摘要
对真空蒸馏法深度脱除精镉中铊和铟进行了理论分析和实验研究,考察了蒸馏温度对Tl和In脱除效果的影响,并探讨了钢质材料中Fe元素对实验结果的影响。理论分析表明,在真空条件下,Tl和In与Cd均具有分离的可能性,且分离效果较好,即利用真空蒸馏法获得更高纯度的金属Cd是可行的。实验结果表明,随着蒸馏温度的升高,Cd的挥发率呈快速增加趋势,挥发物中的Tl含量增加迅速,Tl的脱除率减小幅度较大,挥发物中In含量增加缓慢且保持在较低水平,In的脱除率减小的幅度较小,挥发物中Fe含量一直保持在较低水平,含量始终保持在1×10^(-8)以下,说明利用钢质材料对提高精Cd纯度不会产生影响;当系统压力为2~5 Pa,蒸馏温度为643 K,保温时间为7 h条件下,精Cd的挥发率为16.21%,挥发产物中Tl含量为2.83×10^(-7),Tl的脱除率为99.76%,In的含量为2.327×10^(-7),In的脱除率为97.97%,可获得纯度为99.9999%的金属Cd。
The theoretical analysis and the experimental study on intensive removal of T1 and In from pure Cd by vacuum distillation were investigated respectively. Furthermore, the effect of distillation temperature on separating process was analyzed, and the influence of iron in steel materials on experimental result was discussed. According to the theoretical analysis, there was a possibility that T1 and In might be separated from Cd under vacuum conditions with ideal effect, which demonstrated that much purer Cd could be available through vacuum distillation. The experimental result showed that the volatilization rate of Cd had an increase trend as temperature of distillation rose. In content of volatiles increased rapidly, while its removal rate decreased a lot. In content of volatiles increased slowly, as its removal rate decreased a little and was kept at a low level with a rising temperature of distillation. Fe content of volatiles was almost always low, under 1 × 10 ^-8, and the result showed that iron in steel materials did not affect the purification of Cd. When the system pressure was 2 - 5 Pa, the distillation temperature was 643 K and the holding time was 7 h, the volatile rate of Cd was 16. 21%, the volatile content of T1 was 2.83 ×10^-7, the removal rate reached 99. 76%, In content was 2. 327 ×10^-7, the removal rate reached 97.97%, and the purity of Cd was 99. 9999%.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2016年第5期515-520,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金青年基金项目(51304096)
教育部"创新团队发展计划"项目(IRT1250)
云南省复杂有色金属资源清洁利用国家工程实验室开放基金项目(CNMRCUKF1403)
云南省科技厅面上自筹项目(2013FZ034)资助
关键词
精镉
真空蒸馏
钢质坩埚
铊
铟
pure cadmium
vacuum distillation
steel crucible
thallium
indium
