Hazard Overview: Fluorosilicic acid solutions are corrosive and can injure skin, eyes, and the respiratory tract. Fluoride-containing solutions and any free HF present require careful exposure control and appropriate emergency planning.
Handling: Use suitable enclosed transfer equipment or local exhaust ventilation. Avoid inhaling mist or vapor and prevent skin or eye contact. Select chemical-resistant protective equipment using the current SDS and the assessed operation.
Storage and Compatibility: Use compatible, properly closed containers and secondary containment. Protect from heat and follow the current SDS for storage conditions and segregation. Glass and silica-containing materials can be attacked by the solution.
Transport Reference: UN 1778, FLUOROSILICIC ACID; Class 8; Packing Group II. Confirm shipment classification, approved packaging, and labeling against the current SDS and applicable transport rules.
Emergency Procedures and Disposal: Follow the product SDS and site procedures for exposure, spills, and waste handling. Personnel should be trained for the specific fluoride-acid hazards, with appropriate emergency facilities available.
Hexafluorosilicic Acid CAS 16961-83-4
Fluorosilicic Acid (Hexafluorosilicic Acid) CAS 16961-83-4: Industrial Aqueous Solution
Fluorosilicic acid, also known as hexafluorosilicic acid or fluosilicic acid, CAS 16961-83-4, is supplied commercially as an aqueous solution with acid content expressed as H₂SiF₆. It is used in fluorosilicate manufacturing, selected metal surface treatments, and specialized refining processes. The industrial grade referenced on this page has a reported H₂SiF₆ content requirement of ≥ 40%. Aure Chemical supports China chemical sourcing and international export requirements through specification review, quality documentation, supplier coordination, and logistics planning.
Basic Information of Fluorosilicic Acid
The following information describes the acid component and the commercial aqueous form. Concentration and impurity results for one production lot are presented separately in the Reference Quality Analysis section.
| CAS No. | 16961-83-4 |
|---|---|
| EC No. | 241-034-8 |
| Chemical Formula | H₂SiF₆ (acid component) |
| Molecular Weight | 144.09 g/mol (H₂SiF₆ basis) |
| Commercial Form | Industrial-grade aqueous solution |
| Reference Concentration Requirement | H₂SiF₆ ≥ 40%, as stated in the reference COA |
| Appearance | Colorless, transparent liquid, as described in the reference COA |
| Odor | Pungent |
| Chemical Nature | Acidic, fluoride-containing aqueous solution |
| Material Compatibility | Attacks glass and silica-containing materials; confirm compatibility of containers, seals, and process equipment using the current product SDS |
| Transport Reference | UN 1778, FLUOROSILICIC ACID, Class 8, Packing Group II; confirm against the current product SDS and applicable transport requirements |
| Formula Illustration |  SiF₄·2HF stoichiometric representation of H₂SiF₆. The commercial product is an aqueous solution. |
Density, freezing behavior, and thermal properties depend on concentration and composition. Request the relevant grade-specific technical data when these properties are needed for storage, transfer, or process design.
Reference Quality Analysis
Industrial Grade: H₂SiF₆ Content ≥ 40%
The following parameters provide a technical reference for evaluating this industrial aqueous grade, including H₂SiF₆ content, free fluoride reported as HF, and sulfate reported as H₂SO₄. The results represent one production lot.
Standard cited in the reference COA: HG/T 2832-2008. This edition has been superseded by HG/T 2832-2020. The limits below reproduce the reference report; confirm the applicable standard edition and agreed purchase specifications for new orders.
| Test Item | Reported Specification | Reference Result |
|---|---|---|
| Fluorosilicic acid content (H₂SiF₆) | ≥ 40% | 40.46% |
| Free fluoride (reported as HF) | ≤ 1.00% | 0.23% |
| Sulfate (reported as H₂SO₄) | ≤ 0.50% | 0.27% |
The HF and H₂SO₄ reporting bases are retained as stated in the COA. H₂SiF₆ content describes the concentration of the aqueous product.
These analytical values support preliminary technical evaluation and do not guarantee the specifications or results of every shipment. Contact Aure Chemical to confirm the required concentration, impurity limits, applicable standard, and relevant batch-specific Certificate of Analysis (COA) before ordering.
Primary Applications of Fluorosilicic Acid
Application suitability depends on acid concentration, free HF content, other impurities, equipment compatibility, and the requirements of the intended process.
Fluorosilicate and Inorganic Chemical Manufacturing:
Used as a raw material for selected fluorosilicate salts and other inorganic fluoride products. Acid concentration and impurity requirements should be reviewed against the synthesis route and the specification of the finished product.
Electrolytic Lead Refining:
Used in specialized fluorosilicate-based electrolyte systems for lead refining. The required acid composition and impurity limits depend on the electrolyte formulation and operating process.
Metal Surface Treatment:
Used in selected acidic fluoride formulations for surface cleaning, treatment, or etching. Suitability requires assessment of the metal or alloy, free HF content, bath chemistry, and equipment materials.
Selected Textile and Industrial Cleaning Processes:
Used in certain industrial textile or laundry formulations for acidity adjustment and surface cleaning. Formulation compatibility and safe operating procedures require process-specific evaluation.
Masonry and Ceramic Surface Processing:
Used in selected mineral surface-treatment formulations. Treatment conditions and substrate compatibility must be qualified for the intended application.
Water Treatment Grade Qualification:
Suitably qualified fluorosilicic acid grades are used in water fluoridation. Potable-water applications require confirmation of the applicable approvals, certification, and contaminant limits. The industrial-grade reference analysis above does not establish drinking-water treatment approval.
Aure Chemical: Fluorosilicic Acid Sourcing and Export Support
Aure Chemical is a chemical trading and export supply business. We coordinate with suppliers to review proposed fluorosilicic acid grades, supporting documentation, and order requirements.
Concentration and Specification Review: Review the required H₂SiF₆ concentration, free HF and sulfate reporting bases, and any additional buyer requirements against the available product documentation.
Supplier Coordination: Confirm the proposed industrial grade, available quantity, packaging options, and dispatch timing for the specific order.
Quality and Safety Documentation: Coordinate requests for the relevant batch COA, grade-specific technical data, current SDS, and clarification of the applicable standard edition. Application approvals are subject to separate verification.
Packaging and International Export Logistics: Coordinate compatible packaging, labeling, shipping documentation, and transport arrangements according to the supplied grade, destination, and carrier requirements.
For a sourcing inquiry, please provide the intended use, required concentration, impurity limits, order quantity, packaging requirements, and destination.
Safety, Handling & Documentation
Obtain the current SDS for the proposed concentration and commercial grade before handling, storage, or transport. Confirm the applicable GHS classification, pictograms, and label statements from that document.
Packaging
200 L HDPE drum
Final packaging, capacity and net weight are confirmed in the quotation and order.
