Mullite Finish
1. Low creep mullite brick
Using synthetic mullite clinker, super high bauxite clinker as raw material, adding some high purity quartz and additives, low creep mullite brick can be made.
The molding is carried out on a 300t friction press. The bulk density of the billet should be controlled above 2.70g/cm3. The billet is dried at 50 ~ 110℃ and the drying time is 16h. The residual moisture of the body after drying should be less than 0.5%. The maximum firing temperature of the product is 1600℃, and the heat preservation is 16h. The physical indexes of the products are as follows: apparent porosity 19 ~ 21%; Bulk density 2.55 ~ 2.60g/cm3; Compressive strength 69 ~ 116MPa; 1450°C, 50h pressure creep rate 0.12%.
2. Low creep sintered mullite brick
Sintered mullite brick can be made by using andalusite as aggregate, sillimanite as intermediate particle, sillimanite powder, bauxite powder, industrial alumina powder and clay powder as substrate.
The sintering temperature is 1490℃, holding for 19h, the porosity of the product can reach 17.15%, the bulk density is 2.53g/cm3, the pressure strength at room temperature is 136.5MPa, and the load softening temperature is 1627℃. At 1450℃, the creep rate can reach 0.87% for 50h. If the firing temperature is 1450℃ and the holding time is extended to 26h, the purpose of sintering can also be achieved. However, the physical performance index is lower than that of the products fired at 1490℃. For example, at 1450℃, the creep rate for 50h is 0.98%.
