Characteristics of Residual Fine Particles in a Blast Furnace

Fine particles can reduce the blast furnace's gas and liquid permeability. The residual fine particle sampling and screening of the overhaul blast furnace were carried out to obtain particle size distribution. Chemical analysis, XRD, and SEM-EDS were used to analyze the chemical and phase composition, degree of graphitization, and microstructure to clarify the characteristics and evolution of fine particles. The results show a clear correlation between particle size and chemical composition. Although the phase components of different-size particles are similar in the same area, their chemical contents are quite different. The chemical and phase composition of particles with the same particle size significantly differ in the other regions. The fine particles in the S1 region mainly consist of coke powder, ZnO, and alkali metals. Significant amounts of slag iron minerals and C coexist in the fine particles of the S2 area. The slag iron minerals contents and the carbon graphitization degree of fine particles increase as the furnace burden descends.