THE HYDROXIDE ALUMINUM MANUFACTURING METHOD WHICH USES THE ALUMINIUM DROSSES

摘要

PURPOSE: A method for manufacturing aluminum hydroxide using aluminum dross is provided to improve the collecting rate of the aluminum hydroxide by reacting the aluminum dross and a caustic soda aqueous solution. CONSTITUTION: Aluminum dross is prepared as a raw material(S100). Impurities are eliminated from the raw material(S110). The raw material is introduced into a sealed container filled with a caustic soda aqueous solution. A high temperature and pressure is applied to the raw material in order to obtain a sodium aluminate solution(S120). Hydrogen carbonate and hydrogen are trapped(S130). Ammonia is trapped(S140). The sodium aluminate solution and residue are separated. The separated residue is washed with washing water and is dried. The separated aluminate solution is mixed with Al(OH)_3 and is precipitated. The precipitate is filtered to separate aluminum hydroxide and a remained solution. The separated aluminum hydroxide is washed and dried.