The Study of Thermodynamic and Experiment for Desulfurization between CaO-Al2O3-SiO2-TiO2 Slag and Hot Metal
Based On the coexistence theory of molecules and ions,the controlling equation of mass action concentrations for structural units of CaO-Al2O3-SiO2-TiO2 slag system was established in order to explore the influence of each component in the system on the desulphurization a-bility of refining slag.The mathematical model of sulfur distribution ratio between slag and steel was constructed,and the influence of slag ba-sicity,Al2O3 content and TiO2 content on sulfur distribution ratio and desulfurization rate was quantitatively characterized,which was compared with the hot state experimental results of tube furnace.The results of thermodynamic calculation and hot state experiment show that the order of the influence of each component of slag on the sulfur distribution ratio is basicity＞w(TiO2)＞w(Al2O3),and the order of the influence on the desulfurization rate is basicity＞w(Al2O3)＞w(TiO2);With the increase of alkalinity,the desulfurization rate and phosphorus distribu-tion ratio increase gradually,and with the increase of w(Al2O3),the desulfurization rate and phosphorus distribution ratio decrease gradually,while with the increase of TiO2 content,the desulfurization rate and phosphorus distribution ratio increase first and then decrease.Based on the theoretical study and hot state experiments,the optimal composition of quaternary CaO-Al2O3-SiO2-TiO2 slag system is obtained as follows:6＜R＜7,w(TiO2)＜5％,25％＜w(Al2O3)＜30％.
ion and molecule coexistence theorythe desulfurization ratephosphorus distribution ratio
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