Removal of B from Si by Hf addition during Al-Si solvent refining process.

A small amount of Hf was employed as a new additive to improve B removal in the electromagnetic solidification refinement of Si with an Al-Si melt, because Hf has a very strong affinity for B. The segregation ratio of Hf between the solid Si and Al-Si melt was estimated to range from 4.9 × 10 to 8.