Lac des Iles mine enters commercial production

After suffering through an icy winter startup, the Lac des Isles platinum group metals (PGM) mine, 60 miles north of Thunder Bay, Ont., has entered the “commercial production” phase.

An operating profit of $61,000 was achieved in the first quarter, says C.D. McDoulett, president of majority owner North American Palladium (TSE). Close to 60% of the revenue for the period is derived from palladium production; the remainder is attributed to the other PGM and the gold-copper-nickel contingent.

The 3,000-ton-per-day mill was first activated in late November and experienced several setbacks, most of which stemmed from the extreme cold of this past winter.

“It was bloody cold,” stresses McDoulett, a newcomer to northern Ontario from the southern U.S. “We had huge processing problems, mostly because the water kept freezing.”

Operators are currently focusing on improving the performance of certain circuits. The disc filter, for example, achieves 13-14% moisture content, but McDoulett is aiming for 10%. The crushing circuit, too, is expected to be upgraded.

Nevertheless, he said, “it’s all coming together.”

Currently, concentrates are shipped to Falconbridge’s smelter in Sudbury, Ont. However, the company has tested a hydrometallurgical process (employing an acid leach and autoclave) to treat its own concentrates and is in the midst of choosing a site for the pilot plant.

The 6.5-million-ton (proven and probable) Roby zone is being mined by open-pit methods. Another 1 million tons are contained in a nearby zone where diamond drilling to 1,800 ft. has intersected ore-grade mineralization at minable widths.

The stripping ratio, currently 1.3-to-1, should average 2.2-to-1 over the life of the mine. The mill is operating at about 2,200 tons per day. The mine and mill are owned 50/50 by North American and the Sheridan Group. However, the ownership structure is the subject of a lawsuit.