The main raw materials of black silicon carbide abrasive are quartz sand and petroleum coke, which are then smelted at high temperature in a resistance furnace. If you want to make green silicon carbide, you need to add the right amount of salt to the charge.
To smelt silicon carbide, the furnace must first be set inside a batch resistance furnace. The two ends of the resistance furnace are the end walls, and there are graphite electrodes near the center of the furnace. The furnace core body is connected between the two electrodes. A furnace is also arranged around the furnace core, mainly to participate in the reaction, and a heat preservation material is provided outside the furnace.
When making silicon carbide, after the electric furnace is energized, the temperature of the furnace core will rise to 2600-2700 °C. The electric heat will be transferred to the furnace through the surface of the furnace core. When the temperature reaches above 1450 °C, a series of chemical reactions will occur, and eventually silicon carbide will be formed and carbon monoxide will be released. As the heating time increases, the high temperature range of the furnace will also increase, and the resulting silicon carbide will also increase.
Silicon carbide will continue to form in the furnace, this process will evaporate and move and crystallize, and finally gather into a cylindrical crystal cylinder. When the inner wall of the crystallizing cylinder begins to decompose at a high temperature of over 2600°C. The decomposed silicon combines with the carbon in the furnace, eventually forming new silicon carbide.
After refining, the materials in the furnace will form unreacted materials, silicon oxycarbide layer, adhesive layer, amorphous layer, second-grade silicon carbide, first-grade silicon carbide ingots, Furnace core body graphite and other material layers.
