Silicon Carbide (SiC) Manufacturing Process

Raw Materials of Silicon Carbide (SiC)

Main materials are silica sand and carbon; accessory materials are sawdust, salt and return scraps.

(1) Silica Sand (SiO₂), also called quartz sand: River sand, sea sand and vein quartz are frequently used for smelting SiC. River sand and sea sand are used for smelting black SiC, and vein quartz for green SiC. The grit size of silica sand will not only affect the silicon's production but also the power consumption, so it's better to choose those of good quality and small particle size.

(2) Carbon: Provid SiC with needed cabon. Petrolum coke, pitch coke and low ash coal are commonly used.

(3) Sawdust: Increase the permeability and Expand the reactionzon.

(4) Salt: Composition percertage within 97%-99%; grit size is less than 2mm. When smelting green SiC, adding salt can accelerate out impurities for purification and catalyzing, but not necessary in smelting black SiC. 

Manufacturing Process 

Resistance furnace is the main equipment for smelting SiC. It mainly works in two ways: one is to put the matched materials into the furnace's reaction zone directly; while the other into the next reaction zone of the furnace for smelting. The detailed process can be directed as: burden—shove—smelt—cool down & griddle—desalt—tap off & grade—pelletize.