Tungsten

Content maintained by David Champion, Roy Towner and Aden McKay

• Tungsten
• Resources
• Accessible EDR
• JORC Reserves
• Exploration
• Production
• World Ranking
• Industry Developments

Tungsten (W) metal and its alloys are amongst the hardest of all metals. It occurs as wolframite, (Fe, Mn) WO₄, which is an iron manganese tungstate mineral, 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.

Ferrotungsten (FeW) is a high value-added intermediate product and is used in steels and alloys where hardness and heat resistance is required.

Australia's total Economic Demonstrated Resources (EDR) of tungsten at December 2010 was 403 kilotonnes (kt), more than double the resources in 2009 (196kt). The majority of the increase was in Western Australia (WA) where resources were more than 16 times or about 211 kt up on 2009, primarily at O'Callaghans with about 186kt and Big Hill with 29.5kt.

Australia's EDR are in deposits at Dolphin and Bold Head on King Island in Bass Strait off Tasmania (Tas), Kara and Mount Lindsay (Tas), at Watershed in Queensland (Qld), O'Callaghans, Big Hill and Mount Mulgine in Western Australia (WA) and Molyhil in the Northern Territory (NT).

The bulk of Australia's EDR of tungsten are in WA with 56%, followed by Tas with 29% and Qld with 13%. The WA share is up from 7% in 2009.

In 2010, Subeconomic Demonstrated Resources (comprising Paramarginal and Submarginal Resources), which account for about 0.5% of the total Demonstrated Resources, remained essentially unchanged from 2009. Queensland accounts for 46% of Subeconomic Demonstrated Resources followed by Tas with 37%.

Inferred Resources decreased by about 53% from 204kt in 2009 to 110kt in 2010. Queensland accounts for 51%, followed by WA with 27%, Tas with 18% and NSW with 13%.

All of Australia's EDR for tungsten are unencumbered.

Joint Ore Reserve Committee (JORC) Code reserves comprise total tungsten in Proved and Probable Ore Reserves as defined in the JORC Code. In 2010, JORC Code reserves of 217kt accounted for approximately 54% of Accessible Economic Demonstrated Resources (AEDR).

Increase in the demand for tungsten, together with restrictions on exports of tungsten concentrates from China, has led to an increase in exploration and re-evaluation of tungsten mines and deposits, mainly in north Qld, Tas and WA. Data on exploration expenditure for tungsten are not reported by the Australian Bureau of Statistics.

Following release of a resource estimate in April 2008 for the Attunga deposit 20 kilometres (km) north of Tamworth in New South Wales (NSW), Peel Exploration Ltd undertook additional drilling in 2009. Results include 27 metres (m) grading 0.54% WO₃, 0.06% molybdenum (Mo) from 19m, including 2m grading 3.38% WO₃ and 0.27% Mo from 22m and 2m grading 0.59% WO₃ and 0.03% Mo from 58m. Mineralisation at the deposit occurs within skarns developed at the contact of a lime-rich sequence with the Inlet Monzonite. In 2010/11 the company undertook a study investigating development options, which showed that conditions were favourable for a low capital expenditure operation. In 2010, the company undertook drilling at the nearby Kensington gold prospect, 5km north of the Attunga tungsten deposit, targeting tungsten and gold mineralisation, on the basis of historic data, which suggested the presence of a shallow large low-grade tungsten resource. Although drilling returned favourable gold intercepts the drilling did not show tungsten mineralisation.

Frontier Resources Ltd continued exploration of their Moina Project area, including the stratiform gold-base metal Narrawa 40km southwest of Devonport, Tas and gold-bismuth Stormont skarn deposits 190km northwest of Hobart. This exploration targeted mineralisation, including tungsten and tin, associated with the Dolcoath Granite. The company recently completed a detailed soil geochemical program over 4km² encompassing the Narrawa deposit, identifying zones anomalous in tungsten, tin, molybdenum, copper and bismuth as well as gold. The company has previously undertaken a positive Conceptual Mining Study (completed 2009) investigating possible mining and processing of the gold and base metal mineralisation at the Narrawa and Stormont Deposits.

Hazelwood Resources Ltd released an initial ore reserve estimate at a cut off grade of 0.05% WO₃ for the Big Hill deposit of Proven Reserves of 18.78 million tonnes (Mt) averaging 0.11% WO₃ and Probable Reserves of 6.43Mt averaging 0.11% WO₃. This forms part of the overall resource estimate at a cut-off grade of 0.05% WO₃ of Measured Resources of 22.94Mt averaging 0.11% WO₃, Indicated Resources of 11.95Mt grading 0.1% WO₃, and Inferred Resources of 12.54Mt grading 0.08% WO₃ for a total resource of 47.43Mt averaging 0.1% WO₃. The deposit is part of the Cookes Creek tungsten project located 70km from Nullagine, WA. Hazelwood resources Ltd also undertook diamond drilling (five holes) at the Mulgine Hill deposit, Mount Mulgine tungsten project (70% Hazelwood, 30% Gindalbie Metals Limited), about 300km east-south-east of Geraldton, confirming the presence of near-surface high grade tungsten mineralisation. Drill intersections include 2m at 3.17% WO₃, 34m at 0.20% WO₃, and 15m at 0.16% WO₃. This followed release of new resource figures for the deposit in March 2011, comprising Indicated Resources, at a cut off grade of 0.1% WO₃, of 5.87Mt averaging 0.22% WO₃, for a contained 13 000 tonnes of WO₃. The company also indicated that 95% of the resource is within 100m of the surface. Hazelwood acquired its 70% share of Mount Mulgine from Vital Metals Ltd in 2010.

Newcrest Mining Ltd released a maiden ore reserve and revised resource figures for its O'Callaghans polymetallic (tungsten-copper-zinc-lead) skarn deposit about 10km south of Telfer, WA, with Probable Reserves of 51Mt grading 0.34% WO₃, Indicated Resources of 69Mt grading 0.34% WO₃ and Inferred Resources of 9Mt grading 0.25% WO₃. On current figures the O'Callaghans deposit represents about 44% of Australia's EDR of tungsten. Mineralisation occurs within a sub-horizontal skarn at the contact between a large granite body and overlying limestone.

YTC Resources undertook reconnaissance rock chip sampling over the historic Marobee tungsten field, located about 25km north of the Tallebung tin field northwest of Condoblin in NSW. A number of the collected samples returned good results of up to 3.9% W, up to 3.7 grams per tonne (g/t) Au and up to 0.8% Sn.

During 2010, 28 tonnes of high-grade scheelite concentrates averaging 75% WO₃ together with magnetite was produced at the Kara scheelite mine near Hampshire in northwest Tas, representing 17.9 tonnes of contained tungsten. The scheelite and magnetite were produced from skarn within Ordovician limestone adjacent to the contact with Devonian granite.

In 2010, world economic resources of tungsten are estimated to be 2900kt based on United States Geological Survey (USGS) data and updated by Geoscience Australia for Australia's resources. According to the USGS, China holds approximately 65% of the resources followed by Russia 8.6% and the USA 4.8%. Australia has a 14.5% share of world resources, based on the USGS figures for world economic resources of tungsten and Australia's 2010 figures presented here.

The USGS estimates that world production of tungsten in 2010 amounted to 61kt compared with 58kt in 2009. China was the major producer with 85% of world production, followed by Russia with 4%. USA production was not recorded for confidential reasons. Over the past few years, the Chinese Government has restricted the amount of its tungsten ores which can be offered on the world market, favouring instead the export of value-added downstream tungsten materials and products.

The price of tungsten has risen dramatically over the past 18 months from a low of less than US$200 per metric tonne unit (MTU = 10kg) of ammonium paratungstate (APT) in late 2008 to early-mid 2009, following the global financial crisis, to reach new highs of US$480 per MTU in mid 2011. This price increase reflected the tightening of supply by China and increased demand. Prices have eased since to around US$460-440 per MTU, reflecting the Eurozone and other debt crises. The rise of tungsten prices has seen an increased interest in tungsten and renewed activity at a number of projects.

Metallic Minerals Limited's Wolfram Camp tungsten-molybdenum project, 90km west of Cairns in Qld, has been under care and maintenance since late 2008. In May, 2010 the company's 76% owned-subsidiary, Planet Metals Limited released a revised total resource estimate of 1.42Mt grading 0.6% WO₃ and 0.12% Mo comprising 0.78Mt grading 0.56% WO₃ and 0.13% Mo in Indicated Resources and 0.64Mt grading 0.65% WO₃ and 0.11% Mo in Inferred Resources. Planet Metals Limited also undertook studies into enhancing the run of mine pre-concentrate in order to improve the mill-feed grade. In May 2011, Planet Metals Limited announced it had successfully undertaken a Share Sale Agreement with Deutsche Rohstoff AG to sell its 100% owned subsidiary, Wolfram Camp Mining Pty Ltd, which holds an 85% stake in the Wolfram Camp tungsten-molybdenum project.

Vital Metals Limited's 100% owned Watershed scheelite project, 150km northwest of Cairns, Qld, has an Indicated Resource of 15.1Mt at an average grade of 0.46% WO₃ using a cut-off grade of 0.10% WO₃, for 69 300 tonnes of contained WO₃. The company has completed a pre-feasibility study, including a full Environmental Impact Study, which has been accepted by the Queensland Environmental Protection Agency. However, the 2008-09 decline in tungsten prices had an adverse impact on the project's economic viability. The subsequent price increase in late 2010 resulted in Vital Metals Limited undertaking a review of the pre-feasibility study. In May 2011 Vital Metals Limited announced it had entered into an earn-in agreement with Japan Oil, Gas and Metals National Corporation (JOGMEC) for 30% of the Watershed project by funding completion of a bankable feasibility study for the project. JOGMEC confirmed the farm-in in August 2011.

In July 2011, Icon Resources approved the purchase and relocation of a second hand plant and equipment for the reprocessing of tailings at the Mount Carbine mine, about 130km northwest of Cairns, Qld. Production from the 2Mt of tailings is envisaged to commence in late 2011. It has an anticipated project life of about two years, expected to be producing around 5000 metric tonne units (mtu, 1 mtu = 10kg) of WO₃ in concentrate a month. The company is undertaking feasibility studies into the viability of processing low grade stockpiles from late 2012, with a project life of around five years producing about 10 000 mtu of WO₃ in concentrate a month. The company is also planning to commence production from the hard rock resource in the medium term with an anticipated project life, based on current resource estimates of more than 10 years, producing around 20 000 mtu of WO₃ in concentrate a month. The Mount Carbine project has Inferred Resources for the hard rock mineralisation of 113.6Mt grading 0.06% WO₃. This includes an Inferred Resources of 39.8Mt at 0.14% WO₃ at a 0.05% WO₃ cut-off beneath and adjacent to the old Mount Carbine open-cut mine, which closed down in 1987. The company plans to undertake further drilling in 2011/12 of the hard rock resource and extensions as well as in the neighbouring Iron Duke tungsten and Mount Holmes tungsten-tin prospects.

The Dolphin Joint Venture between King Island Scheelite (KIS) and Chinese Hunan Nonferrous Metals Corporation (HNC) to redevelop the former King Island scheelite mine on southeast King Island off Tas was terminated mid December 2010. HNC transferred its 50% interest in the joint venture assets to KIS's wholly owned subsidiary Australian Tungsten Pty Ltd (ATPL). HNC has a royalty of 2% on future project revenue from the project, capped at $3.9 million. KIS is currently undertaking a feasibility study investigating both retreatment of tailings and re-opening the underground mine. The current development plan is to produce 1000 tonnes of WO₃ per annum from tailings from late 2012, increasing to 3500 tonnes of WO₃ concentrate with commencement of underground operations in late 2014. King Island Scheelite reported Indicated Resources for the Dolphin Mine and Bold Head Mine at a cut-off grade of 0.25% WO₃, as 8.42Mt averaging 0.95% WO₃, and 2.3Mt averaging 0.73% WO₃, respectively, for a combined total of 96 780 tonnes of contained WO₃. Estimates of Probable Reserves were upgraded in August 2011 to 2.69Mt averaging 1.04% WO₃, and containing 27 940 tonnes of WO₃. In June 2011, the company also reported Measured Resources for the tailings at the Dolphin Mine at a cut-off grade of 0.08% WO₃ as 2.7Mt averaging 0.17% WO₃, containing 459 000 tonnes of contained 4590 tonnes of WO₃.

Venture Minerals Limited announced a JORC-compliant resource upgrade for the Mount Lindsay tin-tungsten deposit in western Tas, with revised combined resources of 43Mt at 0.4% Sn equivalent at 0.2% cut-off) or 10Mt at 0.7% Sn equivalent at 0.45% cut-off. The latter figure includes Indicated Resources of 6.2Mt at 0.4% Sn and 0.3% WO₃. The deposit also includes an iron ore resource. The Mount Lindsay prospect is located 15 km northwest of Renison Bell tin mine and 20km west of Rosebery in western Tas. The prospect is in magnetite (Fe₃O₄) rich skarns within the contact aureole of the Meredith granite, which is part of a suite of Devonian granites that are the source rocks for a number of large tin, tungsten and magnetite deposits in western Tas and on King Island in Bass Strait off Tas. The company completed a successful prefeasibility study for Mount Lindsay in March 2011 that confirmed the economics of the project. The company is undertaking a bankable feasibility study which is expected to be completed in 2012. Ongoing regional and infill drilling has been undertaken during the past year in association with the feasibility study. Infill drilling in the McDonald tin zone (Main Skarn) returned favourable tin results and identified broad zones of tungsten mineralisation, including 30m at 0.35% WO₃, and 44m at 0.24% WO₃. Venture Minerals Limited submitted a Mining Lease Application for the company's Mount Lindsay project on 15 September 2011.

Thor Mining PLC has reported total Proved and Probable Reserves of 2.21Mt grading 0.47% WO₃ and 0.21% molybdenum disulphide (MoS₂) for its Molyhil tungsten-molybdenum project, 250km northeast of Alice Springs, NT. Potential development of the project has been hampered by the global financial crisis and decline in international metal prices, resulting in the company subsequently scaling back activities. The company had signed an off-take agreement with CITIC Australia Trading Limited, one of China's largest State-owned companies, committing CITIC to take all of the molybdenum and tungsten concentrates produced from the project. The agreement has now lapsed. The recent increase in tungsten prices has resulted in renewed interest and Thor Mining initiated a definitive feasibility study of the deposit in June 2011. Initial findings were favourable with capital and operating cost estimates for the first phase of production of 1.4 million tonnes of ore to be $66 million and $79 per tonne, respectively with an annual throughput of 400 000 tonnes of ore. The company also undertook drilling in mid 2011 to test extensions of the resource and to better define the known resource. Initial results indicate existence of mineralisation outside the existing resource. Best results include 16m at 0.81% WO₃ and 0.44% MoS₂ from 189m and 13m at 0.38% WO₃ and 0.13% MoS₂ from 290m.

Hazelwood Resources Ltd has completed an integrated pre-feasibility study incorporating its Big Hill tungsten deposit, about 220km northwest of Newman, WA, and a ferrotungsten (FeW) project in Vietnam. Asia Tungsten Products Company Ltd (60%-owned by Hazelwood Resources Ltd) is constructing a FeW plant in the Vihn Bao district near the Port of Haiphong in northern Vietnam. The company is currently undertaking a definitive feasibility study for the Big Hill deposit, including further metallurgical test work. Stage 1 of the Vietnam ferrotungsten plant was finalising practical completion in June 2011, with cold commissioning expected August, 2011 and hot commission and trial production some time later. Stage 1 of the plant is expected to have a capacity of approximately 3000 tonnes of contained tungsten in the form of 75% grade ferrotungsten per annum. A decision on stage two, involving the construction of a second furnace, is yet to be made. If undertaken this would increase capacity to around 6000 tonnes of contained tungsten, enough to supply 25% of projected global demand. The company indicates it plans to develop the Big Hill project and begin production from by 2013 with the deposit providing most of the feedstock for the Vietnam ferrotungsten project.