Appearance : white crystalline powder .
Molecular formula : Na2SO3
Packing : double-layer plastic woven bag.
Uses : used in medicine, papermaking, tannage, leather, printing, dyeing, bleaching and food .
Quality standard : Q/320124JM02-2003
Index name
|
Premium grade
|
Super grade
|
First grade
|
Salable product
|
Industrial grade
|
Sodium sulfite ( Na2SO3 ) , % ≥
|
97.0
|
96.0
|
93.0
|
90.0
|
Fe , ?≤
|
0.003
|
0.005
|
0.01
|
/
|
Water insoluble matter , % ≤
|
0.02
|
0.03
|
0.05
|
/
|
Free alkali ( as Na2SO3 ) , % ≤
|
0.10
|
0.40
|
0.60
|
/
|
Na2SO4 , % ≤
|
2.50
|
/
|
/
|
/
|
NaCl , % ≤
|
0.10
|
/
|
/
|
/
|