CanTung ready to ship tungsten

Vancouver — After a six month start-up period North American Tungsten (NTC-V) is set to ship the first load of tungsten concentrate this month from its CanTung mine in the Northwest Territories.

The mine is situated 310 km northeast of Watson Lake, Yukon and hosts reserves of 630,000 tonnes grading 1.82% tungsten trioxide. North American Tungsten reports that the start-up operation continues to run smoothly. The mine site infrastructure has even withstood unusually heavy snowfall and temperatures down to minus 37C with no work interruption.

"We are extremely pleased that our CanTung mine will resume its position as the western world’s largest producer of high-grade, clean, tungsten concentrates and that our company has established a long term mutually beneficial strategic alliance with two of the world’s leading producers of tungsten products, cemented carbides and consumers of tungsten ore," said Udo von Doehren, North American Tungsten’s president and CEO.

Rehabilitation of the mine, mill and plant is complete and late last year the power generating capacity was increased to meet full production requirements. The company is currently testing power, water, compressed air and control systems and the mining equipment fleet is being readied for production. The mine boasts a work force of 130 employees with 90 on site. All supply and service contracts such as transportation of concentrates, transport of personnel, back haul of fuel, catering and supply of high volume consumables are in place.

North American Tungsten has presold three years of its tungsten production, budgeted at 900,000 metric tonne units (mtu) (1 mtu = 10 kg) to its strategic allies, Pennsylvania-based Osram Sylvania Products (a subsidiary of Siemens of Germany) and Stockholm-based Sandvik, at a guaranteed floor price.

The CanTung deposit was discovered in 1958 by prospectors who identified scheelite mineralization hosted in a sulphide-bearing skarn. Over the following three years, an extensive exploration program delineated an open-pit deposit with reserves of 1.3 million tonnes grading 2.5% tungsten trioxide and 0.5% copper. The mine was commissioned in 1962 and operated until 1986, when low tungsten prices resulted in a shutdown.

While operating, the mine produced high-grade scheelite concentrates in excess of 75% tungsten trioxide, as well as lower-grade concentrates averaging 35% tungsten trioxide. The product was shipped to markets in the U.S. and western Europe. North American Tungsten purchased the CanTung mine and the MacTung property from Aur Resources (AUR-T) in 1997.

Geologically, the area that hosts the mine is underlain by a series of late Proterozoic-to-Mississipian-aged sedimentary rocks of the Selwyn Basin. The rocks range from argillite, with minor carbonates, to dolomite and quartzite. In the vicinity of the mine the rocks form a northwest-trending synclinal structure that is intruded by Cretaceous-aged quartz monzonite to granodiorite plugs.

The CanTung scheelite deposits were formed by metasomatism within the thermal aureole of a granodiorite-quartz monzonite intrusion. The main tungsten mineralization is hosted in a limestone unit that is folded into a recumbent anticline. The open pit was on the upper limb of the fold, whereas the underground E-zone is on the lower limb of the fold, about 1000 ft. below the pit.

Scheelite is the only tungsten mineral identified at CanTung; it is associated with pyrrhotite and minor chalcopyrite. Most of the remaining resources are underground, in the West Extension zone.