Selective recovery of zinc from zinc oxide dust using choline chloride based deep eutectic solvents
(1. Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China;
2. State Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization, Kunming University of Science and Technology, Kunming 650093, China)
2. State Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization, Kunming University of Science and Technology, Kunming 650093, China)
Abstract: Deep eutectic solvents (DESs) are a kind of potential lixiviant for selective metal processing due to their versatile complexation properties. In this study, we investigated the recovery of zinc from zinc oxide dust using choline chloride-urea- ethylene glycol (ChCl-urea-EG) DESs. The zinc extraction efficiency can be up to 85.2% when the slurry concentration is 50 g/L, leaching temperature is 80 °C and stirring speed is 600 r/min. The leaching process is controlled by the diffusion and the corresponding activation energy is 32.1 kJ/mol. The resultant solution was directly used for the electrodeposition of zinc. The pure zinc deposit is obtained with a current efficiency of 82.6%. Furthermore, the ChCl-urea-EG DESs can be recycled. This approach is shown to be promising for the recycling of zinc from the zinc-containing dust.
Key words: deep eutectic solvent; selective leaching; zinc oxide dust; zinc; direct electrodeposition