Initial Wetting and Spreading Rates Between SiC and CaO-SiO2-MnO Slag

Abstract

The wetting of CaO-SiO2-MnO slag on silicon carbide was studied with a variety of slag compositions at 1823 K (1550 A degrees C). Wetting experiments were performed by the dispensed drop technique. We observed complete wetting of the slag on SiC (within 1 second) without a bubble reaction regardless of the basicity (=CaO/SiO2 = C/S ratio). However, after 8 seconds, the bubble reaction was observed under conditions of C/S = 0.8 and 1.1, whereas it was not observed at temperatures lower than 1823 K (1550 A degrees C). The contact angle was independent of MnO content, while the spreading rate increased with the increasing MnO content at the early stage of wetting. Inertial force acts on the early stage of spreading, and viscous force acts with lower MnO content due to higher viscosity. The low-viscosity slag did not fit with the nonreactive viscous model. However, the high-viscosity slag fitted the model well. (C) The Minerals, Metals & Materials Society and ASM International 2016