METHOD FOR PRODUCTION OF CHROMIUM BORIDE Russian patent published in 1994 - IPC

FIELD: production of chromium bromide. SUBSTANCE: process of melting of product per block in ore-smelting electric furnace is carried on with use of charge in which relation between boron trioxide and chromium sesquioxide and carbonin charge to sum of chromium and boron oxides equal 0.3-0.45 and 0.25-0.4, respectively. Then, block produced in ore-smelting furnace is subjected to fine grinding with subsequent sieving to separate class of minus 0.4 and useful fraction is subjected to gravitation-air cleaning up to carbon concentration of 1.0-2.0. Produced intermediate product is subjected to final grinding to size of minus 0.4 mm, mixing with sifting, fraction of minus 0.2 is sifted, and remaining part is subjected to gravitation air or hydraulic cleaning from free carbon to concentration of 0.5-1%. Then, semifinished product is subjected to final grinding up to size of minus 0.2, mixing with siftings, hydraulic cleaning from free carbon and subsequent treatment with mineral acids. EFFECT: higher efficiency. 4 cl, 6 tbl