Cihly s vysokým obsahem oxidu hlinitého jsou typem žáruvzdorného materiálu a hlavní složkou této žáruvzdorné cihly je Al2O3.
If the Al2O3 content is higher than 90%, it is called corundum brick. Due to different resources, national standards are not completely consistent. For example, European countries have set a minimum Al2O3 content of 42% for high alumina refractory materials. In China, the Al2O3 content in high alumina bricks is usually divided into three classes: Class I - Al2O3 content>75 procent; Třída II - obsah Al2O3 je 60-75 procent; Stupeň III – Obsah Al2O3 je 48-60 procent.
