... :98% stable supply ability, quality:ISO9001:2008 competitive price Iron II sulfate Monohydrate Index purity 98.0%min iron(fe) 19 ... as reducing agent, electroplate factory ,will revert hexavalent chromium to 3 chromium. can replace sodium sulfite,sulfur dioxide etc. 2. used ... as flocculating agent. for industrial waste water. 3.as precipitator,take dyeing factory for example,can remove sulfide ...