METHOD OF DECOMPOSING ALUMINATE SOLUTIONS Russian patent published in 2017 - IPC C01F7/14 

FIELD: metallurgy.

SUBSTANCE: invention can be used in processing of low-quality aluminum-containing material, including nephelines. Decomposition of aluminate solution is performed by way of carbonization with gases containing CO₂, at temperature from 20 to 40 °C at initial concentration of caustic alkali in a solution from 26 to 95 g/l in terms of Na₂O_k and alumina to caustic ratio of solution from 1.5–1.9. Content of CO₂ in gas from 12 to 98 %. Rate of neutralisation of caustic alkali in terms of Na₂O_k from 2.2 to 80 g/l⋅h. Process is carried out until achieving required concentration of alkali and degree of decomposition of aluminate solution. Aluminum hydroxide formed during carbonization, is separated from liquid phase and processed on alumina.

EFFECT: invention enables to obtain finely dispersed aluminum hydroxide and alumina based thereon with a given average particle diameter, corresponding to crystalline structure of gibbsite and having an isometric shape or corresponding crystalline structure of bayerite and having a plate or spherical shape, higher yield of aluminum hydroxide.

1 cl, 6 dwg