METHOD OF WET-PROCESS PHOSPHORIC ACID PRODUCING Russian patent published in 1994 - IPC

FIELD: chemical technology. SUBSTANCE: phosphate raw is treated with reusable phosphoric and sulfuric acids in the presence of recirculating pulp. Pulp (2.5-35% ) feeding at the stage of calcium sulfate crystallization is treated by pressure changes at frequency 0.5-6.0 KHz, pulse value with pressure excess (0.2-6.0)10⁵ Pa, and multiplicity effect 1-50. Precipitate of calcium sulfate is crystallized following by separation of product from precipitate by filtration. Precipitate is washed, and wash waters are fed for raw treatment. Yield of P₂O₅ is up to 96.8-97.4% . Method is used for mineral fertilizing production. EFFECT: improved method of phosphoric acid production, enhanced yield of product. 4 tbl