Petrographic analysis and characterisation of a blast furnace coke and its wear mechanisms

- Coke samples were retrieved from the tuyere drilling of an operating blast furnace.
- Petrographic analysis of the blast furnace feed and tuyere cokes was carried out.
- Tribological testing compared the wear behaviour of the feed and tuyere cokes.
- Mechanisms of coke wear varied with location from the blast furnace tuyere entrance.
- Coke wear modes were linked to coke microtexture and textural interfaces.

Petrographic analysis of coke samples from the tuyere level of an operating blast furnace was carried out using a combination of advanced microscopy techniques including high resolution bireflectance and maximum reflectance measurements. A novel tribological approach was employed to investigate the wear mechanisms of the same cokes. The study showed that the wear mechanisms of coke are influenced by its microstructure and microtexture, as well as the strength and nature of the interfaces between the different coke textural constituents. The wear mechanisms of the cokes were found to vary with location from the tuyere entrance of the blast furnace and also differed to the feed coke. This is the first example of the application of petrographic analysis of cokes from an operating blast furnace to identify the difference in hardness and interaction strength of the distinct coke textural constituents. This research contributes towards improving understanding of the complex mechanisms of coke degradation in operating blast furnaces.