The development of recycling processes that enable the recovery of valuable metals from industrial residues with significantly lower CO2 emissions is necessary due to the aggravating circumstances of climate changeClimate change, resource availability, and land consumption caused by the landfilling of residues. It is possible that processes based on chlorination reactions will become significant in the future in this context. To extract the valuable metal copperCopper from the refractory matrix, this process was assessed in this context for the treatment of spent refractorySpent refractories bricks from the copperCopper industry. The paper explains the behaviour of the identified most suitable reactant, magnesium chloride (MgCl2·6H2O), as well as the principles of chlorination and reaction mechanisms of different salts.