Silicon carbide (SiC) is made from quartz sand and petroleum coke or coal tar, wood chips and other raw materials by smelting in high temperature electric resistance furnace . In the high technology non-oxide refractory raw materials , such as C, N, B ,silicon carbide is the most widely used and one of the most economic material. It can be called corundum or refractory sand. In China, there are two kinds of silicon carbide: Green Silicon Carbide and Black Silicon Carbide.
Main Chemical Composition
The main chemical composition of Silicon carbide is SiC. Green silicon carbide containing SiC more than 97%, black silicon carbide containing SiC more than 95%.
Colour
Black silicon carbide is black, so named black silicon carbide.
Green silicon carbide is green, so named green silicon carbide.
Smelting
Black silicon carbide is made from petroleum coke, quartz sand, sawdust by smelting in the resistance furnace.Raw materials of green silicon carbide is similar with black silicon carbide production , the other processing salt as reaction agent and accelerator in the resistance furnace.
Texture and Application
Compared with corundum abrasives, black silicon carbide is crisper and harder. Its toughness is inferior to corundum abrasives.
For tensile strength of the base material, such as non-metallic materials (all kinds of sheet such as wood plywood, particle board, including density fiber board, bamboo board, calcium silicate board, leather, glass, ceramic, stone, etc.) and non-ferrous metals (aluminum, copper, lead, etc.) and other materials processing, black silicon carbide is especially suitable. For processing of hard and brittle materials it is also ideal abrasive.
Green silicon carbide more purer and harder than black silicon carbide.The grinding usage of green silicon carbide is same as black silicon carbide. And the green silicon carbide is more suitable for materials of fine grinding, such as thread, grinding measuring tool in a wider range of grinding material artifacts for hard alloy, diamond products.
Because the green silicon carbide in the cost of production is higher than the black silicon carbide(such as using different ratio of raw material, plus a salt auxiliary materials and power consumption and processing, etc.), so the green silicon carbide products are sold at a higher price than the black silicon carbide.
On the comparison with black silicon carbide, in terms of nonmetal and non-ferrous metal materials，it is generally not choose green silicon carbide, and choose green silicon carbide use in the main grinding hard alloy and precision grinding. As grinding material, green silicon carbide is less used in the abrasive belt and other coated abrasive.