Process for separating a phosphoric acid-solvent solution

A countercurrent multi-zoned process for separating an organic solvent from a phosphoric acid-solvent-solution whereby the organic solvent is miscible in all proportions with phosphoric acid and water to separate substantially all of said organic solvent as a mixture of water and organic solvent by the addition of an alkali material comprising the steps:

• (a) introducing said phosphoric acid-solvent-solution into a first zone of a multi-zoned extractor;
• (b) introducing an alkali (M) compound wherein the cation is selected from the group consisting of sodium, potassium, and ammonium ions into said multi-zoned extractor in a zone downstream from said first zone of said multi-zoned extractor to effect a countercurrent contact in said multi-zoned extractor of said solution, the amount of alkali compound being added to cause in each zone a phase separation of said solution into an aqueous alkali phosphate phase and a solvent phase whereby an aqueous alkali phosphate phase in each zone of said multi-zoned extractor has a mole ratio of M.sub.2 O:P.sub.2 O.sub.5 of from 0.45:1 to 0.90:1;
• (c) separating by decantation in each zone of said multi-zoned extractor said alkali phosphate phase and said solvent phase, prior to passage of said respective phases to an upstream and downstream zone, respectively, of said multi-zoned extractor;
• (d) withdrawing said aqueous organic solution substantially free of phosphoric acid from a last zone of said multi-zoned-extractor;
• and
• (e) withdrawing said aqueous alkali phosphate solution having a ratio of M.sub.2 O:P.sub.2 O.sub.5 from 0.45:1 to 0.90:1 substantially free of organic solvent from said first zone of said multi-zoned-extractor.