SIC REFRACTORY RAW MATERIAL AND ITS PREPARATION, AND SIC REFRACTORY OBTAINED BY USING THE SAME

摘要

PURPOSE:To provide an uniform, stable SiC refractory excellent in high- temperature durability, virtually free from any deformation and dilation even if used at high temperatures for a long time, also developing no cracks, thus having excellent thermal shock resistance, suitable for the shelf boards for burning ovens. CONSTITUTION:The first objective SiC refractory raw material can be prepared by incorporating (A) =60wt.% of SiC particles containing (1) 10-50wt.% of SiC particles 21.5-5.0mm in diameter and (2) 70-10wt.% of SiC particles 1=0.1mm in diameter with (B) an auxiliary binder, (C) an antioxidant, (D) 2-8wt.% of water, and (E) an organic binder, followed by granulation to =10mm in mean granular diameter. This raw material is so designed that =50wt.% of the resulting granules 3 enclose the SiC particles 2 and the granules consisting of SiC particles =1.0mm in diameter account for =25wt. of the whole material. The second objective SiC refractory is =2.0 in the weight ratio of cristobalite to the SiC existing in the surface layer and inner layer (Cri/SiC).