US20090191107A1 - Processes for the recovery of ruthenium ...
Processes for the recovery of ruthenium from materials containing ruthenium or ruthenium oxides or from ruthenium-containing noble metal ore concentrates, with the steps of A. the introduction of the material into a highly alkaline alkali hydroxide melt in the presence of nitrate as oxidising agent with the formation of an oxidised melt residue with water-soluble ruthenate (RuO 4 ) 2−, B ...