Tantalum
What is Tantalum?
Tantalum (Ta) is a rare, hard, corrosion-resistant, blue-grey, lustrous transition metal.
It is primarily found in the mineral tantalite, and usually occurs along with niobium, an element which shares many chemical and physical characteristics with it. Tantalum containing minerals are mostly found in pegmatite ore bodies. Tantalum-bearing tin slags (a by-product of tin smelting) are an additional source of tantalum.
Tantalum (Ta) is a highly ductile, highly refractory metal (chemically inert and resistant to heat and wear), with a very high melting point (fourth highest of the metals). It is very resistant to corrosion due to the formation of a thin surface layer of tantalum oxide, which also has the property of being an insulating layer. This thin layer of tantalum oxide results in favourable dielectric properties, hence the major usage of capacitors for the electronics and telecommunications industry.
World Reserves and Production
World niobium and tantalum resources are poorly reported. Central Africa is known to host major resources but dependable resource estimates are rarely available. According to world estimates published by the USGS, world economic resources of tantalum in 2018 totaled about 123 kt. These figures, however, are a minimum, given that they are based on resources from Australia and Brazil alone and do not include Rwanda, Congo, Nigeria, Brazil or China.
Africa is the largest producer from multiple resources and accounts for an estimated 35% of total production. Australia supplies approximately 17% of tantalum production with other significant production coming from Brazil (20%), Canada, and China.
Deposits
Brazil provides the biggest tantalum reserves with 88 Kt Ta, followed by Australia with 78 Kt Ta, Nigeria with 7 Kt Ta, and Canada with 5 Kt Ta.
Australia
More than 90% of Australia's tantalum resources occur within four deposits (Toongi, Wodgina, Pilgangoora and Greenbushes).
Applications
Tantalum is primarily used in electronic capacitors for the electronics and telecommunications industry, which are widely used in equipment such as mobile phones and laptops.
Tantalum-based capacitors have significant advantages over other materials in terms of response times, weight and space-saving for high-end telecommunications, data storage and medical devices.
Tantalum is also used in the production of cutting tools, optical glass for camera lenses, ink-jet cartridges and in X-ray phosphors.
Other uses include within alloys and superalloys, to increase ductility, melting point and corrosion resistance (e.g., high temperature applications, turbine blades), within medical and dental applications (using its inertness and biocompatibility) and chemical process industries (making use of its high temperature and corrosion resistance properties, e.g., heat exchangers, vacuum furnaces).
Market
Tantalum is a small industry and has historically been susceptible to rapid changes in market balance with volatile price movements.
In recent years, low-cost Australian production as a by-product of lithium mining has grown rapidly to account for 5% of global production in 2018, at the expense of some traditional mining in Africa. Australian by-product mines continued to ramp up through the first half of 2019 but external factors in the lithium market began to limit their development and, by the end of 2019, production was much lower than expected with one new producer expected to leave the market. Despite this, Australia’s contribution to global tantalum supply still increased to around 17% in 2019 and is expected to exceed 20% by 2020
During the Australian ramp up, tantalum prices responded with a sharp decline, falling from US$100/lb in mid-2018 (for 30% Ta2O5 concentrate, CIF China) to US$54/lb by Q3 2019, as quoted by Asian Metal. With low cost by-product contributions to global supply now expected to grow less rapidly, Roskill forecasts price recovery in late 2019/early 2020
Pricing
Tantalum is typically sold as a tantalum pentoxide (Ta2O5), as a tantalum salt (K2TaF7) or tantalum metal.
Most tantalum is used in the aerospace industry (including space flight), the electronics (technology) industry or in the health industry. Tantalum concentrate prices (for 30% Ta2O5 content) have decreased in prices significantly due to excess supply and have historically exhibited significant variability. Tantalum pentoxide prices, having much lower price volatility, range from US$250 to $310 per kilogram dependent on the quality.