Mullite, aluminum silicate refractory, is generally used in stainless steel precision casting process. Refractoriness is about 1750 degrees, the higher the aluminum content in mullite sand, the lower the iron content and the smaller the dust, the better the quality of mullite sand products. Mullite is kaolin sintered at high temperature. Mullite production area is mainly distributed in Shandong Zhangqiu and Anhui Huaibei and other places, Shandong Zhangqiu Jujinbao Casting Material Co., Ltd. produced by Mullite compared with other areas of the product low impurity content, high volume density, good fire resistance, for precision casting preferred.

      Mullite can be classified into 8-16 mesh, 16-30 mesh, 30-60 mesh, 60-80 mesh and 80-120 mesh. Mullite powder generally has 200 mesh, 300 mesh and so on.

      In the precision casting process,

      General surface slurry, zirconium powder: 325 mesh + silica sol sand: zirconium sand 120 mesh

      Back layer slurry: 325 mesh + silica sol + Mullite powder 200 mesh sand: Mullite 30-60 mesh

      Reinforcement layer: mullite 200 mesh + silica sol sand: Mullite 16-30 mesh

      Sealing slurry: Mullite powder 200 mesh + silica sol

      YB/T5207-2005 National Enterprise Standard:

      General chemical composition: 46%≥Al₂O₃≥42%, 53%≥SiO₂≥51%, 1.2≤Fe₂O₃1≤1.5%, Na₂O+K₂O≤0.3%, CaO+MgO₂≤0.6%, TiO₂≤0.1%. Physical indicators: density ≥2.5g/cm3, true specific gravity >2.6g/cm3, water content < 0.03%, refractoriness ≥1750℃, burning reduction ≤0.3-0.4%, dust content ≤0.01-0.03%, PH value 7-9, shell hardness > 8.0mpa.

      Advantages: casting, easy to shell, no deformation, not easy to scale, good finish, high yield.