Sodium fluorosilicate is the most commonly used type of fluorosilicate in the construction and building materials industries. It is mainly used as enamel cosolvent, glass opal agent, acid resistant cement, acid resistant concrete coagulant and wood preservative, and used in pesticide industry to manufacture pesticides. Used as a preservative in the wood industry; A moisture absorbent for acid resistant cement. Used as an emulsifier for glass and enamel; Used as a coagulant in natural latex products, as an additive in electroplating, nickel, and iron ternary coatings, and as a plastic filler. In addition, it is also used for fluorination treatment in pharmaceuticals and drinking water, as well as sodium fluoride in the production of artificial cryolite.

 

Basic information

Chinese name: Sodium fluorosilicate

Chinese alias: Sodium hexafluorosilicate (2-); Sodium hexafluorosilicate; Sodium fluorosilicate; Sodium hexafluorosilicate; Sodium silicofluoride; Sodium silicofluoride

Foreign name: sodium hexafluorosalicate

English alias: disodium hexafluorosalicate; Sodium Silico Fluoride; Sodium fluorosilicate; SODIUM FLUOSILICATE; Destruxolapplex; Disodium hexafluorosalicate; Disodium hexafluorosalicate (2-); Diodiumsilicofluoride; Ens zemweevilbait; Ent1501; Fluosilicatedesodium; Hexafluoro-silicate (2-diodium; Sodium Fluor-silicate; Sodium Fluoro (oxo) silanolate

Nickname: Sodium fluorosilicate

CAS number: 16893-85-9

Molecular formula: Na2SiF6

Molecular weight: 188

SMILES: [O -] [Si] (F) ([O -]) [O -] [Na+] [Na+] [Na+] [1]

 

Physical property data

Character: Colorless hexagonal crystal. Odorless and tasteless. Has hygroscopicity. 2. Density (g/mL, 25/4 ℃): Undetermined 3. Relative vapor density (g/mL, air=1): 2.6794. Melting point (º C): Undetermined 5. Boiling point (º C, atmospheric pressure): Undetermined

Boiling point (º C, 5.2kPa): undetermined 7. Refractive index: undetermined 8. Flash point (º C): undetermined 9. specific rotation (º): undetermined 10. Self ignition point or ignition temperature (º C): undetermined 11. Vapor pressure (kPa, 25 º C): undetermined 12. Saturated vapor pressure (kPa, 60 º C): undetermined 13. Heat of combustion (KJ/mol): undetermined 14. Critical temperature (º C): undetermined 15. Critical pressure (KPa): undetermined 16. Pairs of oil-water (octanol/water) distribution coefficient: undetermined 17. Upper explosive limit (%, V/V): Undetermined 18. Lower explosive limit (%, V/V): Undetermined 19. Solubility: insoluble in alcohol, soluble in solvents such as ether. The solubility in acid is greater than in water. Cold water solutions are neutral, while hot water solutions are alkaline.

 

Storage method

1. It should be stored in a ventilated, cool, and dry warehouse
2. Do not store or transport together with food, feed, or acid products

 

Synthetic method

1. The by-product method of superphosphate involves the reaction of phosphate rock powder with sulfuric acid to produce superphosphate or the fluorine containing waste gas that escapes during the extraction of phosphoric acid. Water is used to absorb silicon tetrafluoride to form fluorosilicic acid. When the concentration of fluorosilicic acid solution reaches 8% to 10%, it is still and clarified, impurities are removed, and sodium chloride (about 25% excess) is added to the clarified fluorosilicic acid solution for reaction to generate sodium fluorosilicate. After centrifugation, washing, airflow drying at a temperature below 300 ℃, and crushing, the finished product of sodium fluorosilicate is prepared. The reaction formula is as follows:

2. Adopting the by-product method of superphosphate. Absorb the fluorine containing waste gas from the production process of superphosphate (or extracted phosphoric acid) with water, and then react with sodium chloride to obtain it.

3. Add a small amount of theoretical amount of fluorosilicic acid aqueous solution in batches to the reagent sodium carbonate aqueous solution for reaction: after the reaction is completed, let it stand and filter, centrifuge and shake dry, and dry at 120 ℃.

4. The by-product method of superphosphate involves the reaction of phosphate rock powder and sulfuric acid to produce superphosphate, or the fluorine containing waste gas that escapes during the extraction of phosphoric acid. Water is used to absorb silicon tetrafluoride to form fluorosilicic acid. When the content of fluorosilicic acid solution reaches 8% to 10%, it is allowed to settle and remove impurities. Sodium chloride (about 25% excess) is added to the clarified fluorosilicic acid solution for reaction to generate sodium fluorosilicate. After centrifugation, washing, airflow drying at a temperature below 300 ℃, and then crushing, the finished product of sodium fluorosilicate is prepared. The reaction formula is as follows:

5. Treat fluorosilicic acid containing 4.6% silica and Na2SiH620.5% with an excess of 10% to 20% stoichiometric sodium sulfate 27% solution to obtain a sodium fluorosilicate suspension in a silica sol. Then separate the hydraulic force at a pressure of 152-202.7kPa. The by-product mother liquor is neutralized with dry sodium carbonate at a ratio of 8.8-9.3 parts by weight per 100 parts by weight. Fluorosilicic acid is treated with 86% -95% stoichiometric sodium sulfate to obtain a slurry containing 78.5-80.5% Na2SiH6.

 

Main purpose

1. Used as a whitening agent for glass and enamel, flux, agricultural insecticide, hygroscopic agent for acid cement, coagulant, and filler for certain plastics. It is also used for wood preservation, pharmacy and fluorination of drinking water.

2. Melt decomposition of silicates. An alloy of beryllium and aluminum. Glaze for ceramic ware. Manufacturing milky white glass. Anti moth wool products and wood preservation. Used as opacifying agent and flux for glass and enamel, wood preservative, agricultural insecticide, moisture absorbent for acid resistant cement. Used as a coagulant in natural latex products, as an additive in electroplating, nickel, and iron ternary coatings, and as a plastic filler. In addition, it is also used for the fluorination treatment of pharmaceuticals and drinking water, as well as the production of artificial cryolite and sodium fluoride.

3. Used as a retarder in concrete admixtures. It can also be used as opacifying agent, flux for glass and ceramics, wood preservative, agricultural insecticide, and moisture absorbent for acid resistant cement. Used as a coagulant in natural latex products, as an additive in electroplating, nickel, and iron ternary coatings, and as a plastic filler. In addition, it can also be used for the fluorination treatment of pharmaceutical and applied water, as well as for the production of artificial cryolite and sodium fluoride.

4. Used as chemical analysis reagents, agricultural insecticides, fungicides, and preservatives. It can also be used in the enamel industry to make milky white glass. 5. Sodium fluorosilicate can be used for matte treatment of aluminum and alloys, and can also be used as an additive in aluminum and alloy passivation treatment solution to improve its passivation effect.

 

Security information

Risk term Toxic by incidence, in contact with skin and if allowed Toxic by inhalation, skin contact, and ingestion. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice In case of accident or if you feel unwell, seek medical advice immediately (show the label when possible).

System number

CAS number: 16893-85-9

MDL number: MFCD00003491

EINECS number: 240-934-8

RTECS number: VV8410000

PubChem number: 24886228

 

Science data

Acute toxicity: Oral LC50 in mice: 70mg/kg; Rat LD50: 125mg/kg. This product is toxic and has a stimulating effect on the respiratory organs. In cases of accidental oral toxicity, severe gastrointestinal damage symptoms may occur. The lethal dose was 0.4~4g.

 

Calculate data

1. Reference value for hydrophobic parameter calculation (XlogP):

2. Number of hydrogen bond donors: 03, number of hydrogen bond receptors: 74, number of rotatable chemical bond: 05, number of tautomers: 6, topological molecular polar surface area (TPSA) 07, number of heavy atoms: 98, surface charge: 09, complexity: 62.710, number of isotope atoms: 011, number of determined atomic building centers: 012, number of uncertain atomic building centers: 013, number of determined chemical bond building centers: 014 Uncertain chemical bond structure center quantity: 015, covalent bond unit quantity: 3

 

Ecological data

Usually, it is slightly harmful to water bodies. Do not expose undiluted or large amounts of products to groundwater, waterways, or sewage systems. Do not discharge materials into the surrounding environment without government permission.

 

Stable in nature

1. Stable at room temperature and pressure

Materials to avoid: moisture/moist oxides. Soluble in solvents such as ether, insoluble in alcohol. The solubility in acid is greater than in water. Decompose in alkaline solution to generate fluoride and silica. After being heated at 300 ℃, it decomposes into sodium fluoride and silicon tetrafluoride. Toxic!

2. The solubility of sodium fluorosilicate in acid is greater than that in water. Decompose in alkaline solution to generate fluoride and silica. After being heated (above 300 ℃), it decomposes to form sodium fluoride and silicon tetrafluoride. Toxic

3. This product is toxic and has a stimulating effect on the respiratory organs. Those who accidentally take it orally may experience severe gastrointestinal damage symptoms

 

Security information

Packaging level: III

Hazard category: 6.1

Dangerous goods transportation code: UN 2674 6.1/PG 3

WGK Germany: 2

Hazard category code: R23/24/25

Safety instructions: S26-S45

RTECS number: VV8410000

Dangerous goods label: T: Toxic