Conventional versus microwave-assisted roasting of sulfidic tailings: Mineralogical transformation and metal leaching behavior

•Roasting treatment for sulfidic tailings increases the extractability of valuable metals.•Conventional and microwave-assisted heating induce different roasting pathways.•Formation of intermediate sulfate phases is prevalent during conventional roasting.•Direct pyrite oxidation to oxide phases is the main mechanism during microwave-assisted roasting.•Conventional roasted tailings leaches more targeted metals in water compared to microwave-roasted tailings.