Lower SO₂ Emissions in the Sintering Process Utilizing the Difference of Sulphur Contents of Iron Ores

Abstract

The current treatment of sintering flue gas pollutants is mainly focused on the end-of-pipe treatment, but some problems still exist. It will be more simple and efficient to start from the source to control the pollutants elements. In this paper, the iron ores are classified into two parts utilizing the difference of sulphur contents of iron ores and their adding ratio, “High Sulphur” iron ores and “Low Sulphur” iron ores. Both parts of the iron ores are located inside or outside of the tested pellet, respectively, by granulating with other sintering materials. The experiment results of SO₂ emissions reduction are similar in the tubular electric furnace experiment and the sinter-pot test. The sinter-pot test performed in this study reveals that about 41.02% and 34.20% of SO₂ are reduced, respectively, through the method in which the “High Sulphur” iron ores are located inside and outside of the tested pellet compared with the traditional method. The falling strength and tumbler strength of sinter decrease by 3.04% and 1.51% when the “High Sulphur” iron ores are located inside of the tested pellet, respectively. While the falling strength and tumbler strength increase by 5.44% and 0.08% when the “Low Sulphur” iron ores are located inside of the tested pellet, respectively. Reduction index (RI) decreases by 1.38% and 4.96%, respectively, while the characteristic value (S) decreases by 19.89% and 70.50%, respectively. The reducibility of sinter decreases, but the softening-melting properties of sinter improve obviously. Compared with the traditional method, the methods introduced in this article have some advantages from the perspective of SO₂ emissions reduction and the improvement of the softening-melting properties of sinter. In general, the method in which “High Sulphur” iron ores are located outside of the pellet would be more preferable than that of located inside.