In:
ECS Meeting Abstracts, The Electrochemical Society, Vol. MA2017-01, No. 18 ( 2017-04-15), p. 1047-1047
Abstract:
Indium is an essential element for the fabrication of transparent conductive oxide (TCO) materials. However, it is very rare element and is obtained as a byproduct of zinc metal refining. Moreover, its recycling rate is less than 1%. This provokes the need to recycle indium from its end products. Indium and tin (Sn) are especially well suited for molten salt electrolysis because of their low melting points. In this paper, reduction processes on molybdenum electrode at 500 o C in molten LiCl–KCl eutectic (55.7-44.3 mol %) containing varying amount of InCl 3 was studied by Cyclic Voltammetry (CV) and Chronopotentiometry (CP). In-Sn alloy was used as raw material. Thermodynamic calculations showed poor stability of InCl 3 with metal based crucibles. So, Al 2 O 3 crucible was utilized for the experiments. Concentration of InCl 3 was changed from 1 wt% to 3 wt% and it was found that the reduction of indium ions take place by a two-step electrochemical reaction: In 3+ /In + and In + /In o at the potentials of 0.78 and 0.24 V versus Ag/AgCl. Number of transferred electrons and diffusion coefficient of In +3 ion species in molten salt with varying InCl 3 content was estimated with the help of CV measurements. However, at 500 o C, InCl 3 shows chemical reactivity with Sn metal according to the following reaction: InCl 3 + 1.5Sn → 1.5SnCl 2 + In. This problem was overcome by shifting the molten chloride system to molten fluoride system (LiF-KF-InF 3 ) as fluoride based salts shows high chemical stability with metals. As a result of electrorefining, In-Sn alloy was recycled into pure indium with low levels of impurities.
Type of Medium:
Online Resource
ISSN:
2151-2043
DOI:
10.1149/MA2017-01/18/1047
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2017
detail.hit.zdb_id:
2438749-6
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