Specific Features of Dissolution of Metallic Rhodium in Acid Oxidative Media under Hydrothermal Conditions

Dissolution of metallic rhodium in solutions of hydrochloric acid was studied under hydrothermal autoclave conditions. The influence exerted by various factors on the depth of rhodium(0) transfer to solution was examined. It was found that the quantitative dissolution of rhodium(0) is reached in a mixture of hydrochloric and hydrobromic acids in the presence of manganese dioxide at 20°C in autoclaves. The results obtained can be used both for an analytical determination of rhodium and for processing of rhodium-containing raw materials and synthesis of complex rhodium compounds.