钠化焙烧钛渣的酸浸动力学研究

Acid Leaching Kinetics of Roasted Titanium Slag with Sodium Carbonate

研究了钠化焙烧—酸浸工艺制备高钛渣过程中酸浸动力学、酸浸溶出规律和溶出反应的控制步骤,探讨了反应温度、盐酸浓度、搅拌速度对钛转化率的影响。结果表明,在下述最优工艺条件下,钛转化率达93%,TiO2品位达98.68%:搅拌速度400r/min、液固比10∶1、酸浓度20%、110℃酸浸90min。钛渣焙烧产物酸浸过程受固体产物层的内扩散控制,钛渣酸浸过程符合收缩未反应核模型,表观活化能为11.37kJ/mol,浸出钛渣动力学方程为1+2(1-x)-3(1-x)^(2/3)=0.244exp[-11370/(RT)]t。

Acid leaching kinetics,acid leaching dissolution rule,and control steps of dissolution reaction of high titanium slag prepared by sodium salt roasting and acid leaching were analyzed.The effects of reaction temperature,hydrochloric acid concentration,and stirring speed on titanium conversion rate were investigated.The results show that titanium conversion rate is 93%above,and TiO_2 content in product is98.68% under the optimum conditions including stirring speed of 400r/min,L/S of 10∶1,hydrochloric acid concentration of 20%,leaching temperature of 110℃,and leaching time of 90 min.Decomposition of titanium slag is controlled by mass diffusion in residual layer with apparent activation energy of 11.37kJ/mol,which is in accordance with unreacted shrinking core mode.Leaching dynamics equation of titanium slag can be described as 1＋2（1-x）-3（1-x）^（2/3）=0.244exp[-11370/（RT）]t.