Abstract Distribution model of highly volatile impurity in distillate was established based on the mass-transfer rate equation in the liquid boundary layer, the calculated methods of model parameters were determined, and a verification experiment of vacuum distillation purification of terbium (Tb) metal had been carried out. The research results indicated that, the mass-transfer processes of highly volatile impurities of Mn and Cr are controlled by the mass transfer in the liquid boundary layer, impurities concentrations in the gas phase are equal to that in the liquid phase, and impurities concentrations in distillate present exponentially decreasing tendency as the distillation proceeds; the calculated results of Cr impurity are slightly larger than experimental results, whereas that of Mn impurity are much larger than experimental results in the former stage of the distillation experiment, which the average standard deviations of Cr and Mn impurities are ± 0.104 and ± 0.333 respectively, so Cr impurity has a better agreement than Mn impurity; the calculated removal rate of Cr impurity is 75.03%, which is slightly lower than experimental removal rate of 79.85%, while the calculated removal rate of Mn impurity is 75.11%, which is much lower than experimental removal rate of 94.55%.

中文翻译：

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稀土金属馏出液中高挥发性杂质的分布模型

摘要 基于液体边界层传质速率方程，建立了馏出液中高挥发性杂质的分布模型，确定了模型参数的计算方法，并进行了金属铽（Tb）真空蒸馏提纯验证实验。执行。研究结果表明，Mn、Cr等高挥发性杂质的传质过程受液相边界层中的传质控制，气相中的杂质浓度与液相中的杂质浓度相等，杂质浓度在液相边界层中。随着蒸馏的进行，馏出物呈指数下降趋势；Cr杂质的计算结果略大于实验结果，而Mn杂质比蒸馏实验前一阶段的实验结果大得多，Cr和Mn杂质的平均标准偏差分别为±0.104和±0.333，因此Cr杂质比Mn杂质具有更好的一致性；Cr杂质计算去除率为75.03%，略低于实验去除率79.85%，而Mn杂质计算去除率为75.11%，远低于实验去除率94.55%。