Evaluation of High-Temperature Chlorination as a Process for Separation of Copper, Indium and Gallium from CIGS Solar Cell Waste Materials

CIGS (copper indium gallium diselenide) is a semiconductor used in high efficiency thin film solar cells. Several of these elements are considered to be fairly rare and thus expensive. In order to ensure future supply of the metals, an efficient recycling process for CIGS is needed. We have previously published a process for the separation of high purity selenium from CIGS solar cell waste materials. In the present paper we evaluate the possibility of using high-temperature chlorination to separate copper, indium, and gallium from the residue obtained in the selenium separation process. The chlorination agents used were chlorine gas, hydrogen chloride gas, and ammonium chloride. The goal was to use different temperatures to separate the metal chlorides formed. Ammonium chloride was shown to be the most promising chlorination agent for future process optimization.