(1. 西安建筑科技大学 冶金工程学院，西安 710055；
2. 中南大学 冶金与环境学院，长沙 410083；
3. 青海西部水电有限公司，海东 810800)
摘 要: 采用热分析法研究K3AlF6、LiF和AlF3等含量对铝电解质Na3AlF6-K3AlF6-AlF3-LiF- CaF2-MgF2-Al2O3熔盐初晶温度的影响，分析熔盐组成对初晶温度的影响机制。结果表明：含Li熔盐初晶温度随K3AlF6含量的增加而降低，当熔盐中LiF含量分别为0和4%(质量分数)时，随着熔盐中K3AlF6含量从3%增加至12%，熔盐初晶温度分别降低27.4 ℃和21.2 ℃；LiF对含K电解质熔盐初晶温度有降低作用，当熔盐中K3AlF6含量分别为0和6%，随着熔盐中LiF含量从0增加到4%，熔盐的初晶温度分别降低31.2 ℃和27 ℃；AlF3对Li、K共存复杂电解质熔盐初晶温度有降低作用，当熔盐中LiF含量为1%、K3AlF6含量为9%时，熔盐中AlF3含量每增加1%，熔盐的初晶温度将降低6.3 ℃；而当熔盐不含Li、K时，熔盐中AlF3的含量每增加1%，可引起熔盐初晶温度的降低值为7.6 ℃。复杂电解质熔盐中锂盐和钾盐分别以Li2NaAlF6和K2NaAlF6形式存在，其在熔盐中含量是影响熔盐初晶温度的主要原因。
关键字: 铝电解；复杂电解质；钾冰晶石；初晶温度；锂盐
（1. School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
3. Qinghai Western Hydropower Company Limited, Haidong 810800, China）
Abstract:The thermal analysis was applied to study the impact of K3AlF6, LiF and AlF3 on the liquidus temperature of Na3AlF6-K3AlF6-AlF3-LiF-CaF2-MgF2-Al2O3 electrolyte molten melts, and the influence mechanism of the molten melts composition to the liquidus temperature was also investigated. The results show that the liquidus temperature of Li-containing molten melts decreases with the increase of K3AlF6 content, and when the contents of LiF in the melts are 0 and 4% respectively, with the increase of K3AlF6 content from 3% to 12%, the liquidus temperature of molten melts decreases by 27.4 ℃ and 21.2 ℃, respectively. LiF has the effect to reduce the liquidus temperature of K-containing molten melts. When K3AlF6 content of melts is 0 and 6%, with the increase of LiF content from 0 to 4%, the liquidus temperature of molten melts decreases by 31.2 ℃ and 27 ℃. AlF3 has the minus effect on the liquidus temperature of Li-K-containing complex molten melts, when the content of LiF in the melts is 1% and K3AlF6 content is 9%, the liquidus temperature of melts will decrease 6.3 ℃ with every 1% addition of AlF3. While, when the melts don’t contain Li and K, the drop of the liquidus temperature with every 1% addition of AlF3 is 7.6 ℃. Li and K in the complex electrolyte melts exist in the form of Li2NaAlF6 and K2NaAlF6, respectively, and its content in the melts is one of the main reason affecting the liquidus temperature of the molten melts.
Key words: aluminum electrolysis; complex electrolyte; potassium cryolite; liquidus temperature; lithium salts
