外包法直接还原钛铁矿过程的动力学研究

采用外包还原剂的方法对钛铁矿进行直接还原试验,研究了直接还原钛铁矿的动力学。结果表明,半焦粉直接还原钛铁矿分为两个阶段,第一阶段是升温阶段和恒温的初始阶段,受界面化学反应控制,表观活化能为113.14kJ/mol;第二阶段为恒温阶段,受固相中气体的内扩散控制,表观活化能为180.13kJ/mol。温度对还原度和还原速率的影响显著。随着温度的升高,还原度随之升高,反应速率加快;延长恒温时间也可以提高还原度,但恒温阶段反应速率增加缓慢

Study on Kinetics of Direct Reduction Process of Ilmenite

Direct reduction of ilmenite was conducted by reductant wrapping to investigate kinetics of direct reduction of ilmenite. The results show that the process of semi-coke powder direct reduction of ilmenite is divided into two stages. Controlled by interfacial chemical reaction with activation energy of 113.14 kJ/mol, the first stage is of characteristics of temperature rising and initial homoiothermy. The second stage is a period of constant temperature controlled by diffusion of gases in solid phase with activation energy of 180.13 kJ/mol. Temperature has a remarkable effect on reduction in terms of degree and speed. Increasing temperature results in rise of both reduction degree and reaction rate. Prolonging constant temperature period can improve reduction degree with a slow increase of reaction rate.