Refractory Materials are usually non-metallic materials having those chemical and physical properties that make them applicable for structures, or as components of systems, that are exposed to environments above 1,000 °F (811 K; 538 °C)。

Kao lin

Used in ceramics, glass, paper-making and chemical industries.
Al2O3: 35% min
SiO2: 60%min
Fe2O3: 0.5% max
Packing: in plastic woven bags of about 25/50 kg net each.