The Chehel-Kureh copper deposit in southeastern Iran contains Complex sulfide ores rich in copper, lead, and zinc, posing significant challenges for conventional flotation processing. Despite various flotation strategies, the plant has struggled to produce clean copper concentrates and separate lead and zinc products, resulting in low recoveries and environmental concerns due to metal losses in tailings. In this study, the application of Waelz kiln technology—a process commonly used for zinc recovery from metallurgical residues—was investigated as an alternative approach for metal recovery from Chehel-Kureh ore. Reduction roasting experiments were conducted on raw ore, as well as differential and bulk flotation concentrates, using coal as a reductant. The effects of roasting temperature, duration, and coal ratio on metal volatilization were examined. Under optimal conditions, volatilization of lead, copper, and zinc reached 89%, 84%, and 75% for the raw ore; 92%, 62%, and 74% for the differential concentrate; and 68%, 62%, and 43% for the bulk concentrate, respectively. These findings indicate that the Waelz process can achieve high metal volatilization efficiencies, particularly for lead and zinc, offering a promising alternative for pre-treatment and recovery of valuable metals from Complex Cu–Pb–Zn ores while potentially minimizing environmental impacts.