A Basic Study of the Oxidizing Roasting in the Sintering Process of ISP.

As a basic study of the oxidizing roasting in a Dwight-Lloyd sinterig machine in the ISP, lead-zinc concentrate, zinc concentrate, recycled sinter fines, and pulverized sinter fines were roasted in air, and behavior of sulfur-containing compounds was investigated.The results can be summarized as follows.1. The charge to the sintering machine is discharged before it is brought, as a whole, to equilibrium with the gas phase in the machine.2. The roasting reactions are complicated owing to competitive formation and/or decomposition of oxides, sulfates, and basic sulfates.3. Most sulfur remains in the sinter as basic sulfates of lead and zinc.4. Desulfurization of recycled sinter fines and pulverized sinter fines by roasting in air is slow at temperatures below 1, 200°C which prevail in the sintering machine.