Abstract
Accelerating climate targets and resource constraints demand processes that recover valuable metals from complex industrial residues with minimized CO2 emissions. This paper introduces selective chlorination as an innovative, sustainable separation method that exploits controlled chlorination–dechlorination equilibria to differentiate matrix elements from valuable metals by their volatility, and reactivity. The approach engineers phase transformations into chlorides, oxychlorides, or stabilized oxides under tailored temperature profiles and gas atmospheres, creating pathways for multi‑metal systems without reliance on high‑carbon reductants. The present research combines comprehensive thermodynamic equilibrium calculations to define suitable process parameters with laboratory validation for selected residues from nonferrous industry. Emphasis is placed on hydrated chloride donors such as magnesium-, iron-, or aluminium-chlorides, which release HCl in situ. Overall, the results confirm that selective chlorination can be an important basic technology for the circular economy in the metallurgical sector, combining high extraction performance with sustainability and practical applicability.