【摘要】 以氯氧化锆(铪)溶液为料液,用2-乙基己基膦酸单2-乙基己基酯(P507)萃取剂在盐酸介质中萃取锆铪。研究了P507浓度、料液浓度、萃取温度和时间、盐酸或氯离子浓度、添加剂浓度等因素对锆铪萃取率、分配比和分离系数的影响。结果表明:P507萃取锆铪的反应为吸热反应;萃取速率较慢,平衡时间≥40min,改变金属离子和萃取剂浓度,以及在有机相中添加仲辛醇等均难以使萃取速率得到有效提高;饱和法测得有机相中萃取剂与金属离子的物质的量之比为3左右;锆、铪的分配比随着P507浓度的增加而增加,但增加的幅度在低浓度区域和高浓度区域各不相同。锆铪之间的分离系数在萃取剂浓度0.9mol.L-1附近呈极小值;盐酸和氯离子浓度的影响较复杂,呈波浪式变化。更多还原

【Abstract】 In this paper, 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (P507) was used to extract Zirconium(Ⅳ) and Hafnium(Ⅳ) from zirconium(hafnium) oxychloride solution in chlorhydric acid media. The effects of extraction temperature and time, the concentration of P507 and Zr (Hf), chlorhydric acid or chlorine ion as well as additive on the extraction rate, distribution ratio and separation coefficient were investigated. The results showed that the extraction reaction of Zr(Hf) by P507 was endothermic; the extraction rate was slow with extraction equilibrium time≥40 min; It was hard to increase extraction rate by changing metal ions or extractant concentration and adding 2-octanol content in organic phase. The molar ratio of extractant to metal ions saturated in organic phase was determined to be around 3. The distribution ratio of Zr(Hf) increased with P507 concentration increasing,however, the increase extent was different in high or low concentration region Therefore, the separation coefficients displayed minimum value at around 0.9 mol.L-1 of P507. However, the effect of chlorhydric acid or chlorine ion concentration on separation coefficient showed a pattern of a wave-like change.更多还原