The electric arc furnace dust (EAFD) is the residue from the gas collection system of steel mills which contains significant amounts of iron, zinc, and lead. The EAFD management presents scientific and technical challenges, due to its classification as hazardous waste, which significantly impacts the economics of steelmaking. Normally, this kind of waste is treated by specialized waste management companies; however, valuable metals can be recovered. In collaboration with a steel manufacturer, this work studies the management of steel mill residue with a process synthesis approach using mathematical programming. The results show that savings of 23 USD per ton of dust can be achieved by recovering pure Zn and Pb through hydrometallurgical dissolution and electrodeposition. Finally, this work provides a decision-making management tool for toxic waste that combines data from both pilot-scale operations and metallurgical companies, and insights from expert judgment, thereby offering a comprehensive framework for informed decision-making.