Sodium Metasilicate Pentahydrate

Product Overview

Understanding Sodium Metasilicate Pentahydrate and its industrial applications

Sodium Metasilicate Pentahydrate (Na₂SiO₃ · 5H₂O) is a white crystalline solid with a melting point of 72.2°C and bulk density of 0.8–1.0 g/cm³. It is readily soluble in water and dilute alkali solution, but insoluble in alcohols and acids.

Its aqueous solution is alkaline with strong detergency, excellent pH buffering capacity, and outstanding emulsifying, dispersing, wetting, and penetrating properties. It provides corrosion protection for light metals including aluminum and zinc, protects glassware and ceramic ware, and offers superior soil suspension and water-softening capabilities.

Available in both granular and powder forms, each with Superior and Normal grade options, our pentahydrate delivers consistent performance across a diverse range of industrial applications.

How This Grade Is Produced and Checked

Our sodium metasilicate pentahydrate is made downstream of our own sodium silicate. The silicate solution is reacted with alkali to a fixed SiO₂/Na₂O molar ratio of 1.0, the pentahydrate is crystallised from that solution, then dried below its dehydration point and screened into granular or powder form. Because the silicate step is run in-house, the modulus entering crystallisation is controlled by the plant rather than bought in.

The critical control point for this grade is the crystal water: over-drying turns part of a lot into lower hydrates, which shows up downstream as inconsistent assay. Every batch is released against Na₂O content, crystal water, whiteness, dissolution behaviour and insoluble matter, and shipped with its own Certificate of Analysis. TDS and SDS are available for the grade.