Rex Minerals Targeting South Australia Copper Mine

Australian junior company Rex Minerals has released a prefeasibility study (PFS) for its Hillside copper-gold project on the Yorke peninsula in South Australia. The PFS describes an open-pit mine supple-mented by underground mining that would produce 70,000 mt/y of copper and 50,000 oz/y of gold in a copper-gold con-centrate over a minimum mine life of 15 years. Additionally, the tailings from the Hillside copper-gold circuit would be treat-ed to recover 1.2 million mt/y of high-qual-ity (67% Fe) iron ore concentrate.

Capital costs to develop the Hillside project are estimated at A$900 million, including an A$90 million contingency. Cash costs are estimated at $1.20/lb of copper produced after byproduct credits.

Combined indicated and inferred resources at the Hillside project, at a 0.2% copper cut-off grade, total 330 million mt grading 0.6% copper, 0.16 g/mt gold, and 13.7% iron, equating to 2 million mt of copper, 1.7 million oz of gold, and 44 million mt of iron ore.

The PFS assumes development of an open-pit mine with an average waste-to-ore strip ratio of approximately 4:1 and an average mining cost of about A$3/mt. Copper mineralization extends beyond the maximum depth of the planned Hillside open pit, and the PFS considers mining 30 million mt of this mineralization by under-ground longitudinal and transverse sub-level caving methods. The underground resource remains open at depth and is expected to grow over time.

Processing plant design for the Hillside project calls for 15 million mt/y of through-put capacity and a conventional copper-gold flotation circuit. Flotation tailings would be treated by magnetic separation methods to produce iron ore concentrate.

Rex has started work on a bankable fea-sibility study of its Hillside project and is pursuing a number of financing options. The company will submit the required South Australia government approval documenta-tion in early 2013. The company anticipates that the feasibility study, government approvals and final financing will be com-pleted before the end of 2013 in time for project construction to begin in early 2014.

Drilling is continuing within the limits of the Hillside PFS open-pit design, with the objective of defining 10 years of reserves in time for use in the bankable feasibility study in the second half of 2013.

Rex Minerals Managing Director Mark Parry said, “The Hillside PFS confirms the economics of a robust and significant cop-per project, possibly the best open-pit proj-ect in Australia since Ernest Henry 25 years ago.”

As featured in Womp 2012 Vol 12 -