Non-metallic building materials for industrial furnaces, namely, non-metallic trays composed primarily of carbon composite material, non-metallic trays formed of carbon, non-metallic grates composed primarily of carbon composite material, non-metallic grates composed primarily of carbon, non-metallic hearths composed primarily of carbon composite material, non-metallic hearths composed primarily of carbon, non-metallic plates composed primarily of carbon composite material, non-metallic plate...