协同萃取法回收地浸采铀工艺树脂中铼

Synergistic Extraction of Rhenium from In-Situ Leach Uranium Mining Technology Resin

介绍了伯胺和磷酸三丁酯协同萃取回收铼的实验研究,考察了水相初始pH值、萃取剂组成、相比(O/W)对铼萃取率的影响。结果表明:协同萃取体系在pH 2～10范围内铼的萃取率均在97%以上,但酸性条件下伯胺N1923溶解损失较大,水相初始pH 9.5为最佳萃取酸度,以有机相30%N1923-50%TBP-20%磺化煤油萃取铼效果最佳,并采用3%NaOH反萃铼,萃取和反萃相比均控制1∶1。铼的萃取率可达99%以上,反萃率达97%以上。萃取分配比随水相中铼初始含量增大而越大,水相中大量铀的存在不影响铼的萃取,硝酸根的存在对铼的萃取率也影响较小。硫酸地浸采铀工艺中,铀和铼分别以[UO2(SO4)2]2-,[UO2(SO4)3]4-,ReO 4-阴离子形式转入地浸液,同时被阴离子交换树脂D231吸附。适采用一定浓度硝酸盐或氯化物解吸铀工艺树脂中的铀,以10%NH4NO3-8%NH4OH解吸树脂中的铼。伯胺和磷酸三丁酯协同萃取法可有效用于铀工艺树脂解吸液中铼的回收,从而为铀矿中铼的回收进一步工业试验提供参数。

Synergistic extraction of rhenium with primary amines and tributylphosphate was studied.The effects of initial pH value,composition of the extractant,and volume ratio of organic phase to aqueous phase on the extraction of rhenium were studied.The results showed that the synergistic extraction efficiency of rhenium was above 97% at pH 2~10,while dissolving loss of primary amine（N1923） in acid condition was great.The optimum conditions were obtained with initial pH value of 9.5 with 30% N1923,50% TBP and 20% sulphonating kerosene as extractant,3% NaOH as stripping reagent,phase ratio of 1∶ 1.The extraction efficiency was above 99%,and stripping efficiency was above 97%.The distribution ratio of rhenium increased with the increase of initial concentration of rhenium,and the extraction rate of rhenium was not influenced by the uranium existed in aqueous phase,and hardly influenced by nitrate.During the progress of in-situ sulfuric acid leaching technique of uranium,U and Re in the forms of 2-,4-,ReO-4 were brought into leaching solution,and simultaneously absorbed by anion exchange resin D231.Uranium was stripped by nitrate or chloride from in-situ leach uranium mining technology resin,then rhenium was stripped by 10% NH4NO3 and 8% NH4OH.It was effective for the recovery of rhenium from desorption solution by primary amines and tributylphosphate synergistic extraction that provided parameters for further industry investigation for recovery of rhenium from uranium ore.