Wettability and Spreading Kinetics between Some Refractory Materials and Molten Calcium Aluminate Slag

The wetting properties and interface behavior of molten slag have a significant impact on the metallurgical process. The wetting behavior between molten calcium aluminate slag and substrates (Mo, MgO, graphite, BN, and Al 2 O 3 ) is investigated at 1673 K. The findings indicate that molten slag has preferable wettability with Mo, MgO, and Al 2 O 3 substrates, and low wettability with graphite and BN substrates. The addition of FeO in molten slag can reduce the time to reach wetting equilibrium, and increase the thickness of boundary layer in the wetting system. The dissolution and reaction phenomena are present at the interface between molten slag and MgO and Al 2 O 3 substrates. No significant reaction products are observed at the interface between molten slag and the graphite, Mo, and BN substrates. The spreading process between molten slag and different substrates can be divided into four stages: physical spreading, reaction spreading, diffusion spreading, and wetting equilibrium. Based on the empirical model ( R n ∼ t ), the spreading kinetic parameter n is calculated. When n is smaller than 10, the interfacial reaction is primarily what causes the spreading. When n is bigger than 10, inert driving forces (dissolution, permeation, adsorption, etc.) are mostly responsible for the wetting.