It is used as a desoxydating or bleaching agent for printing and dyeing industry, as a developer for photographic industry. As a lignin-removing agent for paper industry, as a stabilizer for syntheticfiber for textile industry, as a reducing agent for chemical industry, or for electroplating industry etc.
|
Items |
Norms (industrial grade) | ||
|
Superior-grade |
First-grade |
Qualified-grade | |
|
Na 2 SO 3 -content % ≥ |
97. 0 |
96. 0 |
93. 0 |
|
Fe-content % ≤ |
0. 003 |
0. 005 |
0. 02 |
|
Water-insoluble matter content % ≤ |
0. 02 |
0. 03 |
0. 05 |
|
Free alkali (as Na)content % ≤ |
0. 10 |
0. 40 |
0. 80 |
|
Na 2 SO 4 -content % ≤ |
2. 5 |
||
|
NaCL-content % ≤ |
0. 10 |
||