| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a silica glass block in which, by markedly reducing the bubbles within the silica glass block, the quality of a silica glass block can be improved, contamination of the silica glass block can be prevented, and the yield of the silica glass block can be improved. <P>SOLUTION: The method comprises: a preparing step for preparing a natural or synthetic silica raw material powder; a packing step for packing the silica raw material powder into a glass melting furnace; a preheat treating step for preheat-treating the silica raw material powder packed into the melting furnace; a melting step for heating and melting the preheat-treated silica raw material powder; and a cooling step for cooling a silica glass melt melted in the melting furnace, wherein the silica raw material powder packed into the melting furnace is closely packed to close packing density in the packing step, and an evacuation and a rare gas or H<SB>2</SB>gas introduction treatment are performed in the preheat treating step. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
