Methods of Purification of Zirconium Tetrafluoride for Fluorozirconate Glass

MacFarlane, Douglas R.; Newman, Peter J.; Voelkel, Alice T.

doi:10.1111/j.1151-2916.2002.tb00320.x

Cited by 10 publications

(7 citation statements)

References 9 publications

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“…For instance, the model predicts an average total flux of 7.34 g.m -2 .s -1 for ZrF 4 and HfF 4 subliming at 850°C. This predicted value is 3.9 times higher than the 1.87 g.m -2 .s -1 value estimated from results by MacFarlane, Newman and Voelkel (2002). One reason for the area-dependent rates differing might be the presence of impurities in the sample, since this can have a direct influence on the rate of sublimation (Ti, Esyutin and Scherbinin, 1990b).…”

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confidence: 38%

“…Fe, Co, Ni and Cu (Abate and Wilhelm, 1951;Dai et al, 1992;Kotsar' et al, 2001;MacFarlane, Newman and Voelkel, 2002;Pastor and Robinson, 1986;Solov'ev and Malyutina, 2002a;Yeatts and Rainey, 1965). Sublimation methods for the separation of Zr and Hf have been reported in the literature, but these methods are all carried out under vacuum conditions (Monnahela et al, 2013;Solov'ev and Malyutina, 2002b).…”

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confidence: 99%

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Selective sublimation/desublimation separation of ZrF4 and HfF4

Postma

Crouse

2017

J. South. Afr. Inst. Min. Metall.

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The separation of zirconium and hafnium, which is essential in the nuclear industry, is difficult due to the great similarities in their chemical and physical properties. In contrast to the traditional aqueous chloride separation systems, the current process focuses on dry fluoride-based technologies, which produce much lower volumes of chemical waste. In the present work, separation is achieved in both a sublimation and a desublimation step, where the Zr/Hf mole ratio varies between 160 and 245 across the length of desublimer and 86 to 40 within the sublimer. Model predictions for the sublimation/desublimation rates fit the experimental results well, with deviations becoming more apparent as sublimation proceeds. This may be attributed to crust formation preventing the system from reaching thermodynamic equilibrium. The model adequately predicts time-and temperature-dependent mole ratios of both the sublimer residue and of the desublimed mass. zirconium, hafnium, fluoride, sublimation, desublimation.

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confidence: 38%

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confidence: 99%

Selective sublimation/desublimation separation of ZrF4 and HfF4

Postma

Crouse

2017

J. South. Afr. Inst. Min. Metall.

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“…A variety of ZBLAN synthesis routes have been reported with the majority of them starting from commercial anhydrous fluoride or oxide precursors [12,13]. Various solid-state and vapor processes for reducing impurity levels in the starting materials have been explored, including reactive atmosphere processing, sublimation (where possible), distillation, chemical vapor purification, and zone refinement [14][15][16][17][18][19][20]. Other studies have used solvent-based purification techniques such as ion exchange and solvent extraction [21,22].…”

Section: The Path To Practical Optical Refrigeratorsmentioning

confidence: 98%

Laser cooling of rare-earth doped solids: the next step

2006

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A quantitative description of optical refrigeration in rare-earth doped solids in the presence of impurities is presented. The model includes the competition of radiative processes with energy migration, energy transfer to transition-metal ions, and multiphonon relaxation. The cooling efficiency is sensitive to the presence of both 3d metal ions with absorption in the near infrared and high-frequency vibrational impurities such as OH. A case study of ZBLAN:Yb 3+ identifies Cu 2+ , Fe 2+ , Co 2+ , and OH as the most problematic species and establishes a 1-10 ppm upper limit for each of these impurities for a practical ZBLAN:Yb 3+ optical cryocooler operating at 100-150 K to become feasible. The model results form the basis for an advanced strategy for the synthesis of high-purity ZBLAN:Yb 3+ that exploits the potential of available purification techniques in an aqueous intermediate step. Such high-performance ZBLAN:Yb 3+ is expected to enable optical cryocoolers with ~1% overall efficiency at 120 K and find use in a wide range of applications that require highly reliable, noise-free, and vibration-free cooling of electronic and optoelectronic components.

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“…1, Table 2) was also described in detail by MacFarlane et al [13]. They proposed a combined technique for analysis for transition metal cation impurities, which comprised ZrF 4 dissolution, complexation of transi tion metal impurities, extraction, ZrF 4 distillation, and analysis.…”

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Purification of fluorides for optical materials synthesis

Бреховских

Федоров

2014

Inorg Mater

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This paper considers processes for the ultrapurification of starting materials for the preparation of heavy metal fluoride glasses with the lowest possible impurity content. Based on the results of physicochem ical studies of reactions between fluorination agents and components of fluoride glasses, we have proposed novel techniques for the preparation of fluorides and glasses free of oxygen containing impurities.

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Methods of Purification of Zirconium Tetrafluoride for Fluorozirconate Glass

Cited by 10 publications

References 9 publications

Selective sublimation/desublimation separation of ZrF4 and HfF4

Selective sublimation/desublimation separation of ZrF4 and HfF4

Laser cooling of rare-earth doped solids: the next step

Purification of fluorides for optical materials synthesis

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