CHROMIUM OXIDE PRODUCTION PROCESS Russian patent published in 2005 - IPC

FIELD: industrial inorganic synthesis.

SUBSTANCE: invention relates to production of chromium oxide appropriate for use in manufacture of magnetic media as well as primers, enamels, paints, polishing pastes, abrasive material, and metallic chromium. Process comprises decomposition of sodium bichromate and ammonium sulfate, which is conducted in solution having concentration 400-450 g/L for CrO₃ at 100-105°C for 45-60 min at constant stirring to form ammonium bichromate and sodium sulfate. The latter is separated from solution and ammonium bichromate-containing solution is cooled to crystallization temperature, after which ammonium bichromate crystals are submitted to thermal decomposition at 440-1400°C to form chromium oxide.

EFFECT: simplified process, improved quality of chromium oxide due to reduced content of impurities and increased content of chromium oxide, and enabled production of chromium oxide for various destinations.