A principally new method for obtaining fine dispersed corundum from technical-grade gibbsite is proposed. This method includes the treatment of initial aluminium hydroxide with lithium salts at 90-95 °С. After this, the hydroxide is calcined without fluorinating agents at a temperature of 1150-1200 °С. Diluted aqueous solutions of lithium salts after concentrating are repeatedly used at the initial stage of the process.
Specific surface | 10 -15 m2/g |
Size of primary corundum particles | 0.2 - 0.3 mm |
Size of secondary particles | 1 - 3 mm |
Sodium content | 0.01 - 0.02 % |