Extraction and separation of thorium from cerium and lanthanum by Cyphos® IL 101 ionic liquid

A novel split anion extraction system was developed to separate thorium from cerium and lanthanum nitrate solutions. The ionic liquid Cyphos® IL 101 with chloride as the anion was used without extra extractants in the extraction process. The results showed efficient separation of thorium and the extraction mechanism is believed to be based on co-extraction with nitrate anion. The maximum loading capacity for thorium was 1395.26 mg/L and the extracted metals were stripped using EDTA solution with 0.5 M NaCl. This split anion extraction system provides a safe, green, and economical method for separating thorium from rare earth elements. (author)