Selective extraction of Sm from LiCl-KCl molten salt into wasteforms via liquid bismuth

•A novel two-step approach for processing the electrorefining waste salt was proposed.•Sm is electrochemically separated from the waste salt using liquid Bi cathode.•Sm in the Bi alloy is extracted in the glass melt through the selective oxidation.•Sm is immobilized in ZIT and LABS glass/ceramic wasteforms with optimal loadings.•The electrorefining waste salt and the bismuth are purified for reuse in the electrorefiner.