<p>The valorization of Waelz slag generated during electric arc furnace (EAF) dust processing is of growing industrial and environmental importance due to its content of valuable metals and hazardous compounds. This study investigates the sulfuric acid leaching of the Waelz slag for selective recovery of zinc, copper, and iron. Thermodynamic modeling combined with experimental investigation was performed to determine the influence of acid consumption, solid–liquid ratio, oxidant addition, temperature, and leaching time. Optimal parameters, namely, H₂SO₄ and H₂O₂ consumptions of 1.32&#xa0;g/g and 0.005&#xa0;g/g of the Waelz slag, respectively, an S/L ratio of 0.2&#xa0;g/mL, a temperature of 70&#xa0;°C, and a leaching time of 5&#xa0;min, resulted in 99.3%, 98.2%, and 87.2% dissolution of Fe, Zn, and Cu, respectively. The solid residue, composed mainly of calcium sulfate, carbon, and amorphous silica, has a chemical composition that suggests a potential application in cement production. Sequential treatment of the leachate enabled the separation of enriched products: a Cu-rich cementation precipitate with 48 wt.% Cu, Fe₂O₃-based fractions with 55.5–60.7 wt.% Fe, Zn-containing precipitates with 29.6–33.5 wt.% Zn, an Al-rich fraction with 12.1 wt.% Al, and a Mn-Mg precipitate with 20.1 wt.% Mn and 18.8 wt.% Mg. These findings demonstrate that sulfuric acid leaching combined with consequent selective precipitation offers an efficient route for Waelz slag valorization, contributing both to metal recovery and waste minimization.</p> Graphical Abstract <p></p>