Novel methods of separation and purification are envisaged for natural uranium, containing 0.7% of fissile ²³⁵U, a precious resource that fuels nuclear power plants. The present study demonstrates Solid phase extraction (SPE) of uranium as a sustainable alternative to conventional liquid-liquid extraction, leading to minimisation of organic inventory and enhancement of ease of operation concerning usage of viscous eutectic solvent. Overcoming the issue of the low solubility of organophosphorus extractant tri-octyl phosphine oxide (TOPO) in a hydrocarbon diluent, the aqueous insoluble, non-ionic eutectic solvent could be prepared with biodegradable menthol having TOPO: menthol mole ratio of 1:2 (MT2), 1:3 (MT3) and 1:4 (MT4). Eutectic solvents were sorbed on radio chemically stable Chromosorb W resin as solid support (MTC2, MTC3, MTC4), with loading of 45% for MTC2 and 40% for both MTC3 and MTC4, confirmed by weight difference and thermogravimetry. Batch sorption studies of U(VI) from nitric acid medium revealed attainment of equilibrium at 60 min., following a pseudo-second-order rate equation, Langmuir adsorption isotherm and a static capacity of 19 mg g⁻¹. The U(VI) uptake was found to increase with the increase in acid molarity indicating solvating mechanism of extraction (K_D = 1240 ± 4, 4 M HNO₃). Recyclability was established and stripping was effective with 0.5 M HNO₃. Column operation was also successfully demonstrated (breakthrough capacity = 18.9 mg g⁻¹). The U(VI) uptake of >98% was indicated for nitric acid-digested crude yellow cake matrices viz. sodium diuranate (SDU), magnesium diuranate (MDU) and heat-treated uranium peroxide (HTUP). For higher matrix content, near complete uranium uptake and suppression of extraction of representative impurities (Fe, Mn, Ni, Ce) was revealed indicating facile uranium separation and purification from matrices relevant to the front end of the nuclear fuel cycle.

^{天然铀含有 0.7% 的可裂变235} U，这是一种为核电站提供燃料的宝贵资源，人们设想采用新的分离和纯化方法。本研究表明，铀的固相萃取（SPE）是传统液-液萃取的可持续替代方案，可最大限度地减少有机物库存并提高粘性共晶溶剂使用的操作简便性。克服了有机磷萃取剂三辛基氧化膦（TOPO）在烃稀释剂中溶解度低的问题，可以用可生物降解的薄荷醇制备水不溶性非离子低共熔溶剂，其中TOPO：薄荷醇摩尔比为1：2（MT2 )、1:3 (MT3) 和 1:4 (MT4)。将低共熔溶剂吸附在作为固体载体的放射化学稳定的 Chromosorb W 树脂（MTC2、MTC3、MTC4）上，MTC2 的负载量为 45%，MTC3 和 MTC4 的负载量为 40%，通过重量差和热重分析证实。硝酸介质中 U(VI) 的批量吸附研究表明，遵循伪二阶速率方程、Langmuir 吸附等温线和 19 mg g ^-1的静态容量，在 60 分钟内达到平衡。发现 U(VI) 吸收随着酸摩尔浓度的增加而增加，表明萃取的溶剂化机制 (K _D  = 1240 ± 4, 4 M HNO ₃ )。确定了可回收性，并且使用 0.5 M HNO ₃可以有效去除。色谱柱操作也得到成功证明（突破容量 = 18.9 mg g ^-1）。硝酸消化的粗制黄饼基质即 U(VI) 吸收率 >98%。重铀酸钠（SDU）、重铀酸镁（MDU）和热处理过氧化铀（HTUP）。对于较高的基质含量，近乎完全的铀吸收和代表性杂质（Fe、Mn、Ni、Ce）的提取受到抑制，这表明铀可以从与核燃料循环前端相关的基质中轻松分离和纯化。