Softening–Melting Behaviors of a MgO-SiO2-FeO Slag System on a Coke Bed

• Published in: JOM (1989) 2022-05, Vol.74 (5), p.2019-2028
• Main Authors: Bai, Kaikai, Zuo, Haibin, Wang, Yajie, Chen, Yanbiao, Wang, Jingsong, Xue, Qingguo
• Format: Article
• Language: English
• Subjects: Chemistry/Food Science; Earth Sciences; Energy consumption; Engineering; Environment; Investigations; Iron compounds; Magnesium oxide; Melting; Metallurgy; Pellets; Physics; Pollutants; Progress on Recovery of Critical Raw Materials; Silicon dioxide; Slag; Softening; Temperature
• ISSN: 1047-4838; 1543-1851
• DOI: 10.1007/s11837-022-05167-6

MgO is crucial for improving the softening–melting properties of pellets. By considering primary slags of magnesium pellets with high FeO and SiO 2 and moderate MgO contents, the effect of MgO/SiO 2 and FeO contents on the softening–melting behaviors of a MgO-SiO 2 -FeO slag system were studied. Relevant mechanisms were clarified using FactSage 7.0, XRD, and EPMA. By increasing the MgO/SiO 2 ratio from 0.3 to 0.9, the softening and melting temperatures of the slag increased by approximately 30°C. As the FeO content increased from 5% to 20%, the softening and melting temperatures of the slag decreased from 1368°C to 1271°C and 1395°C to 1342°C, respectively. The MgO/SiO 2 and FeO contents had little effect on the permeation temperature. Increasing the MgO/SiO 2 ratio improved the softening and melting temperatures of slag; however, increasing the FeO content decreased these temperatures owing to the substitution effect of Mg 2+ on Fe 2+ .