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)。

China clay

For manufacture of ceramics, porcelain and sanitary wares.
Grade 1:
Al2O3: 24% min
SiO2: 56-65%
Fe2O3: 1%max Grade 2:
Al2O3: 38% min
SiO2: 45%
Fe2O3: 0.3% max
Moisture: 15% max (exceeding part, if any, to be deducted from weight)
Packing: 1. in bulk 2. in plastic woven bags of about 25/50 kg net each.