Redução do teor de fósforo dos aços em convertedores LD através de adição de briquete

Abstract

The text of match in iron ores comes considerably increasing and this makes it difficult the steel production with rigorous requirements of qualities. To attend the demand for steels with low phosphorus content in the LD, a methodology of desphosphorization of the steel by means of the briquet addition was developed of iron and in the races where the silicon content of pig iron was inferior 0.5%, iron-silicon briquetted slag (FeSi)addition. There had been collected given of produced races in accordance with the practical standard of the plant and carried through slag samplings of blow end, for evaluation, by means of chemical analysis of the free content lime. The addition briquettes of iron were carried through in function of the result of free content lime analysis. Theexperience was divided in two stages, being that it has left of the races had been manufactured only with the adjustment of the silicon content of pig iron and excessively, beyond the adjustment silicon of pig iron, with addition of briquetted iron around 50% of the blow time. The preliminary results had shown that the use of this method made possible to improvethe partition of phosphorus around 20% and a reduction of the time of blow in 15%, about two minutes. Moreover, a formation of faster slag was gotten and with better characteristic of fluidity, reducing the steel projections during the blow and skull formation and in the splashes during the blow. One still promoted profit ambient, in view of that, in the development of this work two ambient liabilities (iron and FeSi slag) and had been used, moreover, it approximately had a reduction in the consumption of flux material around 12kg/t of steel.