Dialdehyde Chitosan/Semicarbazide Synthesis for Lanthanum, Cerium, and Neodymium Ions Recovery from Phosphate Leachate
来源:ACS Publications
Rare earth elements are among the world’s most crucial strategic minerals. Cell phones, lamp lights, televisions, wind turbines, and other contemporary electronics rely heavily on rare earth elements. As a result, this work aimed to prepare eco-friendly dialdehyde chitosan with semicarbazide (SC/DiACs), a promising method for recovering lanthanum, cerium, and neodymium from phosphate leach solution. Different analytical techniques were utilized to determine the physicochemical properties of SC/DiACs before and after adsorption. Sorption was conducted at pH 5 for 60 min using 50 mg SC/DiACs and 200 mg/L La, Ce, and Nd ions. The sorption capacities were 193.52 mg/g for La, 186.77 mg/g for Ce, and 171.37 mg/g for Nd. The studied ions sorption onto the SC/DiACs sorbent was well-fitted by the pseudo-first-order (PFO) and the isotherm produced by Langmuir. Besides, it was discovered that the sorption thermodynamic characteristics were both spontaneous and exothermic. La, Ce, and Nd ions were successfully desorbed from the SC/DiACs by imperiling it to 0.7 M/L HNO3 and 35 min at 25 °C with a 1:40 solid/liquid (S/L) ratio. Also, the SC/DiACs sorbent was rejuvenated after seven cycles of sorption–desorption. SC/DiACs sorbent was exploited to recover RE ions from the phosphate leach solution. Ion purity levels of 90.18% were achieved by calcining the precipitate to RE oxides. Finally, the SC/DiACs sorbent was found to have excellent sorption characteristics for RE ions in their solution, as evaluated by the REEs recovery behaviors.
This paper suggests employing dialdehyde chitosan incorporating semicarbazide (SC/DiACs) as an environmentally friendly substitute for La, Ce, and Nd recovery from phosphate leach solutions that contain several metal ions other than rare earth (RE) ions. This adsorbent has several hydroxyl and amino groups that can be reacted with rare earth ions and is simple to make. This technique is good when compared with traditional techniques for RE ions recovery. It examines the sorption process parameters to compare the sorption properties of La, Ce, and Nd ions on SC/DiACs. These variables include temperature, SC/DiACs dosage, duration of contact, pH, and La, Ce, and Nd amounts. The kinetics, equilibrium characteristics, and sorption thermodynamics were also discussed. La, Ce, and Nd desorption was applied, and the regeneration of the SC/DiACs was examined. The leaching parameters were investigated: temperature, solid/liquid ratio, time, stirring assessment, and HCl amount. The optimal parameters were applied to recover REE ions from the leachate solution.