Sodium Metabisulfite
- Molecular formula:
- Na₂S₂O₅
- Content:
- ≥ 96.5% Na₂S₂O₅
- Appearance:
- White to Slight Yellow Powder
- CAS No.:
- 7681-57-4
- HS Code:
- 28322000
Sodium metabisulfite (SMBS), also called sodium pyrosulfite or sodium disulfite, is a sulfite-based reducing agent with the formula Na₂S₂O₅ and CAS 7681-57-4. This page describes a reference industrial grade with Na₂S₂O₅ content ≥96.5% for mining and other industrial procurement. Confirm the application, required specification and current batch documents before ordering.
Sodium Metabisulfite Specifications (SMBS ≥96.5%)
| Item | Unit | Content |
|---|---|---|
| Product Name | / | Sodium Metabisulfite (SMBS) |
| Appearance | / | White to slight yellow powder |
| Na₂S₂O₅ Content | % | ≥ 96.5% |
| Fe Content | % | ≤ 0.003% |
| Water Insoluble Matter | % | ≤ 0.05% |
| Heavy Metals (as Pb) | ppm | ≤ 10 ppm |
These are reference specifications for the grade shown on this page, not a claim that every industrial SMBS grade has identical limits. Please confirm the offered grade, lot and certificate of analysis (CoA) for a specific order.
Mining & Industrial Applications
Sulfide Mineral Flotation
SMBS may be evaluated as a reducing agent or depressant in selected copper, lead-zinc and other sulfide flotation circuits. Its effect on pyrite and other minerals depends on ore mineralogy, oxidation state, pH and the complete reagent scheme; it should not be assumed to suppress pyrite in every circuit. Confirm suitability through metallurgical testing.
For related reagents, see copper sulfate, our mining chemicals catalog and mineral processing support.
Gold-Mine Cyanide Treatment
Some gold-processing plants use SMBS as a sulfur dioxide source in engineered cyanide-destruction circuits. This is a separate use from flotation and requires site-specific process design, controls and a confirmed suitable product grade. See our sodium cyanide product page for the related gold-processing supply context.
Water-Treatment Dechlorination
SMBS can also be used to remove residual chlorine in certain water-treatment systems. Grade and impurity requirements vary by process, especially for membrane systems. Do not assume the industrial grade specified here is suitable for drinking water or reverse-osmosis pretreatment without technical confirmation. Explore our water treatment chemicals range for related products.
Grade, Documents & Inquiry Checklist
The table above describes a reference ≥96.5% industrial grade. For a quotation, tell us the intended application, required Na₂S₂O₅ content and impurity limits, quantity, preferred packaging and destination port. This helps us confirm the appropriate grade and current supply terms.
Ask for the current specification, safety data sheet and batch CoA relevant to the offered lot. Packaging, minimum order quantity, lead time and export documents should be confirmed with the quotation; no public TDS/SDS download is offered on this page.
Keep SMBS in suitable closed packaging and follow the current safety data sheet and site handling procedures. Product suitability and transport requirements depend on the grade, destination and application.
SMBS vs Sodium Sulfite and Sodium Thiosulfate
Sodium metabisulfite, sodium sulfite and sodium thiosulfate are reducing salts with different active content, solution chemistry and dosing behavior. They should not be treated as direct mass-for-mass substitutes in flotation, dechlorination or process-water applications.
Compare SMBS with sodium sulfite when solution pH, sulfite basis and storage stability are important. Review sodium thiosulfate only for a process where its reaction pathway is suitable. Confirm the oxidant or mineral target, water chemistry, dose basis and residual-control objective through laboratory or plant testing.
Frequently Asked Questions
What is sodium metabisulfite used for in mining?
SMBS may be used as a reducing agent or depressant in selected sulfide flotation circuits and as a sulfur dioxide source in some engineered gold-mine cyanide-treatment systems. The appropriate grade and process conditions must be confirmed for each application.
What is the difference between SMBS and flotation collectors?
Collectors promote the flotation of selected minerals. SMBS is a reducing agent that may act as a depressant under suitable circuit conditions. Their roles differ, and reagent selection should follow ore tests rather than a fixed recipe.
What Na₂S₂O₅ content does industrial SMBS require?
This page lists a reference industrial grade with Na₂S₂O₅ ≥96.5%, Fe ≤0.003%, water-insoluble matter ≤0.05% and heavy metals (as Pb) ≤10 ppm. Requirements differ by use and buyer; confirm the offered grade and lot-specific CoA before purchase.
What is the HS code for sodium metabisulfite?
The page lists HS code 28322000 as a reference. Final customs classification and document requirements should be checked for the destination country and shipment. Request current safety and quality documents during the inquiry.
How is SMBS dosed in a flotation plant?
Dosage and addition point depend on ore type, pulp chemistry, target separation and the rest of the reagent scheme. Follow qualified metallurgical testing and the plant's safety procedures; this product page does not provide a universal dosage.
How can I get a sodium metabisulfite quotation?
Use our contact page and include your application, required grade, quantity, packaging and destination port. Ask which current specification, safety data sheet and batch documents can be supplied for the offered lot.
Shipment Photo:
Request a Quote
For sodium metabisulfite (SMBS) industrial supply, contact YuXing with the application, specification, quantity, packaging and destination port. We will confirm the suitable grade, available documents and quotation terms for your inquiry.
Product Information Notice
- The values shown are typical reference information and are not a guaranteed sales specification. Final specifications are subject to the confirmed product, grade and batch COA.
- Packaging, transport method and hazard classification must be confirmed according to product grade, order quantity, destination regulations, shipping route and the current SDS.
- TDS, SDS/MSDS and COA files are provided according to product, batch and destination requirements. Public documents should not be treated as final delivery documents unless issued for the current batch.
- This page is for procurement discussion and technical selection reference only. It does not replace safety, regulatory, process design or site operating advice. Users must follow local regulations and the latest SDS.
