Influence of SiO₂ on the Compressive Strength and Reduction-Melting of Pellets

• Main Authors: He Guo, Xin Jiang, Fengman Shen, Haiyan Zheng, Qiangjian Gao, Xin Zhang
• Format: Article
• Language: English
• Published: MDPI AG 2019-08-01
• Series: Metals
• Subjects: SiO₂; pellet; compressive strength; reduction; melting behavior
• Online Access: https://www.mdpi.com/2075-4701/9/8/852

The effects of SiO₂ content on the compressive strength, reduction behavior and melting-dripping properties of the pellets were investigated under experimental conditions. The experimental results indicated that the compressive strength of pellets gradually decreased with increasing SiO₂ content, mainly because the pellets with high SiO₂ had poor crystallization capacity, a more liquid phase and more pores. With increasing SiO₂ content from 2.19 wt% to 8.13 wt%, the reduction degree of pellets descreased due to the generation of 2FeO·SiO₂. Based on the morphology analysis, inside of the pellets, 2FeO·SiO₂ caused the compact structure and fewer microspores with increasing SiO₂ content, which was unfavorable for the reduction process and resulted in the decrease of the reduction degree. Also, increasing the SiO₂ content had negative effects on the melting-dripping properties of pellets. The melting-dripping properties can be improved by adding some sinter with high basicity in the mixed burden. The current work established the relation between SiO₂ content and reduction-melting behavior of pellets, which can provide theoretical and technical support for the effective utilization of pellets with different SiO₂ content in blast furnace process.