The use of such metals as cadmium, selenium is entailed in the manufacture of thin filmphotovoltaic (PV) modules. The increasing awareness of environmental concerns and risksassociated with the toxicity of these heavy metals has prompted the recycling of the PVmodules at the end of their useful life. A hydrometallurgical processing route, namely,H2SO4/H2O2 leaching cation exchange separation electrowinning, to recycle metals fromcadmium-telluride (CdTe) PV modules are proposed and investigated at the BrookhavenNational Laboratory. In the leaching procedure, the stripping of both cadmium and telluriumfrom PV module substrates was achieved through leaching with hydrogen and dilute sulfuricacid solution using a tumbling machine. Our leach tests showed that both cadmium andtellurium were readily solubilized within 30 minutes with low strength of acid (1.0 M H2SO4) atambient temperature. Leaching the CdTe PV module scraps yielded complete extraction of bothcadmium and tellurium. In the separation step, cation exchange resin was used to remove andseparate cadmium completely from tellurium-rich leach liquor of 0.5 M H2SO4. Through thisoperation, the cadmium was exchanged to the resin while the tellurium, on the other hand,remained in the leach liquor for the recovery. Ion exchange column studies showed that elutionof the resin with high strength of H2SO4 solution generated concentrated cadmium solution,which was subjected to the recovery of cadmium using an electrowinning process. This paperdetails the leaching of CdTe PV modules with sulfuric acid solution and separation of cadmiumfrom tellurium by cation exchange resin.
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