Chemical Dissolution of Lead in Slags Containing Zinc.

For the purpose of determining the amount of chemically dissolved lead in ISF slag, molten lead was equilibrated with molten slag containing several mass% of zinc in a magnesia crucible under partial pressures of zinc vapor and oxygen. The partial pressures were controlled by utilizing the equilibrium reaction between a CO-CO 2 gas mixture and Zn 2 SiO4 . From the results, the solubility of lead in the ISF slag was obtained as a function of the oxygen partial pressure and temperature as follows : The amount of chemically dissolved lead in the actual slag tapped at 1,523 K, for example, was calculated to be 0.10 - 0.26 mass% from available oxygen partial pressure data of the slag. Also, from the activity coefficient of zinc oxide in the slag, the equilibrium zinc vapor pressure from the actual slag at the hearth of the ISF was estimated to be 0.64 - 0.95 atm, which seems to meet the stable operating condition of the ISF.