基于新颖硅基软配体功能材料次锕系元素色谱分离新方法

The long-lived minor actinides (MAs such as Am and Cm) are usually contained in highly active liquid waste (HLLW) generated in reprocessing of nuclear spent fuel. It is reported that MA might has potential and a long-termed adverse impact on environment. Based on the partitioning and transmutation (P&T) strategy, MA is required to partition from the HLLW. However, effective separation of MA from has been one of the challenging works. In the present work, some derivatives of 2,6-bis(5,6-dialky- 1,2,4-triazine-3-yl)pyridine (R-BTP), 6,6-bis(5,6-dialky-[1,2,4]-triazin-3-yl)- [2,2]bipyridine (R-BTBP), and 2,9-bis(5,6-dialky-[1,2,4]-triazin-3-yl)-1,10- phenanthroline (R-BTPhen) such as CABTP, CyMe4-BTP, BenCyM-BTBP, CyMe4-BTBP, C5BTBP, CyMe4-BTPhen and the others are synthesized. It is characterized by elementary analysis, FT-IR, TG-DSC, EI-MS, 1H NMR, XRD and others. The novel macroporous silica-based soft-ligand functional materials CABTP/SiO2-P, CyMe4-BTP/ SiO2-P, BenCyM-BTBP/SiO2-P, C5BTBP/SiO2-P, CyMe4-BTBP/SiO2-P, CyMe4-BTPhen/SiO2- P and the others are prepared. It is performed by impregnation and immobilization of the soft-ligand molecule into the pores of the SiO2-P particles with the size of 40-60 μm and the mean pore of 0.6 μm utilizing vacuum sucking technique. Meanwhile, the novel macroporous silica-based soft-ligand functional materials (CABTP+M)/SiO2- P, (CyMe4-BTP+M)/SiO2-P, (BenCyM-BTBP+M)/SiO2-P, (C5BTBP+M)/SiO2-P, (CyMe4-BTBP+ M)/SiO2-P, (CyMe4-BTPhen+M)/SiO2-P and the others are synthesized by modified with molecular modifier.It is characterized by FT-IR, TG-DSC, XRD, MAS 29Si NMR, BET and others. The adsorption behavior of some typical fission and non-fission products such as Am(III), La(III), Y(III), Cs(I), Sr(II), Ba(II), Rh(III), Pd(II), Zr(IV), Ru(III), and Mo(VI) etc. onto R-BTP/SiO2-P, R-BTBP/SiO2-P, and R-BTPhen/SiO2-P is investigated at 298 K. It is conducted by examining the effects of contact time and the HNO3 concentration in a range of 0.1 - 5.0 M. La(III) and Y(III) are used to simulate the adsorption behavior of all of the rare earths (REs(III)), while Am(III) is used as a representative of all of the minor actinides (MAs(III)). Meanwhile, the bleeding of R-BTP/SiO2-P, R-BTBP/SiO2-P, and R-BTPhen/SiO2-P in HNO3 solution is evaluated by TOC. In terms of the adsorption of the tested elements onto R-BTP/SiO2-P, R-BTBP/SiO2-P, and R-BTPhen/SiO2-P, the chromatographic partitioning of Am(III) from a HNO3 solution containing La(III), Y(III), and the other elements is performed by R-BTP/SiO2-P, R-BTBP/SiO2-P, or R-BTPhen/SiO2-P packed column operation. Based on the static-state and the dynamic-state adsorption experiment results, a new partitioning process entitled MASEC (Minor Actinides Separation from HLLW by Extraction Chromatography) for effective recovery of the long-lived minor actinides from a simulated high level liquid waste has been developed.

对含多N多环吡啶类母体化合物进行分子修饰，合成与表征一系列新颖的多N软配体试剂R-BTP、R-BTBP及R-BTPhen衍生物；利用独特的固定化与真空活化灌注技术，以制备粒径40-60μm和孔径0.6μm的硅基复合物(SiO2-P)为载体，创新性合成一系列新型大孔硅基软配体功能材料R-BTP/SiO2-P、R-BTBP/SiO2-P、R-BTPhen/SiO2-P及其被分子修饰的新颖大孔硅基协同软配体功能材料(R-BTP+M)/SiO2-P、(R-BTBP+M)/SiO2-P及(R-BTPhen+M)/SiO2-P；基于动态-静态吸附和色谱分离理论，考察以HNO3为介质的模拟高放废液(HLLW)中,新颖大孔硅基软配体功能材料对次锕系元素及典型共存元素的识别能力和选择性，明确稀土元素和其他若干典型裂片元素等各种因素对吸附性能的影响，建立从模拟酸性HLLW中色谱分离次锕系元素新技术新方法。

高放废物(HLLW)处理处置是核燃料循环的重要组成部分，长寿命核素MA(III)有效分离是HLLW处理的重要技术环节，长期以来尚未有效解决，其解决对安全处理处置HLLW以及目前正在研究中的大科学装置ADS系统具有极其重要的理论意义和现实意义。本项目制备与表征了十余种含N软配体R-BTP、R-BTBP及R-BTPhen衍生物，其中九种衍生物尚未见报道；建立了合成技术路线；培养与研究了部分衍生物单晶及其结构，发现了其分子内及分子间氢键形成以及与水分子间的氢键作用；考察了含N软配体对十余种典型金属离子的萃取行为，明确了除Pd(II)强烈被萃取外，其它共存金属离子不被萃取或萃取能力较弱这一事实；通过ITC滴定、ESI-MS、常温和低温1H NMR滴定，明确了软配体萃取Pd时所得配合物的组成、结构及其物种分布，发现了1:1和1:2型配合物及其物种分布；培养了Pd(iPr-BTBP)(NO3)2单晶并进行了结构解析和验证；基于DFT计算，通过结构优化和结合能评价，对Pd配合物物种的复杂性、1:1和1:2型物种占比以及Pd(II)形成罕见1:2型变形八面体结构进行了理论解释，实验结果与DFT计算结果一致；创新性合成了新型大孔硅基R-BTP、R-BTBP及R-BTPhen软配体功能材料；通过组成与结构表征，明确了硅基功能材料复合机理；研究了在模拟HNO3溶液中大孔硅基功能材料对十余种典型金属离子的吸附性能，以langmuir吸附和Freundlich模型评价了吸附机制；以TOC浓度变化评价了软配体功能材料的稳定性；经筛选，研究了两种性能出色的大孔硅基软配体功能材料吸附Am的行为，考察了R-BTP中直链烷基变化对Am的吸附特性及Am/Eu吸附分离系数的关系；明确了大孔硅基软配体功能材料对Am(III)和Pd(II)出色的吸附能力和高选择性；以色谱分离技术验证了从模拟HLLW中有效分离Am(III)和Pd(III)的可能性和可行性；提出了直接从模拟HLLW中吸附分离Am+Pd新材料新技术新方法。这些研究结果，为进一步直接从真实HLLW中高效分离MA(III)提供了理论与实验依据。