The loosening effect caused by the expansion of the iron spray oxide to form spinel can also be made into a magnesia chrome brick by using a synthetic co-sinter. In addition, there are non-calcined magnesia chrome bricks, for example, non-calcined magnesia chrome bricks combined with an inorganic magnesium salt solution. The non-burned magnesia chrome brick has a simple production process, low cost and good thermal stability, but the high temperature strength is far less than that of the fired brick. In the late 1950s, a so-called "direct combination" magnesia chrome brick was developed. The brick is characterized by pure raw materials, high firing temperature, direct combination of high temperature phases such as periclite and spinel, and low-melting phase such as silicate is island-shaped, thus significantly increasing the high temperature of the brick. Strength and slag resistance. The production process of firing magnesia-chrome bricks is similar to that of magnesia bricks.

        In order to eliminate the fine powder prepared by calcining MgO and Cr2O3, Al2O3 or chrome ore-magnesium co-grinding compact in the process of firing, the method of making bricks with coarse particles of magnesia is an effective measure to eliminate the loose effect. . Compared with ordinary magnesia chrome bricks, the magnesia chrome bricks produced by this method have low porosity, high compressive strength, load softening temperature and flexural strength. Magnesia-chrome bricks made of chrome ore-magnesite powder compacts and high-temperature calcined synthetic magnesia-chrome sands are better than other magnesia-chrome bricks in slag resistance and high temperature strength.