Selected quality quartz as materials, combined with advanced ceramic processing workmanship, mainly used for platinum, gold, and other high temp alloy melting, high purity, anti-corrosion . The main component SiO2≥99.0％, and other materials （K2O、Na2O、Fe2O3）less than 0.10％, good hardness, compress resistance ≥70MPa, high thermal shock resistance.