MINING IN MEXICO — Cominco Res. studying Mariquita copper

With one Mexican copper project in production, Cominco Resources International (TSE) is continuing efforts to develop the Mariquita project in northwest Mexico.

The company has been evaluating financing alternatives for Mariquita, where proposals for an open-pit mine are under study. The copper would be recovered by heap leaching, followed by solvent extraction-electrowinning. Capital costs are estimated at US$25-35 million, to equip an operation producing 20-25 million lb. cathode copper per year. Cominco Resources says large-column testing of bulk samples of copper mineralization indicates “excellent” recoveries.

Mariquita is near Cananea, in the vicinity of Cominco Resources’ 49%-owned Maria copper mine. This high-grade mine operated profitably throughout 1992. During the first six months of this year, the operation treated 114,800 tonnes averaging 7.4% copper. The company’s share of copper in concentrates produced during the second quarter was 4.6 million lb., bringing the total for January through June to 8.8 million lb.