Tantalum

Subhash Jaireth (subhash.jaireth@ga.gov.au)

The main use of tantalum (Ta) is in the manufacture of capacitors required for the electronics and telecommunications industries. Because they are small and have high reliability, these capacitors are used in miniaturised electronic circuits, mainly in mobile phones. Because of its anti-corrosive properties tantalum metal is used in the chemical industry in applications such as tantalum carbide in tools for metal cutting and machining as well as in metal alloys in the aerospace and electricity-generating industries. Overall, approximately 60% of annual world consumption of tantalum is used in the electronics industry, with more than half of this currently used in the manufacture of mobile phones.

Tantalum minerals have more than 70 different chemical compositions, of which tantalite ((Fe,Mn)Ta2O6), microlite (CaTa2O6), and wodginite (Mn(Sn,Ta)(Ta,Nb)2O8) are of greatest economic importance. It is common practice to name any mineral concentrate containing tantalum as tantalite.

Australia has historically been the world's largest producer of tantalum (as tantalite concentrates), providing approximately half of the world's mine output through mining operations at Greenbushes 250 kilometres (km) south of Perth, Western Australia (WA) and at Wodgina 100 km south of Port Hedland, WA.

For location of tantalum deposits refer to Fig. 14 in the Tin chapter

Resources

In WA, granitic rare-metal pegmatites are the dominant host rock for primary tantalum mineralisation. The only exceptions are the carbonatite type deposit at Mount Weld in the eastern goldfields of WA and an unusual form of subalkaline granite–syenite mineralisation at the Brockman-Hastings deposit, southeast of Halls Creek, WA.

Australia's Economic Demonstrated Resources (EDR) are estimated to be 62 kilotonnes (kt) of tantalum in 2011, a 17% increase on 2010 resource of 53 kt. Of these, 86% are in WA and 14% in New South Wales (NSW). More than 92% of the EDR in WA are associated with Global Advanced Metals' (formerly Talison Tantalum) Greenbushes and Wodgina deposits. The remaining EDR occur at Mount Cattlin, Mount Deans, Dalgaranga, Arthur River and the Brockman-Hastings (formerly known as Brockman) deposits (all in WA). In NSW, all the EDR are associated with the Toongi deposit.

The Brockman-Hastings Rare Metals deposit, which is owned by Augustus Minerals Limited, is located 18 km southeast of Halls Creek, WA. It is hosted by a fine-grained volcaniclastic unit (informally known as the Niobium Tuff) within a sequence of thick volcanic-sedimentary rocks. The Niobium Tuff can be traced over a strike length of 3.5 km and varies in width up to 35 metres (m). The deposit has a Joint Ore Reserve Committee (JORC) Code compliant resource of 36.2 million tonnes (Mt) grading 0.89% ZrO2, 0.36% Nb2O5, 0.018%Ta2O5 comprising an Indicated Resource of 27.1 Mt grading 0.018% Ta2O5 and an Inferred Resource of 9.1 Mt grading 0.018% Ta2O5.

The Toongi deposit, 20 km south of Dubbo in NSW, accounts for 14% of tantalum EDR. The deposit is a sub-volcanic intrusive trachyte body (vertical) with dimensions of approximately 900 by 600 m, which has been drilled out to a depth of 55 m to provide a Measured Resource of 35.7 Mt grading 0.03% Ta2O5, and between 55 and 100 m for an Inferred Resource of 37.5 Mt grading 0.03% Ta2O5.

Subeconomic Demonstrated Resources account for about 29% of total Demonstrated Resources. The Paramarginal and Submarginal Resources amount to 18 kt, an increase from 15 kt in 2010. Western Australia is the largest holder of Paramarginal Resources with 61% followed by NSW with 39%. All the Submarginal Resources occur in WA.

Inferred Resources totalled 29 kt compared to 30 kt in 2010, which results from marginal upgrading the resources at Brockman-Hastings Rare Metals deposit and the removal from the national inventory of historical estimates which pre-date the JORC Code and so do not comply with its requirements. Western Australia and NSW account for 69% and 31% of Inferred Resources respectively.

Accessible EDR

All of Australia's EDR of tantalum is accessible.

JORC Reserves

The Joint Ore Reserve Committee (JORC) Code reserves comprise total tantalum in Proved and Probable Ore Reserves as defined in the JORC Code. In 2011, JORC Code reserves of 29 kt accounted for approximately 47% of Accessible Economic Demonstrated Resources (AEDR).

Exploration

Data on exploration expenditure for tantalum are not available.

Production

Western Australian Department of Mines and Petroleum has not reported tantalum production figures for 2011. However Galaxy Resources reported production from Mount Cattlin deposit of 0.465 kt of tantalum concentrate containing 3.3% Ta2O5.

World Resources and Production

Based on estimates published by the United States Geological Survey (USGS) and Geoscience Australia, the world resources of tantalum in 2011 totalled 131 kt. The world's largest holder of tantalum resource is Brazil with an estimated 65 kt, followed by Australia with 62 kt and Mozambique at 3 kt.

Using USGS data, Geoscience Australia estimated world production of tantalum in 2011 to be 790 tonnes (681 tonnes in 2010). Production in 2011 was dominated by Brazil, with 180 tonnes, which amounted to about 22% of world output. According to the USGS, other main producers were Mozambique with 120 tonnes, Rwanda with 100 tonnes and Canada with 25 tonnes.

Industry Developments

Global Advanced Metals' (GAM) recommenced mining at its Wodgina mine in January 2011 following it being on care and maintenance since December 2008 as a result of the global financial crisis. Throughout 2009 and 2010, the company continued to process tantalum pentoxide from its ore stockpiles. Although the initial recommencement mining rate will be at 700 000 pounds a year, the Wodgina mine has a capacity to produce 1.4 million pounds a year of tantalum pentoxide (Ta2O5) from tantalum-bearing pegmatite ores at the Mount Cassiterite and South Tinstone open cut mines.

GAM's Greenbushes operations in WA includes an open cut and an underground mine, primary and secondary tantalum processing plants, a tin smelter and a lithium plant. The company's primary tantalum plant remains on care and maintenance. Its secondary processing plant treats stockpiles of primary tantalum concentrates from the Wodgina mine. Processing of newly mined Wodgina ore commenced in mid 2011. The company's Greenbushes tin smelter is closed and its lithium operation produces various grades of spodumene products (see Lithium Chapter).

In early 2011, Traxys Tantalum LP, a member of the Traxys Group, agreed to acquire a 20% interest in GAM subject to approval by the Australian Foreign Investment Review Board.

During the December quarter 2010, Galaxy Resources Limited commenced production from the Dowling Pit at its Mount Cattlin lithium-tantalum project (hard-rock spodumene) north-northeast of Ravensthorpe, WA. At full production, the project is expected to produce 137 000 tonnes a year of spodumene concentrate grading 6% lithium oxide (Li2O) and 56 000 pounds a year of contained Ta2O5 in concentrate. In December 2010, Galaxy Resources entered an agreement with GAM to supply it with 200 000 pounds of its Mount Cattlin Ta2O5 ore over 5 years, which will upgrade the material at GAM's Greenbushes plant. The Mount Cattlin deposit has a reported JORC Code compliant resource of 18.188 Mt with an average grade of 1.08% Li2O and 156 parts per million of Ta2O5 containing an estimated 197 000 tonnes of Li2O and 6.26 million pounds of Ta2O5 above a cut-off grade of 0.4% Li2O.

A technical report in December 2011 prepared by SNOWDEN for GAM recommended further exploration and drilling to determine the extent and grade of mineralisation in deeper parts of pegmatite bodies.

A demonstration pilot plant run by Alkane Resources Ltd at the ANSTO Minerals Lucas Heights operation in Sydney, NSW, has recovered several tonnes of zirconia concentrate, niobium-tantalum concentrate and yttrium-rare-earth concentrate. The source material has come from Alkane Resources's Dubbo Zirconia Project based on the Toongi deposit 20 km south of Dubbo, NSW. The company is in the advanced stages of developing a memorandum of understanding with a niobium consumer to form a joint venture to produce ferro-niobium from niobium concentrate for specialised alloy markets.