Dissolution of zirconium in nitric-hydrofluoric acid mixtures

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Corrosion

DOI:https://doi.org/10.5006/1.3280475· OSTI ID:477476

Klein, R ^[1]

---

1. National Inst. of Standards and Technology, Gaithersburg, MD (United States)

There is a linear relationship between the enthalpy of solution of zirconium in nitric-hydrofluoric acid (HNO{sub 3}-HF) mixtures and the molar HNO{sub 3}/HF ratio (R) from R = 0 to 0.55. At R = 0.55, the enthalpy attains a maximum value and remains constant up to at least R = 8. There is a corresponding behavior in a reverse order with regard to hydrogen evolution, which is linear with R from a maximum at R = 0 to zero at R {ge} 0.55. Regardless of composition of the mixed acids, the zirconium-containing product is the same. A mechanism was proposed to account for the relationship of solution enthalpy and hydrogen evolution with the acid ratio. The rate of dissolution of zirconium in HF alone displayed a strong dependence on concentration > 0.5 mol/L. It was not sensitive to addition of HNO{sub 3}, but there was a slowing of the rate for HNO{sub 3} concentrations > 0.4 mol/L.

• Sponsoring Organization: USDOE
• OSTI ID: 477476
• Journal Information: Corrosion, Journal Name: Corrosion Journal Issue: 4 Vol. 53; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
36 MATERIALS SCIENCE
CHEMICAL REACTION KINETICS
CONCENTRATION RATIO
DISSOLUTION
FUEL CANS
HYDROFLUORIC ACID
NITRIC ACID
REPROCESSING
SOLUTION HEAT
ZIRCONIUM