:: BHP Billiton Approves Escondida Sulphide Leach Copper Project

BHP Billiton today announced the approval of the US$870 million (US$500 million BHP Billiton share) Escondida Sulphide Leach copper project in Chile. The project will produce 180,000 tonnes (103,500 tonnes BHP Billiton share) of copper cathode per annum for in excess of 25 years and is scheduled to begin production during the second half of 2006.

The project will utilize a bacterially assisted leaching process on low-grade run-of-mine sulphide ore from the existing Escondida pit and the currently in-development Escondida Norte pit. The resulting solutions from the leaching will then be treated in solvent extraction and electro-winning plants to produce copper cathode.

President Base Metals Diego Hernandez said: "Escondida has been stockpiling low-grade sulphide material since its inception and has been conducting studies on leaching this material since the mid 1990s. New technological developments allow us today to economically process this low-grade material, previously mined as waste. We are excited about this project and the prospects for further application of this technology at other BHP Billiton copper projects."

The total, combined sulphide leach ore reserve to be extracted from both the Escondida and Escondida Norte pits, is estimated at 1.134 billion tonnes at an average copper grade of 0.52%, contained within a copper cut-off grade range of 0.3 to 0.7%. These ore reserves are sub-divided into 249 million tonnes at 0.52% copper of proved reserve and 884 million tonnes at 0.52% copper of probable reserve.

Water supply will come from a 500 litre per second desalination plant to be constructed at the Escondida port-site of Coloso near Antofagasta, Chile. Water will be pumped to the Escondida mine facilities, 170 kilometres southeast of Antofagasta.