Abstract
Pickling of zirconium alloys in nitric-hydrofluoric acid has been widely used in the nuclear materials industry. However, the pickle salts still remain a curiosity and a thorough knowledge of the products of the system Zr–(HNO3–HF) still needs to be well established. The present study investigated the products obtained from the reactions of Zircaloy-4 with an acid mixture of HNO3 (65 wt%) and HF (40 wt%) in a volume ratio of 94 : 6, similar to the one used under nuclear industry conditions. It shows that after the reactions, a gel-like solution was present. When drying it at a high relative humidity (at 25 °C and 70 ± 5% RH), an amorphous solid product formed, while in the case of at a low relative humidity (at 15/25 °C and 25 ± 5% RH), besides the amorphous solid, crystalline zirconium hydroxide nitrates Zr(OH)2(NO3)2·4.71H2O and Zr(OH)2(NO3)2·1.65H2O (possible) with low degree of crystallinity formed. These compounds were identified with the help of successfully synthesizing completely crystalline Zr(OH)2(NO3)2·4.71H2O from the gel-like solution by ultrasonication, which in itself was a breakthrough. Such a study can be expected to provide a deep understanding of pickle salts of zirconium alloys in practical use.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.