Di(2-ethylhexyl)phosphoric acid (D2EHPA, HR) is widely used for solvent extraction of indium from acidic leaching solutions, but indium stripping from the loaded organic phase is difficult because of the high affinity of indium for the extractant. Adding proton-donor additives (HA) to the D2EHPA solution is a way to achieve high stripping efficiency for indium. In this work, monocarboxylic acids, aliphatic alcohols, and phenol derivatives were used as additives. Nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy of the organic phases confirm the formation of intermolecular associates (H-complexes) between all additives and D2EHPA. In the case of alcohols and substituted phenols, the interaction of oxygen atoms of alcohols or phenols with the proton of the hydroxyl group of D2EHPA is predominant, while in the case of monocarboxylic acids, an interaction between the hydroxyl proton of the acid and the PO group of D2EHPA mainly occurs. Despite the high In distribution ratio with D2EHPA (100−1000), in all cases investigated the introduction of additives into the organic phase led to an antagonistic extraction effect, however it facilitated efficient In stripping from the loaded organic phase. This effect depends significantly on the type and structure of the additive. Indium extraction in the presence of additives decreases in the series 4-bromophenol >4-t-butylphenol > octanol, 2-ethylhexanol >4-nitrophenol >2-nitrophenol >2,6-di-t-butylphenol, octanoic acid > Versatic 10. Extraction systems containing D2EHPA and 2-ethylhexanol can be used to recover indium from various industrial solutions, in particular, from those derived from lead‑zinc production and from liquid crystal display panel wastes.

二（2-乙基己基）磷酸（D2EHPA，HR）广泛用于从酸性浸出溶液中溶剂萃取铟，但由于铟对萃取剂的高亲和力，很难从负载的有机相中反萃取铟。在 D2EHPA 溶液中添加质子供体添加剂 (HA) 是实现铟高剥离效率的一种方法。在这项工作中，一元羧酸、脂肪醇和苯酚衍生物用作添加剂。有机相的核磁共振 (NMR) 和红外 (IR) 光谱证实了所有添加剂和 D2EHPA 之间形成了分子间缔合物 (H-配合物)。在醇和取代酚的情况下，醇或酚的氧原子与 D2EHPA 羟基的质子的相互作用占主导地位，主要发生O组D2EHPA。尽管与 D2EHPA (100-1000) 的 In 分配比很高，但在所有情况下都研究了将添加剂引入有机相会导致拮抗萃取效果，但它有助于有效地从负载的有机相中剥离 In。这种效果很大程度上取决于添加剂的类型和结构。添加剂存在下的铟萃取降低系列 4-溴苯酚 >4-叔丁基苯酚 > 辛醇、2-乙基己醇 >4-硝基苯酚 >2-硝基苯酚 >2,6-二叔丁基苯酚、辛酸 > Versatic 10 . 含有 D2EHPA 和 2-乙基己醇的萃取系统可用于从各种工业溶液中回收铟，特别是从铅锌生产和液晶显示面板废料中提取的铟。