| Title | The damage mechanism of SiC-mullite brick in cement industry |
| Thematic area | Cement and Lime |
| Presenter | Mr. Yandun Zhou |
| Authors | Mr. Yandun Zhou, Ruitai Materials Technology, Beijing - China Mr. Xijun Liu, Ruitai Materials Technology, Beijing - China Mr. Juntao Wang, Ruitai Materials Technology, Beijing - China Mr. Songlin Chen, Ruitai Materials Technology, Beijing - China Mr. Lin Yuan, Ruitai Materials Technology, Beijing - China |
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Abstract
SiC-Mullite bricks is widely in upper and latter transitional zone of cement kilns, due to excellent thermal shock resistance, abrasion-resistance and erosion resistance. This essay will focus on SiC-mullite 1680 in the transition zone of 5000 t/d large dry-process cement rotary kiln and explore erosion mechanism by layers connected with Portland cement clink in the upper transitional zone. The brick(the thickness is 220mm) is divided into four parts equally, XRD and SEM is employed to analysis phases changes and relative variable in chemical composition(including mullite,SiC, Fe2O3,K2O and Na2O) of different depth of the SiC-mullite brick; and reaction products between cement clinker and the brick. The results reveal that potassium contained in alkali salt reacted with corundum and mullite phase to produce KAlSi2O6 and KAlO4 of low melting point, which severely influence alkali-resistance and thermal-shock resistance of this brick. Moreover, SiC contained in the reaction layer was oxidized seriously, and the difference of thermal conductivity in different depth of the brick lead to the formation of distortion strain. Therefore the impact of alkali salt and partly oxidation of SiC are the main causes for damage of SiC-mullite brick. |
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