(1137) Effect of Changes in Slag Basicity and Stirring Intensity on Hot Metal Dephosphorization

摘要

The hot metal dephosphorization slag is under solid-liquid phase coexistence. In recent years, a multitude of researches under the premise of multiphase slag have been reported. In this trend, a process simulation model considering multiphase slag has been developed by the ISIJ research group “Process Simulation for Dephosphorization of Pig Iron by Multi-Phases” In this study, the effect of the slag formation route was investigated. The slag basicity and the stirring intensity were intentionally changed during dephosphorization reaction to investigate the influence on the reaction. In addition, the experimental results were analyzed with the process simulation program. The following is what was obtained as the results:　Little stirring intensity affects the decarburization rate and dephosphorization rate under the condition of low slag basicity (CaO/SiO2 is equal to 1.2).　The increased decarburization rate caused by changing the slag basicity can be explained by the CO gas formation rate increased according to the basicity of the slag.　There is an optimum stirring intensity according to the dephosphorization ability of slag. For example, in the case of high dephosphorization ability, without sufficient stirring, only the decarburization is destined to tend to proceed.