Effect of Raw Material Composition on the Sintering Properties

Abstract

A number of the commercial iron ores were tested in a sinter pot to study the effect of iron ore composition on the sintering properties. In the sintering of individual iron ores, under the sinter controlled at the same levels of basicity, SiO₂ and MgO, the sintering properties varied with iron ore type greatly. The sinters made from the dense low alumina iron ores presented the higher tumbler strength and the lower coke rate, but the RDI was not simply related to the alumina level of iron ore. A high alumina ore may produce the sinter with a very low or very high RDI. The sintering properties of blending ores, including productivity, TI, RI, suitable moisture and coke rate, except for the RDI, were approximately equal to the weighted means of the individual ores.
With an increase in the pisolitic iron ore in sintering, the productivity of sinter decreased by approximately 1.3 % on average for each 10 mass% pisolitic ore increased. The decrement varied with the kinds of iron ores replaced by the pisolitic ore. Increasing the pisolitic ore required a higher coke rate and more moisture in raw mix. In the blending ore containing the high ratio of pisolite, reducing the fluxes to decrease the MgO and raise the basicity may improve the productivity, tumbler strength and coke rate in sintering.