NaCl和LiF的添加对铝电解质初晶温度影响的研究

Effect of NaCl and LiF on liquidus temperature of molten cryolite-based aluminum electrolyte

研究了一种新的铝电解质初晶温度的测定方法:采用数字万用表与计算机串口相结合的测量技术,利用热分析法,根据步冷曲线确定电解质体系的初晶温度。用标准熔盐氯化钠和氟化钠验证了该方法的可行性和准确性,误差范围约为1～1·5℃。利用该方法研究了氯化钠和氟化锂的添加对工业铝电解质体系初晶温度的影响,并根据测量结果建立了数学模型,线性回归方程为T=947·588-5·907×w(LiF)-6·223×w(NaCl)。试验结果表明,在铝电解质中复合添加氯化钠和氟化锂能有效地降低电解质的初晶温度,降低生产成本,提高经济效益。

A new method for measurement of liquidus temperature of aluminum electrolyte system with one meter connected to COM port of a computer is introduced. Liquidus temperature is determined based on cooling curve by using thermal analysis method. Liquidus temperatures of NaF and NaCl are measured for comparison. The results prove the method to be reliable and accurate. The range of error is about 1-1.5 ℃ from 801 ℃ to 995 ℃. The effects of NaCl and LiF on liquidus temperature of molten cryolite-based aluminum electrolyte are studied and the mathematical model is established based on the experimental results obtained by this method. The mathematical model obtained is T=947.588-5.907×w（LiF）-6.223×w（NaCl）. The experiments show that the mix addition of NaCl and LiF into molten cryolite-based aluminum electrolyte not only reduces effectively the liquidus temperature of electrolyte but also decreases the production cost and increases the economic benefits.