Radium recovery from mining tailings: A comprehensive review of techniques and applications.

Radium, a naturally occurring radioactive element, has been historically recognized for its medical and industrial applications. However, with the advent of synthetic radioactive iso-topes, radium's prominence declined, and the former radium sealed sources were relegated to radioactive waste. Recent developments include the potential of radium to be used as target in a nuclear reaction to produce a radioisotope used in nuclear medicine. This has prompted the retrieval of radium sources from radioactive waste storage facilities and renewed attention on radium recovery from mining/milling residues. This review explores radium's historical significance, chemical properties, and isotopic characteristics while addressing contemporary challenges in radium extraction and applications. Particular focus is given to radium recovery techniques from residues of uranium, thorium, and rare earth element processing, emphasizing their environmental implications and regulatory considerations. The analysis highlights advancements in radium separation methods, such as ion exchange, co-precipitation, and chromatographic techniques, as well as emerging technologies aimed at optimizing recovery while mitigating environmental risks posed by mining and milling waste. By consolidating current knowledge, this study underscores the dual importance of radium recovery in resource sustainability and environmental stewardship.