Niobium (Nb) and tantalum are often found together in the same ores, namely columbite ((Fe, Mn)Nb2O6) and tantalite ((Fe,Mn)Ta2O6), because of their very similar chemical properties. Niobium is used with iron and other elements in stainless steel alloys. Niobium-titanium alloy wire is used in the medical sector for magnetic resonance imaging. Niobium alloys are strong and are often used in pipeline construction. The metal is used in superalloys for jet engines and heat resistant equipment. At cryogenic temperatures (minus 150°C), niobium is a superconductor.
In 2012, Australia’s Economic Demonstrated Resources (EDR) of niobium remained unchanged at 205 kilotonnes (kt). The bulk of the EDR of niobium is associated with the Toongi deposit (Dubbo Zirconia Project), 20 kilometres (km) south of Dubbo in New South Wales (NSW). This deposit is a sub-volcanic intrusive trachyte body (vertical) with dimensions of approximately 900 by 600 metres which has been drilled out to a depth of 55 metres to provide a Measured Resource (reported in December 2012) of 35.7 million tonnes (Mt) grading 0.46% Nb2O5, and between 55 and 100 metres for an Inferred Resource of 37.5 Mt grading 0.46% Nb2O5.
The other source of niobium EDR is the Brockman-Hastings deposit located 18km southeast of Halls Creek in Western Australia (WA). This deposit, which is owned by Augustus Minerals Limited, is hosted by a fine-grained volcaniclastic unit informally known as the Niobium Tuff within a sequence of thick volcano-sedimentary rocks. The Niobium Tuff can be traced over a strike length of 3.5km and varies in width up to 35 metres. In September 2011, the company reported a Joint Ore Reserve Committee (JORC) Code compliant resource of 36.2 Mt grading 0.89% ZrO2, 0.36% Nb2O5, 0.018% Ta2O5 which included an Indicated Resource of 27.1 Mt grading 0.36% Nb2O5 and an Inferred Resource of 9.1 Mt grading 0.36% Nb2O5. These resources are based on a 1500 parts per million (ppm) Nb2O5 cut-off grade.
Since January 2010, niobium and tantalum zone in the Mount Weld deposits in WA is defined as a separate Crown Polymetallic deposit. In January 2010 Lynas reported a JORC Code compliant resource of 37.7 Mt grading 1.07% Nb2O5, 0.024% Ta2O5 which included an Indicated Resource of 1.5 Mt grading 1.4% Nb2O5 and 0.037% Ta2O5 and an Inferred Resource of 36.2 Mt grading 1.06% Nb2O5 and 0.024% Ta2O5.
Paramarginal Resources totalling 82 kt are unchanged from 2011 and account for all the Subeconomic Demonstrated Resources. They occur in the Hastings (also known as Brockman-Hastings) (67 kt) in the Halls Creek Orogen and in the Crown Polymettalic (15 kt) deposit in the eastern goldfields in WA.
No changes in the Inferred Resources (418 kt) have been recorded in 2012. Western Australia is the largest holder of Inferred Resources with 70% associated with the Mount Weld and the Hastings deposit, while NSW holds the remaining 30% in the Toongi deposit.
All of Australia’s EDR of niobium is accessible.
Joint Ore Reserve Committee (JORC) Code reserves comprise total niobium in Proved and Probable Ore Reserves as defined in the JORC Code. No changes in reserves of niobium (115 kt) have been reported in 2012. All are contained in the Toongi deposit.
Exploration for niobium is occurring in WA and NSW, but there are no statistics available on exploration expenditure for niobium. Alkane Resources Ltd has reported the presence of mineralisation at the neighbouring Railway prospect (4km northwest of the Toongi ore body), where reverse circulation drilling in the trachyte body intersected a zone containing grades ranging from 0.85% to 0.99% ZrO2, 0.21% to 0.23% HfO2, 0.21% to 0.26% Nb2O5, 0.013% to 0.15% Ta2O5 and 0.43% to 0.48% TREO (Y2O3 + REO). The report notes that there has been insufficient exploration of the Railway trachyte to define a mineral resource and it is uncertain that further exploration will result in the determination of a mineral resource.
During 2011, Hastings Rare Metals Limited completed a 51-hole drilling program at the Hastings deposit and reported numerous significant intersections of ZrO2, niobium and rare-earth elements. In November 2012 Hastings announced the acquisition of additional tenements in the Hastings deposit area to focus on the exploration of rare-earth element mineralisation.
Currently there is no production of niobium in Australia. However, in previous years niobium concentrates were recovered as a by-product of tantalum mining.
Based on incomplete world estimates published by the United States Geological Survey (USGS) for 2012, the largest holders of the world’s niobium resources are Brazil with 4100 kt and Canada with 200 kt. USGS data also estimates that world production of niobium in 2012 was 68.7 kt, which represents an increase of 9% on 2011 production of 63.4 kt. The production was dominated by Brazil with 63 kt and Canada with 5 kt.
Historically, Global Advanced Metals (GAM) Pty Ltd (formerly Talison Minerals) Greenbushes mine in WA produced tantalite-columbite concentrate for export. Columbite Fe(Nb,Ta)2O6 is the main niobium ore mineral. The company’s primary tantalum plant at Greenbushes has been under care and maintenance since 2008 while its secondary processing plant treats primary tantalum concentrates from the Wodgina mine in the Pilbara region of WA. In January 2011, GAM announced it would resume operations at the Greenbushes and Wodgina mines but closed them again in early 2012 following softening of demand for tantalum. In 2011, GAM established an agreement with its neighbour, Atlas Iron, allowing it to use the infrastructure at the mine to support its iron ore production.Alkane Resources Ltd is in advanced process of developing a memorandum of understanding (MoU) with a niobium consumer to form a joint venture to produce ferro-niobium from niobium concentrate for specialised alloy markets from the Dubbo Zirconia Project based on the Toongi deposit. In May 2011, the company signed an MoU with a European company committing to the joint venture all of the niobium produced. The company expects to convert the MoU to an off-take/joint venture agreement in early 2013.