Assertion: cryolite's amount | /r/HasProperty | formed
Facets:
Source sentences:
text: O 3 ) over 1.0, and preferably above 1.10; maintaining the equivalent ratio of fluorine to aluminum (6F/Al in the range of 1.0 - 1.2; adjusting the equivalent ratio of fluorine to aluminum (6F/Al suitably so as to ensure that the pH of the solution during the reaction falls within the range 8 - 12; and by effecting the presence of seed crystals in a sufficient amount relative to the cryolite to be formed (two to 10-fold amount of the synthetic cryolite to be formed) to provide an adequate growth area to ensure that fine crystals are not formed, large cryolite crystals could be formed at a reaction temperature between 60° C. and the boiling point of the solution.
text: O 3 ) over 1.0, and preferably above 1.10; maintaining the equivalent ratio of fluorine to aluminum (6F/Al in the range of 1.0 - 1.2; adjusting the equivalent ratio of fluorine to aluminum (6F/Al suitably so as to ensure that the pH of the solution during the reaction falls within the range 8 - 12; and by effecting the presence of seed crystals in a sufficient amount relative to the cryolite to be formed (two to 10-fold amount of the synthetic cryolite to be formed) to provide an adequate growth area to ensure that fine crystals are not formed, large cryolite crystals could be formed at a reaction temperature between 60° C. and the boiling point of the solution.
text: As a result of extensive researches with a view to overcoming the foregoing defect, we found that this defect of the prior method could be overcome by operating in the following manner: maintaining in reaction vessel having a capacity corresponding to a residence time of at least 1 hour, preferably at least 2 hours, seeding of solid silica in an amount corresponding to at least a 1-hour's amount, preferably at least a 2-hour's amount of the silica to be formed; using ammonia as ammonia water in an amount of the silica to be formed; using ammonia as ammonia water in an amount of 1.1 - 1.5-fold of theoretical amount required for ammoniation of the sodium silicofluoride (preferably ammonia concentration is not more than 15 percent); and adding continuously to the slurry of sodium silicofluoride, powdery sodium silicofluoride or its mixtures in an amount such that the concentration of the slurry of silica newly formed, becomes not more than 3 percent (percentages here and hereinafter used are on a weight basis).
text: As a result of extensive researches with a view to overcoming the foregoing defect, we found that this defect of the prior method could be overcome by operating in the following manner: maintaining in reaction vessel having a capacity corresponding to a residence time of at least 1 hour, preferably at least 2 hours, seeding of solid silica in an amount corresponding to at least a 1-hour's amount, preferably at least a 2-hour's amount of the silica to be formed; using ammonia as ammonia water in an amount of the silica to be formed; using ammonia as ammonia water in an amount of 1.1 - 1.5-fold of theoretical amount required for ammoniation of the sodium silicofluoride (preferably ammonia concentration is not more than 15 percent); and adding continuously to the slurry of sodium silicofluoride, powdery sodium silicofluoride or its mixtures in an amount such that the concentration of the slurry of silica newly formed, becomes not more than 3 percent (percentages here and hereinafter used are on a weight basis).
text: As the seed crystals, a concentrated silica slurry (slurry concentration 30 percent) obtained in a silica clarification tank was recycled to the system in an amount such that the added silica as solids would be twofold that of the silica to be formed.