Characterization of semi-coke generated by coal-based direct reduction process of siderite

• Published in: Journal of Central South University Vol. 22; no. 8; pp. 2914 - 2921
• Main Authors: Zhu, De-qing, Luo, Yan-hong, Pan, Jian, Zhou, Xian-lin
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.08.2015
• Subjects: Engineering; Metallic Materials; sinter fuel; coal-based direct reduction; semi-coke; non-magnetic product
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-015-2826-x

Solid wastes derived from metallurgical industries pose a significant threat to environment. The utilization and disposal of these solid wastes are the major concern in the world. Semi-coke generated in coal-based direct reduction process of iron ore is a by-product and its suitable utilization is not available so far. In order to handle it properly, the characteristics of this by-product were comprehensively investigated. A series of analysis methods were used to demonstrate its mineral compositions, petrography and physico-chemical properties. The results reveal that the semi-coke has poor washability. The fixed carbon content of semi-coke reaches 76.11% and the gross calorific value is 28.10 MJ/kg, both of which are similar to those of traditional sinter coke breeze. Also, semi-coke ash possesses lower content of SiO 2 , Al 2 O 3 , S and higher content of CaO and MgO, which could improve the strength of sinter ore when partially substituting for coke breeze in sintering. Semi-coke features well-development porous structure and higher reaction activity, which predicts that the sintering speed could be elevated to some extent when employing it as a partial replacement of coke breeze, so the studies further suggest that the potential adverse effect of the high reactivity on sintering process could be weakened by adequately coarsening the semi-coke’s particle size.