Precious Metals Series

All About Ruthenium – Precious Metals Series

The first of the noble metals on the periodic table, Ruthenium is part of the star members in the group of platinum and gold. These are shiny, expensive metals used often in lab ware and jewelry. Plated jewelry made with Ruthenium is quite common but not as common as gold plated jewelry. Items plated with Ruthenium have a pewter, darkish color compared to platings of rhodium and silver.

The last of the six group-platinum metals to be discovered, it is the last on the list of platinums. Initially, the discovery of ruthenium was assumed to happen in 1828 when Swedish chemists examined crude platinum ore residues after dissolving them in a concentrated solution of nitric acids and hydrochloric acids. It was believed by one of the chemists that there were three new residues of metals called ruthenium, polonium and pluranium. However,  his partner Berzelius was feeling skeptical.

In Kazan, Russa later on in 1844, the results were repeated in order to be clarified by Karl K. Klaus. He wanted to prove that in the residues there was only one metal present. For this new metal, he kept the name ruthenium, which was originally coined by Osann, his partner.

Obtaining The Salt

A lengthy process was used to obtain the salt ammonium chlororuthenate that was necessary to isolate the ruthenium metal and get its properties identified. The name of the element comes from Ruthenia, a Latin word which means Russia in English. The reason for this was because the ores of platinum were originally from Russia’s Ural Mountains.

Characteristics

Ruthenium is a brittle, lustrous, hard and very rare silvery-white metal that at room temperature that  does not tarnish. It can also exist in many states of oxidation, which is typical of transition metals. The most common oxidation state is state 2, 3 and 4. Acids, water and air do not affect this metal. Rather, it reacts with halogens and molten alkali and can explosively oxidize.

You can find Ruthenium in nature freely with other groups of platinum metals. It can be obtained commercially from pentlandite, a sulfide of nickel and iron, which both contain small ruthenium quantities. It can also be extracted from nuclear fuel that has been spent. On the other hand, if this is how you obtain it, it will contain isotopes that are radioactive. It needs to be safely stored for a decade until the isotopes that are radioactive go through decay.

Ruthenium uses

In order to harden palladium and platinum, small amounts of ruthenium are used. This can also be alloyed together with them in order to create electric contacts for severe resistance and wear. When you add 0.1 per cent of ruthenium it improves titanium’s corrosion resistance a hundred times. With the catalytic property of Ruthenium, light is able to split hydrogen sulfide in the presence of a suspension of aqueous suspension of particles of cadmium sulfide loaded with ruthenium dioxide. What’s interesting is that some nibs of Parker pens use ruthenium, such as the Parker 51 which has a nib marked RU, consisting of 3.8% iridium and 96.2% ruthenium.