Method for producing silicon using microwave, and microwave reduction furnace

摘要

A method for producing silicon using microwave and a microwave reduction furnace for use therewith are disclosed, with which it is possible to quickly reduce silica to quickly produce silicon. A material of a mixture of a silica powder and a graphite powder of a mixture of a silica powder, a silicon carbide powder and a graphite powder is set in a refractory chamber. Then, the material set in the chamber is irradiated with microwave. The graphite powder absorbs a microwave energy to increase the temperature, after which silica and graphite react with each other to further increase the temperature while producing silicon carbide, and the heated silica and silicon carbide react with each other. SiO produced through this reaction and silicon carbide are allowed to react with each other, thereby producing high-purity silicon.

主权项

1. A method for producing silicon using microwave, the method comprising:
supplying a material of a mixture of a silica powder and a graphite powder or a mixture of a silica powder, a silicon carbide powder and a graphite powder into a refractory chamber of silica or silicon carbide; irradiating the material in the chamber with microwave so that the graphite powder absorbs a microwave energy to increase a temperature, and a reduction reaction is allowed to occur between the silica and the silicon carbide and/or the graphite after the temperature is increased, thereby producing an SiO gas as an intermediate product, and the SiO gas is allowed to be in contact with silica, graphite and/or silicon carbide while preventing the SiO gas for reaction from escaping out of the refractory chamber, thus reducing silica through a gas-solid reduction reaction, thereby allowing for continuous production of molten silicon; and discharging the molten silicon out of the chamber; passing generated discharge gas containing CO gas and unreacted SiO gas through a cyclone; and retrieving the unreacted SiO gas from said discharge gas in the cyclone and capturing Si.