TANTALUM
Abundance and extraction
Tantalum is the element with atomic number 73 and is symbolized by Ta. It belongs to the family of transition metals. Tantalum is present in small quantities in the Earth’s crust (2ppm). In 2023, the main producers of tantalum were the Democratic Republic of Congo, Rwanda, and China*.
Tantalum is mainly mined from open pits or tunnels. It is found in small amounts in various minerals and is exclusively extracted from coltan, which typically contains the most tantalite, the mineral from which tantalum is derived. The refining of tantalum is carried out chemically through a complex multi-step process.
Depending on the required properties, tantalum is used in its pure form or as part of an alloy.
Alloys and superalloys of tantalum
Tantalum alloys typically include additives like tungsten and molybdenum. Additionally, tantalum is frequently used as an additive in numerous superalloys, primarily intended for the aerospace and space industries.
Properties
This metal has numerous qualities. Its exceptional electrical conductivity explains why the majority of tantalum is absorbed by the electronics industry. The aerospace industry values tantalum for its high melting point of 3017°C, which is particularly useful in the manufacture of turbine blades.
Furthermore, tantalum offers exceptional corrosion resistance, has a high density (16.56 g/cm³), and is known for its biocompatibility.
Tantalum’s use in watchmaking remains very rare and is currently limited to a few casing components.
Niobium and tantalum were identified simultaneously at the beginning of the 19th century. As they come from the same mineral and have very similar compositions, they were not initially distinguishable. It was not until 1844 that niobium was clearly identified and differentiated from tantalum. Tantalum began to be used in the electronics industry in the 1940s, followed by the aerospace industry in the 1950s. In watchmaking, tantalum made its appearance in the 1990s, but its implementation remains limited to casing components.
The use of tantalum in watchmaking is rare, primarily confined to the production of cases and occasionally bracelets. Tantalum pairs well, both in terms of colour contrast and physical properties, with other metals in the creation of bi-metallic cases or bracelets (tantalum-gold, tantalum-platinum, tantalum-steel).