This part of ISO 2597 specifies a titrimetric method for the determination of the total iron content of iron ores, using potassium dichromate after reduction of the trivalent iron by tin(II) chloride. The method is applicable to total iron contents between 30 % (mass fraction) and 72 % (mass fraction) in natural iron ores, iron ore concentrates and agglomerates, including sinter products. NOTE An equivalent International Standard that does not use mercury(II) chloride is ISO 9507:1990, Iron ores — Determination of total iron content — Titanium(III) chloride reduction methods. A suggested procedure for removal of mercury from the waste solutions before discharge to effluent drains is given in Annex C.