Pamour win Heap leaching test success in Ontario

The first successful heap leach test ever in northern Ontario has be en completed by Pamour Porcupine Inc., and the company is gearing up for commercial production next year.

The success of the test has President Dennis MacLeod predicting an eventual change in the complexion of gold mining across the Canadian Shield. It is the first time that reasonable recoveries have been obtained from Precambrian rock in a large-scale test.

“This test has opened up a whole new ball game in the north,” says Mr MacLeod, who has made a career out of profitably mining low grade ore and recovering gold from tailings.

Mines Manager Peter Rowlandson tells The Northern Miner that a 68.4% recovery was obtained over three months from a 10,000-ton heap. The heap grade d 0.037 oz gold per ton and came from the Pamour No 3 pit.

Extensive lab testing on the ore had the company predicting recoveries of about 65% when crushed to minus 3/8 in and, as Mr Rowlandson says, “we were quite surprised that the recoveries came in even higher.” He adds that “it is the first time that the heap leach technology has been successful this far north.”

The plan now is to go into commercial production next year with at least 200,000 tons and possibly as much as 500,000 tons, depending on mining plans at the Pamour No 3. The material for the heaps has to be mined to get at higher grade milling ore, so costs of the new source are expected to be very low. Mr Rowlandson says the company expects costs of $4-$5 per ton, including everything except mining. He also says he expects to heap leach about two million tons from the No 3 pit over the next five years.

The company is anticipating operations to run from April to the end of October and it is already experimenting with ways to continue it into the winter months.

But Pamour isn’t stopping at that. Already the company has begun preparing another 10,000-ton heap test on material from the Hollinger pit and testing will begin early next spring. On top of that, Mr MacLeod says the company has the potential for millions of tons of low grade reserves in the Timmins area on its properties (which have produced about 40 million oz gold during the past 75 years) and he expects that heap leaching will become a major source of revenue for the company.