Removal and Recovery of Indium from ITO Coated Glass and Scraps Using Molten Salt Electrolysis

Abstract

Indium is an important strategic resource due to the scarcity for the metal. In the present study, molten salt electrolysis is used to reduce indium from ITO coated glass and scraps in order to seek a new way to recycle the value resource. The electrochemical behavior of indium and tin oxides was studied by cyclic voltammetry at 450 °C in molten LiCl-KCl. The reduction peaks were observed in the cathodic scan for In2O3 and SnO2. Constant voltage electrolysis was performed at 1.7 V and 450 °C for ITO. The deposits between ITO layer and the cathode were collected and analyzed by XRD. The reduction reaction occurred at the interface of the oxide pellets and the cathode. Metallic indium and Sn-In alloys were detected after electrolysis. The ITO covered glass was reduced by electrochemical method in molten LiCl-KCl at 450 °C under argon with Mo wire contacting electrode. The findings, together with SEM and EDX analyses, confirmed ITO layer was removed from the glass surface.

Microporous Polymer-Modified Glassy Carbon Electrodes for the Electrochemical Detection of Metronidazole: Experimental and Theoretical Insights

“…In addition, energy dispersive spectroscopy (EDS) analysis was performed to verify the successful electropolymerization of each monomer on the ITO electrode. EDS confirmed the composition of ITO (In 11.77 at%, O 51.03 at%, Si 20.68 at%, Sn 1.42 at%, C 12.52 at%, Ca 2.58 at%)—as the presence of indium, tin, and oxygen was expected for this coating [ 56 , 72 ]—and the silicon and calcium content for the glass substrate [ 73 ]. Carbon appeared in the EDS spectrum, presumably due to surface contamination of the electrode during handling for electropolymerization and the previous XPS analysis.…”

“…In Figure 5 a, comparative XPS survey spectra are presented for the bare ITO electrode (red line) and polymer-modified ITO electrodes: ITO/PCBP (blue line), ITO/PTPTCzSiOH (green line), and ITO/PTCB (black line). The survey spectrum of the pristine ITO electrode revealed the presence of oxygen (O), indium (In), and tin (Sn), attributed to the ITO composition, along with a carbon core level (C) associated with surface contamination (C–O–H, C–(C,H), C ꞊ O… bonds) [ 56 , 57 , 58 , 59 , 60 ]. On the other hand, the spectra of all MPN-modified electrodes indicated increased carbon and nitrogen peaks, attributable to the organic composition of the polymers.…”

“…. bonds) [56][57][58][59][60]. On the other hand, the spectra of all MPN-modified electrodes indicated increased carbon and nitrogen peaks, attributable to the organic composition of the polymers.…”

Estimating the Capital Costs of Electrowinning Processes

“…In recent years, innovative electrowinning processes have been proposed and reimagined for the primary extraction and production of metals, such as copper 5 , iron 6 , titanium 7 , molybdenum 8 , rhenium 8 , rare earth metals 9 , and aluminum master alloys, such as those of scandium 10 . Meanwhile, electrochemical approaches have been the focus of many new recycling and recovery technologies for strategic metals such as indium 11 , cobalt 12 , and lithium 13 .…”

Recovery and Reuse of Spent ITO Targets through Electrochemical Techniques

“…The whole reduction process was carried out at 1150 °C, which is too high, and consumes a lot of energy. Cui et al 29 studied the electrochemical redox processes of In 2 O 3 and SnO 2 using a molybdenum rod working electrode at 450 °C in molten LiCl-KCl. However, the reduction mechanism of In 2 O 3 and SnO 2 was only studied separately.…”