Abstract: This study focused on utilizing mineral particles in lead−zinc flotation overflow water to catalyze the ozone for the degradation of organic matter, aiming to address issues of separation index deterioration and environment threaten when directly returned to flotation or discharge. The results showed that the direct ozone treatment for the overflow water resulted in a higher removal efficiency of organic matter compared to filtration, attributed to the in−situ catalytic capacity of minerals in the overflow water. Furthermore, it was observed that the order of ozone catalysis by minerals was lead concentrate > tailings > zinc concentrate. Under the optimal conditions, removal efficiency of 51.85% for COD and 46.30% for TOC were achieved representing improvements of 0.78 and 0.62 times, respectively, compared to that ozone treatment without minerals after filtration. The active sites on the mineral surface could catalyze ozone to generate highly reactive ·OH, resulting in the conversion of hydroxyl and long chain hydrocarbons in organic matter to smaller molecular organic compounds such as CS₂, which were subsequently mineralized into CO₂ and H₂O. When the treated overflow water through the direct ozone treatment was recycled to flotation the lead concentrate exhibited a Pb content of 69.93% and a Zn content of 2.31%, with corresponding recoveries of 92.51% and 2.69%, respectively. In comparison to the untreated overflow water and the filtered ozone−treated overflow water, there were increases in lead recoveries by 4.56% and 2.8%, respectively. The zinc concentrate contained 43.69% Zn and 0.88% Pb, achieving recoveries of 92.14% and 2.01%, respectively, with improvements in zinc recoveries of 8.24% and 4.88%, respectively. The application of in situ catalytic ozone treatment on organic matter in the overflow water effectively reduced the lead−zinc interpenetration in the concentrate and improved the grade and recovery of concentrate. The research results can serve as a valuable reference for achieving high−quality reuse of flotation wastewater.