Sodium metabisulfite is a white or yellow crystalline powder or small crystal with a strong SO2 odor, a specific gravity of 1.4, soluble in water, and the aqueous solution is acidic. When it is in contact with a strong acid, it releases SO2 to form a corresponding salt. When it is left in the air, it oxidizes. It is Na2S2O6, so the product cannot be stored for a long time. Above 150 degrees Celsius, SO2 is decomposed.
Usage:
Chemical industry
It is used for the production of insurance powder, sulfamethazine, analgin, caprolactam, etc., as well as the purification of phenylpropane sulfone and benzaldehyde. The photographic industry is used as a fixative for the fixer. The perfume industry is used to produce vanillin. Used as a preservative for brewing industry, a rubber coagulant and a bleaching agent for cotton bleaching. Organic intermediates, dyes, and tanning are used as reducing agents for electroplating, wastewater treatment in oil fields, and as a mineralizer for mines.
industry
It is used in printing and dyeing, organic synthesis, printing, tanning, pharmaceutical and other departments; as a preservative, bleaching agent and loosening agent in food processing.
Used as a chemical reagent
(Printing and dyeing, photography, etc.), used as bleach mordant, reducing agent rubber coagulant, also used in organic synthetic pharmaceuticals and spices.
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INDEX OF SODIUM METABISULFITE |
CONTENT |
|
|
FOOD GRADE |
INDUSTRIAL GRADE |
|
|
PURITY (AS NA2S2O5) |
97%MIN |
96%MIN |
|
SO2 |
65.0%MIN |
65%MIN |
|
AS |
0.0002% MAX |
– |
|
HEAVY METALS (AS Pb) |
0.0005% MAX |
– |
|
SE |
0.0005% MAX |
– |
|
IRON (Fe) |
0.001% MAX |
0.002% MAX |
|
WATER TREATMENT |
0.02% MAX |
0.05% MAX |
|
PH VALUE |
4.0-4.8 |
4.0-4.8 |
|
PURITY (AS NA2S2O5) |
97% MIN |
96% MIN |