Selective Precipitation of Valuable Metals from Steel Slag Leach Liquor: Experimental and Theoretical Approaches

In this study, we develop a selective precipitation process for the recoveryRecovery of titaniumTitanium, magnesium, and aluminum from the steel slagSteel slag leach liquor. To accurately predict the precipitation behavior of the target elements in the complex sulfate system, we conduct thermodynamic modelingThermodynamic modeling and experimental measurement of metal hydroxide precipitation titration curvesTitration curve. The investigation focuses on three key operating parameters: initial solution pH, initial metal ion concentration, and reaction temperature. We examine the ion interaction, precipitation pH, amount of precipitant required, and species equilibrium. Subsequently, hydroxide precipitation testing is performed using sodium hydroxide as a single precipitant to selectively recover the target elements. We evaluate the effects of precipitation pH level, reaction temperature, stabilization time, and precipitant reagent type on metal recoveryMetal recovery and product purityPurity. Following process optimization, we achieve an 83% purityPurity of titaniumTitanium precipitate with 85% recoveryRecovery, along with > 90% purityPurity of magnesium and aluminum precipitates with 100% recoveryRecovery.