Ruthenium is never found free in nature, and it is very rare. Mineral ores which contain elements from the platinum group sometimes contain minute quantities of ruthenium. The ore pentlandite is the ore that is most frequently used for ruthenium isolation. The isolation process of ruthenium is complex due to the many other elements that it is found with; isolating ruthenium out of these other elements involves a number of steps.
The first step to ruthenium isolation is treating the ore with sodium bisulphate and heat; the melted ore contains rhodium sulfate which is insoluble. The liquid ore is then combined with sodium peroxide, and the mixture is then extracted with water to yield the salts of ruthenium and osmium in addition to iron oxide. The salt form of ruthenium is reacted with chlorine gas to yield the highly volatile oxide of ruthenium, RuO4. This oxide is treated with hydrochloric acid; the oxide dissolves in the acid and is precipitated out by treating the solution with ammonium chloride. The precipitate is then subjected to drying and burning under hydrogen gas to yield pure ruthenium metal.
