Falconbridge (FL-T) says that commissioning of the US$654-million Collahuasi Rosario project in Chile began in late April, some five weeks ahead of schedule and under budget.
The project, which began in 2001, is designed to maintain production of copper in concentrate at a long-term average of 400,000 tonnes per year, and involved:
- pre-stripping of 114 million tonnes of overburden to access the Rosario orebody;
- construction of a 9-km-long series of high-speed ore belt conveyors from the deposit to the plant at Ujina;
- boosting the concentrator plant’s capacity by 83% to 110,000 tonnes per day; and
Construction of the new grinding circuit took 20 months and employed some 5,000 contractors during the peak of activity. The work program also included upgrades to the operation’s associated infrastructure, power supply, 200-km long concentrate pipeline, and tailings facilities. Work to enlarge concentrate storage facilities at the port at Punta Patache has yet to be completed.
With the Rosario mine already producing and the high-capacity conveyor system fully operational, the ramp up of production through the new milling circuit has proceeded ahead of schedule. 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 worth of copper-in-concentrate production during the first quarter of 2004, down from 44,211 tonnes a year earlier, as grades at Ujina fell by 7.6% to 1.45% copper. Similarly, Falconbridge’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. The company’s share of total copper production in 2004 is expected to climb to 206,000 tonnes as the expansion kicks in during the second half of the year.
At the end of 2003, Collahuasi was home to proven and probable reserves totalling 1.8 billion tonnes grading 0.91% copper; the bulk of those tonnes are classified as probable. Measured and indicated resources stood at 477 million tonnes of 0.63% copper, with inferred resources weighing in at 1.8 billion tonnes running 0.72% copper.
Falconbridge says the reserves and resources are sufficient for further expansion; water rights for such an expansion have already been secured. The company also says that the Rosario orebody contains enough molybdenum to possible warrant the construction of a molybdenum recovery circuit.
Collahuasi is a joint venture between Falconbridge and Anglo American (AAUK-Q) (both with 44% interests); a Japanese consortium lead by Mitsui and Co. holds 12%.
The current contract with unionized employees at Collahuasi is set to expire on June 30, 2004.