Pyrometallurgical processes for the separation of hafnium from zirconium

Mallikarjunan, R.; Sehra, J.C.

doi:10.1007/bf02747145

Cited by 12 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, as expected from the close sublimation temperatures of ZrCl 4 and HfCl 4 (604 and 588.6 K, respectively), the difference in vapor pressures is small and complete separation through a single distillation is impossible. Therefore, a molten salt such as KCl-AlCl 3 is employed for a multistage, countercurrent continuous process where the molten salt is fed from the top of a 50-m distillation extraction tower and a mixed chloride gas is injected to the upper middle section [86,99,100]. This process is also called extractive distillation and is operated at Cezus, a subsidiary of Areva Co. in France, where a KCl-AlCl 3 molten salt is used at around 623 K.…”

Section: Process For Separating Zirconium and Hafniummentioning

confidence: 99%

Rare Earth, Titanium Group Metals, and Reactive Metals Production

Takeda

Uda

Okabe

2014

Treatise on Process Metallurgy

View full text Add to dashboard Cite

Section: Process For Separating Zirconium and Hafniummentioning

confidence: 99%

Rare Earth, Titanium Group Metals, and Reactive Metals Production

Takeda

Uda

Okabe

2014

Treatise on Process Metallurgy

View full text Add to dashboard Cite

“…The main drawback of the extractive distillation approach is that it requires these post treatment units for the removal of the solvent salt from the tetrachlorides, which might give a rise to significant cost. Several approaches for the removal of the solvent salt from the tetrachlorides are described elsewhere [24].…”

Section: Optimal Design Of Extractive Distillation Columnmentioning

confidence: 99%

“…In addition, the lowest operating temperature of the column must be higher than the sublimation temperature of HfCl4 at atmospheric pressure [22]. Several candidate solutions have been described [23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Design of an Extractive Distillation Column for the Environmentally Benign Separation of Zirconium and Hafnium Tetrachloride for Nuclear Power Reactor Applications

et al. 2015

View full text Add to dashboard Cite

Nuclear power with strengthened safety regulations continues to be used as an important resource in the world for managing atmospheric greenhouse gases and associated climate change. This study examined the environmentally benign separation of zirconium tetrachloride (ZrCl4) and hafnium tetrachloride (HfCl4) for nuclear power reactor applications through extractive distillation using a NaCl-KCl molten salt mixture. The vapor-liquid equilibrium behavior of ZrCl4 and HfCl4 over the molten salt system was correlated with Raoult's law. The molten salt-based extractive distillation column was designed optimally using a rigorous commercial simulator for the feasible separation of ZrCl4 and HfCl4. The molten salt-based extractive distillation approach has many potential advantages for the commercial separation of ZrCl4 and HfCl4 compared to the conventional distillation because of its milder temperatures and pressure conditions, smaller number of required separation trays in the column, and lower energy requirement for separation, while still taking the advantage of environmentally benign feature by distillation. A heat-pump-assisted configuration was also explored to improve the energy efficiency of the extractive distillation process. The proposed enhanced configuration reduced the energy requirement drastically. Extractive distillation can be a promising option competing OPEN ACCESSEnergies 2015, 8 10355 with the existing extraction-based separation process for zirconium purification for nuclear power reactor applications.

show abstract

“…The complex combination of the hydro-and pyrometallurgical operations makes the whole production process lengthy, and accordingly leads to the high production costs. In pyrometallurgy, the known separation methods were developed based on the following reaction features: redox characteristics, [9,10] volatility, [11][12][13][14] electrochemical properties, [15][16][17] and molten salt extraction. [18,19] Among all these methods, the extractive distillation process is a significant advance in Zr-Hf separation technology, [14] which is the only industrialized pyrometallurgical Zr-Hf separation method.…”

Section: Introductionmentioning

confidence: 99%

Zirconium and hafnium separation with molten salt extraction in Sn–Cu–Zr–Hf and Cu–Zr–Hf alloy systems

Xiao

Sandwijk³

et al. 2016

Separation Science and Technology

View full text Add to dashboard Cite

Chemical-grade zirconium contains about 1-3 wt% hafnium, which is harmful for nuclear applications due to its high neutron-capture cross section. In the present paper, Zr-Hf separation in Sn-Cu-Zr-Hf and Cu-Zr-Hf alloy systems using molten salt containing CuCl 2 or CuF 2 was thermodynamically evaluated and lab-scale experiments on zirconium and hafnium separation in different molten salt systems were conducted. The best single-step Hf removal efficiency and Zr-Hf separation factor of about 95% and 9.0, respectively, were obtained with a NaCl-CaCl 2 -CuCl 2 (3 wt%) molten salt system at 850°C and the CuCl 2 /Hf stoichiometric ratio of 1.5.

show abstract

Pyrometallurgical processes for the separation of hafnium from zirconium

Cited by 12 publications

References 12 publications

Rare Earth, Titanium Group Metals, and Reactive Metals Production

Rare Earth, Titanium Group Metals, and Reactive Metals Production

Design of an Extractive Distillation Column for the Environmentally Benign Separation of Zirconium and Hafnium Tetrachloride for Nuclear Power Reactor Applications

Zirconium and hafnium separation with molten salt extraction in Sn–Cu–Zr–Hf and Cu–Zr–Hf alloy systems

Contact Info

Product

Resources

About