地浸采铀过程中伴生微量铼资源回收关键技术研究

In China, uranium ore is featured with a less reserve, wide distribution, multiple types, multiple associated minerals, small scale, low grade and shallow buried depth. A lot of uranium resources will not be able to exploit economically by relying on the existing technology. In terms of the associated feature of low grade uranium, exploration of synchronous recovery is one of the most effective method to expand the amount of uranium resources in China and uranium production. Rhenium is one of the mostly scarce resources in the world. It is widely applied in different walks of life such as national defense and economy for its excellent physical and chemical properties. Recently, several uranium ores associated with recyclable rhenium resources have been discovered in Xinjiang, Inner Mongolia. As far as leaching rhenium is concerned, the former Soviet Union has been studied the mining and smelting of rhenium from leaching process of sandstone type uranium deposit systematically. The related research results have been applied successfully in Uzbekistan. Recovering rhenium resources from sandstone type uranium deposit still is a blank in China. The biggest challenge to achieve effective recovery of rhenium resources is due to the fairly low rhenium concentration in leaching. Based on review of the rhenium recovery technology at home and abroad, and also on the basis of deep investigation of leaching uranium somewhere in xinjiang, two methods on rhenium recovery from the uranium depleted resin with synergistic extraction and from adsorption solution by ion exchange method were put forward in this paper. Systematic investigations were carried out on the detection of micro amount of rhenium with complex matrics, leaching procedure of uranium and rhenium in core, rhenium recovery study by solvent extraction and ion exchange method. exploration of synchronous recovery is one of the most effective method to expand the amount of uranium resources in China and uranium production . The present study will provide foundation for exploration of synchronous recovery of uranium for the development of nuclear power development in China and provide security for development of nuclear power industry.

我国铀矿分布广、类型多，但多为伴生矿、规模小、品位低、埋藏浅，仅依靠现有工艺，很多铀资源无法经济开采。开发伴生资源回收技术，是扩大我国铀资源量及铀产品产量的有效途径。在我国新疆、内蒙多个铀矿伴生有铼资源，铼是最为稀缺的资源之一，广泛应用于国防及国民经济多个行业。乌兹别克斯坦某矿有从砂岩型铀矿床中回收铼的报道，我国对于此尚属空白。本项目针对铼的浸出和分离富集两个问题，通过开展岩芯矿物学研究、室内搅拌试验、柱浸条件试验等手段，掌握矿石中铀、铼的浸出规律；通过对TBP-N1923协同萃取体系对高本底铀溶液中微量铼的萃取分离条件及机理研究的结果，指导伯胺-TBP特效吸附树脂改性合成、进一步开展新树脂的吸附、解吸机理研究，实现对浸出液中痕量铼资源有效回收。相关成果将增加我国铀矿资源储量及铀产品产量，为国防科技工业发展提供物质基础，并对地浸液中回收其他有价元素（如钼、硒等）的研究提供借鉴。

铼是涉及国防和经济建设的战略物质，急需增产增储。针对我国内蒙、新疆多个砂岩型铀矿伴生铀铼但同采回收技术缺失的现状，课题组在国家自然科学基金的支持下，以新疆、内蒙砂岩型铀矿为研究对象，瞄准铼的浸出和分离富集两个关键环节，通过开展岩芯矿物学分析、室内搅拌试验、柱浸条件试验研究，进一步明确了砂岩型铀矿伴生铼资源的分布及赋存状态，并明确在保证浸出液体系Eh>540 mv，铀的浸出率超90%，铼的浸出率超过85%的工艺条件，由此掌握砂岩型铀矿伴生铼资源共同浸出规律，建立铀铼共同浸出工艺技术。通过对高本底铀溶液中微量铼的协同萃取机理研究，指导设计并合成对复杂基体中微量铼具有高选择性的特效吸附树脂，通过静态吸附、动态吸附等实验，确定了吸附解吸条件，并从热力学和动力学角度探讨了可能的吸附、解吸机理，把握了新材料的吸附解吸规律。研究表明，新材料在pH为2.5，初始浓度为250 mg·L-1时，LSL-1对Re(VII)的饱和吸附容量为154.13 mg·g-1，且在pH为2时，铼铀最大分离系数(βRe/U)接近204.82。吸附过程符合Langmuir等温模型和准二级动力学模型，属于化学反应为主的单分子层吸附。FT-IR和XPS分析表明，吸附过程是由阴离子交换反应所驱动，高铼酸根阴离子与季胺基通过N - O键结合。动态柱实验中，树脂也展现出了对Re(VII)很好的富集能力，动态吸附过程符合Thomas模型。此外，团队还初步探索了电子辐照表面改性技术在新材料合成方面的应用，在复杂背景极低浓度铼的分离富集方面，材料的吸附容量、选择性和吸附效率均展示了非常好的应用前景。