Pore Radius Distributions of Iron Reduced from Hematite Containing Several Foreign Oxides

Abstract

The pore-radius distribution of the reduced iron from hematite containing several foreign oxides was measured by the mercury penetration method. Hematite was reduced by hydrogen and carbon-monoxide at about 800° and 1000°C.
These foreign oxides were grouped into four types depending on the effect on the pore radius.
(1) The oxides such as Al₂O₃, Cr₂O₃ and TiO₂ which are considerably soluble in hematite and magnetite but practically insoluble in wustite.
(2) The oxides such as CaO which are considerably soluble in wustite but have limited solubilities.
(3) The oxides such as MgO which form continuous solid solutions with wustite and do not have limited solubilities.
(4) The oxides such as SiO₂ which are almost insoluble in any iron oxides.
According to the present work, the effects of those oxides on the pore radius in reduced iron are as follows.
The oxides in group 1 form the micro pores of the radius which decreases with increasing the amount. The oxides in group 2 form the macro pores of the radius which increases with increasing the amount. The oxides in group 3 show practically little effect on the pore radius. The oxides in group 4 do not influence the pore radius.