Title

REFRACTORY PROPERTY IMPROVEMENT BY INTRODUCING NEW MATERIAL: ALUMINUM OXY-NITRIDE (1)

REFRACTORY PROPERTY IMPROVEMENT BY INTRODUCING NEW MATERIAL: ALUMINUM OXY-NITRIDE (1)

Authorship

HOSAKA, TAKAO; TAKEDA, KENZO

HOSAKA, TAKAO

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TAKEDA, KENZO

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DOI

10.5151/2594-5300-18Aciaria-59-70

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Abstract

The current trend in the steel industry is, on the one hand, a continuous reduction of production costs and, on the other hand, a continuous development of steel qualities and grades. Refractory products have been catching up with these trends in respect to both cost and quality. Particularly where it is applied in new steel manufacturing technology including preliminary treatments such as de-sulphurization and de-siliconization, the refractory's damage is more observed and a higher technical refractory concept is demanded. In these applications, the refractory's damage is statically observed due to metal erosion, gas corrosion, spalling and fluid abrasion, etc. as seen in other ordinary applications. However, no firm analysis confirmation of the dynamic mechanism for acceleration of the damage has been made. The writers of this paper put forth a hypothesis that the formation of FeO in the molten metal and slag and its reaction with the refractory is the major factor in the damage acceleration. Thus, our approach to refractory quality development has been to lower the FeO reactions. There are two methods to lower the reaction with FeO. One is to make the structure of the refractories dense so not to permit penetration, and the other is to make the mineralogical composition of the refractories not susceptible to FeO. We have been developing new refractories with this concept. Recently, our development research succeeded by following the latter method which applied a new material, Aluminum Oxy-Nitride.

The current trend in the steel industry is, on the one hand, a continuous reduction of production costs and, on the other hand, a continuous development of steel qualities and grades. Refractory products have been catching up with these trends in respect to both cost and quality. Particularly where it is applied in new steel manufacturing technology including preliminary treatments such as de-sulphurization and de-siliconization, the refractory's damage is more observed and a higher technical refractory concept is demanded. In these applications, the refractory's damage is statically observed due to metal erosion, gas corrosion, spalling and fluid abrasion, etc. as seen in other ordinary applications. However, no firm analysis confirmation of the dynamic mechanism for acceleration of the damage has been made. The writers of this paper put forth a hypothesis that the formation of FeO in the molten metal and slag and its reaction with the refractory is the major factor in the damage acceleration. Thus, our approach to refractory quality development has been to lower the FeO reactions. There are two methods to lower the reaction with FeO. One is to make the structure of the refractories dense so not to permit penetration, and the other is to make the mineralogical composition of the refractories not susceptible to FeO. We have been developing new refractories with this concept. Recently, our development research succeeded by following the latter method which applied a new material, Aluminum Oxy-Nitride.

Keywords

refractories, aluminum oxy-nitride, FeO reaction, steel industry, refractory improvement

refractories, aluminum oxy-nitride, FeO reaction, steel industry, refractory improvement