低温铝电解可以大幅减少铝电解能耗，NaF-KF-AlF3电解质体系是最有希望实现工业应用的铝电解低温电解质体系。本项目将解决CaF2及LiF引起的NaF-KF-AlF3低温电解质中氧化铝溶解性能急剧恶化的问题。采用实验研究结合热力学数据及Factsage软件计算的方法对NaF-KF-AlF3-CaF2-LiF电解质的初晶温度及氧化铝溶解度进行研究，在此基础上得出初晶温度及氧化铝溶解度与电解质成分之间的经验公式。采用旋转刚玉片法研究氧化铝溶解速度，获得溶解反应级数、反应速度常数及阿累尼乌斯公式。通过上述研究筛选出780-850℃下氧化铝溶解性能可以满足电解要求的电解质成分。采用量子化学计算、高温拉曼光谱结合LECO定氧仪的氧吸收峰对该电解质体系的熔盐结构进行解析，在此基础上探究氧化铝的溶解机理以及熔盐结构对氧化铝的溶解性能的影响。本项目研究成果将为该低温电解质体系的工业化应用提供基础数据及基础理论支持。

Lowering operating temperature of the aluminum reduction cell can efficiently reduce the energy consumption. KF-NaF-AlF3-based electrolyte is the most promising low-temperature electrolyte for aluminum reduction. The deterioration of alumina solubility caused by the addition of CaF2 and LiF will be resolved in this project. Liquidus temperature and alumina dissolution properties in NaF-KF-AlF3- based low-temperature electrolyte will be investigated, and the mechanism of dissolution will be discussed. Liquidus temperature and alumina solubility will be measured by cooling curve and rotating corundum disk method, respectively, and both of them also be calculated by Factsage phase diagram software and thermodynamic data. On those bases, the emprical formula between liquidus temperature, and electrolyte component will be derived, the emprical formula between alumina solubility and electrolyte component will also be derived. The dissolution speed of alumina will be tested by rotating corundum disk. After processing the data of dissolution speed, the order of dissolution reaction, as well as the rate constant of dissolution reaction and the Arrhenius equation will be derived. The suitable electrolyte for aluminum reduction at 780 to 800 degree C will be choosed after the research on solubility and dissolution speed of alumina. The structure of molten NaF-KF-AlF3-CaF2-LiF-Al2O3 bath will be analyzed by quantum chemistry calculation，Raman spectra test, and by the analysis of oxygen absorbing peak of LECO oxygen analyzer. The relationship between bath structure and dissolution properties，the mechanism of alumina dissolution will be discussed as well. The work on this project will provide fundamental theory and data to the industrial application of KF-NaF-AlF3-based electrolyte.