Alkaline leaching is used for the extraction of uranium from rarely available carbonate ore. A hyperbranched cross-linked polymeric adsorbent (HCPA) was developed for selective recovery of uranium(VI) (U) from real-life alkaline leach liquor. HCPA was synthesized using the free radical copolymerization of acrylamide and N, N-methylene bis(acrylamide). In addition, potassium persulfate (as the initiator) and dodecanethiol (as the brancher) were used to transfer the radicals for faster chain formation and smooth branching of the long-chain polymer. Several methods were used extensively to characterize the adsorbent. The Langmuir maximum U adsorption capacity of HCPA was 1012 mg/g at 303 K, and 98% of U was removed from alkaline leach liquor. U was adsorbed at pH 8.5 in the presence of various interfering co-ions and desorbed at pH 11.5 in the form of sodium diuranate (Na₂U₂O₇) precipitate. The adsorption was monolayer, exothermic, and spontaneous in nature. The C–N, CO–NH₂, and C–OH groups of HCPA interacted with uranyl ions initiating the coordinative and electrostatic interactions leading to U adsorption. Continuous fixed-bed column runs were performed using the actual leach liquor, and a fundamental kinetic model was used to quantify the performance of columns. The transport parameters were estimated from the model, and scaling-up calculations were performed using these parameters. Five adsorption–desorption cycles were conducted to determine the reusability and structural stability of the synthesized polymeric adsorbent.

中文翻译：

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使用聚合物吸附剂有效吸附和解吸铀 (VI)：结合实际碱性浸出液的理论和实验方法

碱浸用于从稀有的碳酸盐矿石中提取铀。开发了一种超支化交联聚合物吸附剂 (HCPA)，用于从现实生活中的碱性浸出液中选择性回收铀 (VI) (U)。采用丙烯酰胺和N, N-亚甲基双(丙烯酰胺)自由基共聚合成HCPA 。此外，过硫酸钾（作为引发剂）和十二烷硫醇（作为支化剂）用于转移自由基，以加快长链聚合物的链形成和平滑支化。多种方法被广泛用于表征吸附剂。 HCPA在303 K时的Langmuir最大U吸附容量为1012 mg/g，并且从碱性浸出液中去除了98%的U。 U 在各种干扰共离子存在下在 pH 8.5 下被吸附，并在 pH 11.5 下以重铀酸钠 (Na ₂ U ₂ O ₇ ) 沉淀的形式解吸。吸附本质上是单层、放热和自发的。 HCPA 的C-N、CO-NH ₂和 C-OH 基团与铀酰离子相互作用，引发配位和静电相互作用，导致 U 吸附。使用实际浸出液进行连续固定床柱运行，并使用基本动力学模型来量化柱的性能。根据模型估计传输参数，并使用这些参数进行放大计算。进行五个吸附-解吸循环以确定合成的聚合物吸附剂的可重复使用性和结构稳定性。