METHOD OF DEPOSITION AND CLASSIFICATION OF ALUMINUM HYDROXIDE Russian patent published in 2005 - IPC

FIELD: production of alumina.

SUBSTANCE: proposed method includes delivery of supersaturated aluminate solution into cooling loops by two flows; lesser flow is delivered to agglomeration stage and larger flow is directed to two crystal growth stages; after agglomeration stage, pulp is combined with part of larger flow directed to first crystal growth stage. After each crystal growth stage, pulp is subjected to classification; after first crystal growth stage, three stages of classification are performed for obtaining unloading flows. Finely-dispersed particles obtained in discharge of third classification stage are directed for agglomeration. After second crystal growth stage, classification is performed in one stage at obtaining production aluminum hydroxide; unloading flows obtained after each stage of three-stage classification performed after first stage of growth are used for seeding at two growth stages; granulometric composition of production hydroxide thus obtained is controlled by partial redistribution of unloading flows of classifiers. Proposed method makes it possible to increase size of aluminum hydroxide without reduction of deposition loop productivity and to reduce production floor at agglomeration and classification stages.

EFFECT: enhanced efficiency.

1 dwg, 2 tbl