METHOD FOR OBTAINING MAGNETITE Russian patent published in 2021 - IPC C22B1/00 C01G49/08 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy and can be used to obtain magnetite in order to increase the efficiency of processing red mud, which is a waste of alumina production. Autoclave processing of red mud is carried out at a temperature of 230-250°C and a pressure of 27-50 MPa in the presence of a reducing agent and a 30% sodium hydroxide solution with the introduction of calcium hydroxide, the content of which is 2.0-2.5 wt.% in terms of СаО from the mass of the original sludge. As a reducing agent, aluminum granules are used in an amount of 10-25 wt.% Of the weight of the original sludge. After that, it is cooled, diluted with distilled water at a temperature of 80-90°C until the ratio L:T = (10-11):1 is obtained and filtered.

EFFECT: invention provides high conversion of hematite to magnetite.

1 cl, 2 ex