Adequação do processo de fabricação de aço LD, utilizando ferro-gusa líquido com baixo teor de silício

Abstract

One of the most important variables to the success of steel primary refining is slag volume. Although the volume applied by the steelmakers do not vary so much, a reasonable range to be considered range is 70 until 80kg of slag per ton of liquid steel Silicon input on the total charge of BOF influences strongly the slag volume because the refining process must follow the determined binary basicity (%CaO/%SiO2) to reachthe end blow target. A Work plan was made in three stages: Firstly it was elaborated one model for calculations flux additions.In the second phase some heats with and without recycled slag were produced. Samples of steel and slag in different blow times were collected. In the last phase some heats were produced to compare with Belgo´s row time product.The main objective of this paper is to evaluate the utilization of recycled slag (from primary refining) focused on BOF operational parameters. Recycled slag was used to complement slag volume and to help in slag formation when using low silicon hot metal. Preliminary results have shown a great possibility of recycled slag utilization during primary refining as well a cost reduction. Environment gains could be considered once the recycling