| 摘要 |
FIELD: chemical technology. SUBSTANCE: aluminium hydroxides (or oxides) were subjected for thermosteam treatment using crystallization activating agents of different origin. Treatment with steam is carried out in high pressure vessels under pressure 30-400 atm at 350-400 C. Activating agent taken at amount 0.01-1% of parental substance weight (for example, hydragillite) is applied on aluminium hydroxide or oxide surface by adsorption from an aqueous solution. Treatment is carried out for 1-5 days. Method ensures to obtain corundum crystals of size from 10 to 300 mcm and required habitus: bipyramidal, prismatic, rhombohedral and pinacoidal (plates) since activating agents exhibit selectivity of action. Obtained product can be used as abrasive material and raw for ceramics making and sapphire monocrystal growing. Proposed method provides preparing finely crystalline corundum of formula (α-AlO) of required habitus. EFFECT: control of corundum crystal morphology. |
