Simultaneous extraction of more than one ion by liquid membrane process

A liquid membrane process for removing metallic ionic impurities contained in a phosphoric acid solution, and separating such ionic impurities, which comprises:

• (a) contacting the phosphoric acid solution containing a first ionic impurity selected from the group consisting of magnesium, calcium, aluminum, iron and mixtures thereof, and as a second ionic impurity uranium ion with an emulsion comprising an external phase which is immiscible with said phosphoric acid and comprising a first complexing agent which is a sulfonate capable of forming a first complex with said first ionic impurity and a second complexing agent selected from the group consisting of phosphonates and pyrophosphates capable of forming a second complex with uranium ion, said first complexing agent, said second complexing agent, said first complex, and second complex being soluble in said external phase and an internal phase comprising a strong acid;
• (b) forming in said external phase a first complex of said first ionic impurity of said first complexing agent and a second complex of uranium with said second complexing agent;
• and
• (c) decomplexing said first complex by action of said strong acid on said first complex in said internal phase whereby said first ionic impurity remains in said internal phase and the uranium remains in said external phase in said second complex.