A Study on the Mechanism of Segregation of Fusion Cast AZS Refractories
Qiu Biyun Huang Yuanlin Bao Zhuowu, (The Glass & Enamel Eesearch Institute, Ministry of Light Industry, P. R. China)
The samples of fusion cast zirconia corundum refractory (AZS) serial products (containing ZrO2 33%, 36% and 41%) were studied. By analyzing chemical compositions of the samples from different layers of blocks, and by observing the samples with reflective microscope, it is demonstrated in this paper that the segregation of chemical compositions of the products was quite apparent, and the structure of the products were inhomogeneous, while the Al2O3/SiO2 weight ratio of different layers changed slightly. In accordance with the phase equilibrium principle of Al2O3ZrO2-SiO2 ternary system, and supported by the abundant data of segregation of chemical compositions, it has been proved that the result of analysis is in keeping with some scholars' description about the "Structural Model of Segregation and Solidification Process of ZrO2 Primary Crystalline Phase in Fusion Cast AZS Refractories". The factor causing segregation during the solidification of fusion east AZS refractories is that, under the action of gravity field, ZrO2 primary crystalline phase is induced by the variation of temperature field. It deposits and accumulates, presenting the phenomenon of segregation, of which the transitional zone is rich in ZrO2 phase.