METHOD FOR COMPLEX PROCESSING OF ALUMINIUM-CONTAINING SALT SLAGS Russian patent published in 2021 - IPC C22B7/04 

FIELD: metallurgy.

SUBSTANCE: invention relates to a method for complex processing of aluminium-containing salt slags. The method includes preliminary crushing, separation and washing from salts of the slag containing aluminium oxide, the slag washed from salts is then purified from iron oxides and separated into a saline solution evaporated to produce crystals of NaCl and KCl salts and slag, wherein in order to evaporate the saline solution and produce crystals of NaCl and KCl salts, N₂, CH₄, C₂H₂ gases released by washing the slag from salts are burned and the heat of combustion thereof is used, and the NH₃ gas released by washing the slag from salts is used to produce ammonium sulphate, then magnesium hydroxide is isolated from the slag and carbonised, followed by treating the slag with sulphuric acid and separating the resulting solution from the insoluble sludge by filtration, the sludge is washed, and the purified solution is supplied to a crystalliser, cooled, and crystals of aluminium sulphate are separated from the master solution including sulphuric acid, wherein the aluminium sulphate crystals are dissolved in a small amount of water, heated, and free sulphuric acid is neutralised with aluminium hydroxide, followed by re-crystallising, drying and packing, wherein the master solution including sulphuric acid is purified from impurities of sulphates of by-product metals and used in the subsequent stages of processing of the slag.

EFFECT: provided are an increase in the quality and quantity of the yield of aluminium-containing products without the use of organic solvents with a simplification of the production chain and a reduction in the manufacturing power consumption due to the conversion of aluminium-containing salt slags into a finished product.

1 cl, 2 dwg