METHOD OF PROCESSING APATITE USING SULFURIC ACID TECHNOLOGY Russian patent published in 2025 - IPC C01B25/223 C01F11/46 C22B3/08 C22B59/00 

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing phosphorus-containing fertilizers. Disclosed is a method of processing apatite by opening with sulfuric acid to obtain phosphogypsum, which involves multistage washing of phosphogypsum with water. Phosphogypsum is washed with a solution of sulfuric acid with concentration of 20–40 g/dm³ at temperature of 70–90 °C and during blowing with air or live steam. Rare-earth elements are extracted from the obtained phosphate-sulfuric acid solution. Filtrate is returned to the head of apatite opening with sulfuric acid. At the next stage, phosphogypsum is washed with water to remove sulfuric acid. At the last stage, lime milk solution containing an equivalent amount of calcium oxide in relation to the amount of remaining sulfuric acid is treated in a countercurrent.

EFFECT: invention reduces costs for purification of phosphogypsum and extraction of rare-earth elements, simplifies the process of processing apatite and increases efficiency of the process.

3 cl, 3 dwg, 6 tbl, 7 ex