Bubble Generation in MgO-C Crucible Charged with Slag and Metal in Relation to Local Corrosion

Abstract

The local corrosion of MgO-C crucible by molten slag (Ca0-Si02-Al 2 03-(Fe,0)) and metal is greatly influenced by the bubbles generated at the crucible-slagmetal three-phase boundary and at the crucible-metal interface. Bubbles generated at the crucible-slag-metal three-phase boundary suppress the local corrosion, while bubbles generated at the crucible-metal interface enhance the local corrosion. Mechanism of the bubble generation was studied by in-situ X-ray observation and also by theoretical analysis. It is revealed that bubbles form mainly according to the reaction between (FeO) in the slag film between crucible and metal and C (s) in the crucible: (FeO)+C( S) =Fe ( i ) +CO (g) . (FeO) in the slag film comes from the reaction: 2Fe+(Si0 2 )=2(Fe0)+Sj for the FeO-free slag-electrolytic iron system.

Oxidation Resistance and Wetting Behavior of MgO-C Refractories: Effect of Carbon Content

“…The MgO-C refractory is subjected to extreme circumstances, including ultra-high temperature, severe convection, and oxidizing atmospheres, where it becomes damaged and its service life is shortened [2,3]. Many studies have investigated the mechanism of the degradation of MgO-C refractory in slag or slag-steel systems via stationary or rotary immersion methods [4,5,6]. Jansson et al [7] suggested that dissolution of the MgO into the slag was the first step in the corrosion of the MgO-C refractory, followed by penetration of the grain boundaries and dispersion of the grains in the slag.…”

Evaluation of Factors Affecting the MgO–C Refractory Lining Degradation in a Basic Oxygen Furnace

“…The FeO in Equation ( 4) is produced by the reaction presented in Equation (5). Iron oxide (FeO) passes from the slag-metal phase interface to the slag-refractory phase interface, where it reacts with carbon to generate CO bubbles, according to Equation (4) [34]:…”