The effect of adding andalusite is better
The higher the impurities, there is no need to add some expensive performance-improving raw materials. But you can mainly choose high purity raw materials to proporly increase the performance of the clay brick, such as thermal shock. You can change relatively high-grade refractory brick. It depends on your conditions of usage if the requirement is strict. The thermal shock resistance of clay brick itself is not bad, and will almost all be affected, because the clay brick is very cheap, inside the glass phase more. Creep.