alumosilikaatne tulekindel materjal Al2O3-sisaldusega üle 45 %, a refractory containing substantial amounts of alumina (Al2O3) that reacts with silica (SiO2) to form mullite (aluminosilicate material 3Al2O3. 2SiO2 to 2Al2O3.SiO2) when fired to high temperature; used in applications where severe temperature and load conditions exist