Effect of Carbon Dissolution Reaction on Wetting Behavior between Liquid Iron and Carbonaceous Material

Abstract

Synopsis : A low carbon operation is an unfavorable situation for liquid permeability around cohesive zone, because liquid volume will increase against solid coke in there. In order to keep a healthy operation with this technique, information of wetting behavior between liquid iron and coke should be correctly understood. However, there is not enough information about wetting behavior between them, because of many difficulties about wettability measurement from an active reaction between iron and carbonaceous materials. In this study, a sessile drop method with molten sample injection system was applied to measurement of wetting behavior between liquid iron and carbonaceous material at 1673 K for excluding reaction between samples before starting measurement. Carbonaceous material's substrates were made from mixture powder of graphite and alumina by hot press at 1873K. From the results, following knowledge was revealed. Molten iron samples un-saturated with carbon showed bigger values of contact angles, 110°~120°, at initial stage, than apparent constant values of them, 85°~100°, at latter stage. It indicated a reaction between iron and carbonaceous materials had obvious effect on wetting behavior between them due to decrease an interfacial energy during the reaction. Mixed alumina powder in the substrate prevented to wetting behavior of iron sample on carbonaceous materials, and they changed their apparent constant contact angles from 115° to 130°. The alumina powder had effects on not only wetting behavior but also reaction between iron and carbonaceous materials.

Flux‐Mediated Wetting of Alumina by Liquid Fe–Ti–Csat

“…As documented by Wu et al, molten iron initially did not wet a carbon substrate (θ greater than 90 ), but within 10 s, the angle decreased to above 60 then stabilized at 100 after 100 s. [7] When using precarburized iron (greater than 3.7 wt%), the reaction is not strong enough to cause wetting. [8] Wetting does not have to be transient to be characterized as reactive. The primary features are that it is enabled by chemical reaction and the time to reach the equilibrium contact angle is 10 1 -10 4 s. [6] Dissolved species can also strongly affect the surface tension.…”