利用磷化渣制备电池级磷酸铁

以含锌磷化渣为原料,先用氢氧化钠浸取制得磷酸钠溶液,再采用萃取法去除该溶液中的微量锌,在净化液中加入六水合氯化铁反应制得磷酸铁产品。实验结果表明：采用氢氧化钠浸取磷化渣,能有效地去除磷化渣中的金属离子,获得含微量锌的磷酸钠溶液,磷酸根的浸取率可达93.97%,磷酸根的总利用率可达78.31%;采用双硫腙与P204萃取剂对该溶液进行萃取,其双萃取剂混合萃锌效果明显优于它们相应的单种萃取剂萃锌效果。在有机相与水相体积比=1∶5时,锌的单级萃取率可达55.39%,产品磷酸铁中锌含量低于30.0 μg/g。研究表明,采用氢氧化钠浸取和双硫腙与P204双萃取剂除杂的方法,可有效回收含锌磷化渣中的磷酸根并制备出电池级磷酸铁。

Preparation of battery grade iron phosphate from phosphating slag

Using zinc-containing phosphating slag as raw material,firstly use NaOH leaching to obtain Na₃PO₄ solution,then remove the trace amount of zinc in the solution by extraction method and add FeCl₃·6H₂O to the purified liquid to obtain iron phosphate product.The experimental results showed that NaOH leaching can effectively remove the metal ions in the phosphate ing slag and then obtain the Na₃PO₄ solution containing a trace amount of zinc.The leaching rate of the phosphate can reach 93.97% and the total utilization rate can reach 78.31%.The dithizone and P204 extractants were used to extract the solution.The zinc extraction effect of double extractant was significantly better than their corresponding single extractant effect.When O∶A=1∶5,the extraction rate of zinc was up to 55.39% and the content of zinc in the product iron phosphate was less than 30.0 μg/g.Research showed that the use of NaOH leaching and dithizone and P204 double extractant impurity removal method can effectively recover the phosphate in the zinc-containing phosphating slag and prepare battery-grade iron phosphate.