Tantalum could confidently take a leading place among metals. But its low abundance (the Earth’s crust contains only 0.0002% Ta), very high weight, and high cost substantially limit its applications. With density 16.65 g/cm³, melting temperature 3,017°C, and Young’s modulus (ability to resist tension, compression, and elastic deformation) of 185 GPa, tantalum is stronger than steel, heavier than lead, and more ductile than copper. And below −268.7°C it becomes a superconductor.
Tantalum is inert: even in hydrochloric acid heated to 200°C, the metal’s corrosion rate is only 0.006 mm per year. Another Ta feature is biocompatibility: tantalum implants are not rejected by human body tissues, but their high cost (almost 500 times more expensive than titanium) makes them unavailable for widespread use.
Despite the high cost, some quantity of this supermetal is present in almost everyone’s everyday life: capacitors from tantalum and its oxides are widely used in automotive electronics and microprocessor technology, including PCs, smartphones, tablets, etc. Almost 60% of all tantalum mined in the world goes to this industry.
In addition, metallic tantalum is used in melting ultra-strong alloys for producing:
Tantalum pentoxide (Ta2O5) is used to manufacture special glasses for camera lenses, reducing weight and raising lens quality. Extremely hard composite materials are made from tantalum carbide and then used to produce tool tips, in particular metal-cutting products.
In nature tantalum occurs mainly in minerals: tantalite, loparite, hatchettolite, columbite, euxenite, etc. The main ones, besides tantalum, contain niobium (Nb): if Nb quantity is more than 50% — it is columbite; if more than 50% Ta — tantalite.
Until 2008 the main tantalum mining was concentrated on the African continent. But an unstable economic situation and some countries’ ban on exporting raw materials from conflict zones pushed other states to develop their own deposits. For example, Brazil’s share in tantalum mining, which in 2010 barely reached 5%, today is more than 20% — about 450 tonnes of tantalum oxide are mined here annually. Meanwhile African countries that quite recently were almost the only tantalum suppliers in the world today produce just over half of tantalum raw materials.
Over the last decade not only suppliers of tantalum ores but also ideas about tantalum deposits themselves have changed. In the 2010s a widely spread “fact” was that 80% of world tantalum resources are in Central Africa, in particular the Democratic Republic of the Congo. But this assertion was refuted: according to current USGS calculations, the African continent accounts for no more than 10% of world Ta reserves, South America about 20%. Most tantalum ores are concentrated in Australia — scientists estimate more than 60% of world Ta reserves are there.
According to Russian geologists there are also significant tantalum ore deposits on RF territory, but their quality is substantially lower than in countries conducting industrial metal mining. Most domestic deposits contain potentially industrial ores that even in the late 1820s were of no commercial interest.
The main tantalum producer in Russia is the Solikamsk Metallurgical Plant, whose main activity is mining and processing rare-earth metals. Tantalum is produced here from loparite concentrate mined on the Kola Peninsula (where the largest niobium-tantalum mine on RF territory is located). Besides tantalum, the Solikamsk plant also obtains strontium, titanium, niobium, thorium, and other rare earths from the feedstock.
