Item

Index

Grade A

Grade B

Grade C

appearance

It is yellow or light yellow,
No visible impurities to the naked eye

Mass fraction of sulfur（S）/% ≥

99.95

99.50

99.00

Mass fraction of water /% ≤

2.0

Mass fraction of ash (on a dry basis)/% ≤

0.03

0.10

0.20

Mass fraction of acidity（ H2SO4 ）（on a dry basis）/% ≤

0.003

0.005

0.02

Mass fraction of organic matter（C）（on a dry basis）/% ≤

0.03

0.30

0.80

Mass fraction of arsenic（on a dry basis）/% ≤

0.0001

0.01

0.05

Mass fraction of iron（on a dry basis）/% ≤

0.003

0.005

—

Mass fraction of sieve residue a%≤

particle size greater than 150μm

0

3.0

The particle size ranges from 75μm to 150μm

0.5

1.0

4.0

a The residue on sieve indicator is only applicable to powdered sulfur.