Acta Metallurgica Slovaca

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Year 2009

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Year 2009 No 2

Borovský T., Kijac J., Domovec M.

ANALYSIS OF THE SLAG AND METAL INFLUENCE ON THE LIFE OF ELECTRIC ARC FURNACE HEARTH REFRACTORY LINING

Abstract
MgO-based refractory linings for electric arc furnace (in further EAF) hearth are most preferred worldwide. Potential for elimination and knowledge of causes, mechanisms of refractory wear coupled with continuous correction of plant parameters is needed in order to prolong refractory life. Wear process can be significantly modified by changes in technology. The most critical location in the EAF hearth is a slag line. Slag compatibility (i.e. dual saturation of slag both with CaO and MgO) with refractory lining using dolomitic lime, MgO- briquettes or refractory wastes is an effort of slag management. Slag foaming is very beneficial against wear. Governing of FeO content in the slag is a critical aspect of both slag foaming and refractory wear point of view.
This study deals about analysis of slag and metal composition influence on the EAF hearth refractory lining wear level based on the statistical evaluation of plant data. Influence of specific slag (CaO, MgO, FeO, Al2O3, SiO2, basicity) and metal (C, Mn) constituents on the extent of EAF hearth lining wear was analysed at selected number of 24 campaigns. Average values of slag composition of mentioned campaigns together with wear data were plotted to the pseudoternary diagram which expresses the relation between basic, acidic oxides and oxides with oxidation potential. Results were affected by scattering factor of used EAF shop statistical data reinforced with human factor (manual slag and metal sampling, non-ideal method of wear extent measurement), factor of oxygen lance use just before sampling in the same location as well as contribution of other various (except of slag and metal) non-constant factors acted in some campaigns.

No 2 (2009), p. 77-85