Sodium Sulphite 96% Boiler Water Oxygen Scavenger

Sodium Sulphite 96% Anhydrous Industrial Grade is a water-soluble inorganic reducing agent widely used as an oxygen scavenger in boiler feedwater and industrial water-treatment systems.

The product is supplied as a white crystalline powder with a minimum sodium sulphite content of 96.0%. Its main function in boiler-water treatment is to react chemically with dissolved oxygen, helping reduce oxygen-related corrosion and pitting in properly managed boiler systems.

The reaction between sodium sulphite and dissolved oxygen can be represented as:

2 Na₂SO₃ + O₂ → 2 Na₂SO₄

Through this reaction, sodium sulphite converts dissolved oxygen into sodium sulphate. This makes it suitable for use in appropriately designed boiler-water treatment programs, particularly where chemical oxygen removal is required after mechanical or thermal deaeration.

In addition to boiler feedwater treatment, Sodium Sulphite may also be used in selected industrial-water deoxygenation, dechlorination, wastewater-treatment, pulp and paper, textile-processing, oilfield-water, and general reducing-agent applications.

The correct dosage should always be determined from water analysis and the specific treatment program because operating requirements vary according to dissolved oxygen concentration, boiler pressure, temperature, feedwater quality, condensate return, deaerator performance, pH, system metallurgy, and the desired sulphite residual.

Product Information

Product Name: Sodium Sulphite Anhydrous
American Spelling: Sodium Sulfite
Chemical Name: Sodium Sulfite
Alternative Name: Disodium Sulfite
CAS No.: 7757-83-7
EC No.: 231-821-4
Chemical Formula: Na₂SO₃
Molecular Weight: 126.04 g/mol
HS Code: 28321000
Grade: Industrial Grade
Physical Form: Crystalline Powder
Appearance: White Crystalline Powder
Assay: Na₂SO₃ ≥96.0%
Water Solubility: Soluble
Function: Oxygen Scavenger / Reducing Agent
Primary Application: Boiler Feedwater Treatment
Standard Packaging: 25 kg PP Woven Bag with PE Inner Liner

Key Features

• Sodium Sulphite content ≥96.0%
• CAS 7757-83-7
• Industrial Grade
• Anhydrous form
• White crystalline powder
• Water-soluble reducing agent
• Effective oxygen-scavenging chemistry
• Suitable for boiler feedwater treatment
• Supports dissolved-oxygen control
• Supports boiler corrosion-control programs
• Helps reduce the risk of oxygen-related pitting
• Suitable for selected industrial-water deoxygenation applications
• Suitable for selected dechlorination applications
• Useful as an industrial reducing agent
• Easy-to-handle dry powder
• Standard export packaging available
• Bulk packaging available where applicable
  
  
  

Technical Specification

Actual contractual specification should match the approved manufacturer TDS and batch-specific COA.

Oxygen Scavenging Mechanism

Dissolved oxygen is one of the factors that can contribute to corrosion in boiler feedwater and steam-generation systems.

Sodium Sulphite reacts chemically with dissolved oxygen according to:

2 Na₂SO₃ + O₂ → 2 Na₂SO₄

This reaction removes oxygen from the water by converting sodium sulphite to sodium sulphate.

The theoretical stoichiometric requirement is approximately:

7.88 mg pure Na₂SO₃ per 1 mg dissolved O₂

For a product containing 96% Na₂SO₃, the theoretical requirement is approximately:

8.2 mg product per 1 mg dissolved O₂

This value is a stoichiometric calculation only and should not be treated as a universal operating dosage.

In practical boiler treatment, the applied dosage may be higher to account for:

• Product purity
• Oxygen ingress
• Desired sulphite residual
• Water temperature
• Boiler pressure
• Feedwater flow
• Condensate return
• Deaerator efficiency
• System demand
• Mixing conditions

The operating feed rate should be established by the boiler-water treatment program.

Boiler Feedwater Treatment

Sodium Sulphite is commonly used as a chemical oxygen scavenger in appropriate boiler-feedwater treatment programs.

Potential treatment locations may include:

• Boiler feedwater lines
• Feedwater storage tanks
• Deaerator outlet systems
• Feedwater pump discharge
• Economizer feedwater circuits
• Compatible boiler-water treatment systems

The product is typically used where dissolved-oxygen control is required as part of a broader corrosion-management program.

The exact feed location should be selected according to system design and the overall water-treatment strategy.

Boiler Corrosion Control

Dissolved oxygen can contribute to localized pitting and corrosion of steel equipment in boiler and feedwater systems.

Potentially affected equipment includes:

• Boiler tubes
• Economizers
• Feedwater piping
• Steel tanks
• Feedwater pumps
• Heat-transfer equipment
• Condensate-system components

By chemically removing dissolved oxygen, Sodium Sulphite can support corrosion-control programs.

However, it should not be considered a complete corrosion-control treatment by itself because boiler corrosion can also be affected by:

• pH
• alkalinity
• chloride
• carbon dioxide
• dissolved solids
• temperature
• deposits
• metallurgy
• condensate chemistry

A complete boiler-water treatment program may require additional chemicals and monitoring.

Deaerator Support

Mechanical or thermal deaeration can remove a large portion of the dissolved gases from boiler feedwater.

Sodium Sulphite may then be applied to react with residual dissolved oxygen remaining after deaeration.

This combination can provide more effective oxygen-control performance in suitable boiler systems.

The required sulphite residual should be determined according to the specific treatment program rather than applying one universal target.

Industrial Water Deoxygenation

Sodium Sulphite may be used in selected industrial water systems where chemical removal of dissolved oxygen is required.

Potential applications include:

• Industrial process water
• Utility water
• Closed-water systems
• Process-water storage
• Selected oilfield-water systems
• Drilling-water systems
• Industrial circulation systems

The appropriate treatment concentration depends on dissolved-oxygen concentration, process requirements, temperature, pH, and the overall chemical program.

Dechlorination

Sodium Sulphite is a reducing agent and can be used in appropriate industrial systems to reduce residual oxidizing chlorine species.

Potential applications include:

• Industrial process water
• Wastewater treatment
• Water-reuse systems
• Selected pretreatment systems
• Process effluent treatment

The required dosage depends on the type and concentration of residual chlorine and the chemistry of the water.

One universal dechlorination dosage should not be applied to every water system.

Wastewater Treatment

Sodium Sulphite may be used as a reducing agent in selected wastewater-treatment applications.

Potential functions include:

• Dechlorination
• Reduction of oxidizing residuals
• Chemical reduction processes
• Process-water conditioning
• Treatment before discharge

Application requirements should be determined according to wastewater composition and applicable discharge requirements.

Oil & Gas and Drilling Water

Sodium Sulphite may be suitable for selected oilfield and drilling-water applications where dissolved-oxygen control is required.

Potential uses may include:

• Drilling-water systems
• Oilfield utility water
• Selected injection-water systems
• Process-water systems

Dissolved-oxygen reduction can form part of a broader corrosion-management program.

Compatibility with other oilfield chemicals should be evaluated before use.

Pulp & Paper Applications

Sodium Sulphite is also used in selected pulp and paper processes as a reducing agent.

Potential applications include:

• Pulp processing
• Bleaching-process support
• Chemical reduction
• Process-water conditioning
• Selected paper-manufacturing applications

The required grade and concentration depend on the specific manufacturing process.

Textile and Dyeing Applications

Sodium Sulphite may be used in selected textile and dyeing processes.

Potential functions include:

• Reducing-agent chemistry
• Dye-processing support
• Bleaching-process support
• Deoxidation
• Textile-processing formulations

Application suitability should be evaluated according to the specific textile process.

Chemical Manufacturing

Sodium Sulphite can be used as an industrial reducing agent in selected chemical processes.

Potential functions include:

• Oxygen removal
• Oxidant neutralization
• Chemical reduction reactions
• Process stabilization
• Chemical synthesis

Compatibility and process conditions should be evaluated for each application.

Dosage Guidance

There is no universal Sodium Sulphite dosage suitable for every boiler or industrial-water system.

Treatment requirements depend on:

• Dissolved oxygen
• Boiler operating pressure
• Feedwater temperature
• Feedwater flow
• Product purity
• Deaerator performance
• Condensate return
• Oxygen leakage
• Desired sulphite residual
• pH
• System design
• Treatment strategy

The theoretical requirement for pure sodium sulphite is approximately:

7.88 mg Na₂SO₃ per mg dissolved O₂

For a 96% product, the theoretical requirement is approximately:

8.2 mg product per mg O₂

Actual operating dosage should be established by water analysis and the specific boiler-treatment program.

Boiler Pressure Consideration

Sodium Sulphite should not automatically be described as suitable for every boiler pressure.

Its suitability depends on factors such as:

• Boiler operating pressure
• Steam purity requirements
• Temperature
• Dissolved-solids limits
• Treatment philosophy
• Downstream steam use
• Boiler manufacturer recommendations

For some high-pressure boiler systems, alternative oxygen-control programs may be preferred.

Recommended application wording:

Suitable for appropriately designed industrial boiler-water treatment programs.

Packaging

Standard Packaging

25 kg PP Woven Bag with PE Inner Liner

This packaging helps protect the product from moisture, contamination, and handling damage during storage and transportation.

Bulk Packaging

Where available:

• 500 kg Jumbo Bag
• 1000 kg FIBC Jumbo Bag

Only actual available packaging configurations should be offered.

Storage

Store Sodium Sulphite in a:

• Cool location
• Dry warehouse
• Well-ventilated area
• Tightly sealed package
• Moisture-protected environment

Protect the product from:

• Humidity
• Rain
• Water
• Direct contamination
• Strong oxidizing agents
• Strong acids
• Excessive heat

Opened bags should be resealed promptly.

Sodium Sulphite can gradually oxidize to Sodium Sulphate when exposed to air and moisture, so prolonged exposure should be minimized.

Handling

Handle according to the current product-specific Safety Data Sheet.

Avoid:

• Dust inhalation
• Eye contact
• Prolonged skin contact
• Ingestion
• Uncontrolled contact with incompatible chemicals

Recommended workplace controls may include:

• Protective gloves
• Safety goggles
• Protective clothing
• Adequate ventilation
• Dust-control measures
• Eyewash facilities

Do not mix uncontrolled quantities of Sodium Sulphite with strong acids because acidic conditions may release sulfur dioxide gas.

Keep the product away from strong oxidizing agents.

Chemical Compatibility

Sodium Sulphite is a reducing agent.

Compatibility should be confirmed before combining or feeding near:

• Chlorine products
• Oxidizing biocides
• Peroxides
• Strong acids
• Other oxidizing agents
• Other reducing agents
• Corrosion inhibitors
• Scale inhibitors

Where incompatible products are used in the same treatment program, separate feed points may be required.

Quality Control

Typical batch-quality parameters may include:

• Appearance
• Sodium Sulphite content
• Sodium Sulphate
• Sodium Carbonate
• Chloride
• Iron
• Water-insoluble matter
• pH
• Packaging integrity

Batch-specific values should be reported on the Certificate of Analysis.

Technical Data Summary

Product: Sodium Sulphite Anhydrous
Chemical Name: Sodium Sulfite
CAS No.: 7757-83-7
EC No.: 231-821-4
Formula: Na₂SO₃
Molecular Weight: 126.04 g/mol
Grade: Industrial Grade
Appearance: White Crystalline Powder
Na₂SO₃: ≥96.0%
Na₂SO₄: ≤2.5%
Na₂CO₃: ≤0.8%
Chloride: ≤0.10%
Iron: ≤0.005%
Water Insoluble Matter: ≤0.05%
pH, 10% Solution: 8.5–11.5
Water Solubility: Soluble
Function: Oxygen Scavenger / Reducing Agent
Primary Application: Boiler Feedwater Treatment
Packaging: 25 kg PP Woven Bag with PE Inner Liner

Supporting Documentation

Available documentation may include:

• Technical Data Sheet (TDS)
• Safety Data Sheet (SDS)
• Batch-Specific Certificate of Analysis (COA)
• Commercial Invoice
• Packing List
• Certificate of Origin

Additional certifications or third-party inspection documents should only be offered when valid and applicable to the actual supplied product.

Product Summary

Sodium Sulphite 96% Anhydrous Industrial Grade, CAS 7757-83-7, is a water-soluble inorganic reducing agent used primarily as a boiler-feedwater oxygen scavenger.

The product reacts with dissolved oxygen to form sodium sulphate, helping support dissolved-oxygen control and corrosion-management programs in appropriately designed boiler systems.

It is supplied as a white crystalline powder containing a minimum of 96.0% Na₂SO₃ and may also be used for selected applications including industrial-water deoxygenation, dechlorination, wastewater treatment, oilfield-water treatment, pulp and paper processing, textile applications, and general reducing-agent service.

Standard export packaging is 25 kg PP woven bags with PE inner liners, with bulk packaging available where applicable.

The correct dosage and treatment conditions should be determined from actual water chemistry, dissolved-oxygen concentration, operating conditions, boiler pressure, system design, and the requirements of the specific treatment program.