EXTRACTION OF RARE EARTHS FROM CHLORIDE LEACH LIQUOR OF PHOSPHOGYPSUM USING NANOCLAY COMPOSITES

This study focuses on the efficient extraction and recovery of Rare Earth Elements (REEs) from chloride leach liquor of phosphogypsum using nanoclay-based composites. Phosphogypsum, a by-product of phosphoric acid production, was leached with hydrochloric acid to recover REEs alongside contaminants such as calcium and iron. The synthesized nanoclay composites, embedded with titanium dioxide (TiO₂) and molybdenum (Mo), exhibited superior adsorption and elution efficiency compared to unmodified clay. The results demonstrate that Nano Clay/Ti+Mo achieved the highest adsorption capacity (165 mg/g) at optimal conditions (pH 4, 30 minutes, 1 g/L S/L ratio), with significant resistance to interference from phosphogypsum ions. The synergistic effects of Ti and Mo functional groups were evident, enhancing both adsorption and elution performance under competitive conditions. The elution study using 1 M nitric acid revealed that Nano Clay/Ti+Mo retained 100% elution efficiency, while Clay exhibited only 25% efficiency under similar conditions. The study underscores the critical role of material modifications, such as nanocomposite functionalization, in overcoming challenges associated with complex leachate systems. These findings offer a sustainable, cost-effective approach for REE recovery from industrial waste, with significant implications for resource optimization and environmental sustainability.