Registration Dossier
Registration Dossier
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EC number: 273-761-1 | CAS number: 69012-64-2 Amorphous silicon dioxide particles from the volatilization and vaporization of furnace feed materials in the manufacture of ferrosilicon and silicon.
Hydrolysis
Administrative data
Link to relevant study record(s)
Description of key information
Silica fume, amorphous SiO2 undergoes hydrolysis/dissolution to water soluble silicic acid Si(OH)4. Hydrolysis is relatively slow and may normally take days – depending on conditions even weeks or more until equilibrium (ca. 100 mg/l at pH 7) is reached (see more information under physical chemical properties). Half- life for hydrolysis has not been determined here. Literature data express hydrolysis/solubility diagrams showing highly increased solubility at pH above 9. Metallic impurity oxides and other impurities present in silica fume dissolve, by their characteristic ways.
Key value for chemical safety assessment
Additional information
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