<p>Removal of boron and phosphorus from silicon was examined using a hybrid technique of slag and solvent refining. In this method, Si–Fe alloy containing boron and phosphorus was refined by CaO–SiO₂–Al₂O₃–Na₂O slag, while purified Si crystals were simultaneously formed during cooling leaving impurities in the alloy melt. The purified silicon crystals that formed during the solidification were later extracted from the alloy matrix using chemical digestion. The process efficiency was evaluated by determining the distribution coefficient of impurities between the purified Si and the alloy melt. A modified technique involving a slower cooling rate was implemented to facilitate the removal of trapped Si–Fe alloy from the purified Si. The thickness of Si crystals was measured using SEM images of the samples. The distribution coefficient values of fast and slow-cooled samples were also determined.</p>