RESUMO
The pulp production process generates a CaCO3-rich solid waste known as white mud (WM), and its improper disposal is a cause for global concern. The present study investigates the composition, microstructure, and thermal decomposition characteristics of WM and proposes a strategy for replacing limestone with WM for iron ore sintering. Granulation and sinter pot tests were performed to evaluate the influence of added WM on the granulation and sintering processes. We assess the feasibility of using WM as a flux and discuss the mechanism through which WM affects the mineral phase and strength of the sinter based on metallographic and micropore observations. The results indicate that the sintering rate remains stable after replacing 50% of the limestone with WM via moisture control, and the quality and production indicators of the sinter do not change. Moreover, the mineral phase and microporosity remain similar to the basic case without WM, and the comprehensive index decreased by only 5.5%. Overall, this study demonstrates that it is feasible to replace 50% of limestone with WM in industrial sintering plants, which could significantly increase our WM disposal capacity and bring additional economic benefits.
