| Abstract Scope |
In this work, the extraction efficiency of the elements Ce, La and Nd from monazite found in waste from alluvial gold mining was studied. In this sense, the monazite was concentrated through consecutive gravimetric, magnetic, and electrostatic separation processes for its subsequent dephosphorization treatment. The highest extraction of rare earths was achieved with H2SO4 as a leaching medium against HCl in all the concentration, time and temperature conditions evaluated. It was found that the addition of of H2O2 increases the dissolution of rare earths up to 93% in H2SO4 medium. Thermodynamic analysis indicates that H2SO4 solutions have a greater capacity to solubilize REE compared to HCl solutions, supporting the experimental results. Rare earths in sulfuric acid liquor can be recovered to ~100% by precipitation with oxalic acid, the oxalate precipitate obtained was calcined. The final product was characterized by XRD obtaining a composition of CeO2, La2O3 and Nd2O3. |