Since the early 1950s, magnesia chrome refractories have been used in the high temperature zone of cement rotary kilns. In the 1960s, magnesia chrome bricks have been developed to combine directly with magnesia chrome bricks, which have better properties and have become the leading materials used in the high temperature zone of large cement rotary kilns.
Since the 1980s, the problem of "chromium pollution" caused by chrome containing refractories has been put on the agenda. It is considered that the metal oxide of trivalent chromium reacts with the alkali salt in the material at high temperature to form hexavalent chromium compound, which is a water-soluble carcinogen and pollutes the environment. Therefore, it is necessary to seek to replace the chrome containing alkaline brick with chrome free alkaline brick.
Based on the consideration of environmental protection, in order to create chrome free green refractories, many domestic manufacturers actively explore and research. The development process of refractories for non chrome cement kiln has been effectively promoted, and some products have achieved good results in practical application.
