硫酸浸出赤泥渣回收二氧化钛的研究

Study on Recovering Titanium Dioxide from Red Mud Vitriol Leached Residue

对硫酸浸出赤泥渣的反应机理进行研究,参照晶粒模型将酸浸过程分为化学反应控制阶段、孔隙率控制阶段和传质扩散速率控制阶段,并通过试验对其进行了分析。通过正交试验考察了酸浸温度、硫酸浓度、酸浸时间和液固比(L/S)对二氧化钛浸出率的影响。最佳浸出条件为:酸浸温度150℃,硫酸浓度9mol/L,酸浸时间2h,L/S=6∶1。在此条件下,二氧化钛的浸出率达到了95.2%。

The reaction mechanism of red mud residue leached by sulfuric acid was discussed in detail. With reference to grain model, the acid leaching process could be divided into three stages, i.e. chemical reaction control stage, porosity control stage and mass transfer control stage. Analysis was conducted on the above three stages by experiments. The effects of acid leaching temperature and time, vitriol concentration, and ratio of liquid to solid （L/S） on leaching rate of titanium dioxide were investigated with orthogohal test. The optimum leaching conditions including acid leaching temperature of 150℃, vitriol concentration of 9 tool/L, leaching time of 2 h and L/S of 6 ： 1. Under the above mentioned conditions, the leaching rate of titanium dioxide reaches 95.2 %.