Production of high-purity hafnium and the study of some its properties

Vjugov, P. N.; Kozhevnikov, O.E.; Merisov, B. A.; Khadzhai, G. Ya.; Булатов, А. С.; Korniets, A. V.

doi:10.1134/s0036029511070160

Cited by 2 publications

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the presented work, the process of refining zirconium and hafnium was carried out by the zone recrystallization method, including in an electric field, on a crucibleless electron-beam zone melting facility in a vacuum. A description of the process and experimental setup was presented in detail in an article [4].…”

Section: Methodsmentioning

confidence: 99%

Zone Recrystallization of Zirconium and Hafnium

Kozhevnikov

Pylypenko

Kozhevnikova

2021

EEJP

View full text Add to dashboard Cite

The work studied the possibility of obtaining of the high-purity samples of zirconium and hafnium by the method of zone recrystallization of round rods with electron-beam heating in a vacuum of 1∙10-4 Pa. Some meltings were carried out in a constant electric field with the variability of its connection. It is shown that the simultaneous passage of several refining processes (evaporation of highly volatile metallic impurities, zone recrystallization with directional displacement of impurities to the end of the sample, electrotransport) made it possible to efficient refining of zirconium both from metallic impurities and from interstitial impurities. The best degree of purification was achieved when zone melting carrying out in an electric field directed opposite to the zone movement. In this case, the displacement of interstitial impurity ions coincided with the direction of movement of the liquid zone. Samples of zirconium with a purity of 99.89 wt. % were obtained (the concentration of aluminum was reduced by 5, iron - 11, copper - 45, chromium - 75, silicon - 10, titanium - 2.5, oxygen - 3.3, nitrogen - 3, carbon - 2 times). The hafnium samples refined by the zone recrystallization method were characterized by a purity of 99.85 wt. %. The concentrations of both all metal impurities and interstitial impurities were significantly reduced (concentration in wt% oxygen was 0.011, carbon - 0.0018, nitrogen - 5∙10-5). A study of gas evolution from samples of iodide hafnium and refined hafnium was carried out. It was found that the maximum gas release peak fell on the temperature range of 500 ... 550 °C. The use of an integrated approach, including high-temperature heating, stages of zone melting at different rates, and thermal cycling in the range of the polymorphic transformation temperature, made it possible to obtain single-crystal hafnium samples. According to X-ray diffraction data, the parameters of the hafnium crystal lattice were determined: а = (0.31950 ± 5·10-5) nm and с = (0.50542 ± 5·10-5) nm (at 298 K), which corresponds to the density ρ = 13.263 g/cm3 and axial ratio с/a = 1.5819.

show abstract

Section: Methodsmentioning

confidence: 99%

Zone Recrystallization of Zirconium and Hafnium

Kozhevnikov

Pylypenko

Kozhevnikova

2021

EEJP

View full text Add to dashboard Cite

show abstract

“…Hafnium sponge prepared by Kroll method could not satisfy the nuclear and optic applications due to high impurities contents. [4,5]. The iodide refining process is a very effective refining method.…”

Section: Introductionmentioning

confidence: 99%

Iron Removal from Hafnium Crystal Bar by Iodide Process

Tian

Yan

Wang

2014

AMM

View full text Add to dashboard Cite

Crystal bar hafnium prepared by the iodide process was studied. The influences of three important factors (filament temperature, retort materials and feed types) on the removal of iron from hafnium crystal bar under iodide process were investigated. Results show that the impurity contents of iron in the hafnium crystal bar decreased with the rising K value. Both the retort materials and feed types have obvious influence on the iron impurity contents of hafnium crystal bar. It is proposed that the optimal condition was attained when hafnium turnings was used as feed, stainless steel with molybdenum cylinder liner as retort materials, and K value was at a relatively high level.

show abstract

Production of high-purity hafnium and the study of some its properties

Cited by 2 publications

References 5 publications

Zone Recrystallization of Zirconium and Hafnium

Zone Recrystallization of Zirconium and Hafnium

Iron Removal from Hafnium Crystal Bar by Iodide Process

Contact Info

Product

Resources

About