Avaliação da substituição do CaF2 por B2 O3 em escórias sintéticas dessulfurantes no processo de refino secundário
Evaluation of replacement of CaF2 for B2 O3 in desulfurizing synthetic slags in the secondary steelmaking process
Jorge Luís Coleti, Felipe Fardin Grillo, Eduardo Junca, Rafael Giuga Borba de Mello, Denise Crocce Romano Espinosa , Jorge Alberto Soares Tenório
Resumo
O objetivo deste trabalho foi avaliar a substituição do CaF2 por B2 O3 na composição de escórias sintéticas para o refino secundário de aço e comparar os efeitos daqueles compostos sobre a eficiência de dessulfuração de escórias com a utilização do software FactSage. Os testes foram realizados com amostras de aço SAE 1020 a 1600°C sob fluxo de argônio. Após a completa fusão, foi retirada uma amostra do aço para determinação do teor de enxofre inicial. Depois, adicionou-se as escórias sobre o banho e iniciou-se o processo de agitação. Amostras foram retiradas a cada 5 minutos a fim de analisar a variação do teor de enxofre no aço. Investigou-se também a influência da proporção de fases liquidas/ sólidas e viscosidade das escórias sintéticas, bem como composição final dos aços com o software FactSage. Os resultados mostraram uma eficiência de dessulfuração de 68,8% para escórias com 5% de B2 O3 e 65% para escórias com 7% de CaF2 . O teor de fase liquida deve ser em torno de 80,9% para promover a melhor eficiência de dessulfuração. Os resultados também demonstraram que as escórias sintéticas contendo B2 O3 apresentaram velocidade de dessulfuração menores que escórias sintéticas contendo fluorita.
Palavras-chave
Abstract
The aim of this paper was to evaluate the replacement of CaF2 by B2 O3 in the composition of synthetic slag for secondary steel refining and comparing the effects of those compounds on the slag desulfurization efficiency using the FactSage software. The tests were performed with SAE 1020 steel at 1600°C under argon flow. After the steel melting, a sample was taken to determine the initial sulfur content. Then, the synthetic slag was added on the bath and, the stirring process started. Samples were taken in each 5 minutes to determine the variation of the sulfur content in the steel. The influence of the both proportion of liquid / solid phases and viscosity of synthetic slags was also investigated, as well as the final composition of the steels using the FactSage software. The results showed that the desulfurization efficiency was 68.8% for slags containing 5% B2 O3 and 65% for slags containing 7% CaF2 . The content of liquid phase to promote the highest desulfurization efficiency was 80.9%. The results also showed that the synthetic slags containing B2 O3 presented a lower desulfurization rate than synthetic slags containing fluorite.
Keywords
Referências
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Submetido em:
31/07/2020
Aceito em:
19/10/2020
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