Ruthenium volatilisation

Ruthenium silicide is a very hard, white substance, of great stability. It volatilises in the electric arc. Chlorine slowly attacks it, fluorine readily. It burns in oxygen at high temperatures, and is decomposed by sulphur vapour at red heat. Boiling acids do not affect it. 

Detection of Ruthenium, in Osmiridium.—Ruthenium may be detected in and separated from osmiridium by ignition in a current of oxygen at about 1080° C. Osmium tetroxide and ruthenium dioxide are volatilised, the latter being the first to condense. 

Detection of Ruthenium in Platinum Alloys.—In order to detect the presence of ruthenium in platinum alloys, a portion of the alloy is fused with lead. The melt is extracted with nitric acid and the residue ignited in contact with air in order to volatilise the osmium. The mass may now contain platinum, iridium, rhodium and ruthenium, and is fused with potassium nitrate and hydroxide. The whole is dissolved in water, treated with excess of nitric acid and allowed to stand in a flask covered with filter-paper. In a few hours (12-24) the filter-paper darkens if ruthenium is present, in consequence of the evolution of vapour of its tetroxide. To confirm the presence of ruthenium, the paper is ignited and the ash fused with potassium nitrate and hydroxide. On extraction with water the orange colour of potassium ruthenate is obtained.1... 

The tetroxides of ruthenium and osmium are solids of low m.p. (RUO4, 25°. OSO4, 41°). R11O4 volatilises when a stream of Clg is passed through an alkaline solution of a ruthenate and is conveniently prepared by oxidising potassium ruthenate with periodic acid (Martin, 1952) ... 

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