<p>Chalcopyrite is one of the most abundant copper minerals found in the Earth’s crust. It typically undergoes a series of concentration stages to produce a copper concentrate, which is then processed through pyrometallurgical methods. Although a hydrometallurgical method presents an interesting alternative, it faces significant challenges owing to the high chemical stability of chalcopyrite, which imparts refractory properties and hinders copper leaching. This study investigates the effect of pH on copper leaching in a PO₄³⁻–H₂O₂ system. The copper recovery was found to be strongly dependent on both pH and H₂O₂ concentration. At a pH of 3, increasing the H₂O₂ concentration to 0.5&#xa0;M enhanced the kinetics of chalcopyrite oxidation at low solid-to-liquid (S/L) ratios (20–50&#xa0;g/L), resulting in rapid and efficient copper recovery (&gt; 90%). In contrast, at higher ratios (100–200&#xa0;g/L), the kinetics and overall efficiency were reduced. Iron dissolution remained below 3%, with phosphate enhancing copper recovery and reducing iron solubility.</p> Graphical abstract: <p></p>