Abstract: Laboratory and industrial experiments were carried out to study the possibility of producing high purity purity mullite-corundum thermal insulating firebricks. The results show that by using industrial alumina, natural powder power, coal gangues and a small amount of additives. high purity mullite-corundum thermal insulating firebricks can be produced The service. temperature of these brick can be up to 1780℃ with low. thermal conductivity and good thermal shock resistance.