A Solvent Extraction Study of Copper in Methanesulfonic Acid Solution Using LIX-984N-C

Chalcopyrite leaching is still remaining as the Holy Grail in hydrometallurgy. Chalcopyrite passivation limits copper leaching in a sulfuric acid system. Methanesulfonic acid (MSA) has been proven to be an alternative lixiviant to leach chalcopyrite. Therefore, solvent extraction tests were performed to confirm the compatibility of MSA. LIX-984N-C was used as an extractant to extract 2 g/L copper from copper-MSA solution at 25℃. Copper extraction enhanced to 97% when equilibrium pH increased to 1.0. The optimum condition for copper extraction was selected when 10 vol% extractant was tested with pH 1.0 at A/O 1.5. Based on the theoretical studies with McCabe–Thiele diagram, copper can be extracted within two stages at A/O 1.5. With 20 g/L sulfuric acid, co-extracted iron of 99% was scrubbed within one stage at O/A 5.0. Stripping efficiency achieved 99% with 200 g/L sulfuric acid at O/A 1.0. Finally, 5.2 g/L copper can be stripped within three stages at O/A 5.0. This study proves that LIX-984N-C can extract copper from MSA leach solution. In addition, loaded organic can be stripped by sulfuric acid.