One of the rarest metals on Earth, ruthenium (Lat. ruthenium) is obtained as a by-product of copper and nickel refining by separating it from the other platinum group metals. The chemical symbol of ruthenium is Ru; its melting point is as high as 2333 °C and its boiling point is 4147 °C. Ruthenium is a silvery-grey, hard metal that is highly resistant to chemicals and also has excellent corrosion resistance.
Ruthenium has a very wide range of industrial applications. It is used in the production of hard disk drives and chip resistors (found in almost all electronic devices). Ruthenium oxide is used to coat electrodes for chlorine production, and ruthenium is used as a catalyst in the chemical industry. However, the amounts of ruthenium in conventional electronic and household devices are very small, so retail recycling of these devices to recover ruthenium is completely uneconomical.
Platinum and palladium alloyed with ruthenium are exceptionally strong, and such alloys are often used in luxury jewellery. Worldwide, there is also growing interest in and demand for ruthenium in the hydrogen industry.
Sources:
https://periodic-table.rsc.org/element/44/ruthenium
https://www.britannica.com/science/ruthenium
https://matthey.com/products-and-markets/pgms-and-circularity/pgm-markets/ruthenium