Acheson Method For Sic Prduction

The shape of the traditional Acheson resistance furnace is like a rectangular trough, which is a hearth made of refractory bricks. Two sets of electrodes penetrate into the furnace bed through the furnace wall, and the special graphite powder furnace core is arranged between the electrodes to provide a conductive channel, which generates a lot of heat when it is energized. The furnace core body is filled with raw materials composed of siliceous raw materials, petroleum coke and wood chips, and the outside is thermal insulation material.

During smelting, the resistance furnace is energized, the temperature of the furnace core body rises, reaching about 2600 ° C, and the heat is transferred to the surrounding mixture through the surface of the furnace core body, so that it reacts to form silicon carbide, and CO gas escapes. Carbon monoxide burns on the furnace surface to carbon dioxide, forming a soft, undulating blue to yellow flame blanket, and a small fraction of the burning carbon monoxide enters the air. After the reaction is complete and cooled, the furnace wall can be dismantled, the charge is classified and sorted by layers, and the required particle size is obtained after crushing, and impurities are removed by water washing, acid-base washing, magnetic separation, etc. to improve the purity, and then dried and screened. Get the finished product.

The Acheson method has simple equipment and low investment, and is widely used in SiC smelting factories on stone steps. However, the main disadvantage of this method is that the pollution caused by dust and waste gas cannot be avoided, the waste gas discharged from the smelting process cannot be collected and reused, and the heavy manual labor during reclaiming and grading cannot be alleviated. At the same time, the length of the furnace is not enough, usually only a few meters to Dozens of meters long, the production economy is not high.