The average particle size of aluminium hydroxide can be achieved by varying the specific surface area of the crystalline species, the decomposition temperature, the form of stirring, etc. The method is a simple process, easy to achieve mass production and can produce aluminium hydroxide micronized in various particle sizes by controlling the decomposition conditions according to the market demand.

Special aluminium hydroxide is added to the refined solution of sintered sodium aluminate at a predetermined decomposition temperature according to a certain seed and stirred to decompose, and the decomposition is stopped after the decomposition rate is reached, and the various physical and chemical indicators of the product are tested and analysed.