PROCESSES FOR THE RECOVERY OF RUTHENIUM FROM MATERIALS CONTAINING RUTHENIUM ORRUTHENIUM OXIDES OR FROM RUTHENIUM-CONTAINING NOBLE METAL ORE CONCENTRATES

摘要

Processes for the recovery of ruthenium from materials containing ruthenium or ruthenium oxides or from ruthenium-containing noble metal ore concentrates, with the steps ofA. 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 (RuO₄)²⁻,B. the dissolution of the oxidised melt residue obtained in water,C. the addition of a reducing agent,D. the precipitation of the metals formed, can also be used for separating off selenium.;Optionally, ruthenium is separated off by distillation, instead of precipitation, following step B, with the steps of5C the treatment of the ruthenate-containing solution with an oxidising agent,5D distilling off of the RuO₄ obtained,5E taking up of the RuO₄ from step 5D in hydrochloric acid.;By way of further subsequent purification steps, processes for the recovery of ruthenium targets are obtained.