醇-酯复合萃取剂萃取湿法磷酸的相平衡研究

Research on equilibrium of extraction of wet-process phosphoric acid by alcohol-ester compound extractant

以醇-酯复合萃取剂为对象,对湿法磷酸溶剂萃取的液相平衡进行了研究,测定了复合萃取剂-磷酸体系在25、45、60、70℃相平衡时磷酸的分配曲线,考察了磷酸分配系数与温度、相比、磷酸初始浓度的关系。结果表明:复合萃取剂能萃取磷酸的最大质量分数不高于50%,温度和相比对分配系数的影响都不大,但水相磷酸初始浓度对分配系数影响很大。

With alcohol-ester compound extractant as the object,liquid equilibrium of extraction of wet-process phos- phoric acid （ WPA } solvent was studied. WPA distribution curves of compound extractant - WPA system at the phase equilibrium temperatures of 25,45,60,70 ℃ were measured. Relations of WPA distribution coefficient with temperature, phase ratio, and initial WPA concentration were investigated. Results showed that the compound extractant＇s maximum mass frac- tion of WPA extration did not exceed 50% ; the influences of temperature and phase ratio on distribution coefficient were very little, but initial concentration of aqueous phosphoric acid had large influence on distribution coefficient.