Indonesia’s energy independence and net-zero emissions (NZE) goals require sustainable uranium extraction from monazite sand, a tin byproduct. This review evaluates covalent organic frameworks (COFs) for uranium–thorium (U/Th) separation in high-concentration monazite systems. Findings highlight SO3H-functionalized COFs, synthesized via dissolution–precipitation and NH4OH ammonization, as optimal for U/Th separation, exhibiting high uranium adsorption (> 300 mg/g), selectivity, and cost-effectiveness. Their stable porous structures align with Indonesia’s monazite processing needs, addressing nuclear fuel cycle challenges. The study underscores COFs’ potential to support NZE targets and energy security, urging future research on scalability, regeneration, and industrial integration to transition from lab-scale to practical applications. © Akadémiai Kiadó Zrt 2025.