Numerical simulation of slag layer and its distribution on hot surface of copper stave based on ANSYS birth-death element technology

Abstract

The core of the long-life copper stave was to ensure the stability of the slag layer, and the uniform distribution of the slag layer was beneficial to restrict the generation of the overthick slag layer. A novel model for calculating the thickness and distribution of the slag layer in the part of copper stave was established based on the finite element theory through the ANSYS birth-death element technology. The distribution and thickness of the slag layer on the hot surface of copper stave were calculated and analyzed when the gas temperature and slag properties tended to be changed, which was applied to characterize the slag-hanging capability of copper stave with the changes of furnace conditions. It was shown that the thickness of hot surface slag layer in the part of copper stave decreased obviously while the temperature of stave body raised rapidly with increasing gas temperature. When the gas temperature was 1400 °C, the inlaid slag layer was gradually melted, and the maximum temperature of the stave body was closed to 120 °C. The change of gas temperature was very sensitive to the adherent dross capability of copper stave which would be enhanced by the promotion of slag-hanging temperature. However, when the slag-hanging temperature was 1150 °C and the gas temperature was lower than 1250 °C, the overthick slag layer was easily formed on the hot surface of the copper stave, and its stability was poor. The improvement in the thermal conductivity of slag could be conducive to the formation of the uniform and stable slag layer on the hot surface of copper stave, especially in the dovetail groove. When the thermal conductivity of the slag was greater than 1.8 W m⁻² °C⁻¹, the inlaid slag layer in the dovetail groove was not melted, although the gas temperature reached 1500 °C.