Separation and Recovery of Valuable Elements from Spent CIGS Materials

Abstract

A separation–recovery method was proposed in this study to recover valuable elements from spent copper–indium–gallium–selenium (CIGS) materials based on the different physical and chemical properties of their components. Spent CIGS materials were first roasted at 1000 °C to achieve phase transformation. During the transformation, 99.9% selenium was volatilized and recovered via oxidation into selenium dioxide. Meanwhile, other metals were converted from selenides to oxides. Subsequently, the indium and gallium in the roasting product were separated from copper via sulfuric acid leaching and precipitation. After the precipitation product was roasted, mixed oxides that contained 90.59% indium oxide and gallium oxide were obtained. The recovery rates of indium and gallium were 97.74% and 97.41%, respectively. Lastly, 99.83% of the copper in the filtrate was recovered via solvent extraction. The selective separation and recovery of valuable metals can be achieved through the rational utilization of the physical and chemical properties of elements in spent CIGS materials.

Valuable metal recycling from thin film CIGS solar cells by leaching under mild conditions

“…For the recovery of the rest of the elements, high temperature chlorination using different chlorination agents was studied [15] and the process was finally optimized for NH 4 Cl (260 and 340 • C for Ga and In recovery, respectively) [16]. Lv et al [17] first thermally removed Se as SeO 2 and then achieved high leaching yields of In, Ga and Cu by leaching their oxides with 4 M H 2 SO 4 at 90 • C. They also proved that recovery of In and Ga from the leachate is possible through their precipitation as hydroxides followed by roasting at 800 • C to obtain a mix of their oxides, while Cu can be recovered as a sulphate after solvent extraction, stripping and crystallization. On the other hand, Hu et al [18] started with leaching a spent CIGS material using 3.2 M HNO 3 at 80 • C. Ga, Cu and some Se were present in the leachate, while In and most of Se remained in the solid residue.…”

Novel Electrodeposition Method for Cu-In-Cd-Ga Sequential Separation from Waste Solar Cell: Mechanism, Application, and Environmental Impact Assessment

“…However, due to the multimetal feature (Cu-In-Cd-Ga) of CIGS-SC, traditional methods suffer from complex separation processes, huge reagent consumption, and toxic substances involved. A combination of phase transformation, leaching, chemical precipitation, roasting, and solvent extraction lacks sufficient selectivity, where In-Ga separation can hardly be achieved through the whole complex processes (final products with a low purity of 90.59%) . Another recovery route for CIGS powder consists of HCl-H 2 O 2 leaching, Cu and Se electrodeposition, and SOCl 2 precipitation-distillation .…”

“…A combination of phase transformation, leaching, chemical precipitation, roasting, and solvent extraction lacks sufficient selectivity, where In-Ga separation can hardly be achieved through the whole complex processes (final products with a low purity of 90.59%). 15 Another recovery route for CIGS powder consists of HCl-H 2 O 2 leaching, Cu and Se electrodeposition, and SOCl 2 precipitation-distillation. 16 Although metal elements were separately recovered, this process involves enormous reagent consumption with expensive H 2 O 2 and toxic SOCl 2 .…”

Liquid-Liquid Extraction of Indium(III) from the HCl Medium by Ionic Liquid A327H+Cl− and Its Use in a Supported Liquid Membrane System

“…Hydrometallurgical recovery of indium from a material containing it requires some steps: the first is to leach the solid product, and in the case of indium, as expected, mineral acids and aqua regia is the media to dissolve the element [3,4], though incursions in the use of bioleaching [5] and deep eutectic solvents [6] are also known. Once dissolved, the approaches to recover the metal include ion exchange [7], precipitation [8], membranes [9,10], counter-current foam separation [11], electrowinning [12], cementation [4], but the main interest seemed to be in the use of solvent extraction using conventional extractants, such as 8-hydroxyquinoline derivatives [13], D2EHPA [14], TBP (tributyl phosphate [15], methylimino-dioctylacetamide (MIDOA) [16], ionic liquids (Cyphos IL101 and Aliquat 336 [17], Cyphos IL104 [18], A324H + Cl − [19], PJMTH + HSO 4…”

“…Hydrometallurgical recovery of indium from a material containing it requires some steps: the first is to leach the solid product, and in the case of indium, as expected, mineral acids and aqua regia is the media to dissolve the element [ 3 , 4 ], though incursions in the use of bioleaching [ 5 ] and deep eutectic solvents [ 6 ] are also known. Once dissolved, the approaches to recover the metal include ion exchange [ 7 ], precipitation [ 8 ], membranes [ 9 , 10 ], counter-current foam separation [ 11 ], electrowinning [ 12 ], cementation [ 4 ], but the main interest seemed to be in the use of solvent extraction using conventional extractants, such as 8-hydroxyquinoline derivatives [ 13 ], D2EHPA [ 14 ], TBP (tributyl phosphate [ 15 ], methylimino-dioctylacetamide (MIDOA) [ 16 ], ionic liquids (Cyphos IL101 and Aliquat 336 [ 17 ], Cyphos IL104 [ 18 ], A324H + Cl − [ 19 ], PJMTH + HSO 4 − [ 20 ]), or chloride-rich deep eutectic solvents [ 21 ]; in all the above cases, the extraction efficiencies of the different extractants were high, i.e., exceeding 95%, though the experimental conditions vary from one investigation to another, i.e., pH 2 [ 13 ] against a medium rich in HCl [ 15 , 19 ], a type of an acidic medium, i.e., HCl [ 16 ] against sulphuric acid [ 20 ], and varying extractant concentrations [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ].…”