Preparation and Characterization of the Lightweight Fired Brick with Low-silicon Iron Tailings

Abstract

This research investigated the possibility of using low-silicon iron tailings together with bentonite, feldspar and rice husk to prepare lightweight fired brick. The bulk density and compressive strength of the lightweight fired brick with different raw material proportions and sintering temperature were studied. The mineral compositions, microstructure and sintering mechanism of the samples were analyzed by XRD and SEM. The results showed that the optimal incorporation amounts of iron tailings, bentonite, feldspar and rice husk were 40%, 30%, 10% and 8% by weight, and the suitable sintering system was 900°C for 1.5h. Under these conditions, the bulk density and compressive strength of the lightweight fired brick were 1.2294g/cm3 and 7.4MPa, respectively. The primary mineral phases of the sample were hematite, muscovite, mullite, quartz, anhydrite and microcline, which were mainly responsible for the mechanical strength of the samples, and the analysis of microstructures revealed the evenly distributed and interconnected pores and the molten minerals made contributions to the tailing brick good properties.