METHOD FOR PRODUCING HIGHLY DISPERSED BAYERITE Russian patent published in 2021 - IPC C01F7/34 C01F7/14 

FIELD: polymer compositions.

SUBSTANCE: invention relates to the processing of aluminum-containing raw materials, including nephelines, for the production of highly dispersed aluminum hydroxide of the bayerite structure, for use as effective filler and retardant in cable insulation and other polymer compositions. The preparation of highly dispersed bayerite is carried out by neutralization of an alkaline aluminate solution with bicarbonate or soda-bicarbonate solution to the residual content of the sum of caustic alkalis in terms of Na₂O in a mixed solution of 1-15 g/l with the formation and subsequent decomposition of a gel with the release of a solid phase. In this case, the desilicated aluminate solution is neutralized with mother liquor after the separation of alumina from the aluminate solution. Neutralization is carried out at a temperature of 56-100ºC for no more than 60 seconds. The solid phase after neutralization is kept for 15-120 minutes and washed with clean water until the residual electrical conductivity of the washing water is no more than 300 mcS/cm.

EFFECT: method provides minimization of the energy costs for obtaining highly dispersed precipitated aluminum hydroxide of the bayerite structure, as well as the most complete adaptation of its production to the conditions of alumina plants that process nepheline raw materials using the sintering method.

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