The two-piece mullite lightweight insulation brick is a new type of high-performance refractory material carefully developed by Rongsheng Kiln Refractory Co., Ltd. It has the characteristics of high temperature resistance, light weight, and low thermal conductivity. It is widely used in the lining of high-temperature equipment such as cracking furnaces, hot blast furnaces, and ceramic roller kilns to optimize the high-temperature working environment and achieve energy saving effects. The insulation brick is mainly composed of mullite (3Al2O3·2SiO2), usually containing 65% to 75% alumina. Depending on the alumina content, it also contains a small amount of auxiliary components such as glass phase, quartz or corundum. The product has a refractoriness of more than 1790°C, a load softening start temperature between 1600 and 1700°C, a compressive strength range of 70 to 260MPa at room temperature, and excellent thermal shock resistance. The two-piece mullite lightweight insulation brick includes sintering and electric melting. Sintered mullite bricks are made of high-alumina bauxite clinker as raw material, and are formed and fired. The fused mullite bricks are made of high-purity bauxite and industrial alumina as raw materials, and are melted by reducing electric melting with appropriate reducing agents, so that the crystals are larger and have strong thermal shock resistance. Its high-temperature performance mainly depends on the uniform distribution of alumina content and mullite phase. While improving the high-temperature resistance of the furnace body, the product also helps enterprises reduce energy consumption and production costs.