Intensification of non-ferrous metal leaching: a mini-review with emphasis on zinc recovery technologies

Abstract

This review examines technological and resource factors governing zinc production route selection. The mineralogical form of zinc is identified as the primary flowsheet design criterion: sulfide ores require oxidative pretreatment, whereas non-sulfide ores undergo acid leaching but risk silica gelation. Pyrometallurgical and hydrometallurgical pathways are compared regarding metal purity, energy intensity, and residue management. Modern intensification methods – microwave pretreatment, ultrasonic cavitation, and surfactant-assisted autoclave leaching – are evaluated as tools targeting distinct rate-limiting stages: matrix liberation, boundary-layer mass transfer, surface passivation. Cross-referencing with recent advances in copper bioleaching and gold microflotation confirms the universal nature of underlying physicochemical barriers.