Sulphide capacities of mulicomponent slags

Abstract: In the present thesis, experimental measurements have beencarried out to determine the sulphide capacities of the binaryslags Al2O3-MnO, "FeO"-SiO2, "FeO"-CaO, "FeO"-MnO, ternary slags Al2O3-MgO-SiO2, Al2O3-MnO-SiO2, Al2O3-CaO-MgO, MgO-MnO-SiO2, Al2O3-MgO-MnO,"FeO"-Al2O3-SiO2, "FeO"-CaO-SiO2, "FeO"-MgO-SiO2, "FeO"-MnO-SiO2,quatenary slags Al2O3-CaO-MgO-MnO, Al2O3- CaO-MgO-SiO2,Al2O3-CaO-MnO-SiO2, CaO-MgO-MnO-SiO2, quinary slag Al2O3-CaO-MgO-MnO-SiO2, and the six component slag "FeO"-Al2O3-CaO-MgO-MnO-SiO2.The technique used was to bring the melt to equilibrium witha gas mixturecontaining Ar-CO-CO2-SO2. Extreme precautions were taken in theexperimental measurements to ensure the accuracy of the resultsobtained.The results have been incorporated into the sulphidecapacity modeldeveloped earlier in the Department ofMetallurgy, Royal Institute ofTechnology. The model parametersup to ternary interactions, which wereobtained based on theexperimental data for corresponding binary andternary systemsare provided. These model parameters were used to predictthesulphide capacities of four-, five- and six component systemsand themodel predictions were compared with experimentalresults for chosen slagscompositions. Good agreement betweenexperimental data and the results ofmodel prediction wasobtained for all the systems investigated.The industrial experiments were carried out at ScanaBjörneborg AB. Theaim was to see if the model, based onlaboratory experiments cansuccessfully be applied to the plantpractice. Comparison with the plantdata enabled a criticalsurvey of the industrial practice and eventualdeviations fromequilibrium conditions.KEY WORDS:Sulphide capacity, Slags, Desulphurization,Model, Sulphur,Multicomponent