The for sliding valve it justifies and above 80wt is contained the silica sand which 65 - 90wt and,

摘要

PROBLEM TO BE SOLVED: To provide a plugging material for sliding nozzle excellent in natural opening ratio. ;SOLUTION: The plugging material for sliding nozzle is the one composed of mixed material of 65-90 wt.% silica sand containing ≥80 wt.% SiO₂ and granular formed material granulated as spherical having 0.1-3.0 mm average grain diameter, ≥0.5 apparent bulk sp. gr. and ≤1150°C m.p. and forming a sintered layer by vitrifying at ≤1200°C. The granular formed material consists essentially of CaO and SiO₂, and 0.5-1.5 CaO/SiO₂ and ≥3 wt.% alkali component content, ≥1 wt.% fluorine compound content and ≥0.2 wt.% carbon content in the silica sand.;COPYRIGHT: (C)1998,JPO