Strategies for Strontium Recovery/Elimination from Various Sources

Not having the same grade of popularity as other metals like rare earth elements, gold, copper, etc., strontium is a chemical element with wide uses in daily life, which is why it appears in the EU 2023 list of Critical Raw Materials. Among the sources (with celestine serving as the raw material) used to recover the element, the recycling of some Sr-bearing secondary wastes is under consideration, and it is also worth mentioning the interest in the removal of strontium from radioactive effluents. To reach these goals, several technological alternatives are being proposed, with the most widely used being the adsorption of strontium or one of its isotopes on solid materials. The present work reviews the most recent advances (for 2024) in the utilization of diverse technologies, including leaching, adsorption, liquid–liquid extraction, etc., in the recovery/elimination of Sr(II) and common 90Sr and 85Sr radionuclides present in different solid or liquid wastes. While adsorption and membrane technologies are useful for treating Sr-diluted solutions (in the mg/L order), liquid–liquid extraction is more suitable for the treatment of Sr-concentrated solutions (in the g/L order).