Phase Transformation of Cohesive Zone in a Water-quenched Blast Furnace

Abstract

The paper investigates the transformation of iron and slag phase in cohesive zone from a water-quenched blast furnace through SEM images, EDS spectra and thermodynamic calculation. The results show that the wustite structure exists as an independent interphase insoluble in slag and iron. The content of carbon keeps about 2% in iron, and the carburization function of coke is inhibited in cohesive zone. The compositions of slag phase fluctuate in cohesive zone, while the basicity maintains about 1.8, higher than that in final slag. The liquids temperature of iron in cohesive zone is about 1673 K, while that of slag phase gradually decreases from top to bottom. The separation between slag and iron is basically completed at lower part of cohesive zone. The blocked voids caused by softening and melting burden restrains the indirect reduction at lower cohesive zone, hence an apparent titanium attachment exists around iron due to the development of direction reduction.