Influence of Al2O3 Content on the Melting and Fluidity of Blast Furnace Type Slag with Low TiO2 Content

Hao Liu,Nengyun Deng,Yanhua Yang,Qianying Zhang,Yuelin Qin

doi:10.1155/2018/9502304

Hao Liu, Nengyun Deng + Show 3 more

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https://doi.org/10.1155/2018/9502304

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Abstract

The increasing usage of iron ores with high Al2O3 content significantly increases the amount of Al2O3 in blast furnace slag and consequently affects its performance. This work uses slag sampled on site to study the effects of changes in Al2O3 content on the fluidity of the CaO–SiO2–Al2O3–MgO–TiO2 slag system that is characterized by high Al2O3 and low TiO2 contents, as well as on the phase transition law during the cooling process. Slag viscosity exhibits a rising trend with an increase in Al2O3 content, and Al2O3 in the tested slag is alkaline. The viscous flow activation energy of molten slag rises from 157 kJ/mol to 172 kJ/mol with an increase in Al2O3 content, and the viscous flow units in the slag become large and complicated. When slag is cooled, the main precipitated phase is melilitite. Spinel, perovskite, and olivine are also observed. The crystallization amount of the melilitite phase decreases constantly with an increase in Al2O3 content.

Highlights

As mineral resources become scarce, the types of iron ore purchased by steel companies have become varied and their compositions have become complicated
The quantity of blast furnace coal injection continuously increases and the amount of blast furnace slag gradually decreases given that the metallurgical method for blast furnace is reinforced constantly
The current study mainly explores the effects of increased Al2O3 content on the melting and fluidity of blast furnace slag with low TiO2 content

Summary

Introduction

As mineral resources become scarce, the types of iron ore purchased by steel companies have become varied and their compositions have become complicated. This type of coal contains a considerable amount of gangue minerals, such as SiO2 and Al2O3, which eventually causes the Al2O3 content of blast furnace slag to increase constantly. As the Al2O3 content of slag increases, the high meltingpoint spinel phase, which is a feature of strong crystallization capacity, may occur in slag, thereby causing blast furnace slag to exhibit high viscosity and poor fluidity and eventually resulting in the decline of slag metallurgical performance [7–10]. Contains a small amount of TiO2, the effect of Al2O3 on the CaO–SiO2–Al2O3–MgO–TiO2 slag system remains unclear To address this issue, the current study mainly explores the effects of increased Al2O3 content on the melting and fluidity of blast furnace slag with low TiO2 content

Experimental

Result and Discussion

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Conflicts of Interest