Difference in microstructural characteristics of stamp-charged coke and gravity-charged coke with approximate macroscopic performance

• Published in: Journal of iron and steel research, international Vol. 31; no. 5; pp. 1050 - 1062
• Main Authors: Zou, Chong, Huang, Zheng-yan, Li, Jian-yun, Li, Bin, Liu, Shi-wei, She, Yuan
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.05.2024
• Subjects: Applied and Technical Physics; Engineering; Machines; Manufacturing; Materials Engineering; Materials Science; Metallic Materials; Original Paper; Physical Chemistry; Processes; Optical texture; Reactivity; Porosity; Stamp-charged coke; Microstructure
• ISSN: 1006-706X; 2210-3988
• DOI: 10.1007/s42243-023-01118-w

The microstructural characteristics including optical texture, porosity and pore structure and chemical structure of stamp-charged coke (SCC) and gravity-charged coke (GCC) with similar conventional macro-indicators were investigated, and the properties including micro-strength, reactivity of coke matrix and that after alkali enrichment were comparatively studied by various characterization methods. The anisotropic structure of SCC is composed of high content of fine mosaic texture, while the content of medium mosaic texture, coarse texture and fibrous texture is low. The statistical average shows that the fine mosaic average of SCC (24.89%) is 3.78 times the GCC average (6.58%), and the coarse mosaic average (1.24%) is only about 1/3 of the GCC average (3.43%). The porosity of SCC is lower than that of GCC, but tamping process does not lead to the fact that the number of closed pores of SCC is significantly lower than that of GCC. Although the structure of SCC is compact, its pore number is large and the pore wall is thin. Pores of coke with diameter less than 150 nm seem unaffected by tamping process. The aromatic structure of SCC was less ordered than that of GCC, which was speculated to be related to the addition of more low metamorphic coal in coking. The microscopic strength and structural strength of SCC are lower than those of GCC. The reactivity of coke matrix is affected by the specific surface area, but it is not the determining factor of its macro-reactivity. The improvement in dissolution reactivity of coke after potassium enrichment is independent of coke type.