SODIUM METASILICATE- ▸ Detergents and cleaners: Alkaline builder and detergency aid in industrial cleaning.
- ▸ Metal cleaning: Alkaline degreasing of metal surfaces.
- ▸ Foundry: Binder for molds and cores.
- ▸ Pulp, paper, and textiles: Bleaching and processing aid.
- ▸ Zeolite and silica feedstock: Starting material for silica gels and zeolites.
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
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Transport classification per the UN Model Regulations / 49 CFR 172.101 Hazardous Materials Table. Confirm against the grade-specific SDS (Section 14) before shipping.
Sodium metasilicate, anhydrous (CAS 6834-92-0) is a strongly alkaline soluble silicate. PubChem and Hawley list its use in detergents and cleaners, metal cleaning, foundry molds, paper and textile bleaching, ore treatment, and drilling fluids, and as a starting material for silica gels and zeolites. It also waterproofs cement and acts as a fireproofing agent.
Sodium Metasilicate: Grades & Alkalinity
Sodium metasilicate's cleaning power comes from its ~1:1 SiO₂:Na₂O ratio — a high reserve alkalinity that saponifies fats, emulsifies oils, and buffers wash water, plus a corrosion-inhibiting silicate film that protects aluminum and zinc. The anhydrous grade is the most concentrated and free-flowing for built powders and CIP; the pentahydrate dissolves cooler with less dust. For lower-alkalinity binder and adhesive duty, liquid sodium silicate (water glass) at a 2–3.3:1 ratio is the usual choice.
Silicate Grades Compared
The soluble-silicate grades buyers choose between, by ratio, form, and alkalinity:
Need a liquid ratio instead of a powder? See sodium silicate solution, or send your target SiO₂:Na₂O ratio and alkalinity on an RFQ.
Frequently Asked Questions
What is sodium metasilicate anhydrous used for?
Sodium metasilicate anhydrous (CAS 6834-92-0) is a strongly alkaline soluble silicate used as an alkaline builder and detergency aid in industrial cleaners, for alkaline metal degreasing, as a foundry mold and core binder, as a bleaching and processing aid in pulp/paper and textiles, and as a starting material for silica gels and zeolites. It is also used to waterproof cement. RawSource supplies it for industrial cleaning and processing applications.
Is sodium metasilicate anhydrous organic or inorganic?
It is inorganic. Sodium metasilicate is a soluble alkali-metal silicate with the formula Na2O3Si (Na2SiO3), built from sodium, silicon, and oxygen with no carbon backbone. RawSource provides a CoA confirming identity and specifications.
What is the difference between sodium metasilicate anhydrous and pentahydrate?
The anhydrous grade contains no water of crystallization, giving a higher silicate content per unit weight and higher alkalinity per kilogram; the pentahydrate carries five waters of hydration and dissolves more readily in cool water. Anhydrous is often chosen for concentrated powder builders, pentahydrate where rapid dissolution is needed. Contact us to match the grade to your formulation.
How is sodium metasilicate anhydrous shipped, given its UN number?
Sodium metasilicate is assigned UN 1759 (corrosive solid) for transport; DOT/IMDG shipping must follow the requirements for that classification, and RawSource ships in compliant packaging with the SDS. It is supplied as powder or granules in bags, drums, and bulk. Request the SDS for handling and transport documentation.
What is the CAS number, formula, and HS code for sodium metasilicate anhydrous?
It is CAS 6834-92-0, formula Na2O3Si, HS classification 2839.11 (sodium metasilicates). RawSource provides a CoA and SDS with each bulk lot. Contact us for available grades and a bulk quote.