Temperatures and enthalpies of melting of alkali-metal perrhenates

Lukas, Wojciech; Gaune‐Escard, M.

doi:10.1016/0021-9614(82)90074-x

Cited by 14 publications

(7 citation statements)

References 7 publications

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“…This phase did not appear to crystallize until the glass was rather cool (≲500°C), estimated based on color of the glass, and well below the processing temperature of the melt (1000°C). This is consistent with the melting temperatures for these salts in the literature, presented in Table . Detailed descriptions of the visual appearance of these various glasses have been presented previously …”

Section: Resultssupporting

confidence: 90%

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Crystallization of Rhenium Salts in a Simulated Low‐Activity Waste Borosilicate Glass

et al. 2013

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This study presents the characterization of salt phases that formed on simulated low‐activity waste glass melts during a rhenium solubility study. This study with rhenium salts is also applicable to real applications involving radioactive technetium salts. In this synthesis method, oxide glass powder is mixed with the volatile species, vacuum‐sealed in a fused quartz ampoule, and then heated in a furnace. This technique restricts the volatile species to the headspace above the melt but still within the sealed ampoule, thus maximizing the concentration of these species that are in contact with the glass. Above the previously determined solubility of Re7+ in this glass, a molten salt phase segregated to the top of the melt and crystallized into a solid layer. This salt was analyzed with X‐ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, as well as wavelength dispersive spectroscopy and was found to be composed of alkali perrhenates (NaReO4, KReO4) and alkali sulfates. Similar crystalline inclusions were found in the bulk of some glasses as well.

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Section: Resultssupporting

confidence: 90%

“…This is consistent with the melting temperatures for these salts in the literature, presented in Table II. 3,[28][29][30][31][32][33] Detailed descriptions of the visual appearance of these various glasses have been presented previously. 34 Representative pictures for glasses produced by this process are presented in Fig.…”

Section: Resultsmentioning

confidence: 99%

Crystallization of Rhenium Salts in a Simulated Low‐Activity Waste Borosilicate Glass

et al. 2013

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“…Lastly, the Mo found in the white phase suggests a possible mixing with Ca, Cs, Na, and Re in a liquid molybdic phase during glass synthesis (attracting cations from the calcine), and then a crystallization after cooling (CsReO4, NaReO4, Na2MoO4, CaMoO4). Volatilization could come from the formation of gaseous species (Mo, Cs, Re, O, Ru) because of the low melting temperature of this phase and the main compounds present (Na2MoO4 -680°C -, CsReO4 -620°C -, NaReO4 -420°C -, LiReO4 -419°C -, KReO4 -551°C -) [26][27]. Moreover, it has to be remembered that the vaporization temperature of eutectics is certainly low compared to that of pure components.…”

Section: General Mechanism Of Cs and Re Volatilizationmentioning

confidence: 99%

Study of the volatilization of cesium and rhenium in the waste vitrification process

Charpin

Ledoux

Michel

et al. 2022

Journal of Nuclear Materials

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“…Its synthesis has so far been devoted to obtaining materials for physico-chemical property determination [1,2,3]. Preparation is generally based on the neutralization of perrhenic acid solution by rubidium carbonate or hydroxide in equimolar amounts, resulting in the precipitation of rubidium perrhenate [4,5]. Then, the product is purified and recrystallized.…”

Section: Introductionmentioning

confidence: 99%

“…Similar to potassium, cesium, and silver, perrhenates are characterized by low water solubility [2]. Their melting temperature is 871–878 K [4,5]. The ion-exchange technique proposed in this manuscript was successfully used for nickel(II) perrhenate, cobalt(II) perrhenate, chromium(III) perrhenate, and cesium perrhenate production and has been described in past works [8,9,10,11].…”

Section: Introductionmentioning

confidence: 99%

Technology to Produce High-Purity Anhydrous Rubidium Perrhenate on an Industrial Scale

et al. 2019

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Technology used to produce high purity anhydrous rubidium perrhenate on an industrial scale from high purity perrhenic acid and rubidium nitrate by the ion-exchange method is described in this paper. This material is dedicated to catalyst preparation, therefore, strict purity requirements have to be fulfilled. These are satisfied by combining rubidium ion sorption on an ion exchange column and the subsequent elution of the high purity perrhenic acid solution, followed by crystallization, evaporation, purification, and drying. In the current study, rubidium and rhenium contents were found to be 22.5 wt.% and 55.4 wt.%, respectively, while contaminations were as follows: <2 ppm As, <2 ppm Bi, <5 ppm Ca, <5 ppm Cu, <3 ppm Fe, <10 ppm K, <3 ppm Mg, <5 ppm Mo, <2 ppm Na, <5 ppm Pb, and <3 ppm Zn.

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Temperatures and enthalpies of melting of alkali-metal perrhenates

Cited by 14 publications

References 7 publications

Crystallization of Rhenium Salts in a Simulated Low‐Activity Waste Borosilicate Glass

Crystallization of Rhenium Salts in a Simulated Low‐Activity Waste Borosilicate Glass

Study of the volatilization of cesium and rhenium in the waste vitrification process

Technology to Produce High-Purity Anhydrous Rubidium Perrhenate on an Industrial Scale

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