Index name

Industrial Grade

Agricultural Grade

Superior

First-rate

qualified

Superior

First-rate

qualified

color

White color

White or light color

Total nitrogen (N) content (dry basis),% ≥

46.3

46.3

46.3

46.3

46.3

46.3

Biuret content,% ≤

0.5

0.9

1.0

0.9

1.0

1.5

Content of water (H2O),% ≤

0.3

0.5

0.7

0.5

0.5

1.0

Iron content (Fe),% ≤

0.0005

0.0005

0.0010

-

-

-

The alkalinity (NH3 meter),% ≤

0.01

0.02

0.03

-

-

-

Sulfate content (in SO) 4-2 meter),% ≤

0.005

0.010

0.020

-

-

-

Water insoluble matter,% ≤

0.005

0.010

0.040

-

-

-

Particle size (φ 0.85-2.80mm),% ≥

90

90

90

90

90

90