Sodium Metasilicate

About This Product

Sodium metasilicate, Na2SiO3 with CAS number 6834-92-0 for the anhydrous salt, is supplied anhydrous or as the pentahydrate in white granules or powder, soluble in water and giving a strongly alkaline solution around pH 12.5. It is specified where alkalinity alone would do damage. Sodium hydroxide cleans aluminium effectively and then keeps going, dissolving the metal itself and leaving a blackened, etched surface, which rules out plain caustic for cleaning aluminium vessels, transport tanks and cookware. Sodium metasilicate delivers comparable alkalinity while the silicate anion adsorbs onto the metal and forms a thin protective film that stops the attack once the soil is removed. That inhibition is the reason it appears in almost every alkaline cleaner intended for mixed-metal or aluminium plant. It also contributes genuine cleaning performance in its own right: silicate is an effective emulsifier and deflocculant for oily and particulate soil, and it buffers strongly, holding the wash solution alkaline as acidic soil is neutralised. It is corrosive to skin and eyes. It is used in alkaline and aluminium-safe cleaners, automatic dishwashing detergents, metal degreasing, laundry products, drilling fluids and as a cement additive. Bio Green Chem supplies sodium metasilicate to specification on Na2O and SiO2 content, ratio, alkalinity, insolubles, moisture and particle size.