Separation and determination of percentage level niobium in gadolinium zirconate using bifluoride fusion and spectrophotometry

• Published in: Microchemical journal 2024-06, Vol.201, p.110642, Article 110642
• Main Authors: Kar, Aishwarya Soumitra, Raut, Vaibhavi V., Jeyakumar, Subbiah, Phatkare, Geeta, Swain, Kallola K., Rath, Bibhu N., Saxena, Manoj K.
• Format: Article
• Language: English
• Subjects: 5-bromo pyrogallol red; Ammonium biflouride; Fusion; Gadolinium Zirconate; Niobium; Spectrophotometry
• ISSN: 0026-265X
• DOI: 10.1016/j.microc.2024.110642

[Display omitted] •First report on % level quantification of Nb in Gd2Zr2O7, a burnable poison.•Simple and quick dissolution of Gd2Zr2O7 using ammonium bifluoride fusion.•Selective and quantitative recovery of Nb was achieved from refractive Gd2Zr2O7.•Formation of aqueous soluble (NH4)3NbOF6 & NH4NbOF4 confirmed by XRD.•Developed method successfully extended to real sample analysis. A simple and reliable method for the determination of percentage level niobium (3.5-8 %) in highly refractive gadolinium zirconate (Gd2Zr2O7) doped with niobium, a burnable poison material of nuclear reactor has been proposed. A fusion procedure using ammonium bifluoride (ABF) with Gd2Zr2O7 was developed. Fusion conditions such as time, temperature and ABF to sample ratio were optimised for realizing quantitative recovery of Nb. The fused masses obtained under different conditions were characterized using SEM-EDX and XRD to comprehend the conversion of the refractive oxide form to soluble fluoro compounds and their identification. The real samples fused under optimized conditions were dissolved in 2 % tartaric acid solution and the same was used for quantifying Nb employing spectrophotometry using 5-bromo pyrogallol red as chromogenic agent. Precision of the measurements was better than 3 % (RSD) for Nb(V) at 0.5 ppm and the accuracy of the method is 99.8 %.