【摘要】 铟是一种稀散金属,具有重要战略价值。当前金属铟主要通过湿法工艺从矿物副产品中提取和回收。基于浸出—萃取净化—电解的工艺流程,从含铟浓度极低(<0.05 g/L)且铜、锌、银等杂质浓度较高的回转窑挥发烟尘浸出液中富集铟。首先对浸出液萃取富集获得了铟、铜及锌的富集液,进一步通过置换还原获得了铟单质及铜锌氯化液,从而实现了浸出液中铟与铜锌的分离。之后,对锌铜氯化物溶液进行置换回收锌铜元素。在铟的萃取阶段,考察了萃取剂种类、pH值、相比(O/A)、温度、萃取时间对铟萃取率的影响。确定最佳萃取条件为:有机相为浓度30%的P204、水相p H值为0.5、相比为1/3、温度为20℃、混合时间5 min。在铟的反萃阶段,负载有机相经过三级洗涤、三级反萃,可使铟的反萃率接近100%。烟尘浸出液经萃取—洗涤—反萃流程后,铟回收率高达96.8%,所获含铟反萃液经锌单质还原可获得98%的海绵铟,置换率高达99%。置换后液经净化除杂、蒸发结晶制备Zn Cl2及电积铜,实现了锌、铜的梯级高效回收。研究结果有望为低浓度含铟液中铟的富集提取与伴生元素的梯次回收提供借鉴。更多还原

【Abstract】 Indium is one of the strategic elements and mainly dispersedly exists with other minerals,which is commonly prepared from by-products during metallurgy of other metals. Herein,indium was enriched from the low-concentration indiumcontaining(<0. 05 g/L) solution based on the extraction-purification-electrodeposition process,with the associated copper and zinc being recovered simultaneously. Firstly,the separation of indium from copper and zinc in the leaching solution was achieved by extraction enrichment and subsequent reduction of indium by zinc metal. Then the resulting solution containing zinc and copper chlorides were used for reclamation of the zinc and copper. For the extraction of indium,the effects of extraction system,pH value,phase ratio,temperature and extraction time were optimized,namely 30% P204( V/V) as the organic phase,pH of aqueous phase being 0. 5,phase ratio(O/A) being 1/3,the temperature being 20 ℃ and the mixing time being 5 min. In the stripping back extraction stage of indium,the stripping rate of indium can reach nearly 100% by three-stage washing and three-stage stripping of supported organic phase. The overall recovery of indium from solution was 96. 8% after extraction-washing-reverse extraction,resulting a recovery of 98% indium metal sponge after further reduction by zinc metal. The remaining solution after reduction by zinc metal was further evaporated for Zn Cl2 preparation and then used for electrodepositon of metal copper,realizing the concomitant recovery of zinc and copper. The results can provide new insights for recovery of indium and simultaneous recycling of associated copper and zinc from low indium-containing indium solution.更多还原