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The formation was studied of the freeze lining in an industrial non-ferrous slag containing CaO-FeOx-SiO2-Al2O3-ZnO-MgO as the main component. Laboratory-scale experiments involved submerging a water-cooled probe into a liquid slag bath and a thermodynamics software package was used to interpret two different sample solidification microstructures. The results showed that for high solidification rates, only local mass transport occurs and small crystals form in an amorphous matrix without exchange of material with the liquid bath. At lower solidification rates, columnar crystals form and bath materials become trapped between the crystals. The growth mechanisms of the different phases and the interaction with the bath affect the growth of the freeze layer. The mass transport of minor elements may also have a strong effect on crystal growth., The formation was studied of the freeze lining in an industrial non-ferrous slag containing CaO-FeOx-SiO2-Al2O3-ZnO-MgO as the main component. Laboratory-scale experiments involved submerging a water-cooled probe into a liquid slag bath and a thermodynamics software package was used to interpret two different sample solidification microstructures. The results showed that for high solidification rates, only local mass transport occurs and small crystals form in an amorphous matrix without exchange of material with the liquid bath. At lower solidification rates, columnar crystals form and bath materials become trapped between the crystals. The growth mechanisms of the different phases and the interaction with the bath affect the growth of the freeze layer. The mass transport of minor elements may also have a strong effect on crystal growth.

A high-temperature submerged plasma zinc fuming process is described for the treatment of Zn leach residues, electric arc furnace dusts and other Zn-containing waste materials. Continuous operation of the process requires high Zn fuming rates while retaining vessel integrity through the formation of a stable freeze lining. A steady-state model was developed using thermodynamics software to describe simultaneously the chemical, thermal and heat transfer conditions in the process. The model was used to investigate systematically the potential effects of operating parameters such as feed composition, fuel:oxygen ratio, electrical power and fluxing parameters on bath temperature, heat loss and Zn content in the slag. Continuous operation at high bath temperatures makes the process more economically viable and the use of hydroelectric power for the plasma reduces greenhouse gas emissions., A high-temperature submerged plasma zinc fuming process is described for the treatment of Zn leach residues, electric arc furnace dusts and other Zn-containing waste materials. Continuous operation of the process requires high Zn fuming rates while retaining vessel integrity through the formation of a stable freeze lining. A steady-state model was developed using thermodynamics software to describe simultaneously the chemical, thermal and heat transfer conditions in the process. The model was used to investigate systematically the potential effects of operating parameters such as feed composition, fuel:oxygen ratio, electrical power and fluxing parameters on bath temperature, heat loss and Zn content in the slag. Continuous operation at high bath temperatures makes the process more economically viable and the use of hydroelectric power for the plasma reduces greenhouse gas emissions.