Collahuasi Rosario commissioning ahead of schedule in Chile

The US$654-million Collahuasi Rosario mine in Chile, co-owned by Falconbridge (FL-T) and Anglo American (AAUK-Q), is producing copper ahead of schedule and under budget.

The mine is designed to produce copper-in-concentrate at a long-term average of 400,000 tonnes per year.

The partners have pre-stripped 114 million tonnes of overburden to provide access to the Rosario deposit, built a 9-km-long series of ore-belt conveyors linking the deposit to the plant at Ujina, and boosted the daily capacity of the concentrator plant by 83% to 110,000 tonnes.

Construction of the concentrator lasted 20 months and employed some 5,000 contractors during the peak of activity. The work program also included upgrades to the power supply, 200-km-long concentrate pipeline, and tailings facilities.

The mill has already exceeded the design throughput rate of 110,000 tonnes per day.

Falconbridge’s 44% stake in Collahuasi netted it 35,369 tonnes of copper-in-concentrate in the first quarter, down from 44,211 tonnes a year earlier, as grades at the Ujina open pit fell by 7.6% to 1.45% copper. Similarly, Falco’s share of copper cathode production fell by 10% to 6,152 tonnes, owing to operational difficulties with the leaching process after heavy rainfall in January and February.

In 2003, Collahuasi produced 169,000 tonnes of copper concentrates and cathode. Falco expects its share of total copper production in 2004 to approach 206,000 tonnes.

At the end of 2003, Collahuasi had a total proven and probable reserve of 1.8 billion tonnes grading 0.91% copper. There was also a measured and indicated resource of 477 million tonnes grading 0.63% copper, and an inferred resource of 1.8 billion tonnes running 0.72% copper.

The reserves and resources are sufficient for further expansion, and water rights for such an expansion have already been secured. Also, the company says Rosario may contain enough molybdenum to warrant the addition of a moly-recovering circuit.

Like Falco, Anglo American has a 44% interest in Collahuasi. The remainig 12% is held by a Japanese consortium led by Mitsui & Co.