| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain black quartz glass having high shieldability by reducing niobium pentoxide sufficiently, when a mixture of niobium pentoxide and quartz glass powder is heated and melted.SOLUTION: A mixture raw material 4 of 25 g niobium pentoxide and 4 kg quartz glass powder is filled into a tool 1 formed by spreading a carbon felt 3 over the inside of a box-like container 1 formed by combining carbon plates 10 each having a gas discharge hole 2, and covered with a carbon felt 31, and a lid 11 of the carbon plate having the gas discharge hole 2 is placed on the container 1, and then the inside of an electric furnace is heated at 1800°C in the vacuum state, to thereby melt the mixture raw material 4. Obtained black quartz glass has similar shieldability to conventional product with the thickness of 3 mm or more.</p> |
