PURIFICATION OF PHOSPHORIC ACID

摘要

The novel process is employed to produce purified phosphoric acid or purified phosphate from a phosphoric acid obtained according to the wet process. This involves bringing the acid into contact with a dialkyl ketone having 5 or 6 carbon atoms. Essentially, the weight ratio is from 0.5:1 to 2:1. The phosphoric acid is then extracted into the organic phase, so that a ketone phase is formed in which the H3PO4 concentration is from 28 to 40% by weight. The organic phase is then brought into contact with water or an aqueous solution of a base. An aqueous phase is thus obtained which contains phosphoric acid or a phosphate with a purity higher than that of the phosphoric acid employed obtained from the wet process. If a ketone having 5 carbon atoms is used, the ketone phase is brought into contact in counter-current with water in at least two stages.