Rheological Studies on Optimizing the Sinter Mix Granulation Mechanism to Sustain Productivity

Abstract

Granulation of the sinter mix is an important step in the iron ore sintering process. This article presents the results of various studies conducted to understand the rheological aspects and methods implemented in industrial‐scale sinter plants to sustain productivity over the last decade. The intergranular bonding material in the mixing and nodulizing drum is characterized to understand its influence on the granulation. Calcined lime, when increased from 20 to 40 kg t−1 of sinter, increases the granulation index and helps in achieving higher productivity. Up to 20 kg t−1, calcined dolo increases productivity, beyond which a decline is noticed. Lignosulfonate and polymer binders in the range of 0.2%–0.7% in the sinter mix, respectively, increase the granulation of the microfines (0.25 and 0.5 mm size). When a magnetic field is applied to water, the granulation improves. Higher electrical conductivity and lower contact angle of the recycled water are found to improve the bonding of the particles. Zeta potentials of fly ash and bentonite solution in water are positive and negative in the cases of calcined lime and calcined dolo. It is suggested to use fly ash as a binder of microfines.