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wyez(金币+1, 翻译EPI+1): 2011-03-20 17:11:23
wyez(金币+60): 2011-03-20 17:11:38
降低高纯金属镉中杂质Zn和Fe的工艺探索
Title: Process investigation on lowering Zn and Fe in high purity Cd
摘要
本人介绍了高纯金属的定义、性质和用途以及制备方法，综述了高纯镉的生产方法，对工业镉真空蒸馏提纯和直拉提纯进行了计算与分析，对工业镉的真空蒸馏和直拉提纯进行了试验研究，提出了一个全新的提取高纯镉的工艺流程。
Abstract: In this article, the definition, preparation, properties and applications of high purity metal were introduced, manufacturing methods of high purity Cadmium (Cd) were overviewed, not only theoretical calculation and analysis but also experimental study was performed to investigate vacuum distillation and Czochralski purification of industrial Cadmium, and a new process was proposed to obtain high purity Cadmium.
通过对工业镉真空蒸馏的热力学分析表明，根据分离系数的大小，工业镉中的杂质元素可分为两类：分离系数β<1的Pb、Ni、Cu、Fe、Sn、Ti，分离系数在1附近的As和Zn。用真空蒸馏的方法能够比较彻底的出去工业镉中的Pb、Ni、Cu、Fe、Sn、Ti，而As和Zn的分离则比较困难；为使工业镉中的杂质在真空蒸馏时与镉很好分离，应采用连续作业的闭式多级真空蒸馏。
According to the thermodynamic analysis of the vacuum distillation process of industrial Cd, the impurity elements in industrial Cd can be divided into two categories based on their separation constants (β): Pb, Ni, Cu, Fe, Sn and Ti (β<1) and As, Zn (β≈1). Thus, Pb, Ni, Cu, Fe, Sn and Ti can be almost completely removed from industrial Cd via vacuum distillation while the separation of As and Zn by vacuum distillation seems relatively difficult. In order to efficiently remove imputities from industrial Cd during vacuum distillation, continuous operation of closed multistage vacuum distillation should be adopted.
在673～723K的温度范围内，对工业镉真空蒸馏的动力学进行了研究，在此温度范围内，温度升高50K，镉的最大蒸馏速度平均增大约3.5倍。镉真空蒸馏过程中，蒸馏速度随压强的降低而增大，但当压强降低到临界压强以下后，蒸馏速度不再随压强的降低而变化而是保持一定值。
The kinetics of vacuum distillation of industrial Cd was investigated in the temperature range of 673～723 K. The maximum distillation rate of Cd increased near 3.5-fold in average with a temperature elevation of 50 K. The distillation rate of Cd increased with the decrease of pressure during vacuum distillation but kept fixed irrespective to pressure when the pressure is lower than the critical pressure.
通过对镉的直拉提纯试验研究，得出了直拉热场、提拉速度、晶轴转速和坩锅转速对提纯效果的影响。
The Czochralski purification experiment provided insights into the effect of thermal field, pulling speed, rotating speed of crystal axis and rotating speed of crucible on purification.
通过以上研究，得出了以工业镉为原料，通过真空蒸馏提纯、直拉提纯的工艺流程制取高纯金属镉的工艺流程，该工艺对降低高纯镉的生产成本和环境保护方面具有重要意义。
Based on the abovementioned comprehensive investigation, a technological process to manufacture high purity Cd from industrial Cd by integration of vacuum distillation and Czochralski method was proposed, and this process was believed to have important implications for lowering the production cost of high purity Cd and for environmental protection.
关键词：高纯金属，镉，真空蒸馏，直拉提纯
Keywords: high purity metal; Cadmium; vacuum distillation; Czochralski method |
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