... ,20% 2)package,25kg/bag 3)Usage, additives,fertilizer,water scavenging agent iron sulfate heptahydrateMolecular Formula: FeSO4·(X) H20 (X=1 or ... for the manufacture of iron salts, ink, iron oxide red and indigo-blue; as mordant ,tanning agent,water scavenging agent,wood preservative, ... 0.002AS %≤0.002-0.0002Fineness (through 180umtest sieve) %≥ 9595-- Iron Sulphate Heptahydrate water scavenging agent