from the conferences organized by TANGER Ltd.
In integrated steel mills, the desulphurization of pig iron from the blast furnace is a crucial pretreatment step before the hot metal is converted into steel in the basic oxygen converter. During this process, significant dust emissions can occur, reaching up to 1 kg per tonne of liquid steel, with dust concentrations in the exhaust gas reported as high as 10 g/m³. The exhaust air from the desulphurization unit is typically cleaned using dry dedusting systems, most commonly electrostatic precipitators or bag filters. The separated dust is often recycled to the sinter plant, closing material loops within the steelworks. In contrast to other residues generated in steel plant off gas cleaning systems, comparatively little information is available on the physical properties and chemical composition of dust originating from pig iron desulphurization. To address this gap, dust samples from desulphurization units at two different steel mills were systematically investigated. Mechanical properties—including bulk density, particle size distribution, flowability, and wall friction angle—were determined alongside detailed chemical analyses. The results reveal substantial differences between the two dust samples, particularly in their carbon content, but also in the concentrations of sulphur, zinc, and alkali metals. Significant variations were likewise observed in key physical properties, including bulk density and particle size distribution. These parameters strongly influence both the handling behaviour of the material and its recycling. Taken together, the findings underscore the importance of plant specific characterization when assessing utilization strategies for desulphurization dust.
Keywords: steel mill, desulphurization unit dedusting, dust composition, physical properties© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.