Lime-mediated sewage sludge partly replacing fluxes and fuels as metallurgy sintering ingredients

Lime-mediated sewage sludge was used in metallurgy sintering. Its impact on the sinter performance was discussed when partly replacing fuels and fluxes as a metallurgy ingredient. Thermogravimetry-differential thermal analysis (TG-DTA) and X-ray diffraction analysis (XRD) show that in the process of room temperature to 1100℃, organic matter in the sludge decomposes to generate heat, meanwhile CaCO₃ and Ca(OH)₂ turn into CaO. Sintering cup experiment results indicate that the sludge has a positive impact on sintering with appropriate carbon quantities and the sinter quality index is improved. When the sludge ratio is 3.00% and the ratios of replacing the flux and fuel with the sludge are 51% and 13.3% respectively, the vertical burning rate of sintering is 21.30 mm·min^-1, the yield is 72.63%, the utilization coefficient is 1.458 t·m^-2·h^-1, and the fuel consumption per ton falls to 59.27 kg from 65.54 kg.