Distribution of impurity elements in slag–silicon equilibria for oxidative refining of metallurgical silicon for solar cell applications

The possibility of refining metallurgical grade silicon to a high-purity product for solar cell applications by the slagging of impurity elements was investigated. Distribution coefficients were determined for B, Ca, Mg, Fe, K and P between magnesia or alumina saturated Al2O3–CaO–MgO–SiO2 and Al2O3–BaO–SiO2 slags and silicon at 1500°C. The partitioning of the impurity elements between molten silicon and slag was examined in terms of basicity …