Thermodynamic Calculations for the Dephosphorization of Silicon Using Molten Slag

摘要

The dephosphorization of metallurgical-grade Si using molten slags has recently attracted much attention. In the current study, the thermodynamic assessment of an Si-P system was first carried out, and then the dephosphorization reaction equilibria between molten Si and CaO-based slags were calculated using the thermodynamic databases for Si alloy and slags. The thermodynamic calculations show that dephosphorization of Si under oxidizing conditions (in the form of phosphate) merely happens, and the dephosphorization under reducing conditions (in the form of phosphide) can cause the significant dissolution of Ca in molten Si.