ITEM
|
FIRST GRADE
|
QUALIFIED GRADE
|
Appearance
|
White powder
|
|
Purity, %≥
|
96
|
95
|
Melting point, ℃≥
|
174.0
|
172.0
|
Zinc content
|
17.0-19.0
|
17.0-20.5
|
Heating loss, % ≤
|
0.30
|
0.50
|
Residue(150μm), % ≤
|
0.0
|
0.10
|