Xstrata Developing Ernest Henry Underground
Construction of the Ernest Henry underground mine is expected to begin in the first half of 2010, with first production in late 2011 and full-scale production from early 2013. Development of the underground mine is being based on a revised ore reserve estimate of 72 million mt, grading 1% copper, 0.5 g/mt gold, and 22% magnetite, a 600% increase over previously published underground reserves.
The existing concentrator at Ernest Henry will be reconfigured to align with the underground production rate, resulting in lower throughput levels and improved metallurgical recoveries and energy efficiencies. A separate extraction circuit will be installed to produce magnetite concentrates, which are not currently produced at the mine.
At full production from 2013, the underground mine is expected to produce about 50,000 mt/y of copper and 70,000 mt/y of gold in concentrates, plus 1.2 million mt/y of magnetite. Copper-gold concentrates will continue to be hauled by trucks to Xstrata’s Mount Isa copper smelter, with anode from Mount Isa then railed to Xstrata’s refinery in Townsville, Queensland. Magnetite will be exported to Asian steel mills. The project is dependent on government environmental approvals.