钛白水解废酸中钪的回收

研究了钛白水解废酸中钪的回收及钪与钛的分离。在P204-TBP萃取体系中进行了钛白水解废酸提钪实验研究，在此基础上绘制了钪的萃取等温线，并进行了串级逆流萃取实验。针对萃取后含钪钛的有机相，提出了用洗脱剂EL洗脱负载有机相中的钛，并进行了相应的实验研究。对除钛后的有机相，考察了钪反萃的影响因素。实验结果表明：P204-TBP萃取体系基本可以实现钪的回收富集，经洗脱剂EL三级逆流洗脱，钛的洗脱率可达到98%，而钪的损失率仅为4%，钪钛的分离效果明显。洗脱钛后的有机相用氢氧化钠反萃，钪的单级反萃率能达到97%以上。钛白水解废酸经一次萃取、洗脱、反萃后得到的粗钪产品纯度可达到85%。

Recycling utilization of scandium from hydrolyzed sulfuric acid of titanium dioxide production

The main research topics are the recycling utilization of scandium from hydrolyzed sulfuric acid of titanium dioxide production and the separation of titanium from the scandium-loaded organic solvent. Based on the experiments of the extracting scandium from hydrolyzed sulfuric acid of titanium dioxide production in di-(2-ethylhexyl) phosphoric acid(P204)-tributyl phosphate(TBP)-sulfonated kerosene system, the extraction isotherm of scandium was plotted, which gave a foundation to carry out the experiments of counter-current extraction. The EL eluant was proposed to do with organic phase containing scandium and titanium after the experiment of counter-current extraction, which could remove titanium from the organic phase. Finally, the main influencing factors of stripping efficiency of scandium were investigated. The results show that the di-(2-ethylhexyl) phosphoric acid-tributyl phosphate-sulfonated kerosene system not only can realize the recovery and enrichment of scandium but also preliminarily separate scandium from other metallic elements, such as titanium, iron and so on. In the experiments of elution, the elution efficiency of titanium can reach 98% through three-stage countercurrent elution, with just a loss ratio of scandium for 4%, which means the better separation result of scandium and titanium. Then the stripping rate of scandium can reach more than 97% with sodium hydroxide added to the raffinate. All in all, the purity of the final product of scandium can reach 85% through the process of extraction, elution and stripping.