Preparation of hafnium powder by calciothermic reduction of HfO2 in molten chloride bath

Abdelkader, Amr M.; Daher, A. M.

doi:10.1016/j.jallcom.2008.02.039

Cited by 22 publications

(15 citation statements)

References 14 publications

(31 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Titanium and zirconium are produced industrially by the Kroll process [15][16][17][18]. This process consists of three steps of operation: conversion from oxide to tetrachloride, subsequent reduction of tetrachloride to metal by liquid magnesium, and molten electrolysis of the byproduct, magnesium chloride.…”

Section: Fabrication Of a Micro-porous Ti-zr Alloy By Electroless Redmentioning

confidence: 99%

Fabrication of a micro-porous Ti–Zr alloy by electroless reduction with a calcium reductant for electrolytic capacitor applications

Kikuchi¹,

Yoshida²,

Taguchi³

et al. 2014

Journal of Alloys and Compounds

View full text Add to dashboard Cite

A metallic titanium and zirconium micro-porous alloy for electrolytic capacitor applications was produced by electroless reduction with a calcium reductant in calcium chloride molten salt at 1173 K. Mixed TiO 2 -70at%ZrO 2 oxides, metallic calcium, and calcium chloride were placed in a titanium crucible and heated under argon atmosphere to reduce the oxides with the calcium reductant. A metallic Ti-Zr alloy was obtained by electroless reduction in the presence of excess calcium reductant and showed a micro-porous morphology due to the sintering of each of the reduced particles during the reduction. The residual oxygen content and surface area of the reduced Ti-Zr alloy decreased over time during the electroless reduction. The element distributions were slightly different at the positions of the alloy and were in the composition range of Ti-69.3 at% to 74.3 at%Zr. A micro-porous Ti-Zr alloy with low oxygen content (0.20 wt%) and large surface area (0.55 m 2 g -1 ) was successfully fabricated by electroless reduction under optimal conditions. The reduction mechanisms of the mixed and pure oxides by the calcium reductant are also discussed.

show abstract

Section: Fabrication Of a Micro-porous Ti-zr Alloy By Electroless Redmentioning

confidence: 99%

Fabrication of a micro-porous Ti–Zr alloy by electroless reduction with a calcium reductant for electrolytic capacitor applications

Kikuchi¹,

Yoshida²,

Taguchi³

et al. 2014

Journal of Alloys and Compounds

View full text Add to dashboard Cite

show abstract

“…Zirconium and hafnium compounds are also used in many biomedical applications including knee and hip replacements, dental implants and other restorative practices, and middle-ear ossicular chain reconstruction [13][14][15]. Zirconium and hafnium in their metallic forms are well known for their application in nuclear reactors and super alloys [6,16,17]. Nano particles of the metals are strong potential for applications such as energy conversion, catalysis, powder metallurgy, and nano composites [3,18,19].…”

Section: Introductionmentioning

confidence: 99%

New extraction technique of zirconium and hafnium from zircon mineral

El_Kareem

2019

Arab Journal of Nuclear Sciences and Applications

View full text Add to dashboard Cite

The present study is concerned primarily with optimizing the extraction of zirconium and hafnium from their naturally occurring mineral, zircon, via a wet chemical process. First, zircon is heated with molten sodium hydroxide to form zironate and silicate frit. Simple separation technique of sodium silicate from the zirconate and hafnate sodium was then applied to obtain a silicate-free frit, then the extraction of the zirconium (IV) and hafnium (IV) basic sulfates from their oxychloride solution leaving almost all other ions soluble in the mother liquor was achieved by adjusting the pH value. The precipitate of zirconium (IV) and hafnium (IV) basic sulfates was dried, weighed, analyzed and the percentage of the zirconium and hafnium extracted were found to be 97% of their original concentration.

show abstract

“…Since the 1950s, the preparation of metal hafnium with a very high melting point(2503K) have become a hot research around the world [1][2][3][4][5]. Hafnium is being intensively studied for a number of potential applications, e.g., getter, bulb and electronic valve [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Electrochemical behavior of hafnium in (NaCl-KCl-NaF-HfO2) molten salt

Ma¹,

Yu²,

Hui-Rong³

et al. 2018

Proceedings of the 2017 3rd International Forum on Energy, Environment Science and Materials (IFEESM 2017)

View full text Add to dashboard Cite

Abstract. The electrochemical reaction mechanism and electro crystallization process of hafnium in the NaCl-KCl-NaF-HfO 2 molten salt were examined at 973K by means of cyclic voltammetry, chronopotentiometry, and chronoamperometry techniques. The results show that the electrochemical reduction mechanism of hafnium in the NaCl-KCl-NaF-HfO 2 molten salt system is Hf 4+ +4e→Hf. The electro crystallization process of hafnium is found to be an instantaneous hemispheroid three-dimensional nucleation process and the hafnium ion diffusion coefficient of 4.744×10 -4 cm 2•s -1 is tested in this study.

show abstract

Preparation of hafnium powder by calciothermic reduction of HfO2 in molten chloride bath

Cited by 22 publications

References 14 publications

Fabrication of a micro-porous Ti–Zr alloy by electroless reduction with a calcium reductant for electrolytic capacitor applications

Fabrication of a micro-porous Ti–Zr alloy by electroless reduction with a calcium reductant for electrolytic capacitor applications

New extraction technique of zirconium and hafnium from zircon mineral

Electrochemical behavior of hafnium in (NaCl-KCl-NaF-HfO2) molten salt

Contact Info

Product

Resources

About