Assertion: cryolite's amount | /r/CreatedBy | at least a 1-hour's amount
Facets:
Source sentences:
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).