Abstract
In the course of the present study, we have attempted to precise the factors which among the ones effective in the course of the preparation of the beryllium hydroxide and oxide and during the sintering have an influence on the final result: the density and homogeneity of the sintered body. Of the several varieties of hydroxides precipitated from a sulfate solution the {beta}-hydroxide only is always contaminated with beryllium sulfate and cannot be purified even by thorough washing. We noticed that those varieties of the hydroxide (gel, {alpha}, {beta}) have different decomposition rates; this behaviour is used to identify and even to dose the different species in ({alpha}, {beta}) mixtures. The various hydroxides transmit to the resulting oxides the shape they had when precipitated. Accordingly the history of the oxide is revealed by its behaviour during its fabrication and sintering. By comparing the results of the sintering operation with the various measurements performed on the oxide powders we are led to the conclusion that an oxide obtained from beryllium hydroxide is sinterable under vacuum if the following conditions are fulfilled: the particle size must lie between 0.1 and 0.2 {mu} and the BeSO{sub 4} content of the powder must be
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Bernier, M
[1]
- Commissariat a l'Energie Atomique, Saclay (France). Centre d'Etudes Nucleaires
Citation Formats
Bernier, M.
Preparation of a sinterable beryllium oxide through decomposition of beryllium hydroxide (1963); Preparation d'un oxyde de beryllium frittable par decomposition de l'hydiloxyde (1963).
France: N. p.,
1963.
Web.
Bernier, M.
Preparation of a sinterable beryllium oxide through decomposition of beryllium hydroxide (1963); Preparation d'un oxyde de beryllium frittable par decomposition de l'hydiloxyde (1963).
France.
Bernier, M.
1963.
"Preparation of a sinterable beryllium oxide through decomposition of beryllium hydroxide (1963); Preparation d'un oxyde de beryllium frittable par decomposition de l'hydiloxyde (1963)."
France.
@misc{etde_20808580,
title = {Preparation of a sinterable beryllium oxide through decomposition of beryllium hydroxide (1963); Preparation d'un oxyde de beryllium frittable par decomposition de l'hydiloxyde (1963)}
author = {Bernier, M}
abstractNote = {In the course of the present study, we have attempted to precise the factors which among the ones effective in the course of the preparation of the beryllium hydroxide and oxide and during the sintering have an influence on the final result: the density and homogeneity of the sintered body. Of the several varieties of hydroxides precipitated from a sulfate solution the {beta}-hydroxide only is always contaminated with beryllium sulfate and cannot be purified even by thorough washing. We noticed that those varieties of the hydroxide (gel, {alpha}, {beta}) have different decomposition rates; this behaviour is used to identify and even to dose the different species in ({alpha}, {beta}) mixtures. The various hydroxides transmit to the resulting oxides the shape they had when precipitated. Accordingly the history of the oxide is revealed by its behaviour during its fabrication and sintering. By comparing the results of the sintering operation with the various measurements performed on the oxide powders we are led to the conclusion that an oxide obtained from beryllium hydroxide is sinterable under vacuum if the following conditions are fulfilled: the particle size must lie between 0.1 and 0.2 {mu} and the BeSO{sub 4} content of the powder must be less than 0.25 per cent wt (expressed as SO{sub 3}/BeO). The best fitting is obtained with the oxide issued from an {alpha}-hydroxide precipitated as very small aggregates and with a low sulfur-content. We have observed that this is also the case for the oxide obtained by direct calcination of beryllium sulfate. (author) [French] Au cours de cette etude, nous avons cherche a preciser les facteurs qui, intervenant tout au long de la preparation de l'hydroxyde, puis de l'oxyde de beryllium et enfin du frittage, peuvent avoir une influence sur le resultat final: la densite et l'homogeneite du fritte. Parmi tous les hydroxydes precipites d'une solution de sulfate, seul l'hydroxyde {beta} est toujours fortement pollue par le sulfate de beryllium qui ne peut etre elimine meme par lavage prolonge. Nous avons pu remarquer que les differents types d'hydroxyde (gel, {alpha}, {beta}) ont des allures de decomposition differentes qui permettent d'ailleurs de les distinguer et meme de doser les melanges des formes {alpha} et {beta}. Ces varietes transmettent a l'oxyde qui en derive la forme sous laquelle ils ont ete precipites. L'heredite de l'oxyde se manifeste par son comportement au cours de sa preparation et de son frittage. La comparaison des resultats du frittage et des differentes mesures effectuees sur les poudres d'oxyde nous a conduit a conclure que, pour etre frittes sous vide, les oxydes issus d'hydroxyde doivent etre constitues de cristallites dont les dimensions sont comprises entre 0,1 et 0,2 {mu}, leur teneur en sulfate de beryllium etant inferieure a 0,2 pour cent en poids, exprimee en SO{sub 3}, par rapport a BeO. L'oxyde provenant de l'hydroxyde {alpha} precipite en fins agglomerats et renfermant peu de sulfate de beryllium semble etre celui qui repond le mieux aux conditions qui viennent d'etre enoncees. Nous avons d'ailleurs pu constater que ces conditions etaient egalement remplies par l'oxyde issu de la calcination du sulfate de beryllium. (auteur)}
place = {France}
year = {1963}
month = {Jul}
}
title = {Preparation of a sinterable beryllium oxide through decomposition of beryllium hydroxide (1963); Preparation d'un oxyde de beryllium frittable par decomposition de l'hydiloxyde (1963)}
author = {Bernier, M}
abstractNote = {In the course of the present study, we have attempted to precise the factors which among the ones effective in the course of the preparation of the beryllium hydroxide and oxide and during the sintering have an influence on the final result: the density and homogeneity of the sintered body. Of the several varieties of hydroxides precipitated from a sulfate solution the {beta}-hydroxide only is always contaminated with beryllium sulfate and cannot be purified even by thorough washing. We noticed that those varieties of the hydroxide (gel, {alpha}, {beta}) have different decomposition rates; this behaviour is used to identify and even to dose the different species in ({alpha}, {beta}) mixtures. The various hydroxides transmit to the resulting oxides the shape they had when precipitated. Accordingly the history of the oxide is revealed by its behaviour during its fabrication and sintering. By comparing the results of the sintering operation with the various measurements performed on the oxide powders we are led to the conclusion that an oxide obtained from beryllium hydroxide is sinterable under vacuum if the following conditions are fulfilled: the particle size must lie between 0.1 and 0.2 {mu} and the BeSO{sub 4} content of the powder must be less than 0.25 per cent wt (expressed as SO{sub 3}/BeO). The best fitting is obtained with the oxide issued from an {alpha}-hydroxide precipitated as very small aggregates and with a low sulfur-content. We have observed that this is also the case for the oxide obtained by direct calcination of beryllium sulfate. (author) [French] Au cours de cette etude, nous avons cherche a preciser les facteurs qui, intervenant tout au long de la preparation de l'hydroxyde, puis de l'oxyde de beryllium et enfin du frittage, peuvent avoir une influence sur le resultat final: la densite et l'homogeneite du fritte. Parmi tous les hydroxydes precipites d'une solution de sulfate, seul l'hydroxyde {beta} est toujours fortement pollue par le sulfate de beryllium qui ne peut etre elimine meme par lavage prolonge. Nous avons pu remarquer que les differents types d'hydroxyde (gel, {alpha}, {beta}) ont des allures de decomposition differentes qui permettent d'ailleurs de les distinguer et meme de doser les melanges des formes {alpha} et {beta}. Ces varietes transmettent a l'oxyde qui en derive la forme sous laquelle ils ont ete precipites. L'heredite de l'oxyde se manifeste par son comportement au cours de sa preparation et de son frittage. La comparaison des resultats du frittage et des differentes mesures effectuees sur les poudres d'oxyde nous a conduit a conclure que, pour etre frittes sous vide, les oxydes issus d'hydroxyde doivent etre constitues de cristallites dont les dimensions sont comprises entre 0,1 et 0,2 {mu}, leur teneur en sulfate de beryllium etant inferieure a 0,2 pour cent en poids, exprimee en SO{sub 3}, par rapport a BeO. L'oxyde provenant de l'hydroxyde {alpha} precipite en fins agglomerats et renfermant peu de sulfate de beryllium semble etre celui qui repond le mieux aux conditions qui viennent d'etre enoncees. Nous avons d'ailleurs pu constater que ces conditions etaient egalement remplies par l'oxyde issu de la calcination du sulfate de beryllium. (auteur)}
place = {France}
year = {1963}
month = {Jul}
}