FIELD: chemistry.
SUBSTANCE: present invention relates to a method for the production of aluminum alpha-oxide. The method includes at least following stages: i) obtainment of a boehmite suspension containing boehmite, wherein sizes of boehmite crystallites in the boehmite suspension are in the range from 3.0 nm to 6.5 nm along (120) axis and from 3.0 nm to 6.0 nm along (020) axis; ii) aging of the boehmite suspension to obtain the aged boehmite suspension containing boehmite particles with a modified size of crystallites having (120) axis and (020) axis, wherein aging is carried out at a temperature from 30°C to 240°C for a period of time from 0.5 hours to 170 hours until: a) the difference between a length along (120) axis and a length along (020) axis of aged boehmite particles is from 0.05 to 1 nm, or b) a size of crystallites of aged boehmite particles along (120) axis is from 30 nm to 100 nm, or c) both a) and b) are met; iii) drying of the aged boehmite suspension to obtain dried boehmite, and iv) calcination of dried boehmite at a temperature from 1300°C to 1400°C for a period of calcination time from 1 hour to 5 hours to obtain aluminum alpha-oxide with a degree of purity from 99.99% to 99.9996%, relative density from 90% to 97.9%, and specific surface determined by the Brunauer-Emmett-Teller method (BET) from 4 m2/g to 10 m2/g. A method for the production of ceramic products or composite products by means of application of pressure and/or sintering of the resulting aluminum alpha-oxide is also disclosed.
EFFECT: obtainment of aluminum alpha-oxide with high purity, high density, and low specific surface, and, in particular, use of the resulting aluminum alpha-oxide in the production of sapphires or in the production of composite and ceramic products.
14 cl, 2 tbl, 5 ex
