The Al–Si ingot was char- acterized by X-ray diffraction, scanning electron microscopy, X-ray fluorescence and electron probe micro-analyzer. The X-ray results indicated that the Al4C3 phase was obtained on the top of the cast. The scanning electron-microscopy, X-ray diffraction and electron probe micro-analyzer results revealed that the Al–Si alloy without silicon carbide phase formed in the cast, which indicated that silicon and silicon carbide can be separated from the slurry by this alloying process.