High Performance Iron-Rich Magnesia-Spinel Composite for Burning Zone of Cement Rotary Kiln

Abstract

The structure and properties of iron-rich magnesia-spinel composite prepared using sintered iron-rich magnesia and MgO-rich spinel for burning zone of cement rotary kiln were analyzed. The results show that fine-grained magnesioferrite precipitation and magnesiowustite improved the flexibility of magnesia. The formation of Mg (Al,Fe)2O4 reaction rim between iron-rich magnesia and MgO-rich spinel by inter-diffusion reaction of Fe3+ and Al3+ improved the direct-bonded degree and high temperature strength. At high temperature, Fe3+ diffused into the grain of periclase of MgO-rich spinel and was precipitated in the from of magnesioferrite during cooling, which strengthened the structure flexibility of MgO-rich spinel. Iron-rich magnesia-spinel composite had a good adhesion property to clinker because of the uniform distribution of FeOn. Under the same content of Al2O3 and Fe2O3, the iron-rich magnesia-spinel composite had higher hot modulus of rupture, better thermal shock resistance and adhesion property to clinker compared to MgO-spinel composite and MgO-hercynite composite.