Materials Properties and Liquid Flow in the Hearth of the Experimental Blast Furnace

Abstract

The materials’ properties in the hearth of the blast furnace are very crucial for the hearth conditions. In this study, a number of coke, slag, metal, and aggregate samples were collected from the hearth of the LKAB’s experimental blast furnace (EBF). Subsequently, the coke, slag, and metal samples were chemically analyzed by X-ray fluorescence (XRF) or optical emission spectrometer (OES); the aggregate samples were analyzed by scanning electron microscope combined with energy-dispersive X-ray spectroscopy (SEM/EDS). The possible flow field of the liquid in the EBF hearth before quenching is depicted according to Cu tracers in the metal samples. Selected elements in the coke, slag, and metal were mapped for two sampling layers in the hearth, as well as in one cross section of the flow field. The results indicate that there exists an area beneath, and in front of, tuyere 3, where the flow resistance of the liquid was high. The high flow resistance contributed to the formation of a cold zone in the close-to-wall region and at the bottom of the EBF hearth. The temperature distribution in the EBF hearth has significant impacts on the chemical properties of the materials in different positions of the EBF hearth, as well as on the radial and vertical distributions of certain elements/components.