METHOD OF PRODUCING MAGNESIUM-AMMONIUM PHOSPHATE FROM SAPONITE SLUDGE Russian patent published in 2024 - IPC C01B25/34 C01B25/45 C22B7/00 

FIELD: chemical or physical processes.

SUBSTANCE: invention relates to production of magnesium-ammonium phosphate from saponite clay slime. Production of magnesium-ammonium phosphate involves supply of starting material into a reactor with constant stirring for mixing with hydrochloric acid, neutralization with ammonia and mixing with sodium hydrophosphate, as well as filtration. Initial raw material used is saponite finely dispersed clay powder, which is stirred at temperature of 95 to 105 °C for 15 to 20 minutes. Obtained suspension is filtered to obtain a solid phase—a precipitate of amorphous silica and a liquid phase—an acidic solution of chlorides, which is directed for neutralization with ammonia with concentration of 13 % until pH=7. Obtained pulp is filtered to obtain solid phase—iron-nickel precipitate and liquid phase—magnesium chloride solution, which at temperature of 105 to 115 °C is mixed with 1M sodium hydrophosphate, and then filtered to obtain a solid phase—magnesium-ammonium phosphate and a liquid phase—a salt solution, which is sent for purification or evaporation to obtain sodium chloride.

EFFECT: method enables to obtain magnesium-ammonium phosphate by leaching with hydrochloric acid from saponite sludge.

1 cl, 4 dwg, 1 tbl, 15 ex