7 kJ/mol.The main products of deep oxidation section is MoO3.When the temperature is about 600 ℃,the maximum rate of reaction generated MoO3,less heat release at this stage,and the activation energy of this stage is 163.2 kJ/mol.