Method for producing spherical silica powder

Abstract

To provide a novel method for producing spherical silica powder, which results in less precipitation of fume components and thereby yields spherical silica powder with a low specific surface area. [Solution] (i) forming a high-temperature flame in a furnace with flammable gas A and oxygen gas B, (ii) supplying base gas C into the furnace, and (iii) supplying raw silica powder into the furnace with carrier gas D to melt and spheroidize the raw silica powder, wherein in (ii), base gas C contains oxygen gas B1, in (iii), carrier gas D contains oxygen gas B2 and inert gas D1, or contains only inert gas D1, in (i), oxygen gas B contains a part of oxygen gas B1 and / or a part or all of oxygen gas B2, and in (i) to (iii), the amount of flammable gas A supplied (Nm 3 The amount of inert gas D1 supplied (Nm³) relative to the amount of inert gas D1 ( / hr) 3 A method for producing spherical silica powder, comprising setting the ratio (D1 / A) of ( / hr) to 1.0 or more and 7.0 or less.

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