For the organic phase containing 2.5 mol L⁻¹ of TBP and an aqueous/organic ratio of the 1/1, 94% of the Zr was extracted and a separation factor of the 13.8 was obtained in one contact of the ...

The maximum separation factor of zirconium over hafnium was around 6.8, and the extracted complexes in the organic phase were suggested to be ZrO(HSO 4) 2 ·3B and HfO(HSO 4) 2 ·2B. Banda et al. [ 19 ] proposed a technology for the effective extraction of two metals from hafnium under 2.5–3 mol/L HCl conditions using trioctylphosphine …

Under the optimal technological conditions: TBP addition 20% (v/v), aqueous phase acidity 3.0 mol/L, ammonium sulfate addition 0.8–1.25 mol/L, room temperature and extraction time 10 min, the ...

This paper provides an overview of the processes for separating hafnium from zirconium. The separation processes are …

Zirconium is an ideal material for nuclear reactors due to its low absorption cross-section for thermal neutrons, whereas the typically contained hafnium with strong neutron-absorption is very harmful for zirconium. This paper provides an overview of the processes for separating hafnium from zirconium. The separation processes are roughly ...

Under the optimal operating conditions of 10 % HCl, 1.5 M KF, 15 minutes and an organic-to-aqueous phase ratio of 2:1, the extraction percentage of zirconium and hafnium is 94.3 % of Zr and 64.3 % ...

This paper describes a systematic study on the polymer-to-ceramic transformation and phase separation of a hafnium alkoxide-modified polysilazane …

Under optimum conditions, the separation factor of Zr over Hf was found to be 6.8. The extracted complexes were determined to be ZrO(HSO 4) 2 ·3B and HfO(HSO 4) 2 ·2B. The extractions of zirconium and hafnium are both exothermic. A counter-current operation was conducted, in which the content of HfO 2 was decreased from 3% to 0.6% …

The optimum zirconium/hafnium separation was achieved using an acidity of 7.0 mol?L?1, nitrate concentration of 9.2 mol?L?1 and 1.5 mol?L?1 of TBP. In these conditions, a separation factor of 12.6 ...

Abstract. Extraction and separation of hafnium (Hf) from zirconium (Zr) in HNO 3 solution were carried out with Cyanex572 as extractant. Hf could be selectively extracted with an optimized extraction rate of 76.8%, and the separation factor between Hf and Zr could reach up to 15.7 when the concentration of Zr(IV), Hf(IV), H +, NO 3-and (NH 4) 2 SO 4 …

The phase ratio (O/A) was fixed at 1:1 with a constant total volume. As. Conclusions. BEAP (B) was used to separate zirconium from hafnium with a separation factor of 6.8 under optimum conditions. The content of HfO 2 in ZrO 2 product was decreased from 3% in the feed to 0.6% in the Zr product after counter-current operation.

DOI: 10.1016/J.JEURCERAMSOC.2011.09.003 Corpus ID: 97622611; Phase separation of a hafnium alkoxide-modified polysilazane upon polymer-to-ceramic transformation—A case study @article{Ionescu2012PhaseSO, title={Phase separation of a hafnium alkoxide-modified polysilazane upon polymer-to-ceramic transformation—A …

technical report: the separation of zirconium and hafnium.third phase formation in the solvent extraction from aqueous nitric acid solutions using tributyl phosphate in various diluents

Effect of solvent on Zr and Hf distribution ratio and separation factor using 5 % wt Aliquat 336; HCl 7M, phase ratio ¼ 1. Zr/(Zr þ Hf) ¼ 0.71, [Zr] i ¼ 2340 mg. L 21 and [Hf] i ¼ 1800 mg. L ...

Hence, hafnium is extracted into the organic phase preferentially, while zirconium remains in the water phase. (2) TBP-HNO 3 and TBP-HNO 3 -HCl systems, in which tributyl phosphate (TBP) is used as the extractant to extract and separate zirconium and hafnium, which is the earliest method adopted in China to produce nuclear …

In this paper, we exploit a novel technique for preparing high density HfO/sub 2/ nanocrystals with an average size > 10nm using spinodal phase separation of Hf-silicate thin film by 900/spl deg/C rapid thermal annealing for nonvolatile memories. The density can be as high as 0.9/spl sim/1.9/spl times/10/sup 12/cm/sup -2/. Owing to the fact that …

The solvent extraction method in wet separation is widely used in the separation of zirconium and hafnium because of its low cost, high yield and thorough …

The suppression of phase separation was observed in hafnium-silicate films with high nitrogen contents. Moreover, small hysteresis changes were observed in the C-V curves. The negative shift of ...

Synthesis of single-phase tantalum hafnium carbide (TaxHf1-xC, 0

S. N. FLENGAS AND J. E. DUTRIZAC. A new process for the separation of hafnium from zirconium has been developed. This process is based on the repeated reaction of the mixed tetrachloride vapors of zirconium and hafnium with alkali metal chloride salts in a solid form; hafnium tends to remain in the condensed phase while …

Separation of lanthanum, hafnium, barium and radiotracers yttrium-88 and barium-133 using crystalline zirconium phosphate and phosphonate compounds as prospective materials for a Ra-223 radioisotope generator. ... Both are layered compounds with the α-ZrP phase having an interlayer spacing of 7.6 ...

1. Introduction. As a strategic material, hafnium (Hf) has a wide range of applications in new fields such as electronic semiconductors, aerospace, medicine, nuclear energy and new material research and development due to its unique physical and chemical properties [1, 2].The Earth's crust has an Hf content of approximately 0.00045%, and Hf …

The separation of zirconium and hafnium isotopes from the early actinides and rare earth elements (REE) with Eichrom's Pb resin has been studied. Batch studies were performed to characterize the behavior of actinium, thorium, zirconium, hafnium, lutetium, and yttrium on Pb resin from HCl solutions (0.001 M to 11 M). The early …

Furthermore, as an excellent extractant for the separation of zirconium and hafnium in solvent extraction, 2-ethylhexyl phosphonic acid mono-(2-ethylhexyl) ester (P507) was carefully selected to modify C(Zn/Co-ZIF) to obtain C(Zn/Co-ZIF)@P507 by impregnation [10]. ... (IV) for C(Zn/Co-ZIF)@P507. This work not only provides an …

Extraction and separation of zirconium from hafnium using Cyanex 923 as extractant cannot be performed for the zirconium concentrations of higher than 8 g/l, due to formation of third phase. As is obvious from Table 4, the separation factor of 186 reported in this work for the separation of zirconium and hafnium is significantly higher than ...

For the organic phase containing 2.5 mol L⁻¹ of TBP and an aqueous/organic ratio of the 1/1, 94% of the Zr was extracted and a separation factor of the 13.8 was obtained in one contact of the ...

Zirconium is an ideal material for nuclear reactors due to its low absorption cross-section for thermal neutrons, whereas the typically contained hafnium with strong neutron-absorption is very harmful for zirconium. This paper provides an overview of the processes for separating hafnium from zirconium. The separation processes are roughly classified …

The optimum acidity of equeous phase for the separation of zirconium and hafnium was 1-1.5 mol·L-1, while the distribution coefficient of hafnium was greater than 1 and the separation coefficient ...

Abstract. Zirconium is an ideal material for nuclear reactors due to its low absorption cross-section for thermal neutrons, whereas the typically contained hafnium with strong …