Ruthenium
Also: Ru, Ruthenium (PGM)
Ruthenium (Ru) is a rare platinum-group metal prized for its exceptional hardness and corrosion resistance, used chiefly in the electronics industry and as an alloying additive.
Ruthenium belongs to the family of platinum-group metals (PGMs) and ranks among the scarcest elements in the Earth's crust. It was isolated in 1844 by the Russian-Baltic chemist Karl Ernst Claus, who named it after the Latin word for Russia. Despite its technical importance, ruthenium remains far less familiar to the general public than platinum or palladium.
Properties
Ruthenium is a silvery-white, brittle transition metal. At 12.45 g/cm³ it has a high density and an extraordinarily high melting point of 2,334 °C. Its hallmark is extreme hardness: even a tiny ruthenium addition (0.1%) markedly stiffens platinum and titanium. The metal resists nearly all acids; even aqua regia attacks it only slowly.
Extraction and occurrence
Ruthenium is recovered almost entirely as a by-product of nickel and copper mining, chiefly in South Africa (the Bushveld Complex) and Russia. Worldwide annual output is estimated at around 35 tonnes — a fraction of gold production. Refining relies on elaborate hydrometallurgical and pyrometallurgical routes.
Applications
| Field of use | Share (approx.) |
|---|---|
| Electronics (resistors, HDDs) | ~50% |
| Electrochemistry / chlor-alkali electrolysis | ~15% |
| Alloys (platinum, titanium, tungsten) | ~15% |
| Chemical catalysis | ~10% |
| Other | ~10% |
In electronics, ruthenium goes into chip resistors and into the antiferromagnetic coupling layer of hard-disk platters. In catalytic converter chemistry it serves as an active component for ammonia synthesis and the Fischer-Tropsch reaction. As an alloying addition it lends platinum jewellery outstanding wear resistance.
Market significance and pricing
The ruthenium market is thin 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 analysts such as Johnson Matthey and Argus Media. The historical price record shows sharp swings — ruthenium has traded below USD 40 per troy ounce at times yet also reached peaks above USD 700 (2007). For investors the market is barely accessible, given the absence of standardised trading products and its low liquidity. (Not investment advice.)
In brief
Ruthenium is a high-technology metal with an indispensable role in electronics and catalysis, yet almost no presence in the investor market. Watching the price behaviour of related PGMs gives an indirect read on the ruthenium market — but a standalone investment remains the preserve of institutional and specialist players.