Oceana Gold (New Zealand) Limited operates the Macraes Gold Mine near Dunedin on the South Island of New Zealand. The orebody is mineralogically complex and comparatively low grade requiring a series of unit processes and resulting in a relatively complex plant. As part of Oceana Gold's ongoing Business Improvement program, a concerted effort has been made to focus on operational efficiency. One aspect of this has been the efficient use of energy in the gold recovery process. A benchmarking process has been developed for the Macraes operation that includes comparison with other operating mines and theoretical design. Criteria for determining operational efficiency have been developed. While benchmarking is, in theory, a simple process, this paper looks at putting benchmarking into practice by catering for variability in ore and associate processing methods. The unit processes discussed include the comminution circuit, flotation plant, pressure oxidation plant and gold recovery circuits._x000D_
FORMAL CITATION:Barns, K, Lane, G, Osten, K and Scagliotta, N, 2004._x000D_
Benchmarking energy efficiency - a case study at Macraes Gold Mine, in Proceedings Metallurgical Plant Design and Operating Strategies 2004, pp 221-260 (The Australasian Institute of Mining and Metallurgy: Melbourne).