Abstract
The specific surface areas of various ferric oxides and iron-ores were measured by BET method, using nitrogen and krypton as adsorption gas. The results show that those specific surface areas decrease remarkably with increase of heating temperature, however, they are little dependent on their particle sizes. They also depend on their kinds; for example, limonite has large values, 50-70 m2/g, hematite 2-40m2/g and magnetite 0.3-1m2/g.
Furthermore, the adsorption volumes of water vapor on various iron-ores were determined. The adsorption of water vapour on those iron-ores may be regarded as physical adsorption and the adsorption volume of water vapor per unit surface area decreases with increase of specific surface areas.
