ELECTROCHEMICAL METHOD OF PREPARING ALUMINIUM OXIDE Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: electrochemical oxidation of metallic aluminium in aqueous ammonium chloride solution NH₄Cl having concentration of 5-25 wt % is carried out using alternating sinosoidal current at industrial frequency of 50 Hz and current density of 0.1- 2.0 A/sq.cm within temperature range of 50-90 C. Gel thus formed is washed off and heat treated. The resulting gel has good specific surface for calcining samples at various temperatures. EFFECT: more efficient electrochemical method. 1 tbl