Boron removal from metallurgical grade silicon using a CaO-Li2O-SiO2 molten slag refining technique

► Effects of composition and basicity of slag on distribution coefficient of boron ► B was reduced from 18 ppmw to 1.3 ppmw with CaO-Li2O-SiO2 slag and MG-Si ratio of 4:1. ► Electrochemical model of boron removal using CaO-Li2O-SiO2 slag was established. ► (BO3)3 − combined into Li2O·2B2O3 with calcium silicate slag containing Li2O.