Research on purifying wet-process phosphoric acid by membrane dispersion extraction

The membrane dispersion extraction process was used to purify wet-process phosphoric acid with stainless steel fiber sintered membrane as dispersion media.The system of water/phosphoric acid/ TBP + kerosene was used to study the effects of flow rate,membrane diameter,kerosene content,phase ratio,phosphate content and extraction cell volume and residence time on the extraction.When flow rate increased,extraction efficiency increased first and then decreased.,When pore diameter decreased and phosphoric acid concentration of water increased,extraction efficiency increased.When extraction cell volume was enlarged and residence time was increased,extraction efficiency increased.With 10 μm stainless steel fiber sintered membrane,at dispersed phase flow rate of 1000 mL/min,kerosene volume fraction of 20%,phase ratio of 1∶1,phosphoric acid content of 30%-70%,extraction cell volume of 30 mL,single-stage efficiency could reach 96%.