气泡支撑油膜萃取富集铀矿地浸液中的低浓度铼

Bubble supported organic liquid membrane extraction for enrichment of low-concentration rhenium in in-situ leaching solution of uranium deposit

砂岩型铀矿地浸液吸附脱铀尾液中的铼含量极低(通常<0.1 mg/L),富集回收十分困难。本文提出一种以酸化叔胺N235为萃取剂,从砂岩型铀矿中性地浸液的吸附脱铀尾液中高效富集和回收极低浓度铼的气泡支撑油膜萃取新方法。考察了萃取剂N235浓度、酸化度、通油速率、水相开路流动连续负载等因素对铼萃取回收率的影响规律。结果表明:铼萃取回收率高达99%。经萃取-反萃后,铼在反萃液中的浓度可达1 g/L,铼的富集浓度是地浸吸附尾液的近15000倍,远高于采用树脂吸附法富集铼的浓度。采用气泡支撑油膜萃取法不仅可高效富集回收铀矿地浸液中的极低浓度铼,还可有效脱除有害氟离子,有利于提高前序吸附脱铀工艺的树脂使用寿命。该工作为处理砂岩型铀矿地浸液回收利用战略金属铼资源提供了一种新思路。

The concentration of rhenium in the uranium-removal tailings of the in-situ leaching solutions of sandstone-type uranium deposit is extremely low,usually below 0.1 mg/L,and it is very difficult to be enriched and recovered economically.A novel approach of bubble-supported organic liquid membrane extraction for high efficiently enrichment and extraction of low-concentration rhenium from the uranium-removal tailings of the insitu leaching solutions of sandstone-type uranium deposit using pre-acidified tertiary amine N235 as the extractant was proposed.The effect from the N235 concentrations in the organic phase,acidification degrees of N235,input flux of the organic phase and continuous loading by open-circuit flow of aqueous feed solutions on the recovery rate of rhenium was investigated.The results show that the extraction rate of rhenium could reach more than 99%.After the extraction and stripping processes,the concentration of rhenium in the stripping solutions can be enriched up to 1 g/L,nearly 15000 times than that in the initial uranium-removal tailings of the in-situ leaching solutions.The enrichment rate of rhenium is much higher than that of resin adsorption method.The bubblesupported organic liquid membrane extraction can not only enrich and recover the extremely low-concentration rhenium in the uranium-removal tailings of the in-situ leaching solutions of sandstone-type uranium deposit,but also effectively remove the harmful fluoride ions,which is beneficial for prolonging the life of resin in the process of adsorption and recovery of uranium.This study provides a guidance for the high efficiently recovery of strategic metal rhenium resources from the adsorption tailings of the in-situ leaching solutions of sandstone-type uranium deposit.