Quadra revises production schedule at Robinson

Vancouver Ground control concerns have prompted Quadra Mining (QUA-T) to modestly reduce its short-term production schedule at the Robinson copper-gold mine near Ely, Nevada.

The Vancouver-based company says unusually wet weather in the second quarter caused premature slope movement at a portion of the Tripp Veteran pit. The problem was addressed by de-weighting an identified slide area on the northeast side of the pit.

The de-weighting plan involved stripping 4 million tonnes of waste from the slide area, which meant diverting equipment from mining activities to stripping of the pit wall. As a result, the mill is now processing material that is lower grade and more metallurgically complex than originally planned.

Quadra notes that since the end of June, the pit-wall movement has slowed. As a result, major equipment has been returned to production activities. The de-weighting operation is continuing, but with a smaller hydraulic shovel and smaller trucks.

Production at Robinson this year is expected to be 133 million lbs of copper and 66,000 oz. gold, compared with the original estimate of 147 million lbs. copper and 62,000 oz. gold. Cash costs should remain the same as forecast, at US$1.09 per lb. copper, though capital costs for the year will be higher owing to the de-weighting plan.

Quadra plans to install a US$7.75-million molybdenum circuit that could produce an estimated 1.6 million lbs. of moly from the Robinson mine, starting in 2006. The company is also advancing its Sierra Gorda copper project in Chile’s Atacama Desert.

Sierra Gorda hosts an indicated sulphide resource of 215 million tonnes of 0.38% copper and 0.066% molybdenum, plus an inferred sulphide resource of 182 million tonnes grading 0.34% copper and 0.024% moly.

The project also hosts an indicated oxide resource of 181 million tonnes of 0.37% copper, plus an additional inferred oxide resource of 36 million tonnes at 0.29% copper.

A US$3.8-million program is under way at Sierra Gorda. The program includes at least 15,000 metres of reverse-circulation drilling to expand known resources and test new targets.