Phase composition and properties analysis of slag crust in large-size blast furnace copper stave 大型高炉铜冷却壁渣皮物相组成及性能分析

The slag crust formed on the hot side of the blast furnace copper stave is the key to ensuring the campaign of the BF. The slag crust on the hot surface of the copper stave was sampled based on the BF mid-repair. The X ray fluorescence spectrometry, X-ray diffraction and scanning electron microscope coupled with an energy dispersive spectrometer, Factsage thermodynamic software and laser thermal conductivity analysis were performed to explore the chemical composition, microstructure, thermal conductivity and phase composition of the slag crust. The results show that the slag crust has a clear layered structure, and the main phases are grossite(CaAlO), gehlenite(CaAlSiO) and anorthite(CaAlSiO). The melting temperature and the viscosity of the slag crust were calculated by Factsage software. It was found that along the growth direction of the slag crust, the melting temperature decreased and the fluidity deteriorated. The heat flow intensity of the slag crust under a reasonable thickness is calculated by the heat transfer method, which provides a theoretical guidance for the BF production practice.