Problem-plagued deposit purchased by Aussie firm

Claiming a coup, East West Minerals N.L., an Australian-based junior mining company, has purchased the Caribou base metals deposit located 30 miles west of Bathurst, N.B. The deposit was purchased for $1.5 million from Atlantic Richfield, the oil giant which has been selling the mining assets of subsidiary Anaconda Canada.

For many in the Canadian mining industry, however, the sale of the Caribou deposit is considered a coup for the seller. Plagued with acute metallurgical problems resulting in recoveries of 50% or less, the deposit was partially developed by Anaconda during the early 1970s. In fact, 800,000 tons of copper ore was mined from an open pit and processed in a 1,000-ton-per-day mill in 1973. Bulk samples were also mined in 1971, the concentrate being shipped for smelting to Sweden.

Anaconda concluded the deposit had potential reserves of 50 million tons grading 2% lead, 4% zinc and one oz silver per ton. Trace amounts of gold are also present.

Despite all the negative facts surrounding the large deposit, including depressed prices for zinc and lead, East West implies that the operation will be a money maker. A crucial component of the company’s plan is an agreement signed with a European smelter covering all the projected output from the mine. East West fails to report just what that output will be.

In order to prepare the mine for production, a $15-million capital commitment will be made by the company for mill construction. The 1,000-ton-per-day mill on site is not suitable for lead-zinc concentrate production. In 1975, Anaconda stated that a 5,000-ton-per-day mine-mill facility would require $50 million to construct. That figure is unadjusted for inflation.

“The project was looked at by a number of companies over the years,” J. L. Davies, director of the Geological Survey Branch, of the provincial Department of Natural Resources and Energy, tells The Northern Miner. “However, I don’t know of any breakthrough (in metallurgy),” he adds, explaining the metallurgical problems which have hindered the deposit since its discovery in 1955. “The grain size of the sulphide minerals is much smaller than that mined at Brunswick.” Brunswick Mining & Smelting Corp ., a subsidiary of Noranda Inc., operates one of the world’s largest zinc facilities near Bathurst, N.B.

In 1974, mine manager Al Buzas told The Northern Miner, the initial open pit mining “presented the toughest metallurgy we have ever seen.” The Northern Miner also noted the fact that the orebody is not uniform added to the mining difficulties.

Strict environmental restraints will also face the new owners of the Caribou deposit. Located at the head waters of the Nepisiquit River and Forty Mile Creek, the future project will be watched closely by local environmentalists. Both rivers have been polluted for many years by other mining ventures in the area.