| Abstract: | The thermodynamic characteristics of desulfurization reaction (CaO)+S]=(CaS)+O] is analyzed based on the detailed composition of liquid steel and slag of Steel Plate Hot Commercial (SPHC) in Jiuquan Iron & Steel Corporation(JISC), where the activities of CaO, CaS and Al2O3 in molten slag are calculated by thermodynamic software FactSage for a more accurate result. The critical values of O%]/S%] for desulfurization at different temperature is are obtained, typically 0.09 at 1873K, which shows directly that it should deoxidize adequately for obtaining a favorable desulfurization condition. In addition, the thermodynamic analysis indicates that the actual dissolved O is much higher than that of equilibrium calculation which shows Al-O reaction in LF is far away from equilibrium, but it is perfect agreement with the computing results when taking the activity of Al2O3 as 1 that due to the inclusion component in LF is mainly Al2O3. Besides, with the temperature rise, the sulfur partition ratio increases softly meanwhile the reaction between Al and O is limited to a great degree resulting in the increase a dissolved oxygen in liquid steel that decreases the sulfur partition ratio seriously. As a result, the sulfur partition ratio appears to decrease with temperature increase in Al killed steel. |
