Densification and resistance to hydration and slag attack of ilmenite-doped MgO-dolomite refractories in relation to their thermal equilibrium and microfabric

Abstract

This work aims at studying rate of densification, resistance to hydration and slag attack of 0.0-2.0wt.% ilmenite-doped MgO-dolomite refractories fired at 1400-1700°C, in relation to their thermal equilibrium and microfabric. XRF, XRD, SEM, EDAX and mercury intrusion were used to characterize the fired samples. The modular system MgO-MF(MA)-C2S-M2S was applied in determining their thermal equilibrium data. The rate of hydration and attack by steel-slag were also measured using CLM.It is concluded that doping the dolomitic-magnesite with 0.5. wt.% ilmenite leads to maximize rate of densification after firing for 4. h at only 1500. °C. Direct-bonded MgO-MgO network is shown enclosing merwinite and monticellite with minor magnesio-ferrite spinel solid solution ex-soluted within the periclase network. Due to the dense microfabric, the hydration resistance is enhanced 8 times compared with the un-doped samples. Also, there is deeper infiltration of the slag/refractory reaction products of the un-doped MgO-dolomite sample as compared with the doped one. © 2014 Elsevier Ltd.