Wettability of molten CaO-Al2O3-MgO slag on some refractory materials at 1773K

Abstract

The interface characteristic of molten slag has an important effect on the interface phenomenon and reaction between molten slag and molten metal/refractory. The wettability of molten CaO-MgO-Al2O3 slag on some refractory materials (including Mo, graphite, boron nitride (BN), MgO and Al2O3) was studied in argon atmosphere at 1773 K. The contact angle between molten slag and substrate material was measured by the sessile drop method; the interfacial tension and work of adhesion were calculated by Young equation and Young-Dupré equation, respectively. The results showed that, except for graphite, the molten slag can well wet these materials, and the contact angle decreases with increasing temperature and eventually converges to a stable equilibrium value. The interfacial tension of different substrate materials is very different, and the interfacial tension between the slag and reactive substrate MgO, Al2O3 and graphite is small, ranging from 71 to 205 mN/m. The molten slag-Mo of the non-reactive substrate is 1323 mN/m and the molten slag-BN is 7297 mN/m. The adhesion work between molten slag and substrate is in the range of 800–1100 mJm−2 except graphite, which is 400 mJm−2.