Detailed introduction:
Synonyms: Dinatriumdisulfit; Disulfito de disodio; Disulfite de disodium; Disodium disulfite; Disodium Salt Pyrosulfurous Acid; Disulfurous acid, disodium salt; Pyrosulfurous acid, disodium salt; Sodium Metabisulfite; Sodium disulfite; Sodium Pyrosulfite
Molecular Formula: Na2S2O5
Molecular Weight: 190.10
Cas No.: 7681-57-4
Melting Point: 150 C (Decomposes)
Specific Gravity: 1.48
Solubility in Water: Freely soluble (470g/l)
pH: 3.5-5.0
HS Code: 2832100000
Standard Executed: GB1893-1998
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Item
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Specification
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Food Grade
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Tech Grade
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Appearance
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White To Slightly Yellowish Crystalline Powder
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Content
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98.0% Min
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98.0% Min
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SO2
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65.0% Min
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65.0% Min
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Na2S2O4
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2.0% Max
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2.0% Max
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Insolubles In Water
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0.05% Max
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0.05% Max
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Particle Size
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85% (Mesh 200)
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85% (Mesh 200)
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pH
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4.5 -5.5
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4 -4.6
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Fe
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5ppm max
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5ppm max
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Heavy Metal
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10 ppm max
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As
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1 ppm max
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Properties:
Sodium Metabisulfite is a white to slightly yellowish crystalline powder with sulfur dioxide odor; readily soluble in water. Sodium metabisulfite containing more than 65.0% SO2 w/w releases sulfur dioxide gas when mixed with water. It forms a bisulfite adduct with aldehyde and with ketones to a sulfonic acid. It is used to purify or isolate aldehydes and ketones.
Applications:
1. It is used as an oxygen scavenger to eliminate the dissolved oxygen in waste water and in pipes.
2. Bisulfite is a reductive bleaching agent.
3. It reduces carbonyl and alcohol groups, which function as colorants of the substances.
4. It is used in bleaching mechanical paper pulp, cotton, wool and kaolin clay.
5. Additional applications include as a preservative (antioxidant), a hair waving agent, and Ensiling agent.
Packing:
25kg P.P Woven bags, 20MT in the 20’FCL
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