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Textile Chemistry
Sodium Metabisulfite
Formula:
Na₂(SO₂SO₃)
GOST/CAS:
CAS 7681-57-4
Sodium Metabisulfite (sodium pyrosulfite) is a highly effective inorganic chemical compound appearing as a white to slight yellowish crystalline powder with a characteristic pungent odor. The product is readily soluble in water and acts as a powerful reducing agent, antioxidant, and dechlorinating agent. Due to its unique chemical properties, it is indispensable in the textile, leather, and pulp & paper industries, as well as in industrial water treatment processes.
Applications
Textile Industry: Widely used as a bleaching agent for wool, jute, and other natural fibers. It is highly effective for antichlor treatment (dechlorination) to neutralize residual active chlorine after fabric bleaching with sodium hypochlorite.
Dyeing and Textile Printing: Functions as a reducing agent during fabric preparation and in screen printing processes. It helps stabilize dyestuffs and ensures excellent uniformity and color fixation on fibers.
Leather Tannery: Applied during the deliming stage to remove excess lime from hides, and used for high-quality purification and bleaching of tanning extracts.
Water Treatment & Eco-Protection: Utilized by textile and dyeing facilities to treat industrial wastewater. It efficiently neutralizes toxic hexavalent chromium, reducing it to a safe trivalent form.
Key Advantages
Powerful Antichlor & Reducer: Instantly neutralizes residual active chlorine, preventing fiber degradation, thinning, and loss of tensile strength in textile materials.
High Bleaching Efficiency: Delivers superior whiteness to natural raw materials (wool, cotton, flax) by eliminating yellow undertones without damaging the fiber structure.
Process Stability: Dissolves perfectly even in cold water, ensuring homogeneous working solutions and reproducible results in large-scale production.
Effective Wastewater Treatment: Enables textile mills to easily meet environmental regulations by precipitating and binding heavy metals in effluent streams.
Storage & Transportation
- Store in dry, cool, and well-ventilated warehouses in tightly sealed original packaging, away from heat sources and open flames.
- Important Notice: Avoid contact with acids, water, and atmospheric moisture. Reaction with these materials releases toxic and corrosive sulfur dioxide gas.
- Protect against direct sunlight and prevent mechanical damage to the bags.
- Transportation is permissible via all modes of covered transport in strict compliance with dangerous goods regulations (classified as ADR Hazard Class 8 due to corrosive properties when exposed to moisture).
- Shelf Life: 1 year from the manufacturing date, provided the original packaging remains hermetically sealed.
Technical Specifications
Appearance
White or light cream crystalline powder
Molecular Weight
190.11 g/mol
Assay
≥ 97.0%
Density (at 20°C)
1.48 g/cm³
pH (5% aqueous solution)
4.0 – 4.8
Solubility in water (at 20°C)
650 g/L
Supply info
- Standard packaging: 25 kg industrial multi-layer moisture-proof paper or polypropylene bags with a polyethylene inner liner.
- Bulk packaging: Available in 1000–1200 kg Big-Bags (FIBC) for large wholesale orders and major textile complexes.