METHOD FOR COMPLEX PROCESSING OF ALUMINA-CONTAINING RAW MATERIALS Russian patent published in 2023 - IPC C01F7/06 C22B3/12 C22B7/00 

FIELD: raw materials processing.

SUBSTANCE: invention relates to the processing of alumina-containing raw materials - bauxite and red mud, alumina production waste. Complex processing of alumina-containing raw materials includes preparation of a charge containing alumina-containing raw materials and soda in an amount of not more than 5% by weight of the charge, while limestone is contained while maintaining the CaO/SiO₂ molar ratio (1.9-2.1):1. The mixture obtained is heated to a temperature of at least 350°C. Then heat treatment is carried out in a fluidized bed at 750-900°C in the presence of a reducing agent, which is carbon monoxide or a mixture of carbon monoxide and hydrogen. The mixture is cooled in an inert gas atmosphere, magnetic separation is carried out in a separator with a magnetic field induction of 300-900 mT on the working surface to obtain a magnetic fraction, which is an iron-containing product, and a non-magnetic fraction, including oxides of aluminum, calcium, silicon and dicalcium silicate. The non-magnetic fraction is subjected to mechanical activation in a vortex mill to a particle size of 7-10 mcm and sent for leaching with a sodium hydroxide solution with a concentration of 110-140 g/dm³ at a temperature of 65-90°C. The aluminate solution is separated from the white mud and sent to obtain alumina. The separated white sludge is washed from alkali and used to obtain foam silicates.

EFFECT: method provides for the complex processing of alumina-containing raw materials while reducing the energy intensity of the process with the production of high-quality iron-containing, aluminum-containing and calcium-silicate products suitable for further use.

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