A more environmentally friendly solvent extraction process was formulated for uranium extraction using diluent-free extractants based on trialkylammonium compounds. The effect of ammonium cations and anions toward extraction efficiency, viscosity and phase separation was also evaluated. These systems were shown to be highly efficient and simple to implement as they rely on the same chemical components as those applied in the actual industrial process. It has also been demonstrated that using such alternatives allows not only to prevent third phase formation and subsequent extractant degradation, but also reduces the evaporation loss of solvent by a factor of 20. Among the systems investigated, the pure [TOAH]₂[SO₄] was selected as the simplest and most efficient. A comparative Life Cycle Assessment (LCA) was also conducted between this system and the conventional solvent to compare more objectively their sustainability. Results based on four environmental indicators show that the new system is 18 times less impactful. Contrary to expectations, this study also showed that the pure (diluent-free) extractant system needs to be at least 2 times more efficient in terms of metal extraction to become significantly more sustainable. Other main effects contributing to the LCA are derived from: (i) the production of chemicals, which is much more harmful for extractants than for aliphatic diluents, (ii) the loss of Volatile Organic Compounds (VOC) to the environment, and (iii) to a lesser extent, the additional centrifugation step that may be required to separate more viscous systems.

采用基于三烷基铵化合物的无稀释剂萃取剂，制定了一种更环保的溶剂萃取工艺用于铀萃取。还评估了铵阳离子和阴离子对萃取效率、粘度和相分离的影响。这些系统被证明是高效且易于实施的，因为它们依赖于与实际工业过程中应用的相同的化学成分。还证明，使用此类替代方案不仅可以防止第三相形成和随后的萃取剂降解，而且还可以将溶剂的蒸发损失减少 20 倍。在所研究的系统中，纯 [TOAH] 2 _[ SO ₄ ] 被选为最简单且最有效的。该系统与传统溶剂之间还进行了比较生命周期评估（LCA），以更客观地比较其可持续性。基于四项环境指标的结果表明，新系统的影响降低了 18 倍。与预期相反，这项研究还表明，纯（无稀释剂）萃取剂系统在金属萃取方面需要至少提高 2 倍的效率，才能显着提高可持续性。造成 LCA 的其他主要影响来自：(i) 化学品的生产，这对萃取剂比对脂肪族稀释剂危害更大，(ii) 挥发性有机化合物 (VOC) 流失到环境中，以及 (iii) ）在较小程度上，分离更粘稠的系统可能需要额外的离心步骤。