Na₂S₂O₅
Technical Grade
Sodium Metabisulfite
Sodium Metabisulfite (Na₂S₂O₅) is a highly water-soluble inorganic sulfur compound with strong reducing properties. In aqueous solution it forms bisulfite (HSO₃⁻) and sulfite (SO₃²⁻) ions, enabling control of redox reactions. It is used for free-chlorine removal, dissolved-oxygen reduction, oxidation control, color stabilization and chemical synthesis. High active SO₂, low insoluble matter and controlled manufacturing support reliable industrial performance.
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WORKING MECHANISM
How it works
in your process.
On contact with water, Sodium Metabisulfite forms bisulfite ions through Na₂S₂O₅ + H₂O → 2 NaHSO₃. These ions reduce free chlorine, hypochlorite and other oxidizing species, helping prevent oxidative damage and protect process equipment. It is widely used to protect polyamide reverse-osmosis membranes from free chlorine.
Technical specifications
- Chemical Name
- Sodium Metabisulfite
- Chemical Formula
- Na₂S₂O₅
- CAS No.
- 7681-57-4
- EC No.
- 231-673-0
- Molecular Weight
- 190.10 g/mol
- Appearance
- White crystalline powder
- Solubility
- Highly soluble in water
- pH (10% solution)
- 4.0–5.5
- Packaging
- 25 kg / 500 kg / 1,000 kg
Applications
Water Treatment
Free-chlorine removal, dechlorination, membrane protection and dissolved-oxygen control in RO, UF, NF and seawater-treatment systems. Neutralizing free chlorine helps protect membranes from oxidative damage and supports service life and system performance.
Pulp & Paper
Pulp processing, bleaching, color control, process chemicals and paper-chemical production. Helps remove residual oxidizing compounds after bleaching and supports process stability.
Textiles
Reducing agent for antichlor treatment, bleaching, dyeing, printing and color stabilization.
Mining
Reducing agent in gold mining, flotation, ore preparation and metal-recovery processes.
Chemical Processing
Process chemical for synthesis, reduction reactions, hydrosulfite production and organic intermediates.
Leather
Reduction reactions in leather bleaching, color adjustment and chemical processing.
Packaging and storage
25 kg PE-lined PP bags · 500 kg Big Bags · 1,000 kg Big Bags · Alternative packaging on request
Store in the original packaging in a cool, dry and well-ventilated area, protected from moisture and direct sunlight. Reseal packaging after use.
TECHNICAL DOCUMENTS
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