Sodium Silicate (Water Glass)

Water glass, or liquid glass, is the general name for an aqueous solution of either Sodium Silicate or Potassium Silicate. The name points that this compound is essentially glass (silicon dioxide) in water. As the water evaporates, the solution solidifies to become a glassy solid.

GENERAL INFORMATION

Chemical name: Sodium Silicate 

CAS No.: 1344-09-8

Molecular formula: Na2SiO3

Standard Executed: GB/T 4209-2008

Packaging: in 25KG/1250KG PP woven bag with PE liner

Contents

Description

The formulations of Sodium Silicate vary, depending on the amounts of Na2O and SiO2. Also, replacing the sodium by another alkali metal, such as potassium or lithium, results in other kinds of silicate glasses. Some compounds are better suited than others for particular applications, but they all share the same essential properties. 

Water glass can be used to make silica gel beads or packets used to protect clothing and electronics from moisture. It’s also effective in passive fire protection, making of cement, stabilizing boreholes when drilling wells, in the cardboard manufacturing, as a flocculant in wastewater treatment. Additional applications are in food preservation, in the processing of lumber and textiles, and for automotive repair.

A water glass solution can seal the pores of the eggs to protect them against bacteria and gases when refrigeration isn’t an option. Fresh eggs stored under cool conditions in a viscous silicate solution remain preserved for months. Liquid glass can also harden the artificial stone, as it’s a naturally occurring chemical in some mineral baths.

Dissolved water glass is moderate to highly alkaline. In detergents, this property supports the removal of fats and oils, the neutralization of acids, as well as the division of starches and proteins. The same property makes the compound useful in the bleaching of paper pulp and the deinking of waste paper.

Small quantities of dissolved water glass can be useful in the treatment of municipal water supplies as well as wastewater. It aids in the formation of loose agglomerations of particles (flocs) through adsorption of metallic ions. That process filters the water from undesirable suspended materials.

Under acidic conditions, liquid Sodium Silicate reacts to form a hard, glassy gel. This property makes it valuable as a bonding agent in cemented products such as concrete and abrasive wheels. It is also an excellent adhesive for porcelain and glass.

Technical specification

Items Standards: Low-mod Standards: High-mod
Purity (Na2SiO3), %
≥99.0
≥99.0
Modulus
2.0-2.2
3.0-3.5
Na2O content, %
30.5-33.0
22.2-24.5
SiO2O content, %
66.50-68.0
75.50-77.7
Ferric (Fe) content, %
≤0.03
≤0.03
Aluminum (Al) content, %
≤0.02
≤0.02
Water Solubility
22.2 g/100ml (25℃); 160.6 g/100ml (80℃)
22.2 g/100ml (25℃); 160.6 g/100ml (80℃)
Melting point
1089 °C
1089 °C
Boiling point
Boiling point in standard state (at 25 ℃[77 °F], 100 kPa) - decomposes
Boiling point in standard state (at 25 ℃[77 °F], 100 kPa) - decomposes
Density
2.4 g/cm3
2.4 g/cm3
Sensitivity
Hygroscopic
Hygroscopic
Stability
Stable
Stable
Storage
Closed containers at temperature lower than 60°C (140°F, 333.15°K)
Closed containers at temperature lower than 60°C (140°F, 333.15°K)
Shelf life/Retest
24 months
24 months
Appearance
White to greenish opaque crystals
White to greenish opaque crystals

Stability/Shelf life

Stable. Incompatible with acids, most metals, many organic materials.

Recommended storage conditions: Solid sodium silicate can be stored in closed containers. Silicate solutions should be stored at temperature lower than 60℃.

Manufacturing

The general formula of sodium silicate (liquid silicate, Metso, or sodium silicate beads) is Na2SiO3. The most common formulas of Water Glass are

  • Na2(SiO2)nO
  • K2(SiO2)nO

 

Alkali and quartz sand are reacted in either the solid or liquid phase to produce a glassy solid with the beneficial property of being soluble in water (water glass). Common alkaline material used in the process is sodium carbonate or caustic soda. Sodium silicate liquid can also be created directly by dissolving silica sand under pressure in a heated aqueous solution of caustic soda. The higher the concentration of ingredients gives the more viscous solution.

Industry use

Water glass is used as a convenient source of sodium for various industrial products. It’s a builder in laundry detergents, soaps, adhesives, as a binder, and a flocculant in water-treatment plants, along with many other applications. It is used in water treatment, and in making drilling fluids and bleaches.

Consumer use

Sodium silicate can be used as a preservative for eggs. It’s ideal for use in some of the most common consumer products, like powdered laundry and dishwasher detergents.

Solubility

Water Glass is one of the few silicon syntheses that dissolve in water. It’s insoluble in alcohol.

Common synonyms

  • Sodium Metasilicate
  • Waterglass
  • Sodium Siliconate

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STPP Group does supply Sodium silicate solution 32% for China market. But due to transportation inconvenience, we do not supply Sodium silicate solution internationally, only Sodium silicate lumps are available.

Low-mod Sodium silicate is used for synthetic detergent powder.

Our MOQ for Sodium silicate is 26 tons in 1*20’’GP.

STPP-June Qin

June Qin

Product Manager