乳状液膜法提取模拟湿法磷酸中的稀土镧

Lanthanum extraction from diluted phosphoric acid with P204 as carrier by emulsion liquid membrane

采用自制的磺化聚丁二烯(LYF)作表面活性剂,以二(2-乙基己基磷酸,P204)为萃取剂,以4mol/L HCl为内相,液体石蜡为膜稳定剂,制成乳状液膜,从模拟湿法磷酸中萃取稀土镧.在膜内比为1.2∶1,制乳搅拌,搅拌速度为2 000r/min,时间为20min,提取搅拌速度为250r/min,时间为10min,水乳体积比为2∶1,磷酸质量分数为10%P2O5,La3+含量为300mg/L时,镧离子的迁移率达到86.67%.同时利用液液萃取通过斜率分析法讨论P204从磷酸中提取镧离子的反应机理.对P204萃取镧离子进行热力学研究,结果表明,萃取反应属于放热反应,反应热为-7.697 1kJ/mol.

Recently attention has been directed to wet-process phosphoric acid as a potential source of lanthanides.In this work emulsion liquid membrane which contained LYF（sulphonated polybutadiene） as surfactant,P204 as carrier,2 mol/L HCl as internal phase,liquid paraffin as stabilizing agent was applied to removal of lanthanides.The results show that the degree of removal of lanthanides could be 86.67% with aqueous/organic phase volumetric ratio = 2∶1,P2O5% = 15%,concentration of La3＋=300 mg/L.The influence of various factors such as the concentration of H3PO4,H2PO42-,P204,HCl on the degree of removal has been established by liquidliquid extraction.The mechanism of lanthanide extraction from phosphoric acid by P204 has been determined via slope analysis.Meantime the results of thermomechanics show that the removal of lanthanide from phosphoric acid is an exothermic reaction with-7.697 1 kJ/mol reaction heat.