METHOD FOR PRODUCING PHOSPHORIC ACID AND CALCIUM SULFATE OF A QUALITY SUITABLE FOR THE PROCESS OF OBTAINING CLINKER FOR COMMERCIAL AND INDUSTRIAL USE OF CALCIUM SULFATE Russian patent published in 2023 - IPC C01B17/50 C01B17/74 C01B25/232 C01F11/46 C04B11/26 C04B7/04 

FIELD: chemical industry.

SUBSTANCE: method for producing phosphoric acid and purified calcium sulfate is proposed. Phosphate feedstock in the first stage is treated with concentrated sulfuric acid and converted into calcium sulfate in the form of dihydrate, hemihydrate or a combination of hemihydrate and dihydrate and phosphoric acid. The calcium sulfate is separated as a solid from the liquid phase of the resulting suspension. Separated from phosphoric acid calcium sulfate and/or calcium sulfate/phosphogypsum from the waste is treated with acid to obtain a suspension with purified calcium sulfate and P₂O₅-containing acid solution. Purified calcium sulfate is separated as a solid from the liquid phase of the resulting suspension. The P₂O₅-containing liquid phase is used as a raw material in the first stage as part of the sulfuric acid required for the processing of phosphate raw materials, and/or the P₂O₅-containing liquid phase is used as a raw material for processing phosphogypsum from the waste. A plant for the production of phosphoric acid and purified calcium sulfate, a method for the production of sulfuric acid and cement clinker and a plant for its implementation are proposed.

EFFECT: increasing the yield of P₂O₅ in the process of obtaining phosphoric acid and at the same time reducing the concentration of impurities that adversely affect the clinker production process and the quality of cement, reducing the impact of deposits and/or burials of phosphogypsum on the environment.

17 cl, 9 dwg, 4 tbl, 11 ex