WASTE-FREE PROCESSING OF BAUXITE AND RED SLUDGE Russian patent published in 2022 - IPC C22B3/12 C22B3/22 C01F7/08 C01F7/46 C22B7/00 

FIELD: aluminum industry.

SUBSTANCE: invention relates to the production of alumina from bauxite ores. The classical bauxite processing according to the Bayer method is proposed, in which, after wet grinding, the pulp is treated with ultrasound, reverse and direct flotation with the separation of sulfur and silica from the pulp is carried out. In this case, the separated red sludge is subjected to countercurrent washing, wet magnetic separation to separate part of the iron concentrate, pressing, drying, annealing, dry magnetic separation with the separation of the second part of the iron concentrate and sent to the process of cold hydrochemical decomposition of sodium hydroaluminosilicate contained therein to obtain a gel of silicic acid and residual sludge. The residual sludge is sent for recycling at the stage of wet grinding of bauxite. In addition, precipitation containing compounds of titanium, chromium, calcium, phosphorus and rare earth elements is collected on the heating tubes and walls of pulp heaters and heating autoclaves.

EFFECT: processing of bauxite with a high silica content, an increase in alumina yield is provided.

4 cl, 2 dwg