Mining Magazine > Panorama > Green light for Ernest Henry development

Panorama

Xstrata Copper has announced corporate approvals for a total investment of US$542 million to extend the life of its Ernest Henry mining operations in Queensland, Australia, to at least 2024. The company plans to transform the mine from an open pit operation to underground workings, together with the construction of an associated magnetite extraction plant.

The decision follows feasibility studies into the construction of a magnetite processing facility and the installation of full scale underground mining operations that have resulted in a revised ore reserve estimate of 72Mt at a grade of 1.0% copper, 0.5gm/t gold and 22% magnetite. The total tonnage represents a 600% increase over previously published underground reserves. Ore will be mined principally from a major hoisting shaft to be sunk to a depth of 1,000m, producing 6Mt/y of ore at full capacity.

The project will enable Ernest Henry to achieve annual production levels of approximately 50,000t of copper and 70,000oz of gold in concentrates from 2012 when processing from open pit mining operations ceases. Copper-gold concentrates from the mine will continue to be hauled by purpose-built trucks to Xstrata’s Mount Isa copper smelter, with the anode then railed to Xstrata Copper’s refinery in Townsville.

The existing concentrator at the Ernest Henry mine will be reconfigured to align with the underground mine production rate, resulting in continuous milling at lower throughput levels to deliver improved metallurgical recoveries and energy efficiencies. A separate extraction circuit will be installed to produce the magnetite concentrates.

The magnetite processing operation at Ernest Henry will produce approximately 1.2Mt/y of magnetite for export to Asia, making it Queensland’s first iron ore producer.

Construction of the underground mine is expected to commence in the first half of 2010 with first production in late 2011 and full-scale operation from early 2013. Construction of the magnetite plant is also expected to commence in the first half of 2010 with commissioning expected by the beginning of 2011.  

Xstrata Copper CEO, Charlie Sartain said: “This project marks an important step towards sustaining our north Queensland copper operations. This is the second of five brownfield projects that Xstrata Copper is planning to move into the construction phase over the next nine months across our global operations, following the approval of the Lomas Bayas extension project in October.

“Overall, these projects form an integral part of Xstrata Copper’s near-term organic growth program that will see total copper production increase by 60% to 1.5Mt/y by the end of 2014, adding significant value for all Xstrata’s stakeholders.”