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Tungsten |
AIMR 2009 |
Tungsten
Tungsten (W) metal and its alloys are amongst the hardest of all metals. It occurs as wolframite, (Fe, Mn)WO4, and scheelite, CaWO4. Tungsten carbide has a hardness approaching that of diamond and is used for cutting and wear-resistant materials primarily in the metalworking, mining, oil drilling and construction industries. Tungsten alloys are used also in electrodes, filaments (light bulbs), wires and components for electrical, heating, lighting, and welding applications.
Resources
Australia's total EDR at December 2008 was 111.5 kilotonne (kt) W, an increase of 29% over the resources in 2007.
Exploration
Data on exploration expenditure for tungsten are not reported by Australian Bureau of Statistics. Tungsten prices have risen substantially since 2004. In response to these rises, companies have commenced exploration and re-evaluation of old abandoned tungsten mines and deposits, mainly in north Queensland (Qld), Tasmania (Tas) and Northern Territory (NT).
Drilling by Peel Exploration Ltd at the Attunga Prospect 1 scheelite deposit, near Tamworth, New South Wales intersected high grade tungsten-molybdenum zones including 2 m at 24.21% WO3 and 1.71% Mo from 22 m, which was part of a larger interval of 42 m at 2.09% WO3 and 0.17% Mo. Mineralisation occurs in a northerly plunging pipe within skarn developed at the contact with a monazite intrusion.
Production
During 2008, scheelite concentrates were produced at the Kara mine (Tas) and Wolfram Camp mine (north Qld). Kara scheelite mine near Hampshire in northwest Tas produced 19 tonnes (t) of scheelite concentrates averaging 55.7% WO3, representing 8.4 t contained W. Scheelite and magnetite were produced from skarns within Ordovician limestone adjacent to the contact with Devonian granite. A trial shipment of 5.5 t of wolframite concentrate was exported by Queensland Ore Ltd from its Wolfram Camp mine near Cairns, north Qld before operation were suspended in late 2008 due to economic considerations.
World Resources and Production
China has the world's largest resources of tungsten with approximately 60% of world resources. Other nations with large resources include Canada and Russia.
World production of tungsten totalled 54.6 kt in 2008, and was dominated by China which accounted for 75% of production. Other large producers were Russia and Canada. In recent years the Chinese Government took steps to regulate production and control the release of Chinese tungsten on to the world market. The lack of supplies of tungsten concentrates from China, together with increased demand in China and elsewhere, has resulted in higher prices since 2005.
Industry Developments
In September 2008 Queensland Ores Ltd made the first shipment of tungsten concentrates to China from its Wolfram Camp tungsten-molybdenum mine, 90 km west of Cairns, in north Qld. This is the first export of tungsten concentrate from Australia in more than 20 years. However, the company suspended mining operations due to the downturn in the world economy and weakness in molybdenum prices. The Wolfram Camp deposit has Measured Resources of 598 200 t averaging 0.42% WO3 and 0.17% MoS2, Indicated Resources of 111 500 t averaging 0.41% WO3 and Inferred Resources of 238 300 t averaging 0.4% WO3 and 0.2% MoS2.
As part of a feasibility study, Vital Metals Ltd announced updated resources for its Watershed project, 25 km north east of the old Mount Carbine mine in far north Qld. At a cut-off grade of 0.15% WO3 , Measured Resources were 1.8 million tonnes (Mt) averaging 0.29% WO3, Indicated Resources 7.7 Mt averaging 0.28% WO3 and Inferred Resources of 5.7 Mt averaging 0.3% WO3.
In June 2008 Icon Resources Ltd reported Inferred Resources of 1.05 Mt with an estimated recovered grade of 0.1% WO3 in the old Mt Carbine open pit which closed down in 1987, and an Inferred Resource of 9.6 Mt averaging 0.2% WO3 beneath the open pit.
King Island Scheelite formed a joint venture with Chinese Hunan Nonferrous Metals Corporation to redevelop the King Island scheelite mine. It is proposed to mine and process 600 000 t of ore per year to produce 3000 t of tungsten oxide annually. Development costs were estimated to be $110 million. The global resources at a cut-off grade of 0.25% WO3 down to 308 m below sea level was reported as Indicated Resources 13.2 Mt averaging 0.64% WO3 and Inferred Resources of 200 000 t averaging 0.35% WO3.
Venture Minerals has discovered two high grade tin-tungsten shoots within its Mount Lindsay project, 20 kilometres west-northwest of Rosebery, Tas, associated with metamorphosed dolomites adjacent to the Meredith Granite. The deposit has 5.7 Mt Inferred Resources averaging 0.3% WO3 (based on cut-off grade of 0.10% WO3) and 23 Mt Inferred Resources averaging 0.2% Sn (based on cut-off grade of 0.1% Sn).
Thor Mining PLC reported total Proved and Probable reserves of 2.21 Mt grading 0.47% WO3 and 0.21% MoS2 for its Molyhil project in the NT. Proved ore comprise 0.461 Mt grading 0.47% WO3 and 0.30% MoS2 and Probable Reserves comprises 1.75 Mt grading 0.47% WO3 and 0.19% MoS2. The company proposes to develop an open cut operations.
