Recovery of indium powders from indium chloride solutions by cementationa

AbstractA three-step, batch type recovery method was developed to produce indium powders from dilute indium chloride solutions prepared by dissolving indium tin oxide (ITO) electrodes from waste liquid crystal display (LCD) panels in concentrated hydrochloric acid (HCl) solutions. A 5–L batch process was used with individual experimental parameters for cementation, such as temperature and time, which were varied to optimise their effects on the physicochemical properties and purity of the recovered indium powders and the recovery rate. A validation experiment was performed by preparing indium bearing solutions in a 5–180 min kinetic study of indium cementation with aluminium in aqueous HCl solutions at 65°C. The indium powders obtained from the cementation processes were further characterised using various analytical tools, such as ICP/AES, X-ray diffraction (XRD), and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS). Cementation at 60°C for 10 min resulted in the optimal proces...