Efficient separation and purification of yttrium from zirconium onto anion exchange sorbent Amberlite A27 from acidic solution

Abstract

The growing adoption of computer-aided design (CAD) and computer-aided manufacturing (CAM) technologies in the dental industry has led to increase production of zirconia waste powder (ZWP), generated during the milling process of dental prostheses. Efficient recycling and processing of ZWP are essential to recover valuable metals and mitigate environmental impacts. This study examines the separation of zirconium Zr(IV) and yttrium Y(III) from ZWP via the use of Amberlite A27 chloride form, a strong base anion exchange sorbent, in acidic media (0.25 M H₂SO₄). This paper focuses on understanding the effects of initial Zr(IV) and Y(III) concentrations, sorbent amount, residence time, and system temperature on the sorption process. The optimum sorption conditions were found to be initial concentrations of [Zr] = [Y] = 100 mg/L, sorbent amount of 0.1 g, and a contact time of 30 min. A time transient study was conducted using pseudo-first-order (PFO), pseudo-second-order (PSO) and fractal time transient models. The results showed that higher initial concentrations of the metal ions decreased the sorption percentage of the sorbent. An optimal maximum sorbent amount was determined to maximize metal ion uptake and found to be 0.25 g. Time transient studies revealed that the sorption of the studied ions onto Amberlite A27 followed the pseudo-second-order model, indicating chemisorption as the predominant mechanism. Additionally, the fractal time transient model provided insights into the complexity and heterogeneity of the sorption sites on the sorbent surface. The best-fitted (R² > 0.95) fractal-like pseudo-second-order (PSO) model demonstrated energetic site heterogeneity. The overall findings showed that Amberlite A27 chloride form selectively recovered zirconium more than yttrium from an acidic sulfuric acid medium. Desorption studies showed that the loaded yttrium scrapped with deionized water and 1 M HCl was completely stripped zirconium with an efficiency of 95%.