【作者】 张超；

【导师】 田忠良； 吕晓军；

【作者基本信息】 中南大学 ， 冶金工程， 2014， 硕士

【摘要】 规整的炉膛是铝电解槽高效低耗稳定运行的基础。但传统自形成铝电解槽炉膛内型可控性差导致铝电解槽能耗高和稳定性下降,而人造炉膛铝电解槽具有可预先构建理想的炉膛内型且无需经历非正常生产期等优点,是一种高效低耗的新型结构铝电解槽。本文以开发人造炉膛材料为目标,以无压液相烧结为主要制备方法,分别对Al2O3/Na3AlF6复合材料、粒度级配Al2O3/Na3AlF6复合材料和Al2O3/MgAl2O4复合材料进行研究。主要研究结论如下：1)随着Na3AIF6含量的增加,A12O3/Na3AIF6复合材料致密度和强度逐渐提高,而复合材料的高温稳定性逐渐变差,但比工业槽中自形成炉膛材料高温稳定性要好。烧结温度对复合材料的致密度和抗压强度影响都呈现出先增大后降低的趋势,烧结温度对Na3AlF6复合材料的高温稳定性影响非常小。2)粒度级配Al2O3/Na3AlF6复合材料致密度随着Na3AlF6含量的增加呈现小幅的下降,而抗压强度则逐渐增大；骨架结构可以有效改善材料的高温稳定性,但随着Na3AlF6含量的增加,高温稳定性逐渐恶化。随着粉料含量增加,粒度级配复合材料致密度大幅下降且高温稳定性变差；粉料含量对粒度级配复合材料的抗压强度影响呈现出先增大后降低的趋势。3)MgO含量的增加可显著地改变A12O3/MgA12O4复合材料的微观结构,并明显提高材料的抗压强度；随着MgO含量升高,复合材料的致密度的变化较小,但高温稳定性逐步改善。1000℃-1200℃温度范围内,烧结温度对复合材料的尖晶石化程度影响较小；随着烧结温度升高,复合材料密度先减小后增大,抗压强度和高温稳定性逐步提高。更多还原

【Abstract】 The regular ledge is the foundation of aluminum electrolysis cells operation with high efficiency, low consumption and stability. However, the profile of self-formation ledge in traditional cells is so hard to control that energy consumption and stability of cells increase and decrease respectively. The man-made ledge cells is a new structure aluminum electrolysis cells with high efficiency, low consumption, the cell’s ledge was built along shell to form ideal profile and don’t need to experience the adjustment period. Based on this background, with the aim of developing satisfactory man-made ledge material, and with the preparation method of pressureless liquid sintering, Al2O3/Na3AlF6composite, particle gradation Al2O3/Na3AlF6composite and Al203/MgAl204composite have been investigated. The main achievements are as follows:1) With the increase of Na3AlF6content, the relative density and compressive strength of Al2O3/Na3AlF6composite increased and the high-temperature stability gradually became poor. The high-temperature stability of composite was better than self-formed ledge material. The relative density and compressive strength of the composite first increased and then decreased when sintering temperature increases. The effect of sintering temperature on high-temperature stability of the composite was insignificant.2) The relative density of particle gradation Al2O3/Na3AlF6composite decreased and the compressive strength increased slightly with the increasing of Na3AlF6content. Although the skeleton structure of the composite could improve the high-temperature stability effectively, the high-temperature stability gradually became poor with the increase of Na3A1F6content. The increasing of powder content not only lowered the relative density but also made high-temperature stability be worse. The compressive strength first increased and then decreased when powder content increases. 3) The microstructure of Al2O3/MgAl2O4composite would be changed notably and compressive strength increased obviously when MgO content increases. Although the relative density of the composite could not improve, the high-temperature stability of the composite gradually became good with the increase of MgO content. The effect of sintering temperature on spinelisation degree of the composite was insignificant at1000℃～1200℃. The relative density of the composite first increased and then decreased, the compressive strength increased and the high-temperature stability would be slightly improved when sintering temperature increases.更多还原