Study of solubility in the systems CaO-P2O5-SO3-H2O and CaO-P2O5-H2O on the example of sulfuric-acid and phosphoric-acid decomposition of phosphoric slag

The results of the theoretical graphical analysis decomposition sulfuric and phosphoric acids from mass wastes production – slag, accumulated reserves which are industrial importance in terms quantity, presented. A representative sample slag Kainar LLP was obtained for research. research showed that main products slag's stage a solution acid with concentration 14-17% P2O5 cake precipitate containing mainly calcium sulfate insoluble impurities (SiO2). Thus, soft dihydrate mode (60°C, formation), weak is obtained, sent to second new portion order obtain phosphate product. Potassium forms K2HPO4, which, entering into exchange Ca(H2PO4)2, can pass more acidic salt K2PO4, anion released this case ion hardly soluble CaNRO4. As result, final product after contains Ca(H2O4)2, small amounts CaNRO4 water-soluble phosphates magnesium, potassium, as well an residue allow conclude valuable secondary raw material, quite suitable processing phosphorus, potassium-containing complex mineral fertilizer.