Purification of metallurgical-grade silicon (MG-Si) by a combination of solvent refining and super gravity separation and acid leaching has been studied. MG-Si was alloyed with tin, and based on this system, the removal of main impurities in MG-Si by solvent refining was investigated. Furthermore, phosphorus removal by calcium addition in molten Si and Sn-Si melt was also studied. Inductively Coupled Plasma (ICP) chemical analysis revealed main impurities including B and P could be efficiently removed by the Sn-Si process and acid leaching. The content of P further reduced when Ca was added to the Sn-Si refining system. Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) analysis showed that the formation of compounds between P and several elements in the grain boundaries during the solvent refining process was an important routine of P removal. The maximum weight percent of P in P-containing impurity phases reached to 17.8% in the refined Si after the Sn-Si refining process with Ca addition. (C) 2013 Elsevier B.V. All rights reserved.