Sodium Metasilicate, Sodium Metasilicate Anhydrate, Sodium Metasilicate Pentahydrate, 6834-92-0, 10213-79-3

Sodium Metasilicate, Sodium Metasilicate Anhydrate, Sodium Metasilicate Pentahydrate, 6834-92-0, 10213-79-3

Sodium Metasilicate 

Basic Chemical Information

• Chemical Name: Sodium Metasilicate

• Molecular Formula: Na₂SiO₃ (basic form)

• Molecular Weight: 122.06 g/mol

• CAS Number: 6834-92-0

• Pentahydrate Form: H₁₀Na₂O₈Si

• CAS Number (Pentahydrate): 10213-79-3

Physical and Chemical Properties

• Appearance: Odorless, white powder or crystalline solid

• Melting Point: ~1090 °C

• Density: 2.61 g/ml

• Freezing Point: Below 0 °C

• Stability: Hygroscopic (absorbs moisture easily)

• Solubility:

  • The solubility and alkalinity depend on the SiO₂/Na₂O ratio.

  • Higher SiO₂/Na₂O ratio → lower solubility and alkalinity.

• Chemical Nature: Strongly alkaline, inorganic salt of silicic acid

• Behavior: Tends to melt when exposed to moisture

Synonyms and Alternative Names

• Metasilicate

• Silicate

• Silicic Acid

• Disodium Metasilicate

• Sodium Metasilicate Pentahydrate

• Silicic Acid, Sodium Salt

• Sodium Silicate Solution

• Water Glass

Applications

• Detergents & Cleaning Products:

  • Used in laundry and dishwashing detergents.

  • Dissolves limescale and mineral deposits, enhancing cleaning efficiency.

  • Common in industrial cleaning agents for factories and kitchens.

• Paper Industry:

  • Mixed with pulp to improve paper strength and durability.

  • Applied in products ranging from newspapers to cardboard packaging.

• Water Treatment:

  • Reduces water hardness in household and industrial systems.

  • Improves processed water quality in industrial facilities.

• Metal Protection:

  • Prevents corrosion on metal surfaces.

  • Extends lifespan of automotive and industrial components.

• Ceramics:

  • Acts as a binder in ceramic production.

  • Improves durability and prevents cracking.

• Firefighting:

  • Stabilizes foam in fire extinguishing systems.

  • Enhances effectiveness of fire suppression.

• Food Storage:

  • Used to protect products like coffee and tea from moisture.

  • Helps maintain quality during storage.

Sector-by-sector breakdown of how Sodium Metasilicate (Na₂SiO₃) and its pentahydrate form are typically applied, including usage methods and dosage ranges.

Detergents & Cleaning Products

• How it’s used: Added as a builder and alkaline agent in laundry and dishwashing detergents.

• Dosage: Typically 5–15% of the total detergent formulation.

• Application: Dissolves limescale and mineral deposits, boosts surfactant efficiency, and stabilizes enzymes.

Industrial Cleaning

• How it’s used: Incorporated into heavy-duty degreasers and industrial floor cleaners.

• Dosage: 2–10% in concentrated cleaning solutions.

• Application: Applied as aqueous solutions; effective against oils, greases, and mineral deposits in factories and kitchens.

Paper Industry

• How it’s used: Mixed with pulp to increase fiber bonding and paper strength.

• Dosage: 0.5–3% relative to pulp weight.

• Application: Added during pulping or coating stages; improves durability of newspapers, cardboard, and packaging.

Water Treatment

• How it’s used: Acts as a softener and corrosion inhibitor in water systems.

• Dosage: 10–50 mg/L depending on hardness levels.

• Application: Dosed directly into water streams; reduces scaling and improves water quality in industrial boilers and household systems.

Metal Protection

• How it’s used: Used in metal cleaning baths and corrosion-prevention coatings.

• Dosage: 1–5% in aqueous solutions.

• Application: Immersion or spray treatment; forms a protective alkaline film that prevents rusting.

Ceramics

• How it’s used: Functions as a binder in ceramic slurry.

• Dosage: 1–3% of total ceramic mixture.

• Application: Mixed into clay or ceramic paste; enhances mechanical strength and reduces cracking during firing.

Firefighting

• How it’s used: Stabilizer in foam-based fire extinguishing systems.

• Dosage: 0.5–2% in foam concentrate.

• Application: Ensures foam persistence and effectiveness during fire suppression.

Food Storage

• How it’s used: Moisture absorber in packaging of hygroscopic products (coffee, tea).

• Dosage: Small sachets or coatings containing sodium metasilicate.

• Application: Prevents caking and maintains product freshness by absorbing humidity.

Key Notes

• Always handled with care due to strong alkalinity (corrosive to skin and eyes).

• Dosage varies by sector and product formulation; industrial applications often require precise concentration control.

• Hygroscopic nature means it must be stored in dry, sealed containers.