Process Optimization and Flowsheet Development for Zinc and Copper Recycling from Reverberatory Furnace Flue Dust

The copper flue dust is an important secondary source for various metals and also a potential threat to the environment. In this study, a process was developed to convert a local copper flue dust containing 20.60% copper, 21% iron and 2.88% zinc into value-added products via a hydrometallurgical route. The response surface methodology was applied for the optimization of base metals leaching by sulfuric acid. Maximum recoveries of 96% for zinc and 76.7% for copper were achieved under the optimum conditions, whereas only 23.92% of the iron content was dissolved. Moreover, various parameters effective on Zn/Fe separation factor were assessed, and favorable separation obtained at pH 3, 2:1 A/O ratio, 20% V/V of D2EHPA in kerosene during 15 minutes. Stripping experiments also showed that 96.35% of zinc was successfully stripped at 1 M sulfuric acid and 2:1 A/O. The mathematical prediction models for leaching, solvent extraction and stripping were proposed and confirmed by statistical analysis and experiments. The proposed process in this study, enhances the copper production in the current leaching plant and makes it possible to recover zinc from industrial waste as a by-product.