Recycling of copper flue dust via leaching-solvent extraction processing

Abstract

A laboratory-/bench-scale investigation relating to copper recovery from Chilean copper flue dust is described. Since the dust contained a high amount of copper (nearly 24%), the considered option consisted in the leaching of the metallic material with ammonium chloride solution, thus enabling the dissolution of copper via its ammoniacal complexes, and also rendering, due to the almost neutral conditions of the leaching solution, a near complete lean solution with respect to the presence of other metal accompanying in the dust. Results obtained show that with ammonium chloride solutions, nearly 90% of the copper contained in the dust can be leached at 20°C. Copper enters the solvent extraction-electrowinning circuit due to the following equilibria:regenerating both the leaching and the solvent extraction reagents. In the above equation, HR represented the active substance of the extractant (Acorga PT5050) used in the solvent extraction circuit; the first of the above equilibria is related to the extraction operation and the second to the strip stage.

Keywords:

• Copper flue dust
• Leaching
• Solvent extraction
• Ammonium chloride
• Acorga PT5050

Acknowledgment

The authors wish to thank the CSIC (Spain) for the support.

Notes

Presented at the 4th International Conference on Environmental Management, Engineering, Planning and Economics (CEMEPE), 24–28 June 2013, Mykonos, Greece