Studies on the recovery of uranyl carbonate and the concentration of the isotopes using durable amino acid resins

1.耐久性氨基酸树脂的合成及树脂性能：采用活性酯化法将氨基酸或模拟氨基酸引入到聚苯乙烯树脂中，合成了15种氨基酸树脂。氨基酸含量约为2-3.7 mmol/g树脂，并通过离子交换容量、含水量、FT-IR等测定对树脂性能进行了评价。我们还研究了树脂的酸、碱浸泡和重复使用的洗涤效果，并阐明所开发的树脂是耐用的和功能性的。对铀的捕集能力和选择性吸附功能：树脂对铀的碳酸盐形态表现出较高的吸附活性。甘氨酸和精氨酸树脂的平衡吸附量均大于950 mg U/g树脂，实现了氨基酸树脂的高度功能化。吸附速率非常快，吸附机理为Langmuir型吸附 ...更多信息 通过对吸附等温线的分析，研究了双金属铀酰的吸附行为。质子化的氨基残基可能作为吸附的驱动力，其功能通过在氨基中引入具有空间位阻的亚胺基氨基酸来证实。考察了碳酸盐浓度、海水基质的影响以及移动的相穿透和洗脱行为，证明所开发的树脂是铀的选择性吸附剂。铀同位素的分离富集行为：采用间歇法，用树脂接触法跟踪天然铀同位素的分离行为。通过<234><238>α-射线的测量来累积每种树脂的分离因子（μ U/μ U）。我们清楚地发现，在高温条件下（90 ℃），同位素浓度效应主要来自与碳酸盐物种的接触。以往开发的酯键型树脂效果较酰胺键型树脂好。这表明氨基酸在树脂中的氧化-还原作用是加速分离的一个因素。有些因子是溶液平衡因子的300倍或更多。虽然用ICP-MS法测定了^<235>U/^<238>U的因子，但由于测量误差较大，无法进行全面的意义评价。然而，我们发现树脂的因子是溶液平衡因子的20倍或更多。因此，所开发的树脂可望应用于具有多级分离的接触系统。少

1. Synthesis of durable amino acid resins and the resin properties : We have synthesized 15 types of amino acid resin, introducing amino acids or imitative amino acids into polystirene resin by the active esterification method. Amino acid contents introduced were estimated to be about 2-3.7 mmol/g-resin and the resin properties were evaluated by the measurement of ion exchange capacity, water content, FT-IR and etc.. We also investigated a washing effect with acids, alkali soaking and repeated use of the resins, and clarified that the developed resins were durable and functonal ones.2. Collection capacity of uranium and the selective adsorption function : The resins showed high adsorptive activity toward carbonate species of uranium. The equilibrium adsorption amounts were more than 950mg U/g-resin in Gly and Arg resins, and the high functionalization of amino acid resin was performed. The adsorption rate was exceedingly rapid and the mechanism was interpreted to be Langmuir type adsor … More ption of dicarbonate uranyl species by the analysis of the adsorption isotherms. The protonated amino residue may behave as a driving force for adsorptions, whose function was confirmed by the introduction of iminative amino acids possessing steric hindrance in amino group. Effect of carbonate concentration and sea water matrixes, and the behaviors of break-through and elution using mobile phase were also examined, and the developed resins were proofed to be a selective adsorbent for uranium.3. Separation and concentration behaviors for uranium isotopes : The separation behaviors of natural uranium isotopes were traced by the resin contact using batch method. The separation factor (^<234>U/^<238>U) of each resin was accumulated by the measurement of alpha-ray. We found clearly that the isotope concentration effect largely emerged from the contact with carbonate species at high temperature condition (90ﾟC). The effect of ester-bonding type resins developed formerly was langer than that of amido-bonding types. It suggests that the oxidation-redox action of amino acid within the resin behaves as a acceleration factor of the separation. Some factors were 300 times or more against those of the equilibria in solution. Although the factiors of ^<235>U/^<238>U were measured by ICP-MS method, we could not perform wholly the meaning evaluation, due to large errors at the measurements. However, we found the resins possessing the factors 20 times or more against those of the solution equilibria. Accordingly, the developed resins can be expected for the application to the contact systems with multistage separations. Less