The invention relates to a preparation method of
alumina powder. The preparation method of the
alumina powder comprises the following steps:
metal aluminum and a
quaternary ammonium base
aqueous solution react in a hot bath to prepare an aluminum
hydroxide precipitate, the aluminum
hydroxide precipitate is filtered, washed, dried, calcined at high temperature and crushed to prepare alpha-phase
alumina powder and gamma-phase alumina powder, and the
quaternary ammonium base
aqueous solution is still used as filtrate capable of being repeatedly used. A
quaternary ammonium base is an
organic base with a
structural formula of R1R2R3R4NOH, wherein R1, R2, R3 and R4 can be same (or different)
alkyl groups (or aromatic groups). The invention has the advantages of low technological condition requirements,
environmental protection, low cost and good product repetitiveness, is particularly suitable for
mass production and can prepare high-pure ultra-fine alumina powder if high-pure aluminum sheets are adopted as an aluminum source, thereby being applied to the fields, such as high-
voltage sodium lighting tubes, long-
afterglow luminescent materials, tricolor fluorescent powder, advanced
grinding materials, artificial lenses, and the like.