Ruthenium
Also: Ru, Ruthenium (PGM)
Ruthenium (Ru) is a rare platinum-group metal with exceptional hardness and corrosion resistance, used primarily in the electronics industry and as an alloying additive.
Ruthenium belongs to the platinum-group metals (PGM) and is one of the rarest elements in the Earth's crust. It was isolated in 1844 by the Russian-Baltic chemist Karl Ernst Claus and named after the Latin designation for Russia. Despite its technical importance, ruthenium is far less well known to the general public than platinum or palladium.
Properties
Ruthenium is a silvery-white, brittle transition metal. With a density of 12.45 g/cm³ and an exceptionally high melting point of 2,334 °C, it is among the most refractory of the PGMs. Characteristic is its extreme hardness: even small additions of ruthenium (0.1%) significantly increase the hardness of platinum and titanium. Ruthenium is highly resistant to most acids; even aqua regia attacks it only slowly.
Production and Occurrence
Ruthenium occurs almost exclusively as a by-product of nickel and copper mining, primarily in South Africa (Bushveld Complex) and Russia. Global annual production is estimated at approximately 35 tonnes – a fraction of gold output. Refining involves complex hydrometallurgical and pyrometallurgical processes.
Applications
| Application area | Share (approx.) |
|---|---|
| Electronics (resistors, HDD) | ~50% |
| Electrochemistry / chlor-alkali electrolysis | ~15% |
| Alloys (platinum, titanium, tungsten) | ~15% |
| Chemical catalysis | ~10% |
| Other | ~10% |
In the electronics industry, ruthenium is used for chip resistors and as a coating for hard-disk platters (antiferromagnetic coupling layer). In catalytic converter technology it serves as an active component for ammonia synthesis and the Fischer-Tropsch reaction. As an alloying additive it imparts exceptional wear resistance to platinum jewellery.
Market Significance and Price Discovery
The ruthenium market is narrow and opaque: there is no exchange fixing comparable to the LBMA fixing for gold or silver. Prices are negotiated bilaterally between producers and buyers and published by analytical firms such as Johnson Matthey and Argus Media. Historical prices show sharp swings – ruthenium has traded at below $40 per troy ounce at times, but also reached highs above $700 (2007). For investors, the market is barely accessible due to the absence of standardised trading products and low liquidity. (Not investment advice.)
Key Takeaway
Ruthenium is a high-technology metal with an indispensable role in electronics and catalysis, yet it has virtually no presence in the retail investment market. Monitoring the price performance of related PGMs provides an indirect picture of the ruthenium market – yet independent investment remains the preserve of institutional participants and specialists.