sepon copper to be expanded

3 December 2007
AUSTRALIAN STOCK EXCHANGE AND MEDIA RELEASE
SEPON COPPER OPERATION TO BE EXPANDED

Oxiana’s Board has approved an expansion of the Sepon Copper operation from 60,000t/a nameplate capacity to 80,000 t/a by 2010. The estimated capital cost is US$178 million and overall life-of-mine cash operating costs will be reduced by approximately 10%.


Background
Oxiana’s Sepon Copper operation in the Lao PDR commenced production in 2005, and in 2007 will produce 60,000t to 63,000t of copper metal cathodes. The operation is based on mining from the high grade Khanong deposit, with the nature of the ore allowing processing - via whole-of-ore leach, solvent-extraction and electrowinning - to final copper cathode metal on site. By the end of 2007 more than 150,000t of copper cathodes will have been produced since commissioning.
Exploration has seen further copper Resources discovered at the Thengkham North and Thengkham South deposits, approximately 7 kilometres west of the plant (Figure 1). These additional Resources, along with further exploration success in and around the Khanong orebody have justified an expansion of processing capacity. A full Resource and Reserve update will be published in March 2008.

Project Scope
Throughput of the plant will be increased from 1.35Mt/a to 2Mt/a. Introduction of lower-grade ore from the Thengkham deposits will see the head-grade reduced from 5.3% copper to 4.3% copper. Sepon will remain one of the world’s highest grade copper mines (Figure 2).
The main additions to the plant under the approved expansion will be a larger new primary crusher, an additional 8 CCD tank train, commensurate leaching capacity additions and 24 new electro-winning cells. A number of debottlenecking and improvement projects will also be undertaken within the expansion scope of works. Work will begin immediately and forecast construction completion is 4th Quarter 2009. Mine life will be in excess of 10 years.