Effect of Oxidizing Additives on Chalcopyrite Leaching in Choline Chloride Deep Eutectic Solvents

Copper recovery from chalcopyrite (CuFeS۲) was examined using deep eutectic solvents (DESS) based on choline chloride (ChCl) with different hydrogen bond donors (HBDs) and oxidizing additives. The baseline ChCl:Urea (۱:۲) system showed poor leaching efficiency (۱.۰% Cu recovery), indicating limited oxidative ability. Adding iodine (I۲) significantly improved dissolution, reaching ۶۸.۶% recovery at ۰.۵ mol by promoting oxidative breakdown of sulfides and forming Cu-I complexes. Ferric chloride (FeCl۳) proved even more effective, yielding ۹۸.۴% copper recovery at ۱.۵ mol due to its dual role as oxidant (Fe۳+/Fe۲+ cycling) and chloride source for complex stabilization. Excess FeCl۳, however, reduced efficiency, likely from increased viscosity. Replacing urea with ethylene glycol (EG) maintained high yields (۹۹%), confirming that the oxidant type and concentration are the dominant factors governing chalcopyrite dissolution.

کلیدواژه ها:

Chalcopyrite ، Copper recovery ، Choline chloride-Urea ، Deep eutectic solvent ، Oxidant agent