Process Safety and Environmental Protection, Vol.146, 267-275, 2021
New understanding about the relationship between surface ignition and low-carbon iron ore sintering performance
Surface ignition is the first and also the important step for iron ore sintering, which provides the initial source of energy to trigger the whole reactions. This investigation mainly focused on revealing the relationship between surface ignition and sintering performance, and elucidated the deep mechanism. Results indicate that the quality of sinter in the surface layer can be effectively improved by adjusting the ignition parameters. The preferred ignition parameters include ignition temperature of 1050 degrees C, ignition duration of 1 min and heat preservation of 1-2 min. The function mechanism of improved sinter quality is attributed to the increased high temperature duration for minerals melting, the enlarged melting zone, and the decreased cooling velocity. These changes facilitate the formation of enough adhesive phase of calcium ferrite, more of which generated in acicular morphology with high mechanical strength. Optimizing the ignition process reduced the solid fuel consumption due to the improved sintering performance, which then decreased the emission of NO and SO2. The research findings are of great significance for providing a guide for the design of desirable ignition system and making further contributions to energy conservation and emission reduction during sintering. (C) 2020 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.