METHOD OF PROCESSING BAUXITE FOR ALUMINA Russian patent published in 2020 - IPC C01F7/38 C01F7/06 

FIELD: metallurgy.

SUBSTANCE: invention relates to nonferrous metallurgy. Method of processing bauxites for alumina using a parallel Bayer-sintering system includes a Bayer branch and a sintering branch. Bayer branch includes crushing and subsequent milling bauxite in recycled solution, autoclave leaching, pulp thickening to obtain aluminate solution and red mud, flushing red mud, decomposition of aluminate solution to produce aluminum hydroxide and mother solution, mother solution evaporation, calcination of aluminum hydroxide to obtain alumina. Sintering branch includes preparation of charge, sintering of charge to produce sinter and dust of electric filters, leaching of obtained sinter to obtain aluminate solution containing silica and red mud of sintering process, desiliconization of aluminate solution to obtain white mud and desilicated aluminate solution, decomposition of desilicated aluminate solution to produce aluminum hydroxide and mother solution, evaporation to obtain recycled solution directed to Bayer branch for bauxite milling. Dust of electrostatic precipitators is subjected to leaching to produce red mud of electrostatic precipitation and alkaline-aluminate electrofiltration solution separated by filtration. Alkali-aluminate solution of electrostatic precipitation is directed to a mixing operation with a desilicated aluminate solution of the sintering branch. Rare-earth elements are extracted from red electric filtration mud.

EFFECT: extraction of compounds of rare-earth elements from dust of electric filters of bauxite raw materials processing.

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