Role of Al₂O₃ in Interfacial Morphology and Reactive Wetting Behaviour between Carbon-unsaturated Liquid Iron and Simulant Coke Substrate

Abstract

Wetting between liquid iron and coke influences liquid flow in the lower part of a blast furnace, which strongly affects the operation of the furnace. With increasing fluidity, the blast furnace performs more favourably and efficiently. To further improve blast furnace operation, the wetting behaviour of liquid iron on coke must be correctly understood. The effects of ash in the coke on reactive wetting in concave formations, such as holes formed at the contact area, must be considered. This study aims to elucidate the effects of the ash component in coke on the reactive wetting behaviour of carbon-unsaturated liquid iron on a simulant coke substrate and concave formations thereof. In this study, reactive wetting between the iron samples and the substrates was measured by a sessile drop method with a molten injection system at 1 673 K. The results revealed that the apparent contact angle significantly decreased with time in the first 300 s after contact. After 300 s, the contact angle stabilized at a constant equilibrium value. The initial contact angles depended not only on the carbon concentration of the liquid iron, but also on the Al 2 O 3 content in the substrates. Concave geometries formed when the carbon-unsaturated iron samples were wetted on substrates containing 0, 5, and 10 vol% Al 2 O 3 . The effect of Al 2 O 3 on the carbon dissolution reaction was the main factor affecting the reactive wetting behaviour of substrates against liquid iron.

In Situ Monitoring and Dissolution Limit of Carbon Dissolution in Hot Metal

“…The presence of Al 2 O 3 also reduced the wettability between carbon materials and iron liquid. [32] The wettability between graphite C1 and molten iron becomes better with carbon dissolution, which further promotes the mass transfer of carbon at the interface. Due to the disorder of carbon structure, the wettability between C2 and molten iron is worse than C1, which results in the slower carbon dissolution.…”

Ash Particle Behaviors during Combustion and Gasification of Coke

“…These cause a change in liquid properties (viscosity, wettability, etc.). [8][9][10][11][12][13][14][15][16] This change affects the liquid and gas permeability in the cohesive and dripping zone. Additionally, a shell layer derived from the ashes of coke and pulverized coal may be formed in the depths of the raceway in the blast furnace.…”

Molecular Dynamics Simulations of Iron/Graphite Interfacial Behaviors: Influence of Oxygen

“…Moreover, wetting between liquid iron and coke influences liquid flow in the lower part of a blast furnace, which strongly affects the operation of the furnace. 22,23) Two hundred years ago, Thomas Young proposed a method by treating the contact angle of a liquid lying on a solid surface as the result of the mechanical equilibrium of a droplet resting on the solid plane. 24) Although a sessile drop method can be used to measure interfacial energy, 25,26) it is still challenging for this method to reveal the influence of interfacial energy on the graphite morphology under various surface conditions.…”