index < XML:NAMESPACE PREFIX = O />< XML:NAMESPACE PREFIX = O />

Wonderful grade

First grade

Up to grade

Purity% ≥

99.6

99.4

99.0

Suiphate group % ≤

0.08

0.10

0.20

Ignition (850 o C) % ≤

0.08

0.10

0.20

Heavy metal % ≤

0.001

0.002

0.02

Iron content % ≤

0.0012

0.002

0.01

Chlorides % ≤

0.003

0.004

0.01

Calcium % ≤

0.0012

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