Transitioning from coal-fired power to nuclear energy presents an opportunity to harness rare earth elements (REEs) from coal fly ash (CFA), a promising secondary resource for critical REEs like dysprosium (Dy) and yttrium (Y). Dy and Y are essential for control rods and moderators in Small Modular Reactors (SMRs) due to their neutron-absorbing and thermal stability properties. This study investigates a dual-phase process involving alkaline pretreatment and acid leaching, followed by staged precipitation, to extract and concentrate Dy and Y from CFA. Alkaline activation with NaOH dissolves silicon and aluminum oxides, enhancing REE accessibility, while subsequent HCl leaching achieves high dissolution rates. The leachate undergoes selective precipitation, removing impurities at targeted pH levels to achieve a 10.2-fold REE concentration increase. This process demonstrates the economic and environmental viability of recovering critical REEs from CFA, providing a potential solution to supply constraints for SMR materials. Our findings support the integration of CFA-derived REEs in nuclear applications, addressing both energy security and sustainability.
Lai et al. (Tue,) studied this question.