Abstract: There is provided a hydrometallurgical process of recovering rhenium values from mixtures thereof with other metal values in which the rhenium values constitute a minority amount, for example super-alloys, which comprises subjecting the mixture to strongly oxidizing acid conditions, preferably an aqueous mixture of hydrochloric acid and nitric acid, so as to form perrhenate species of at least the major proportion of the rhenium values in the mixture, dissolving the perrhenate species and other soluble metal species in aqueous solution, removing insoluble metal species from the aqueous solution, and isolating the rhenium species from the solution.

Abstract: There is provided a hydrometallurgical process of recovering indium and gallium values from mixtures thereof with other metal values for example recycled and scrap solar panel cells which comprises subjecting the mixture to strongly oxidizing acid conditions, preferably via the simultaneous addition of sulfuric acid and hydrogen peroxide to the leach vessel, so as to form indium and gallium salt species of at least the major proportion of the indium and gallium values in the mixture, extracting the indium and gallium values with an organic extractant by adjusting the pH so as to extract individually the indium and gallium values with the organic extractant, stripping indium and gallium values from the extractant using an acid and an alkaline solution respectively and recovering the indium and gallium values.

Abstract: There is provided a hydrometallurgical process of recovering rhenium values from mixtures thereof with other metal values in which the rhenium values constitute a minority amount, for example super-alloys, which comprises subjecting the mixture to strongly oxidizing acid conditions, preferably an aqueous mixture of hydrochloric acid and nitric acid, so as to form perrhenate species of at least the major proportion of the rhenium values in the mixture, dissolving the perrhenate species and other soluble metal species in aqueous solution, removing insoluble metal species from the aqueous solution, and isolating the rhenium species from the solution.