To prepare high-performance MgO-CaZrO3 refractory materials,pre-synthesized calcium zirconate was used as the raw material,and different contents of magnesium oxide were added during the process.The effects of CaZrO3 introduction types and magnesium oxide content on the phase composition,microstructure and physical properties were studied through techniques such as X-ray diffraction,physical property analysis,and scanning electron microscopy.The results show that the presence of MgO promotes the transformation of calcium zirconate to the intermediate product Ca0.15Zr0.85O1.85 to a certain extent.During the high-temperature sintering process,newly generated CaZrO3 could lead to the increase in interfacial reactions and the sintering densification would be greatly improved.When the pre-synthesized CaZrO3 was introduced as well as 30 mass％ of MgO was added,the obtained MgO-CaZrO3 refractories possessed excellent properties.For the obtained MgO-CaZrO3 refractories,the main phases were MgO,CaZrO3,and Ca0.15Zr0.85O1.85,where the average grain size of CaZrO3 was 1.5-2.5μm and that of MgO was 2.5-3.5 μm.According to the analysis of densification parameters,the apparent porosity was 2.56％,the bulk density was 3.85 g/cm3,the linear shrinkage rate was 15.43％,and the compressive strength at room temperature was 376 MPa.Correspondingly,the MgO-CaZrO3 refractories were obtained with excellent properties when the synthesized CaZrO3 was introduced as well as 30 mass％ of MgO was added.The main phases for the prepared MgO-CaZrO3 refractories were also MgO,CaZrO3,and Ca0.15Zr0.85O1.85.The average grain size of CaZrO3 and MgO increased to 2-4μm and 9-11 μm,respectively.Meanwhile,the densification also increased,where the apparent porosity was 0.90％,the bulk density was 4.87 g/cm3 and the linear shrinkage rate was 17.47％.The room-temperature compressive strength exhibited a decrease tendency with a value of 250 MPa at this time.
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