A team of researchers headed by Assistant Professor Resmi Sebastian, Department of Civil Engineering, Indian Institute of Technology (IIT), Ropar, have found the presence of a rare metal, tantalum, in the sand of the River Sutlej in Punjab in November 2023.
According to Resmi Sebastian, her team of researchers were conducting experiments on the characterisation of the Sutlej river sand. They were primarily conducting experiments for investigating the dynamic characteristics of soil and rocks, particularly in relation to their impact during an earthquake. They were conducting detailed research to find out the quantum of metal in the river. They had no intention to do mineral analysis while doing their experiments. In the process of their research, one of the fellow researchers found the presence of tantalum. This discovery has unveiled the potential technological benefits associated with tantalum, significant not only for Punjab but for whole of India because of the multiple uses of this rare metal.
Discovery of Tantalum
A Swedish chemist, Anders Gustaf Ekenberg, had discovered Tantalum in minerals obtained from Ytterby, Sweden in 1802. Initially, the metal discovered by Ekenberg was considered to be a different form of niobium, an element which is chemically similar to tantalum. However, in 1866, a Swiss chemist, Jean Charles Galissard de Marignac, proved that tantalum and niobium were two different elements.
This rare metal has been named after a Greek mythological emperor, Tantalus. The Greek god, Zeus, chastised the emperor for his offence. Tantalus was made to stand in a pool of water surrounded by trees with fruits hanging. Every time, he attempted to reach out for the fruits or drink the water, the fruits would move out of his reach and the water in the pool would recede—a sign of eternal frustration.
According to the US Department of Energy, this name was selected because of the insolubility of tantalum in acids. Thus, when placed in the midst of acids, it is incapable of taking any of them up.
Properties of Tantalum
Tantalum is a rare metal, which is widely used in the electronics and semiconductor industry because of its unique characteristics. Its atomic number (the number of protons found in one atom of an element) is 73. Tantalum is a grey, heavy, exceptionally hard metal. It is also known as the most corrosion-resistant metal which is presently in use. It forms an oxide layer when exposed to the air. This oxide layer is tough to remove even when it interacts with strong and hot acidic environments.
In its pure form, tantalum is malleable in nature. Because of its high melting point, it could be hammered into a thin sheet without breaking. Its melting point is exceeded only by tungsten and rhenium. It is ductile as it could be stretched, pulled, and drawn into a thin wire without breaking. Tantalum is immune to chemical attack at temperatures below 150 °C. It could be attacked only by hydrofluoric acid and acidic solutions containing the fluoride ion and free sulphur trioxide.
Uses of Tantalum
Tantalum is used for making capacitors that have the capability of storing more amount of electricity in smaller sizes without much leakage than any other capacitors. Because of its increased storage capacity in a small volume, tantalum becomes an ideal choice for use in portable electronic devices, such as smartphones, laptops, and digital cameras.
In semiconductors, tantalum is used as thin film for insulating layers. Tantalum oxide films are used as materials in metal-insulator-metal (MIM) capacitors and other semiconductor devices. With the help of these films, semiconductor devices could be used to create high-performing electronic components.
Moreover, tantalum serves as an affordable substitute for platinum, which is frequently used in jewellery and in converters of cars, trucks, and buses. It is most widely used in the defence sector in chemical plants, nuclear power plants, missiles, and fighter jets. It is also used to make surgical equipment and implants, like artificial joints, etc., as it does not react with bodily fluids.
A composite consisting of tantalum carbide (TaC) and graphite is one of the hardest materials known, and is used on the cutting edges of high-speed machine tools.
Economic Impact
This research suggests that there may be other untapped metals lying beneath the riverbed which need exploration. If it is found that the tantalum deposits in the river are significant, then it would place India as a key player in the global tantalum market. Presently, there are only a few countries which supply tantalum and this has often led to market volatility and supply chain challenges. Further, an additional tantalum supply source could ease these pressures and help create a more stable market.
Furthermore, the extraction and processing of tantalum from the Sutlej river could lead to economic development in the region. It might boost infrastructure spending on mining and refining as well as produce income from the regional and national economies leading to the creation of new jobs. However, as the Sutlej river is a very vital ecosystem, any mining operations must be carried out carefully, so as to avoid any ecological harms.
This finding has also highlighted the value of the ongoing scientific investigation and study. As the world becomes more and more dependent on technology, the demand for rare metals like tantalum is bound to grow in the future. In order to maintain technological innovation and economic prosperity, exploring new sources of this metal has become inevitable.
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