Abstract In the electrowinning or chemical reductive extraction process, those mass transfer kinetic parameters, for instance the diffusion coefficient in the liquid cathode or medium, have a strong impact upon the practical extraction rate and separation efficiency. This work aims to calculate the diffusion coefficient of uranium in liquid gallium with galvanostatic intermittent titration technique (GITT) and to deduce its corresponding activation energy. By analyzing the data of GITT, before U saturation in liquid gallium at the temperature range of 673-873 K, the temperature dependence of diffusion coefficients of uranium in liquid gallium was measured as ln D U Ga = − 6.90 ± 1.03 − 1.2 ± 0.8 × 10 3 T and the corresponding activation energy was determined as Ea = −11.0 ± 6.7 kJ/mol. The possible source of errors to calculate the diffusion coefficients, such as reference electrode, small solubility of uranium in gallium, side reactions and geometrical approximation of cathode in the theory formula are also presented and discussed.

中文翻译：

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GITT法测定铀在液态镓中的扩散系数

摘要 在电解或化学还原萃取过程中，传质动力学参数，如液体阴极或介质中的扩散系数，对实际萃取率和分离效率有很大影响。本工作旨在用恒电流间歇滴定技术(GITT)计算铀在液态镓中的扩散系数并推导出其相应的活化能。通过分析GITT的数据，在673-873 K温度范围内液态镓中U饱和之前，测得铀在液态镓中扩散系数的温度依赖性为ln DU Ga = − 6.90 ± 1.03 − 1.2 ± 0.8 × 10 3 T 和相应的活化能确定为 Ea = -11.0 ± 6.7 kJ/mol。