Proceedings of the Seminar on Steelmaking, Casting and Non-Ferrous Metallurgy


ISSN 2594-5300

47th Steelmaking Seminar - International vol. 47, num.47 (2016)


Title

TUNDISH SLAG CAPACITY TO ABSORB INCLUSIONS WHEN USING CALCIUM ALUMINATE BASED COVERING MATERIAL COMBINED WITH RICE HULL ASH

DOI

10.5151/1982-9345-27959

Downloads

Abstract

Tundish is the last reactor where significant metallurgical operations can still be done. Calcium aluminate slags are able to positively contribute to metallurgy considering oxide separation, protection against reoxidation and preclusion of resulphurisation. However, these are poor insulators. When using low melting point slags it is necessary to use another covering material. The deviation from saturation can be used as a measure of absorption capacity. By utilizing computerized construction of ternary and quaternary diagrams it is possible to compare different slags and to find proper slag compositions with reasonable capacity to dissolve inclusions. Objective of the present technical contribution is to evaluate tundish slag capacity to absorb inclusions, considering a particular tundish industrial slag and the changes in its chemical composition during continuous casting of steel. It was observed that slag composition changed during the continuous casting process; this variation is possibly related to interaction between the CaO-Al2O3 liquid slag and the rice hull ash layer which is used above it. Computational thermodynamics was used to determine activity of alumina dissolved in liquid slag; it was observed that the variation in slag composition did not change slag capacity to absorb inclusions, since precipitation of Al2O3 solid phases is not predicted.

 

Keywords

Inclusions, Tundish slag, Tundish covering materials, Calcium aluminate, Rice hull ash

Rice hull ash

How to refer

Pereira, Márcia Maria da Silva Monteiro; Lima, Marco Túlio; Ferreira, Gérson Tolentino; Tavernier, Hervé; Klug, Jeferson Leandro; Heck, Nestor Cezar; Jung, Detlef. TUNDISH SLAG CAPACITY TO ABSORB INCLUSIONS WHEN USING CALCIUM ALUMINATE BASED COVERING MATERIAL COMBINED WITH RICE HULL ASH , p. 546-551. In: 47th Steelmaking Seminar - International, Rio de Janeiro, 2016.
ISSN: 2594-5300 , DOI 10.5151/1982-9345-27959