| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a highly zirconia-based refractory suitable for use in electric melting furnaces which has a high electrical resistivity at high temperatures and does not exhibit a chipping-off phenomenon in which the refractory surface partially chips off at elevated temperatures, and which, even when in contact with a molten low-alkali glass, is reduced in the extraction of components therefrom and, hence, rarely cracks during operation. <P>SOLUTION: There is provided a highly zirconia-based refractory including as chemical components 85-95 mass% (inner base) ZrO<SB>2</SB>, 3.0-10 mass% (inner base) SiO<SB>2</SB>, 0.85-3.0 mass% (inner base) Al<SB>2</SB>O<SB>3</SB>, substantially no Na<SB>2</SB>O, 0.01-0.5 mass% (outer base) K<SB>2</SB>O, 1.5-3.0 mass% (inner base) SrO, and Nb<SB>2</SB>O<SB>5</SB>and/or Ta<SB>2</SB>O<SB>5</SB>in an amount of 0.1-2.0 mass% (inner base) in terms of a value obtained from [(Nb<SB>2</SB>O<SB>5</SB>content)+(Ta<SB>2</SB>O<SB>5</SB>content/1.66)]. <P>COPYRIGHT: (C)2011,JPO&INPIT |
