Abstract
A method was studied for the accurate determination of ferrous iron in samples containing metallic iron, ferrous oxide and ferric oxide. It has been well known that the HgCl2 method is the most accurate one among several methods for this purpose, so that the authors tried to develope it. After the metallic iron was removed by HgCl2 solution, the precipitated Hg was removed by KI-I2 solution. The residue containing ferrous and ferric oxides was dissolved with HCl in the atmosphere of CO2, and then the ferrous iron in the solution was determined by titrating directly with KMnO4 solution. The metallic iron may be determined in the filtrate treated with HgCl2 solution, the amount of the total iron was obtained independently of the above method, and the amount of ferric iron was then found from the difference of the two values. This method was accurate for the determination of ferros iron in materials containing metallic iron and its oxides.
