Effect of alumina pickup on mould flux viscosity in continuous slab casting

Abstract

Mould flux samples were taken from a continuous slab caster mould at various stages during casting sequences. These confirmed that the amount of alumina pickup reaches a steady state level within the first 40 min of casting (in agreement with a simple model of alumina pickup). The steady state level was 3–4 mass-% higher than the original alumina content of the flux. Viscosity measurements carried out on two commercial mould fluxes, with different levels of alumina added, showed that the viscosity increase as a result of a 4 mass-%increase in alumina is not likely to affect mould behaviour. Comparison of the measured viscosities with predictions from literature models showed that no single literature model corresponds consistently to the measured values.