对钠化焙烧钒钛磁铁矿产生的新型焙烧钛渣,采用盐酸加压浸出方法提钛,根据反应前后物相变化,考察了酸浓度、液固比、反应温度、反应时间等对钛浸出率的影响.结果表明,加压酸浸的最优条件为反应温度120℃,反应时间2 h,盐酸浓度30%(ω),液固比8 m L/g.该条件下,Ti O2浸出率可达95%以上.根据固体产物层内扩散控制模型的动力学方程和Arrhenius方程,利用焙烧渣在不同反应温度下的转化率与反应时间的关系得出焙烧渣在盐酸体系中常压分解动力学方程为1+2(1-x)-3(1-x)^2/3=11.4e^-31.2/(RT)t,反应的表观活化能为-31.2 k J/(mol?K).
Aiming at a new type of roasted titanium slag which is prepared with a new process proposed by Institute of Process Engineering, the process of leaching roasting titaniferous slag with hydrochloric acid under pressure was using to solve the problem of low sulfuric acid decomposition rate. The effects of ratio of liquid to solid, leaching temperature, acid concentration, leaching time on Ti leaching rate were studied and the optimal reaction condition was obtained. Roasted titaniferous slag was leaching with 30%(ω) hydrochloric acid which ratio of liquid to solid was equal to 8 m L/g, the whole process was keeping 2 h at 120 ℃, then the leaching rate of Ti O2 can reach up to 95%. According to the dynamics equations of layer diffusion control model of solid product and the Arrhenius equation, kinetic equation of leaching in hydrochloric acid system at atmospheric pressure can be obtained with the effect of reaction temperature on leaching rate of Ti and Ca, which is 1+2(1-x)-3(1-x)^2/3=11.4e^-31.2/(RT)t. Meanwhile, its reaction apparent activation energy is Ea=-31.2 k J/(mol?K).