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Gravimetric silica procedure

Silica content may be determined by either the precise, tedious gravimetric silica procedure (2 or the more rapid but less precise fluosilicate method (3), The gravimetric method involves precipitation of the silica with acid, collecting the precipitate, ashing, volatilizing the silica with hydrofluoric acid and determining the weight loss after volatilization. [Pg.18]

A rapid procedure has been described10 based on sodium peroxide bomb fusion, for the determination of silicon and halogen in fluorine-containing organosilicon compounds and resins. The silicon is separated from the decomposition product as zinc silicate and estimated gravimetrically as silica. The filtrate is concentrated, acidified and, when necessary, reduced with sulphur dioxide. Chloride, bromide or iodide is then determined by the usual methods. Fluoride can be determined in neutral solution either gravimetrically as calcium fluoride, or volumetrically with zirconium tetrachloride or thorium nitrate, or directly in the decomposition solution by titration with zirconium tetrachloride. [Pg.394]

Classical wet chemical methods and instrumental techniques are used for the analysis of soluble sibcates (91). Silica is determined by gravimetric techniques or by the fluorosihcate volumetric procedure. [Pg.11]

However, in the commercial world the ultimate in precision is often not needed to satisfy the situational analytical requirements. Because the gravimetric procedure involves many time consuming steps, the fluosilicate reaction is generally preferable as the usual silica wet chemical assay method. It is not as precise as a normal alkali titration because of the difficulty of observing the end point. [Pg.20]

A wide range of chemical methods and procedures is found in the treatise of Kolthoff and Elving (289). They also give a summary of the chemistry and solubility of silica. Preparation of solutions for analysis, the silicomolybdic acid yellow and blue colorimetric methods including interferences, gravimetric procedures, and special procedures for biological materials are discussed in concise detail. [Pg.95]


See other pages where Gravimetric silica procedure is mentioned: [Pg.223]    [Pg.223]    [Pg.263]    [Pg.117]    [Pg.1229]    [Pg.529]    [Pg.530]    [Pg.7]    [Pg.225]    [Pg.787]    [Pg.288]    [Pg.29]   
See also in sourсe #XX -- [ Pg.18 ]




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