EVAPORATION RATE OF ZINC IN LIQUID-IRON

The evaporation rate of Zn from liquid iron has been observed at 1873K for the fundamental study on mechanism of tramp element removal from remelted steel scrap. In the present work, iron containing Zn was inductively melted and Zn was evaporated by impinging argon gas onto the surface. The evaporation rate of Zn was found to be first order with respect to Zn content in the metal. No measurable effects of the argon flowrate and carbon or sulfur content in the metal on the rate were observed under the condition of argon flowrate above 5 l/min, but the evaporation rate was strongly affected by stirring condition of the melt. Therefore, it was concluded that the evaporation rate of Zn was controlled by the mass transfer in the liquid phase. The mass transfer coefficient in the liquid phase was estimated as 0.032 cm/s at 1873K. The removal rate of Zn in the vacuum treatment was also discussed based on the present result.