Refractories – Raw Materials for Al-Si-Refractories

Raw Material Formula Al2O3 Fe2O3 K2O+Na2O
Fireclays Al2O3•2SiO2•2H2O 25 – 45 1.5 – 3.5 1 – 2
(Kaolin, Ball, Fire, Flint)
Sillimanite Al2O3•SiO2 45 – 65
Kyanite Al2O3•SiO2 45 – 65
Andalusite Al2O3•SiO2 45 – 65
Bauxite Al2O3•2H2O 80 – 90 < 2.0 0.02 - 0.6 (Calcined Refractory Grade)