Achieving efficient recovery and utilization of waste heat during sintering is crucial for iron and steel plants. Previous studies on waste heat utilization have shown that steam and electricity are generated, after which the air and sinter mixture is preheated. However, few studies on the mechanisms of the drying process of the sinter mixture exist. This paper presents the results of an experimental investigation on the drying process that occurs during sintering. The results show that the drying process of the sinter mixture consists of three stages, namely, a short rising-rate stage, a long constant-rate stage, and a falling-rate stage. The moisture contents of specimens are 0.055-0.06 kg/kg in the first 5-7 min, and the critical moisture contents are approximately 0.023-0.03 kg/kg. The drying efficiency is mainly attributed to the temperature and the flow rate of the hot air, and the former one is more significant. (C) 2011 Elsevier B.V. All rights reserved.