METHOD FOR PRODUCING EXTRACTION PHOSPHORIC ACID Russian patent published in 2023 - IPC C01B25/226 C01F11/46 C04B11/26 B01J2/14 

FIELD: chemical industry.

SUBSTANCE: invention relates to a method for producing extraction phosphoric acid (EPA). This method for producing extraction phosphoric acid includes sulfuric phosphoric acid decomposition of phosphate raw materials with the formation of extraction pulp, separation of the pulp into phosphoric acid and calcium sulphate phospho-hemihydrate precipitate by filtration, washing the calcium sulphate phospho-hemihydrate precipitate with water and returning the return solution of phosphoric acid obtained after washing to the process. Phosphate raw materials are pre-granulated using calcium sulphate phospho-hemihydrate as a binder in an amount of 1 to 20% to phosphate raw materials at a moisture content of 2 to 12% to obtain 0.1–2.0 mm granules. The resulting granules are sent to the stage of sulfuric phosphoric acid decomposition of phosphate raw materials. The use of calcium sulphate phospho-hemihydrate as a binder is also proposed in the granulation of phosphate raw materials in a method for producing EPA.

EFFECT: group of inventions makes it possible to provide a closed waste-free technology for obtaining EPA, and also to reduce the loss of raw materials.

5 cl, 1 tbl, 5 ex