MacArthur permits in hand

Permits for development of the MacArthur copper deposit are finally in hand for owner Arimetco International (TSE).

The project is about five miles north of the companys Yerington copper mine near the Nevada town of the same name.

With the permits in place, Arimetco has started constructing a haul road from MacArthur to Yerington. It is also expanding its leach pad and solvent extraction-electrowinning (SX-EW) plant capacity.

The Yerington SX-EW plant was built in 1991 to process oxide ore stockpiles left over from Anaconda Coppers operations on the property. About 40,000 lb. of the red metal are produced on a daily basis at Yerington. This is expected to increase to 50,000 lb. per day by the end of the first quarter of 1994 when the MacArthur ore will have been added. Production is expected to jump to 80,000 lb. per day by the end of 1994 as a result of the planned expansion of the SX-EW plant.

In concert with road construction, development of the MacArthur deposit has also started.

MacArthur outcrops at surface and contains an estimated proven and probable oxide copper reserve of 97 million tons grading 0.21% copper at a strip ratio of 0.16-to-1.

Stockpile reserves at Yerington were last estimated at about 40 million tons grading 0.23%.

Yerington also has an open-pit oxide reserve of about 15 million tons grading 0.32% and a vat leach tailings reserve of about 70 million tons grading 0.15%. Roy Shipes, chairman, said cash operating costs are currently running at US60-65 per lb.

Shipes said cost should drop further as production increases, estimating the cash cost at about US58 per lb. at 50,000 lb. per day, and US53 at 80,000 lb. per day.