METHOD FOR PROCESSING RED MUD FROM ALUMINA PRODUCTION Russian patent published in 2023 - IPC C01F7/06 C22B3/04 C22B7/00 

FIELD: metallurgy of non-ferrous metals.

SUBSTANCE: method for processing red mud from alumina production includes leaching the sludge in a hydrochloric acid solution, separating the chloride solution from the insoluble precipitate and neutralizing the chloride solution with sodium hydroxide to pH=7.5-8.0 to obtain a collective hydrate-salt precipitate. The collective hydrate-salt precipitate is leached in a hydrochloric acid solution at pH=1.3-1.8 with separation of the chloride solution from the insoluble residue based on iron compounds. The resulting chloride solution is neutralized with caustic soda to pH=7.5-8.0 to obtain a hydrate-salt precipitate, which is sent for sintering with alkali. Alkaline cake is leached in water, followed by separation of the aluminate solution from the insoluble residue enriched in rare metals.

EFFECT: efficient complex processing of red mud is provided using a waste-free technology with production of liquid selective products with a recovery of more than 90%.

4 cl, 11 tbl, 2 ex