On the Fundamental Properties of High Basicity Pellets

Abstract

Fundamental properties of fluxed pellets having relatively high basicities (CaO/SiO₂=0, 1.25, 1.5, 1.75 and 2.0) were studied with the samples indurated at 1150, 1200, 1250 and 1300°C, using electric furnace. And following results were obtained. The main structures of fluxed pellets were hematite and hemi-calciumferrite (CaO, 2Fe₂O₃). When indurated at 1300°C, however, hemi-calciumferrite disappeared and slag and magnetite were formed. In the pellets having basicities of 1.75 and 2.0, there existed calciumferrite which was considered 3CaO.EFeO.7Fe₂O₃, when indurated at 1300.
Porosity of indurated pellets decreased with increasing induration temperature, this tendency was more remarkable in fluxed pellets than regular pellets. Crushing strength of indurated pellets increased with increasing temperature but slightly lowered at 1300°C with a exception.
In order to examine the reducibility without the effect of porosity, reduction tests were performed with the samples crushed under 74μ. The reducibility of fluxed pellets was superior to that of regular pellets regardless of induration temperature.