BHP boosts copper resources at Spence by 700%

Resources at BHP Billiton‘s (BHP-N, BLT-L) Spence copper mine in northern Chile has grown by nearly 700%, following a four-year US$30-million brownfield exploration program.

The increase reflects a hypogene extension of the supergene mineralization of the current resource. As a result, BHP has added 2.3 billion tonnes grading 0.43% copper to the resource.

Currently, the 100%-owned Spence project has 2.69 billion tonnes, as noted in the exploration and development report for the quarter ended Dec. 31, 2011.

BHP says this resource boost, plus the previously reported resource increases at the Escondida copper mine in Chile and the Antamina copper-zinc project in Peru, show the fruits of the company’s extensive brownfield exploration program.

Last July, BHP expanded resources in the Escondida mining complex by 129%, and Antamina by 32%.

The increase at the 57.5%-owned Escondida project came thanks to a four-year, US$381-million drill program, which delineated initial resources at the nearby Pampa Escondida and Pinta Verde deposits, and boosted resources at Escondida by 40%.

Escondida currently contains 3.1 billion tonnes of 0.75% copper in the measured category, and 4.7 billion tonnes of 0.59% copper in indicated.

The 33.8%-owned Atamina project has 187 million measured tonnes at 0.85% copper, and 1.01 billion indicated tonnes at 0.91% copper.

Last year, the miner drilled 542,000 metres across the Pilbara, adding 20% to the Western Australian Iron Ore project’s resource, bringing it to 19.3 billion tonnes, while completing a 3D seismic survey and deep drilling on an exploration target in Saskatchewan’s potash basin.  

It also drilled 267,000 metres in Australia’s Bowen basin to increase confidence in the resource underpinning its development coal projects: Daunia and Caval Ridge.

During the last half of 2011, the diversified producer committed more than US$26 billion to its world-class growth pipeline.

For the quarter ended Dec. 31, it approved mine development at Caval Ridge and expansion of the Peak Downs operation, also in Australia. BHP says the projects will add to its coal capacity.

It earmarked another US$1.2 billion for the first phase of the Olympic Dam uranium project in Australia following environmental approvals and the passing of the indenture agreement by the South Australian parliament.

On greenfield exploration, BHP spent US$532 million during the half year, of which US$451 million was expensed.