METHOD FOR PRODUCING SILICON CARBIDE POWDER Russian patent published in 2023 - IPC C01B32/97 C01B33/00 

FIELD: production of silicon carbide powder.

SUBSTANCE: production of silicon carbide powder used as a source for growing single crystals of silicon carbide. To obtain silicon carbide powder, silicon dioxide and carbon are mixed, the resulting mixture is placed in a vacuum furnace, the furnace is filled with an inert gas, and the mixture is subjected to heat treatment in an inert gas atmosphere, followed by annealing of excess carbon in air. The initial components are mixed in the ratio SiO₂:C = 1:(3.2-4.0) (mol.). The thickness of the initial mixture layer is proportional to the square of the average grain diameter of the carbon powder and should not exceed 15-18 cm for an average grain diameter of 120 mcm at a bulk density of 0.6-0.8 g/cm³. Heat treatment in a vacuum furnace is carried out in two stages: first, for 4-5 hours at an inert gas pressure of 0.02-0.03 MPa and a temperature of 1600-1700°C, then reheat and hold at a temperature of 1900-2000°C for 1-2 hours at a pressure of 0.05-0.06 MPa.

EFFECT: invention makes it possible to increase the yield of alpha phase silicon carbide powder.

1 cl, 1 dwg, 1 tbl