硅酸盐学报, 2023, 51 (3): 602, 网络出版: 2023-04-10
氧化钛对镁砂抗热震性能及抗渣渗透性能的影响
Effect of TiO2 on Thermal Shock Resistance and Slag Penetration Resistance of Magnesia
氧化镁 游离氧化钙 氧化钛 抗水化性能 抗热震性能 抗渣渗透性能 magnesium oxide free calcium oxide titanium oxide hydration resistance thermal shock resistance slag penetration resistance
摘要
为改善镁砂抗水化性能、抗热震性能及抗熔渣渗透性能,在轻烧氧化镁粉中添加1% (质量分数)、2%及3%的TiO2微粉制备镁质复合材料,研究了TiO2含量对材料烧结行为、显微结构及各性能的影响。结果表明:随TiO2添加量增加,游离CaO及部分MgO相继转化为CaTiO3及Mg2TiO4相,且MgO晶粒尺寸增大,样品抗水化性能显著提高。CaTiO3及Mg2TiO4晶间相的形成降低了样品的热膨胀系数,诱导裂纹发生偏转,因此,样品的抗热震性能也随TiO2增加逐步提高。此外,添加1%的TiO2样品,因MgO晶粒增大及高稳定性的CaTiO3晶间相形成,抗渣性能明显提高。然而,进一步增加TiO2,低稳定性的Mg2TiO4晶间相的生成显著降低了样品的抗渣渗透性能。
Abstract
To improve the resistance to hydration, thermal shock and slag penetration of magnesia, a magnesia based composite was prepared via adding TiO2 powder (i.e., 1% (in mass fraction), 2% and 3%) into a light burned magnesia powder. The effect of TiO2 content on the sintering behavior, microstructure and properties of the composite was investigated. The results show that free CaO and some MgO transform into CaTiO3 and Mg2TiO4 and the size of MgO grains increases as TiO2 addition increases, leading to an improvement in the hydration resistance. The formed CaTiO3 and Mg2TiO4 phases reduce the thermal expansion coefficient and induce the crack deflection as TiO2 content increases, therefore improving the thermal shock resistance of the specimens. Besides, as 1% TiO2 is added, the slag penetration resistance of the specimens is enhanced due to the increase in MgO grain size and the formation of high stable intergranular CaTiO3 phase. However, the further increasing TiO2 content reduces the slag penetration resistance due to the formation of low stable Mg2TiO4 phase at MgO grain boundaries.
李真真, 徐义彪, 王庆虎, 朱天彬, 戴亚洁, 周芬, 徐超. 氧化钛对镁砂抗热震性能及抗渣渗透性能的影响[J]. 硅酸盐学报, 2023, 51(3): 602. 李真真, 徐义彪, 王庆虎, 朱天彬, 戴亚洁, 周芬, 徐超. Effect of TiO2 on Thermal Shock Resistance and Slag Penetration Resistance of Magnesia[J]. Journal of the Chinese Ceramic Society, 2023, 51(3): 602.