Constellation tests metallurgy at Terrazas

Vancouver – Column leach tests on four composite bulk samples have returned encouraging extraction results from the Terrazas zinc-copper property being advanced to feasibility by Constellation Copper (CCU-T) in Chihuahua State, Mexico.

The four composite samples were extracted from various portions of the property, and after 49 days of leaching, average extractions of 94% of zinc and 70% for copper were achieved. Higher extractions were realized on columns with higher acid strengths, which ranged from 15-30 grams per litre, with average net acid consumption of 100 kg per tonne.

The bulk samples under leach had head-grades ranging from 2.89% to 7.18% zinc, and 0.49% to 0.61% copper, reflecting the grades that are anticipated during the mining phase.

Results of the metallurgical test-work will be incorporated into a feasibility study scheduled for completion in about mid-2006. The study envisions a mine handling 6 million tonnes of resources annually to produce about 40 million lbs. of copper cathode and about 150 million lbs. of zinc ingots annually for at least 13-15 years.

Mine planning is based on a total measured and indicated oxide resource of 85.6 million tonnes grading 1.24% zinc and 0.322% copper. Inferred resources add another 5 million tonnes grading 3.54% zinc and 0.357% copper.

Constellation recently acquired additional surface rights that will be needed for the proposed mine, including areas for mining, waste dumps, and crushing and processing facilities.

Closer to home, the company is poised to produce its first cathode copper from the Lisbon Valley mine in Utah. Construction of the solvent-extraction electrowinning project is almost complete, but a shortage of skilled trades-people for certain aspects of construction has delayed the start of operations beyond late January to late April. Forecast copper production for 2006 was reduced to 43.5 million lbs. copper from the initial estimate of 48 million lbs. copper.