In-situ electrolysis for improving the extraction of metal by heap or dump leaching

摘要

Copper is extracted from a heap of low-grade ore by transforming the heap into an electrolytic cell, and imposing a voltage thereon. Anodic conditions of redox and pH cause the sulphide to break down, and the copper to pass into solution. The copper can be recovered elsewhere if the electrolyte is drawn off, or in-situ if allowed to plate onto the cathode. Electrodes are formed as grids of conductors, or as layers of e.g. graphite.