Phase transformation and roasting kinetics of scrap CIGS materials in chlorination roasting assisted by ammonium chloride

The kinetics of chlorination roasting of Scrap CIGS Materials was discussed. • The control steps for weight gain by roasting and chlorination of Scrap CIGS Materials were determined. • The separation rate of indium and gallium in Scrap CIGS Materials can be improved by studying the roasting kinetics. The strategy of efficient separation of valuable components from spent Copper indium gallium diselenide (CIGS) solar cell via oxidation roasting was proposed. Almost all of Se in the scrap CIGS volatilizes into the gas phase in the form of gaseous SeO 2 , copper, indium, and gallium exist in the form of mixed oxides (CIGO) in the roasting slag. To further achieve the efficient separation of indium, gallium and copper, the paper discusses the thermal behavior of indium, gallium and copper in the roasting slag during the chlorination roasting process using ammonium chloride as the chlorine source. Based on thermodynamic calculations and thermal roasting kinetics, the pyrolysis behavior of indium gallium copper mixed oxide slag during the chlorination roasting process was measured. During the chlorination roasting process of CIGO, as the roasting temperature increases, the order in which chlorides are formed is: indium chloride > gallium chloride > copper chloride. The kinetic mechanisms of indium chloride and gallium chloride during the chlorination roasting process of CIGO were determined by the FWO, KAS and Starink methods. The mean activation energies calculated by the three methods are 95.58 kJ/mol (indium chloride) and 78.87 kJ/mol (gallium chloride) respectively. The roasting temperature has a certain influence on the microstructure evolution of the CIGO chlorination combustion products. This research provides theoretical support for the comprehensive recycling of the discarded CIGS components. Download: Download high-res image (105KB) Download: Download full-size image