Preparation of Sulphoaluminate Cement-Based Material from Municipal Solid Waste Incineration (MSWI) Fly Ash

This letter presents a feasible method for the preparation of Sulphoaluminate cement-based material (SCBM) from a hazardous industrial waste, i.e., MSWI fly ash. The produced materials were characterized by X-ray powder (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and mercury intrusion porosimeter (MIP). Experimental results show that a type of SCBM was successfully prepared from MSWI fly ash by controlling compositional parameters at right values, and firing the raw mixes at 1200°C for 2 h. Results also show that MSWI fly ash improves the burnability of raw mixes significantly, and for the investigated fly ash sample the maximum allowable content is 30 wt%. The morphology of C4A3S in the produced materials appears smaller in size, rounded in shape crystals and tends to form large agglomerates, in contrast to the slightly angular outline of beton-C2S grains. MIP test result indicates that the critical pore diameter decreases rapidly at early ages (< 1 day), and attains to a steady-state after 3 days of hydration.