Microstructure analysis and mineral phase transformation of coke in blast furnace

Abstract

In order to reveal the actual reaction behaviour and degradation mechanism of coke, chemical composition, mineral phase transformation and microstructure of coke at different locations in blast furnace were characterized. Meanwhile, the wear and compressive resistance, as well as the secondary thermal characteristic, were carried out. Results indicated that the mineral species and contents of cokes were significantly affected by alkali metal minerals adhesion and molten slagiron corrosion. The alkali minerals and iron minerals adsorbed on the pore walls contributed to catalytic degradation of the bosh coke and tuyere coke respectively. In the upper zone of BF, the wear and compressive resistance of coke first decreased and then increased. The secondary thermal performance of BF coke was inverse with the content of alkali metal. The macropore structure of the hearth coke with the maximum graphitization disappeared to be replaced by slag and iron.

Characteristics of Residual Fine Particles in a Blast Furnace

“…The alkali metal levels of K 2 O and Na 2 O in the S1 area can reach 2.89% and 1.23%, respectively, several tens of times higher than the BF feed material. Alkali metals are primarily absorbed on the coke pore walls as kalsilite or leucite 23) . The alkali metals K 2 O and Na 2 O accelerate the deterioration of the surface layer, and the surface layer with alkali metals flakes off and turns into fine particles.…”

Classifying coke using CT scans and landmark multidimensional scaling

“…Our approach here is a first step towards developing analysis techniques without the need to calculate von Mises stress. There is a recent study in microstructure analysis and mineral phase transformation in blast furnace (Wu et al 2022). We also point out a recent review paper focussing on the current characterisation methods of the coke structure (Zheng et al 2021).…”