Sodium Meta Silicate Pentahydrate

CAS Number:

10213-79-3

Chemical Name:

Sodium Metasilicate Pentahydrate

Molecular Formula:

Na2SiO3·5H2O. It is often written as Na2SiO2(OH)2·4H2O in its hydrated form.

Molecular Weight:

212.14 g/mol (for the pentahydrate). The anhydrous form is 122.06 g/mol

Common Form:

White crystalline granules, beads, or powder. It is hygroscopic and deliquescent (absorbs moisture from air)

Uses:

It is a strong alkaline builder and multifunctional additive prized for its cleaning, corrosion inhibition, and buffering properties.

Primary Applications:

· Detergents & Cleaners: A key builder in industrial and household detergents, soaps, metal cleaners, and degreasers. It emulsifies fats, disperses dirt, and softens water.

· Metal Surface Treatment: Used in metal cleaning and as a corrosion inhibitor, forming a protective layer on metals like aluminum and zinc.

· Ceramics & Cement: Acts as a deflocculant to improve slurry fluidity in ceramics and as a coagulant in acid-resistant cement and concrete.

· Pulp, Paper & Textiles: Used in paper deinking, as a bleach stabilizer for hydrogen peroxide, and as a pretreatment agent in textiles.

· Other Industries: Egg preservation, fireproofing materials, water treatment, and as a raw material for silica gel and zeolites.

What does Sodium Metasilicate Pentahydrate do in a formulation?

• Strong Alkali & pH Buffer: Provides and maintains high alkalinity (pH ~12-13 for a 1% solution), which is crucial for saponifying fats and oils
• Builder & Water Softener: Sequesters hardness ions (calcium, magnesium) to enhance surfactant performance.
• Corrosion Inhibitor: The silicate component forms a passive protective layer on metal surfaces, reducing corrosion.
• Dispersant & Antiredeposition Agent: Keeps soils and particles suspended in solution, preventing them from redepositing onto cleaned surfaces.
• Key Differentiator: Considered less aggressive on metals and surfaces than caustic soda (NaOH) while providing similar alkalinity, due to its protective silicate film.

Safety Profile:

· Hazard Classification: Danger. Causes severe skin burns, serious eye damage, and may cause respiratory irritation.

· Skin/Eye Exposure: Highly corrosive. Causes severe burns. Requires immediate and prolonged rinsing with water and medical attention.

· Required PPE: Essential. Chemical safety goggles, face shield, acid/alkali-resistant gloves, and protective clothing are mandatory. Use in a well-ventilated area or with respiratory protection to avoid dust inhalation.

· Handling & Storage: Store in a cool, dry, sealed container to prevent absorption of moisture and CO? from air. Always add solid to water slowly while stirring to control heat and splashing.

Technical profile: