1. Basic Product Information
Product Name: Sodium Pyrosulfite
Alias: Sodium Metabisulfite, Disodium Dithionite
Chemical Name: Sodium Pyrosulfite
Molecular Formula: Na₂S₂O₅
Molecular Weight: 190.10
CAS No.: 7681-57-4
HS Code: 2832.10
Payment Terms: T/T, L/C
Trade Terms: FOB, CFR, CIF
MOQ: 20GP ≈ 20-25MT
Appearance: White or slightly yellow crystalline powder with uniform texture, no caking, no black spot impurities and no mechanical foreign matters. It has a slight sulfur dioxide odor, dry and fluffy with good fluidity.
Product Introduction: Sodium pyrosulfite, also known as sodium metabisulfite, is a widely used basic sulfite chemical raw material. It is produced by refined synthetic technology of soda ash and sulfur with stable purity and controllable impurities. The product is divided into general industrial grade and food grade. The industrial grade strictly complies with HG/T 2826-2018 industry standard, and the food grade strictly complies with GB 1886.7-2015 national food safety standard. Featuring excellent reducibility, bleaching performance, oxidation resistance, antisepsis and bacteriostatic ability, it has good water solubility and high reaction activity with outstanding cost performance. It is widely applied in industrial bleaching, water treatment reduction, printing and dyeing mordant, mineral processing and metallurgy, rubber processing, food bleaching and antisepsis, fruit and vegetable preservation, pharmaceutical accessories and other fields, serving as a core essential raw material for industrial reduction desulfurization and food preservation.
2. Physical and Chemical Properties
The product is a white or slightly yellow crystalline powder with a slight pungent odor of sulfur dioxide. It is relatively stable in a dry environment at room temperature, but it easily absorbs moisture, oxidizes, and decomposes to release sulfur dioxide gas in humid air. It is readily soluble in water with a fast dissolution speed, and its aqueous solution is acidic with strong reducibility, bleaching properties, and chelating properties. It is slightly soluble in ethanol and insoluble in most organic solvents. The product has ordinary thermal stability and will decompose rapidly above 150℃, releasing sulfur dioxide and generating sodium sulfite. The batch powder is uniform, has high whiteness, is free of caking and has less dust, is not easy to mix with impurities, and is suitable for automated continuous feeding production lines. The reaction is mild and controllable without violent side reactions, adapting to various fine chemical and food processing working conditions.
3. Executive Standards & Technical Specifications (Dry Basis)
Executive Standard: HG/T 2826-2018 Industrial Sodium Pyrosulfite, GB 1886.7-2015 Food Additive Sodium Pyrosulfite
Product Grade: General Industrial Grade, Food Grade
4. Core Product Characteristics
1. High Purity & High Activity with Strong Reducing Capacity: The product is equipped with sufficient effective sulfur dioxide content, featuring excellent reducibility, bleaching performance and oxidation resistance. It has fast reaction speed and thorough action with stable treatment effect, suitable for various fine reduction, decolorization and desulfurization processes.
2. Fine & Dry Powder with Excellent Fluidity: The powder is uniform with high whiteness, no coarse particles, no black impurities and low dust. It is not easy to agglomerate during long-term storage, adapting to automated precise feeding and continuous mass production without material blockage or equipment jamming, ensuring high production adaptability.
3. Low Impurity & High Cleanliness for High-End Scenarios: Strictly control trace impurities such as iron, heavy metals, arsenic and water insoluble matter. All indicators of food grade comply with national food safety standards with no harmful residues, which can be directly used in food bleaching, antisepsis, fruit and vegetable preservation and food processing fields with reliable safety and compliance.
4. Rapid & Complete Dissolution with Clear Solution: It has excellent water solubility, dissolving rapidly and completely in water without sediment or floating impurities. The aqueous solution is transparent and clear with stable pH value, adapting to precise proportioning and refined production processes without affecting the appearance and performance of terminal products.
5. Outstanding Antisepsis, Bacteriostatic & Antioxidant Effect: It has excellent capabilities of inhibiting oxidation, bacteriostasis, antisepsis and browning prevention, which can effectively block oxidative deterioration of materials and inhibit microbial growth, widely used in food preservation, raw material color protection and industrial material anti-oxidation.
6. Stable Performance & High Cost Performance: Batch indicators are unified with negligible performance fluctuation, maintaining stable reaction under normal temperature conditions and adapting to long-term continuous production. Mass-produced by source factories with stable quality and prominent price advantages, it is a high-cost-performance universal raw material in industrial reduction, bleaching and antisepsis fields.
7. Multi-Grade Adaptation & Customization Support: Complete industrial grade and food grade are available. Custom services including particle size screening, packaging specification adjustment and OEM packaging are supported to accurately match the production standards and process requirements of different industries.
5. Main Application Fields
Food Processing Industry (Special for Food Grade): As a compliant food additive, it is mainly used as a food bleaching agent, antioxidant, preservative, color fixative, and bacteriostatic agent. Widely applied in the processing of preserved fruits, dried fruits, edible fungi, fruits and vegetables preservation, starch, candy, pastries, and wine, it can effectively prevent food oxidative browning, extend shelf life, inhibit bacterial growth, and brighten product color, fully complying with national food safety production specifications.
Printing & Textile Industry: Used as bleaching reducing agent, mordant and dechlorinating agent for cotton and chemical fiber fabrics. It effectively removes fabric pigments and residual chlorine impurities, improves fabric whiteness, stabilizes dyeing effect and prevents fabric yellowing and discoloration, serving as a core auxiliary for decolorization, reduction and setting in textile printing and dyeing.
Environmental Water Treatment Industry: Applied in the reduction treatment of industrial sewage, electroplating wastewater and printing and dyeing wastewater, it efficiently reduces and degrades heavy metal ions and hexavalent chromium, decolorizes and reduces turbidity, and removes oxidative pollutants. It is also used for flue gas desulfurization, denitrification and tail gas sulfur dioxide treatment with stable reduction and purification effect, helping sewage and waste gas meet discharge standards.
Chemical & Pharmaceutical Industry: Served as reducing agent for organic synthesis, sulfonation auxiliary, pharmaceutical intermediate raw material and chemical cleaning agent. It is used in fine chemical synthesis, leather reduction, rubber coagulation, resin processing and other processes with high reaction activity and few by-products, ensuring the purity and quality of finished products.
Mineral Processing & Metallurgical Industry: A special flotation regulator, inhibitor and reducing agent for non-ferrous metal mineral processing. It can effectively inhibit impurity minerals, improve concentrate grade and optimize mineral recovery rate, widely used in the processing of gold, copper, lead-zinc and other minerals.
Daily Chemical & Light Industry: Used for paper pulp bleaching and decolorization, anti-oxidation and antisepsis of daily chemical raw materials, and leather bleaching and degreasing. The raw material is mild and will not damage the base material with uniform bleaching and stable performance.
Other Industrial Fields: Widely applied in oilfield additives, boiler desulfurization, metal surface cleaning, anti-corrosion and rust prevention, feed preservation, and other scenarios. It has strong universality and wide working condition adaptability, serving as an essential basic raw material for industrial production.
6. Packaging, Storage & Transportation
Conventional Packaging: 25kg double-layer sealed woven bags with food-grade moisture-proof polyethylene inner film, featuring moisture-proof, leak-proof, damage-proof and anti-oxidation caking performance. 1000kg ton bulk bags are available. Customized services including film coating, logo printing, OEM split packaging and food-grade special label packaging are supported to meet compliant shipping requirements for industrial and food grade products.
Storage Requirements: Store in cool, dry, ventilated, and clean professional chemical warehouses. Keep away from high temperature, strong sunlight, humidity, and rain to prevent moisture absorption, oxidation, and decomposition. Keep sealed and stacked strictly, and avoid open storage. Prohibit mixed storage with strong acids, strong alkalis, oxidants, toxic and harmful substances, and food raw materials. The shelf life is 6 months. Regular inspection and ventilation are required to ensure stable product quality.
Transportation Requirements: Classified as non-dangerous general chemical goods for normal cargo transportation. Keep rainproof, moisture-proof, sun-proof and damage-proof during transportation with careful handling to avoid package breakage, material leakage and moisture oxidation. Mixed transportation with toxic, odorous, corrosive and oxidative goods is prohibited. Sealed moisture-proof protection is required for bulk sea transportation to prevent deterioration and caking caused by cabin moisture.