摘要
针对硝酸体系低浓度铀的吸附问题,以氯甲基化苯乙烯-二乙烯苯共聚物为骨架,以三氯化磷为功能化试剂,通过傅克烷基化反应及淬灭-水解/醇解反应,将长链羟基及烷基接枝到树脂上,从而得到分别含有磷酸和磷酸酯基功能基团的提铀树脂。通过红外光谱、元素分析、热重分析,对树脂进行了结构表征;在树脂制备过程中,考察了不同工艺参数对树脂含磷量及铀吸附性能的影响,确定了树脂合成的最优工艺参数。通过静态试验考察了pH、平衡铀浓度、吸附时间对树脂材料吸铀性能的影响,并进行了解吸剂的筛选和树脂重复使用性能的验证。结果表明:制备的磷酸酯基提铀树脂对于模拟溶液(1 mol/L HNO_(3)+1 mol/L NaNO_(3))中的低浓度铀(<20 mg/L)具有较好的吸附效果,该树脂对铀的饱和吸附容量为21.9 mg/g干树脂,吸附后残余尾液中的铀质量浓度<0.05 mg/L;以0.4 mol/L NaHCO_(3)与0.1 mol/L Na_(2)CO_(3)作为复合解吸剂,铀的解吸率为98.3%。制备的磷酸酯基提铀树脂可用于酸性硝酸体系中低浓度铀的吸附分离。
In addressing the adsorption issue of low-concentration uranium in nitric acid systems,a chloromethylated styrene-divinylbenzene copolymer was employed as the framework,and phosphorylation was achieved using phosphorus trichloride as the functionalizing reagent.Through Friedel-Crafts alkylation and quenching-hydrolysis/alcoholysis reactions,long-chain hydroxyl and alkyl groups were grafted onto the resin,resulting in uranium adsorbents featuring phosphoric acid and phosphoric ester functional groups,respectively.The resin structural characterization was conducted using infrared spectroscopy,elemental analysis,and thermogravimetric analysis.During the resin preparation,the impact of different process parameters on the phosphorus content and uranium adsorption performance was investigated,leading to the determination of optimal synthesis conditions.Static experiments were performed to assess the influence of pH,equilibrium uranium concentration,and adsorption time on the uranium adsorption properties of the resin.Additionally,a selection of desorption agents and verification of resin reusability were carried out.The results indicate that the prepared phosphoric ester-based uranium adsorbent exhibits excellent adsorption performance for low-concentration uranium(<20 mg/L)in a simulated solution(1 mol/L HNO_(3)+1 mol/L NaNO_(3)).The resin saturation adsorption capacity for uranium is 21.9 mg/g dry resin,and the residual uranium concentration in the leachate after adsorption is<0.05 mg/L.Using 0.4 mol/L NaHCO_(3)and 0.1 mol/L Na_(2)CO_(3)as composite desorption agents,the desorption efficiency for uranium reaches 98.3%.The synthesized phosphoric ester-based uranium adsorbent proves effective for the adsorption and separation of low-concentration uranium in nitric acid systems.
作者
常华
勾阳飞
宿延涛
杨吴馨晨
李默
CHANG Hua;GOU Yangfei;SU Yantao;YANGWU Xinchen;LI Mo(Beijing Research Institute of Chemical Industry and Metallurgy,CNNC,Beijing 101149,China)
出处
《铀矿冶》
CAS
2024年第2期112-118,共7页
Uranium Mining and Metallurgy
关键词
铀
硝酸体系
磷酸树脂
磷酸酯树脂
平衡吸附量
吸附
解吸
uranium
nitric acid systems
phosphate resin
phosphate ester resin
equilibrium adsorption capacity
adsorption
desorption
