A new approach using water as the stripping phase for extraction and recovery of low-concentration Ga (III) from concentrated hydrochloric acid solutions by Aliquat 336-based supported liquid membrane (SLM) is suggested. Generally, the stripping of Ga (III) from the loaded organic phase during liquid-liquid two-phase stirring extraction using quaternary ammonium salt as an extractant is extremely difficult. However, in the present work, an efficient mass transfer of low-concentration Ga (III) through the SLM was observed by introducing a low acidity (pH=2) aqueous solution as the stripping phase of the SLM. It was revealed that dissociation of GaCl₄^- and HCl₂^- anions into Ga³⁺, Cl^- and H⁺ ions at the stripping/membrane phase interface play an important role in driving the mass transfer of GaCl₄^- from the concentrated hydrochloric acid solutions towards stripping phases. Kinetic analysis suggests that the permeability coefficient of Ga (III) ions through the SLM is dependent on the reaction temperature, extractant Aliquat 336 concentrations, and the difference in Cl^- concentrations between the two sides of the liquid membrane phase, but independent of H⁺ concentrations. In view of future’s applications for selective separation and recovery of low-concentration Ga (III) from the concentrated hydrochloric acid leaching solutions of various gallium-containing solid wastes, separation selectivity of Ga (III) against other coexisting metal impurity ions, such as Fe (II), Al (III), Mg (II) and Cu (II), was also evaluated.

提出了一种使用水作为反萃取相通过 Aliquat 336 基支撑液膜 (SLM) 从浓盐酸溶液中萃取和回收低浓度 Ga (III) 的新方法。通常，在使用季铵盐作为萃取剂的液-液两相搅拌萃取过程中，从负载的有机相中汽提Ga(III)是非常困难的。然而，在目前的工作中，通过引入低酸度 (pH=2) 水溶液作为 SLM 的汽提相，观察到低浓度 Ga (III) 通过 SLM 的有效传质。揭示了GaCl ₄ ^-和HCl ₂ ^-阴离子离解为Ga ³⁺、Cl ^-和H ⁺反萃取/膜相界面处的离子在推动 GaCl _{4的质量转移方面发挥重要作用}^-从浓盐酸溶液向反萃取相。动力学分析表明，Ga (III) 离子通过 SLM 的渗透系数取决于反应温度、萃取剂 Aliquat 336 浓度以及液膜相两侧的Cl ^{-浓度差异，但与 H +无关}浓度。鉴于未来在各种含镓固体废物的浓盐酸浸出液中选择性分离回收低浓度Ga(III)的应用，Ga(III)对其他共存金属杂质离子如Fe的分离选择性(II)、Al(III)、Mg(II)和Cu(II)也进行了评价。