| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably produce, in an industrial scale, spherical silica powder having excellent dispersibility fluidity, filling property and the like, and excellent as a filter to be used for preparing various resin compositions. SOLUTION: This process comprises the steps in which siliceous raw material powder is injected into high temperature flame formed by a combustible gas and a supporting gas to heat-treat the siliceous powder, subsequently the treated powder is classified, and spherical silica particles of desired particle sizes are collected, wherein cooling gas is supplied from the position higher than the top of the high temperature flame, being separated from the flame. The apparatus for manufacturing spherical silica powder is provided with a burner (2) on the upper part of the furnace body of a vertical type furnace (6), and a collecting apparatus linked to the lower part of the furnace. In the manufacturing apparatus, a partition wall (4) is placed in such a state that the high temperature flame (3) formed by the above burner is surrounded, and a feeding port (5) for a cooling gas is placed on a side wall of the furnace body so that the cooling gas can be supplied between the partition wall and the above furnace body.</p> |
