|
Name of indicator |
GB535-1995 First-class product |
GB535-1995 Qualified product |
DL/T808-2002 |
|
Appearance |
No visible mechanical impurities |
No visible mechanical impurities |
white or gray white granular or powder, No visible mechanical impurities |
|
Nitrogen（N）content（%） |
≥21.0 |
≥20.5 |
≥18.0 |
|
Water（H2O）(%) |
≤0.3 |
≤1.0 |
≤1.5 |
|
Free acid (H2SO4) content（%） |
≤0.05 |
≤0.2 |
≤2.0 |
