Desulphurization of steel at ladle treatment of metal is one of the important technological operations. The successful course of the desulfurization process is provided by fire refining slag with specific chemical composition, usually based on calcium oxide. The duration of mixing of the metal with the slag in inert gas, the early formation of refining slag, then optimization of the metal oxidation providing the formation of iron oxide FeO in the slag to be less than 0.5 % able process of desulfurization.
Using of rare earth metals for desulphurization of steel is very promising. However, the number of practical and theoretical data on the use of rare earth metals for desulfurization is limited. Therefore the work in this direction …show more content…
This leads to the definition of conclusions
The activity coefficients of sulfur and aluminum will be calculated by using the interaction parameters (which is equal to fS = 0.71, fAl = 1.13), we can estimate the degree of desulphurization of the investigated melt.
Equation (6) shown, that increasing temperature resists desulfurization process thermodynamically. However, increasing temperatures should have a positive effect on the kinetics of the process, for example by reducing the viscosity of the metal and slag, which improves transition of sulfides from metal to slag.
The work assessed the influence of composition of slag mixture on the degree of desulphurization of the melt. On smooth experiences changed the relationship between the oxide of rare earth metals and the consumption of processed feldspar. As shown by experimental data, the greatest degree of desulfurization was obtained when the ratio of rare earth oxide to the fused feldspar as 1:2 and the degree of desulfurization was 42 …show more content…
Figures (5) shows that, the solid line represent the results from calculation of mathematical model at [Al] = 0.5% and the points represent the results of experiments. The practical points proof the mathematical model of desulfurization by mixture of Mischmetal and feldspar and CaF2 has a positive effect on enhancing desulfurization process. While figure (6) shows that, the solid line represent the results from calculation of mathematical model at [Al] = 0.5% and the points represent the results of experiments which proof that, with increasing the proportion of rare earth metal to feldspar decreases Desulphurization degree.
For industrial application using rare earth oxide will be more economic than mischmetal for desulfurization. Because the price of mischmetal is doubled bulk rare earth oxide and it is almost near to each other for the removed sulfur which was 42% for rare earth oxide and 50% for mischmetal. But for general refining and desulfurization, it will be different sight.