In order to reduce the pollution of hexavalent chrome in magnesia-chrome bricks, the first step is to develop magnesia-chrome bricks with low chrome content. Low chrome magnesia chrome bricks are made of high iron magnesia and chromite. Its technological feature is to use a part of magnesia-iron spinel instead of magnesia-chrome spinel. At high temperatures, Fe2O3 in high-iron magnesia dissolves in periclase crystals. During the cooling process, MgO·Fe2O3 precipitated from the periclase crystals, forming small pitted mafic-iron spinels scattered in the periclase.