Ruthenium is a hard whitish member of the platinum group metals (PGMs). Like the other PGMs, it is dense and corrosion-resistant. It was the last of the six metals to be discovered. The British chemists William Hyde Wollaston and Smithson Tenant had between them discovered four new metals in platinum ore in the period 1803-04. Consequently, other scientists pursued additional investigations in the subsequent decades.
Polish chemist Jedrej Sniadecki reported a new PGM metal in 1807 and Gottfired Wilhelm Osann of Russia (but German origin) thought he found three in 1827. But, these claims were not reproduced by Jöns Jacob Berzelius of Sweden (one of the founders of modern chemistry) or other scientists.
Following on Osann's work, Russian chemist Karl Klaus isolated ruthenium from natural platinum in 1844, and Klaus's discovery was confirmed by Berzelius. Klaus retained one of Osann's selected names in honor of their common homeland. "Ruthenia" is the Latin name for the region of the historical Russian Empire.
Mining and Production
Ruthenium is found in natural platinum and in nickel ore containing platinum compounds. These ores are mined in Russia, South Africa, and Ontario, Canada. The PGMs have similar but distinct chemistries, so after nickel is extracted by electroplating, a carefully-chosen sequence of chemistry steps can separate the noble metals.
Ruthenium is difficult to work with because it is hard and brittle, therefore, it is usually refined and delivered in powder form.
Properties and Uses
Ruthenium is hard, brittle, and fairly inert like the other PGMs. Only about 36 tons are consumed each year, around 15% of the demand for platinum or palladium.
Small amounts of ruthenium are alloyed with titanium and sometimes with gold to improve corrosion resistance. Ruthenium is also added to platinum and palladium to harden them. An alloy of ruthenium and iridium is used for pen nibs.
Two of the oxides of ruthenium vaporize easily, making them useful for depositing thin metal oxide layers. Consequently, ruthenium finds various uses in microelectronics, including in disk drives. It is also incorporated into resistors on integrated circuits.
The surface of ruthenium is a catalyst for various chemical reactions similar to the other PGMs. In particular, it decomposes benzene and other organic molecules into hydrocarbon fragments, a critical tool in chemical synthesis. Ruthenium also catalyzes the production of ammonia and acetic acid.
Ruthenium trades on the spot market. Prices are quoted by Johnson Matthey and should be considered starting points for negotiating rather than hard numbers. Similar to iridium, an investment in ruthenium is possible (probably in lots of 100 oz. or more) but not very practical.
If you are interested in ruthenium, you can invest in the mining companies that produce it. These companies, however, are primarily extracting platinum, palladium, and nickel, with the other PGMs as minor byproducts. Thus, their performance is governed by the major metals they produce.