Dissolution Characteristics of CO₂-Treated Fluxed Pellets in Hot Metal Bath

Abstract

Lump lime and iron ore are generally used in the basic oxygen furnace as flux and cooling material, respectively. Owing to high melting point, poor dissolution property, fines generation tendency, and hygroscopic nature of lump lime, delay in process and operational complexities are generally encountered. On the other hand, iron ore charging creates slag foaming. In order to alleviate the above problems and to utilize waste materials, fluxed lime–iron oxide pellets (FLIP) containing waste iron oxides and lime fines (10%–40%) were prepared and subsequently strengthened with CO₂ gas treatment. FLIP may have the potential to partially replace scrap and lump lime in the conventional basic oxygen furnace charge. In order to assess the applicability of FLIP in steelmaking, the dissolution characteristics of these pellets were studied in a high-temperature pot furnace equipped with a charge-coupled device (CCD) camera under varying experimental conditions. It was found that the dissolution time decreased with increasing hot metal temperature, increasing specific surface area of the pellet, and decreasing lime content of the pellet. The melting of the pellet in the absence of hot metal took much higher time than its presence.

Keywords:

• CO₂-treated fluxed pellet
• dissolution
• hot metal bath
• slag formation

ACKNOWLEDGMENTS

Authors would like to express their sincere gratitude to Director, National Metallurgical Laboratory, Council of Scientific and Industrial Research (CSIR), Jamshedpur, India, for his kind permission to publish the article. Authors thankfully acknowledge the financial assistance received from the Department of Science and Technology (DST) under the Ministry of Science and Technology (Govt. of India) for carrying out this investigation.

Notes

Note: LOI, loss on ignition.