High-cleanliness boehmite, preparation method thereof, boehmite slurry and preparation method thereof

The invention belongs to the field of new materials, and particularly relates to high-cleanliness boehmite and a preparation method thereof as well as boehmite slurry and a preparation method thereof. The particle size of the high-cleanliness boehmite is 0.1-3 microns, and the content of + 25-micron magnetic foreign matters is less than 30/kg. The preparation method of the high-cleanness boehmite is characterized by comprising the following steps: S1, adding water into a boehmite raw material to prepare boehmite slurry; s2, carrying out crystal form conversion through a hydrothermal reaction; s3, slurry cleaning; s4, filtering water to obtain blocky boehmite; s5, drying with superheated steam; and S6, removing magnetic foreign matters to obtain the high-cleanliness boehmite. The preparation method has the beneficial effects that the blocky boehmite powder obtained through superheated steam drying is relatively good in dispersity, magnetic foreign matters are easy to remove, in the obtained micron boehmite, th