| Abstract |
| To develop a process for the selective extraction of Hf (IV) over Zr (IV) from a strong sulfuric acid solution, we investigated the stripping of Zr (IV) and Hf (IV) from loaded D2EHPA using alkaline reagents and various acid solutions. Since both Zr (IV) and Hf (IV) were quantitatively stripped by oxalic acid as well as by alkaline reagents (Na2CO3 and (NH4)2CO3), it was difficult to separate the two metals during the stripping step. Among the tested inorganic acids (HCl, HNO3 and H2SO4), only sulfuric acid could strip Zr (IV) and Hf (IV) and the stripping behavior was dependent on the sulfuric acid concentration employed in the extraction. When the extraction of the two metals by D2EHPA was conducted with a 0.5 M sulfuric acid solution, Zr (IV) was selectively stripped from the loaded D2EPA with a sulfuric acid solution of 3-5 M. A separation factor of 10 resulted from the stripping with a 4 M sulfuric acid solution.(Received June 16, 2015) |
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| Key Words |
| zirconium, hafnium, stripping, D2EHPA, sulfuric acid |
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