METHOD OF PRODUCING POLYDISPERSE BORON CARBIDE POWDER Russian patent published in 2016 - IPC C01B31/36 C01B35/00 

FIELD: chemistry.

SUBSTANCE: invention relates to production of inorganic compounds, specifically to carbothermal method of production of polydisperse powders of boron carbide, designed for making an abrasive powders for grinding and shockproof ceramics. Method involves mixing of boric acid and soot, compaction of the mix, its dehydration to produce a sinter of boric anhydride with carbon, carbothermal reduction of boric anhydride to obtain boron carbide powder and cooling. Before mixing the soot is subjected to thermal treatment, the mix is dehydrated is as follows, it is initially heated to 140-160°C and held for 0.5-1 hours, then heated to 240-260°c and held for 0.5-1 hours, then heated to 380-430°c and held for 1-1.5 h, after which the carbothermal reduction of boric anhydride to 700°C is carried out in vacuum, and further heating to 1800-1850°C is carried out at a rate of 4-6 deg/min in a current of argon and held for 2-3 hours after that cooling is performed in vacuum.

EFFECT: result consists in development of effective method of producing high-quality chemically pure polydisperse boron carbide powder of preset grain composition from 5 to 150 mcm, which does not require intense crushing.

1 cl, 2 tbl, 1 ex