Continuous Refining of Hot Metal with Soda Ash in the Trough-type Refining Furnace

Abstract

Studies on the continuous refining of hot metal with soda ash were performed using the trough-type continuous refining furnace. The furnace had ability to process the hot metal at the rate of 45 t/h.
1) [P] and [S] after refining were lowered to 0.015% and less than 0.005% respectively, at the consumption of 20kg·Na₂CO₃ per ton of hot metal(t·HM).
2) Oxidized amount of [Mn] in the refining was 0.08% and nitrogen of refined hot metal was also removed to 10 to 20ppm.
3) Owing to low iron oxide and iron particle content of the Na₂CO₃ slag, iron loss in the refining was nearly 2.5kg/t·HM.
4) Temperature drop of hot metal due to the decomposition and evaporation of charged soda ash was estimated as 4.6°C/kg·Na₂CO₃/t·HM and heat loss in the continuous refining was calculated as 6.5×10³ kcal/t·HM.
Estimation of dephosphorization degree of the refined hot metal by reaction model and the characteristics of continuous refining were discussed.