Sodium silicate

Description

Sodium silicate, 2Na2OSiO2, is the simplest form of glass. It is found as lumps of greenish glass soluble in steam under pressure, white powders of varying degrees of solubility, or liquids cloudy or clear. It is noncombustible; however, when the powdered form is suspended in air, it could cause a dust explosion if an ignition source is present. Breathing the dust may also cause health problems. The glass form could also create a hazard to responders in an accident. It is not listed as a hazardous material in the DOT Hazardous Materials Tables. The primary uses are as catalysts, soaps, adhesives, water treatment, bleaching, waterproofing, and flame retardant.

Chemical Properties

Sodium silicate,NA2Si03 also known as a liquid glass, silicate of soda, sodium metasilicate, and soluble glass, is a grayish-white crystalline powder that has a melting point of 1088 °C (1990 °F). It is soluble in water and has strong detergent and emulsifying properties. Sodium silicate is used to fireproof textiles, insulate electric wire, protect wood and porous stone, grease proof paper containers, and as a catalyst in refining high-octane gasoline.

Uses

Lining Bessemer converters, acid concentrators. manufacture of grindstones, abrasive wheels (as binder only).

Uses

Sodium silicate (Na2O) is known as “water glass” and is used in water treatment and in making soaps, detergents, adhesives, drilling fluids, bleaches.

Uses

Sodium silicate (Na2SiO3), better known as water glass, is one of the few silicon compounds that dissolves in water.It is used in the manufacture of soaps, adhesives, and food preservatives.

Uses

Sodium Silicate is a product used as a preservative for eggs.

Definition

ChEBI: An inorganic sodium salt having silicate as the counterion.

Flammability and Explosibility

Not classified

Industrial uses

Sodium silicate is widely used in mineral flotation as depressant, dispersant and as controlling agent of some soluble ions For example, sodium silicate interacts with calcium ions in solution forming nearly insoluble calcium silicate. For industrial and sulfatetype minerals (barite), sodium silicate is usually part of the reagent scheme. Sodium silicate is extensively used in base-metal flotation.

Industrial uses

Sodium silicate (liquid silicate, metso or sodium silicate beads) has the general formula Na₂SiO₃. The liquid silicates (“O” and “N” brand) are clear, thick liquids, while silicate powder is a granular, white substance. Sodium silicate is a mixture of sodium or potassium salts. Sodium silicates are primarily used in mineral flotation practice.

Toxicology

Aqueous solutions of Sodium Silicate species are a part of a chemical continuum of silicates based on an equilibrium of alkali, water, and silica. This compound, administered orally, is readily absorbed from the alimentary canal and excreted in the urine. Dogs fed 2.4 g/kg/day of Sodium Silicate for 4 weeks had gross renal lesions but no impairment of renal function. It was a severe eye irritant in some eye irritation studies but was irritating or nonirritating in others. A skin freshener containing Sodium Silicate was nonirritating. Rats given Sodium Silicate (600 and 1200 ppm of added silica) in the drinking water in reproductive studies produced a reduced number of offspring: 67% of controls at 600 ppm and 80% of controls at 1200 ppm[1].

Purification Methods

Sodium silicate solution [1344-09-8] pK 1 9.51, pK 2 11.77 (for silicic acid, H4S i O4) Purify by contact filtration with activated charcoal.

References

[1] Elmore, Amy R. “Final report on the safety assessment of potassium silicate, sodium metasilicate, and sodium silicate.” International Journal of Toxicology 24 Suppl 1 (2005): 103–17.