OBJECTIVES

Following leaching and separation, the preferred final recovery step for base metals such as copper, nickel, cobalt and zinc is electrowinning, a process in which the metal ions are reduced and deposit as the pure metal on the cathode. However, electrowinning is capital intensive and has significant labour costs and health risks associated with acid mist generated in the tankhouses. The operating costs are dominated by the cost of electrical power, which has prevented the establishment of plants in areas with high power costs.

The availability of relatively inexpensive gaseous reductants (in the form of natural gas) close to base metal operations in Australia has raised the possibility of using gaseous reduction processes rather than electrowinning for copper, nickel and cobalt ions. The direct use of natural gas as a reductant in a pressure reduction process would have substantial implications for hydrometallurgy in general and could reduce the costs and health hazards associated with the electrowinning process. There is a very large potential market for successful technology in this area.

Therefore, this project aims to evaluate this possible alternative to electrowinning by:

• assessing the technical and financial feasibility of a pressure reduction process for copper recovery that uses hydrogen and, if possible, natural gas directly as the reductant for copper ions in acidic copper sulfate solutions.

INDUSTRY BENEFITS

• a preliminary technical and economic evaluation of a pressure reduction process using natural gas as the reductant for copper production as an alternative to electrowinning: if feasible, this process could have major economic benefits for the Australian copper (and possibly also nickel) industry.

RESEARCH TEAM
Dr Aleks Nikoloski (Project Leader)
Dr Soo-Kyung Kim (Visiting Scientist)
Professor Mike Nicol
(Murdoch University)

RESEARCH COLLABORATION
Korea Institute of Geoscience and Mineral Resources (KIGAM)

PROJECT DURATION
2006-2009