| Abstrakt: |
To improve the hot properties of magnesia-zirconia materials, magnesia-zirconia sand was pre-synthesized with Xiuyan second grade magnesite and desilicated zirconia, and then magnesia-zirconia materials were prepared using the pre-synthesized magnesia-zirconia sand and fused magnesia, mixing, molding, drying and calcining. The effects of the pre-synthesized magnesia-zirconia sand addition (10%, 20% and 30%, by mass) and calcination temperature (1 500, 1 600 and 1 700 °C) on the bulk density, apparent porosity, linear shrinkage rate on heating, cold modulus of rupture, thermal shock resistance and slag resistance of the materials were investigated. The phase composition and microstructure were also analyzed. The results show as follows: (1) as the pre-synthesized magnesia-zirconia sand addition and calcination temperature increase, the bulk density and cold modulus of rupture increase, while the apparent porosity decreases; (2) the linear shrinkage rate decreases with the increasing pre-synthesized magnesia-zirconia sand addition and increases with the increasing calcination temperature; (3) when the pre-synthesized magnesia-zirconia sand addition is 20% and the calcination temperature is 1 600 °C, the sample performs the best thermal shock resistance, which is improved due to microcrack toughening induced by the pre-synthesized magnesia-zirconia sand; (4) when the pre-synthesized magnesia-zirconia sand addition is 20% and the calcination temperature is 1 700 °C, the sample shows the optimal slag resistance, which is mainly due to the fact that ZrO2 reacts with the slag to generate CaZrO3 and spinel, preventing the further corrosion and penetration of the steel slag. [ABSTRACT FROM AUTHOR] |
