Cominco group to develop Chilean copper mine

According to Cominco Resources, discussions regarding the formation of an operating company with ENAMI are already in progress.

The Quebrada Blanca porphyry copper deposit was extensively explored between 1977 and 1982 and is reported to contain a zone of at least 60 million tonnes of secondary enrichment grading 1.5% copper. Reserves in the underlying primary zone are estimated to be 400 million tonnes grading 0.8% copper, “with potential to significantly increase these reserves at lower grades.”

Cominco Ltd. and Cominco Resources will each own a 42.5% interest in the operating company, while ENAMI will retain a 10% carried interest. Sociedad Minera Pudahuel (SMP), a Chilean copper producer, will own a 5% carried interest.

The Cominco group bid provides for an initial $5 million(US) payment to ENAMI plus a total of $21 million to be paid in 12 escalating annual payments starting in 1993.

After the third year of production, ENAMI is to receive 10% of the amount by which the annual average copper price received exceeds $1(US) per lb, after adjustments for inflation.

After the operating company is formed, the Cominco group will initiate a feasibility study and on- site tests using SMP’s patented heap-leaching technology which uses solvent extraction and electrowinning to produce cathode copper.

Cominco Resources estimates that production from the enriched zone of the deposit could exceed 40,000 tonnes per year of cathode copper for more than 15 years. The company said mining and milling of the underlying primary copper zone “could be expected at a later date.”

Cominco Resources, which is 59% owned by Cominco Ltd., also has interests in several advanced gold projects in the Maricunga district of Chile.

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