The knotting material is made of high-purity quartz and fused silica as the main raw materials, and composite additives are used as the sintering agent; the neutral knotting material is mainly composed of alumina and high-aluminum materials, and the composite additive is used as the sintering agent; basic knotting The material is made of high-purity fused corundum, high-purity fused magnesia, and high-purity spinel as the main raw materials, and composite additives as the sintering agent.