摘要 |
A method for producing an ultra fine silica powder, which comprises subjecting a raw material mixture containing a silica powder, a reducing agent comprising a metal silicon powder and/or a carbon powder, and water, to heat treatment at a high temperature in a reducing atmosphere with an oxygen concentration of less than 1 wt % to generate a SiO-containing gas, immediately cooling said gas in an atmosphere containing oxygen, and collecting fine particles.
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