弱碱性阴离子交换树脂对酸性含铀浸出液中铀的吸附机理

摘要

研究弱碱性阴离子交换树脂 D301处理酸性含铀浸出液的吸附机理，分析 D301载铀饱和树脂淋洗异常的原因，优化 D301载铀树脂的淋洗参数。研究结果表明：某酸法地浸浸出液中含不同比例的 UO22+，UO2SO4， UO2(SO4)22−和 UO2(SO4)34−等配合物，D301树脂对 UO2(SO4)22−和 UO2(SO4)34−的吸附是离子交换机理，对 UO22+和UO2SO4吸附是表面络合机理，铀酰络合物与树脂以2种不同的化学键结合是导致淋洗曲线出现2个峰的原因；提高淋洗剂酸质量浓度为30 g/L或提高淋洗剂NaCl质量浓度为90 g/L都可以优化淋洗曲线，其中提高淋洗剂NaCl质量浓度更具实际意义。%The adsorption mechanism of the weakly basic anion exchange D301 resin treating with the acidic leaching solution contained uranium was studied. The cause for unusual desorption phenomenon of D301 uranium bearing resin was analyzed. The desorption parameters of D301 uranium bearing resin were optimized. The results show that the content of complexes UO22+, UO2SO4, UO2(SO4)22− and UO2(SO4)34− are different in an in-situ acid leaching solution. And the adsorption mechanism of D301 resin for UO2(SO4)22−, UO2(SO4)34−is ion exchange mechanism, while that for UO2(SO4)22−and UO2(SO4)34−is ion exchange surface complex formation mechanism. Double peaks on the eluting curve are caused by two different chemical bonds which combine the uranous complex with the resin. For the desorption solvent, the eluting curve can be optimized by increasing the mass concentration of sulfuric acid to 30 g/L or using a NaCl solution of 90 g/L, and the latter one has more practicality value.