Experimental study on co-disposal of multisource metallurgical dusts

Abstract

In this study, the high carbon content of blast furnace dust was utilised to replace coal in the removal of Zn from electric arc furnace dust. Additionally, converter dust was added to adjust the composition of the mixed dust to achieve synergistic disposal of multisource metallurgical dusts. The influence of roasting temperature, duration, and raw material ratio on the treatment efficiency of this co-processing approach was investigated through carbothermic reduction experiments. By comparing the metallization rate, dezincification rate, and residual carbon content of the products, the preferred experimental conditions were determined as using mixed Zn-containing dust having a C/O molar ratio of 1.0 and Zn content lower than 16.5%, roasted at 1150°C for 30 min. Under these conditions, the achieved metallization rate reached 94.99% and dezincification rate reached 99.54%. This multisource metallurgical dust synergistic treatment method can reduce coal consumption by about 0.2 t for every 1 t of mixed dust treated. Kinetic analysis of the reaction process showed that the average activation energy for the co-reduction of the metallurgical dusts was 66.41 kJ/mol. The reaction was found to be relatively easy. The initial stage of the reaction was controlled by interfacial chemistry, and the final stage transitioned to diffusion control.