杂质对共沸精馏浓缩磷酸的影响

The Effects of Impurities on Concentrating Phosphoric Acid by Azeotropie Distillation Method

研究了磷酸中含的Fe^(3+)、Al^(3+)、Mg^(2+)、F^-、Si等杂质对共沸精馏浓缩磷酸过程的影响。试验结果表明,杂质Fe^(3+)、Al^(3+)、Mg^(2+)几乎全部存留在塔釜液酸相中。F^(-1)则以SiF_4气态逸出,遇水冷却后形成SiO_2白色沉淀。挟带剂中含P_2O_5和杂质量极少,不需处理即可直接循环使用。

The effects of impurities Fe^(3+)、Al^(3+)、Mg^(2+)、F^-、SiO_2 on phosphoric acid concentration process by azeotrapic distillation method have been studied. The results state that almost all of the impurities of Fe^(3+)、Al^(3+)、Mg^(2+) are in the acid phase of still solution. The ion of F-formed SiF_4, then SiF_4 reacted with water to form white deposit of SiO_2·Azeotrope former has little P_2O_5 and impurities, so that it can be directly reused without treatment.