Effect of electromagnetic stirring on the enrichment of primary silicon from Al–Si melt

• The efficient separation of primary Si crystals and Al–Si alloy has been achieved.
• The impurity content of Si has been decreased from 777.6 ppmw to 43.3 ppmw.
• The effect of electromagnetic stirring on the enrichment of Si was discussed.

The effect of electromagnetic stirring on the enrichment of primary silicon from Al–Si melt during the process of electromagnetic separation was investigated. It is shown that the enrichment of primary silicon in Al–Si melt strongly depends on the melt flowing and viscosity gradient. The efficient enrichment of primary silicon was achieved by implementing a high current intensity, which induced a high intense melt flowing. Also, the remaining primary Si in Al–Si alloy could be precipitated by gradually decreasing the current intensity. Additionally, the inductively coupled plasma mass spectrometry (ICP-MS) results show that Si purification is attributed with the enrichment of primary silicon. In this work, the impurity content in primary silicon is 43.3 ppmw, which is much smaller than 777.6 ppmw in metallurgical silicon. Therefore, a potential low-cost technology would be provided for the Si purification.