The main crystalline phase in high-aluminum products is mullite and corundum. The content of corundum increases with the increase of alumina content. Corundum products containing more than 95% alumina are a kind of high-quality refractory material with wide application. The chrome brick is mainly made of chrome ore and the main crystalline phase is chromite. It has good corrosion resistance to steel slag, but has poor thermal shock resistance and low temperature deformation temperature. The chrome-magnesia bricks made of chrome ore and magnesia in different proportions have good thermal shock resistance and are mainly used as alkaline flat roof bricks.