November 2008

Bullish about tungsten

North America’s largest tungsten producer foresees good times ahead

By M. Kerawala

Like other mines, Cantung copes with skilled labour shortages

Tungsten is a very special metal. It has none of the allure of gold that fascinated alchemists or lustre that secured silver’s place on royal dining tables. Tungsten’s humble claim to fame is that it is the most robust metal. With the highest melting point, highest tensile strength, a very high specific gravity and lowest coefficient of thermal expansion of all metals, it is widely used in everything from inexpensive light bulbs and simple cutting tools, to complex, billion-dollar spacecraft.

Three-fourths of the world’s supply of this durable, versatile metal comes from China. Most of the remainder is scattered through Austria, Russia, Portugal and Bolivia. The largest producer this side of the Atlantic is right here in Canada — in the western part of the Northwest Territories, to be precise. North American Tungsten Corporation Ltd. (NATC) operates the Cantung mine and is currently conducting a feasibility study at its Mactung property.

A munificent mine

Cantung is located in the Mackenzie Range, 300 kilometres north of Watson Lake, Yukon. The deposit was discovered in 1954, as a result of a search for copper. Open pit mining commenced in 1962 at the rate of 300 short tons per day. Underground production began in 1974 and three years later, production was up to 1,000 short tons per day. In 1986, the mine ceased production, dogged by low tungsten prices.

NATC purchased the Cantung mine in 1997. In 2000, tungsten prices picked up again, spurring NATC to reopen it in December 2001. After a few initial hiccups during which production ceased again, things came on an even keel in November 2004, allowing planning for reopening to commence. Preparatory work for the reopening began in July 2005, and production resumed in late September 2005.

Cantung is part of a group of tungsten skarn deposits located along the eastern margin of the Selwyn Basin, which extends into the Yukon. The tungsten area is underlain by a series of Cambrian sediments, and tungsten mineralization is found within scheelite-bearing skarn associated with the granitic intrusions. The mine has a probable reserve of 1 million tons at 1.17 per cent tungsten oxide (as reported under NI 43-101 as of September 2006), adequate for production up to mid-2010.

A property with potential

Britt Reid, COO of North American Tungsten, is upbeat about the future. The source of his optimism is tucked away in the Selwyn Mountain Range on the Yukon-Northwest Territories border. It is NATC’s Mactung property, which lies eight kilometres northwest of MacMillan Pass. The nearest settlement accessible by road, Ross River, is 250 kilometres to the southwest along the North Canol Road, and the Cantung mine is approximately 160 kilometres to the south.

The Mactung deposit was discovered in 1962 by geologist James Allan of Amax Northwest Mining. From 1963 to 1967, Amax completed geological mapping, rock geochemical sampling, magnetometer surveying and grid geochemical soil sampling on the property. Five surface diamond drill holes were completed in 1968 and an access road linking to the Canol Road was finished in 1970. Surface drilling continued up to 1980 and environmental and feasibility studies continued up to 1985, when falling tungsten prices brought work to a stop. After it changed hands from Canada Tungsten Mining Corporation to Aur Resources Inc., Mactung was acquired by NATC in 1997.

In 2005, the company drilled 25 surface diamond drill holes to better define the west end of the deposit and to upgrade the resource classification of some mineral blocks from the “inferred” to “indicated” category. Mactung has resources, published under NI 43-101, of about 33 million tonnes at 0.88 per cent tungsten trioxide, enough, according to Reid, to last 25 years. A feasibility study is about to be concluded and a year to 16 months of permitting lie ahead. Production is tentatively scheduled to begin in late 2012.

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