大孔硅基材料CyMe4-BTBP/SiO2-P的制备及其对Am(Ⅲ)、Eu(Ⅲ)的分离性能研究

Preparation of Macroporous Silica-based CyMe4-BTBP/SiO2-P and Adsorption for Am(Ⅲ) and Eu(Ⅲ)

  • 摘要: 双三嗪-吡啶萃取剂(CyMe4-BTBP)对三价锕系元素具有很好的选择性,在核燃料循环中的三价镧系和锕系分离流程中有良好的应用前景。以2,2-双吡啶及脂类衍生物为原料,通过优化反应条件制备了高纯度CyMe4-BTBP,HPLC纯度达99.5%。利用真空灌注技术,将制备的CyMe4-BTBP负载到大孔硅基复合材料SiO2-P上得到大孔硅基吸附材料,并用BET、SEM和FT-IR等对材料的微观结构进行了表征,揭示了萃取剂与载体的作用机理。研究了萃取剂负载量、酸度、吸附平衡时间等因素对CyMe4-BTBP/SiO2-P分离特性的影响。结果表明:CyMe4-BTBP/SiO2-P对Am(Ⅲ)和Eu(Ⅲ)具有良好的分离效果;Am(Ⅲ)和Eu(Ⅲ)在CyMe4-BTBP/SiO2-P上的吸附行为在动力学及热力学方面均具有很大的差异;在0.1~4 mol/L HNO3溶液中,萃取剂负载量小于9.1%时CyMe4-BTBP/SiO2-P对示踪量Am(Ⅲ)和Eu(Ⅲ)的分离因子(SF)均在100以上。

     

    Abstract: CyMe4-BTBP (6, 6′-bis(5, 5, 8, 8-tetramethyl-5, 6, 7, 8-tetrahydrobenzoe1, 2, 4triazin-3-yl)-2, 2′-bipyridine) is a promising extractant for separating An(Ⅲ) from Ln(Ⅲ) in spent fuel reprocessing due to its great selectivity for An(Ⅲ) over Ln(Ⅲ). With optimized procedure, CyMe4-BTBP was synthesized by using 2, 2′-bipyridine and ester as starting materials, and the purity is 99.5% determined by HPLC. Macroporous silica-based CyMe4-BTBP/SiO2-P was prepared by the impregnation and immobilization of CyMe4-BTBP into the pores of silica-based resin SiO2-P and characterized by BET, SEM and FT-IR. The effect of the HNO3 concentration, the CyMe4-BTBP loading on the adsorbent and the contact time on the adsorption of Am(Ⅲ) and Eu(Ⅲ) was investigated. The adsorption behavior of Am(Ⅲ) and Eu(Ⅲ) on CyMe4-BTBP/SiO2-P is different both in thermodynamics and dynamics. The results show that with trace amount of metal ions in aqueous solution and 2.4%-9.1% CyMe4-BTBP on SiO2-P, the adsorption of Am(Ⅲ) is much stronger than that of Eu(Ⅲ) and the separation factor is over 100 in 0.1-4 mol/L HNO3 solution.

     

/

返回文章
返回