Softening-melting Properties of High-chromium Vanadium–titanium Magnetite Pellets with Different Basicity

• Published in: ISIJ International Vol. 63; no. 10; pp. 1607 - 1618
• Main Authors: Chen, Bojian, Wen, Jing, Jiang, Tao, Li, Lin, Yu, Tangxia, Tang, Wenbo, Hu, Peng
• Format: Journal Article
• Language: English
• Published: The Iron and Steel Institute of Japan 15-10-2023
• Subjects: basicity; blast furnace; flux pellets; high-chromium vanadium-titanium magnetite; softening-melting properties
• ISSN: 0915-1559; 1347-5460
• DOI: 10.2355/isijinternational.ISIJINT-2023-171

High-chromium vanadium-titanium magnetite (HVTM) is a critical polymetallic ore resource, and its large-scale utilization is considered feasible by smelting flux pellets in blast furnaces. This study investigated the softening-melting properties of pure HVTM pellets (100% HVTM pellets) and HVTM with 30% conventional iron pellets (70% HVTM pellets) with different basicity (R). The results indicated that the softening-melting properties of 100% HVTM pellets deteriorated when R increased from 0.2 to 1.8, and the properties of 70% HVTM pellets first deteriorated and then improved. Moreover, 100% HVTM pellets exhibited superior softening-melting properties for R<1.0, while 70% HVTM flux pellets were better at R>1.6. The gas permeability of 100% and 70% HVTM pellets decreased with increasing basicity, although the permeability of 70% HVTM pellets was higher. Notably, the key components of acid slag are Mg-bearing anosorite and pyroxene, whereas those of basic slag are perovskite and melilite. With the increase of basicity, the content of chromium in dropping iron decreased and that of vanadium increased.