Vanadium (II) Sulfate for the Reductive Leaching of Chalcopyrite: Replacing Smelting with Electrolysis for Copper Production

Abstract

The demand for copper is expected to outpace supply in the coming decades due in part to the emergence of wind and solar technologies, which require about five times as much copper as traditional energy sources. This work introduces a potentially transformative hydrometallurgical process to extract copper from chalcopyrite, and thereby sustain a high rate of copper production throughout the 21 st century. Chalcopyrite is reacted with vanadium (II) sulfate for the first time to enable the rapid, clean, and complete recovery of copper. Reactions between 39 g/L copper concentrate, 1 M vanadium (II) sulfate, and various concentrations of sulfuric acid yielded a final product of solid copper sulfate, which was characterized by Xray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) analysis. The solid products were leached in a subsequent step to demonstrate copper yields ranging from 95-99 %. The vanadium (II) ion may be regenerated by an electrolysis unit that leverages advances in vanadium flow battery technologies.

Anode Electrolysis of Copper Matte to Produce Copper and Iron

“…39 In hydrometallurgical process, the formation of passivation layer and the pyrite or silicates in sulfide minerals with poor conductivity may effect the speed and efficiency of leaching. [40][41][42] As for the anode electrolysis of sulfides in our previous work, it has provided some effective and feasible perspective on molten-salt electrolysis, which achieved an efficient and fast extraction of metals and sulfur. 43 The continuously consumable sulfides in the anode and the deposited metal products on the surface of cathode alleviate the polarization on the electrodes, making the electrolysis quick and efficient.…”