Methods of phase chemical analysis of iron ores have not been sufficiently developed. Methods for the separate determination of iron oxides, hydroxides, and silicates have been particularly poorly studied. When studying them, it is possible to apply sample treatment with gaseous hydrogen chloride. Unlike chlorine, a common and well-studied chlorinating agent, hydrogen chloride is not an oxidizer and does not change the iron valence of the initial compounds when they are converted to chlorides...