Challenge the practice is addressing: This practice addresses the promising trials at the Boliden Kokkola zinc smelter in Finland to recover valuable metals from jarosite residue and convert it into clean slag with potential applications as a construction material.
Concrete practice to achieve the expected goal: Jarosite residue from Kokkkola's landfill is currently stored safely. Boliden is exploring alternatives for processing it. A variety of technical options are explored to recover valuable metals, make marketable slag, and dispose of hazardous wastes from jarosite residue in a safe manner. Jarosite residues can be recovered for valuable metals such as zinc, silver and lead. There are, however, hazardous substances like arsenic in the residue. R&D in pyrometallurgy has shown Boliden can process jarosite residue to produce valuable metal dust and clean slag with low levels of lead and zinc.
Expected impact/goal of the practice: The clean high quality slag from jarosite residue can be used in construction after processing. Trials have shown that different types of cement materials can be created from the processed residue. Additionally, this would avoid possible increased landfill costs.
Who is the target user group of the practice/intervention or implementing the practice/intervention? This practice is mainly relevant for industry contexts.