Strontium minerals as critical raw materials — Market dynamics, processing techniques, and future challenges

Abstract

In 2020, the European Union officially designated strontium as a Critical Raw Material (CRM) due to its diverse applications and limited global producers, with Spain as one of the primary producers and the only one in the EU. This comprehensive review discusses strontium market dynamics, global reserves, and technological advancements in mineral processing techniques to extract and concentrate its main bearing minerals, celestine (SrSO₄) and strontianite (SrCO₃). The review highlights the shift in strontium demand, led until the mid-2000s by applications in cathode-ray tube (CRT) glass, to current uses focused on pyrotechnics, ceramic magnets and drilling fluids.

The study evaluates the progression of beneficiation methods, from manual sorting to advanced techniques such as size separation, gravity separation, flotation, and dense media separation, with recent innovations demonstrating enhanced recovery and purity of celestine concentrates. Industrial case studies from various regions, including Spain and China, illustrate significant advances and regional variations in celestine processing, while emphasising the need for further research and transparency in reporting beneficiation methodologies.

Furthermore, the review addresses the gaps and unavailability of environmental impact assessment of strontium production and underscores the importance of improving circularity through recycling, particularly in light of the negligible End-of-Life Recycling Input Rate (EOLRIR) for strontium in the EU. Emerging applications in magnet technology, medicine, and smart materials present new opportunities, potentially reducing reliance on rare-earth elements and fostering innovation.

The paper also explores the anticipated effects of the CRM status of strontium on future demand, highlighting the need for continued research and technological advances in strontium beneficiation to ensure a stable supply chain. The sustained study and optimisation of extraction and processing methodologies are crucial in meeting the demand from evolving industrial applications and addressing current and future challenges in the supply of this CRM.