Influence of pellets quaternary basicity on softening and melting properties
Jean Philippe Santos Gherardi de Alencar
Abstract
The softening and melting zone is deemed the most critical region within a blast furnace. It is in this region that iron ore commences its softening and melting process, thereby obstructing the flow of ascending gases. The formation of a liquid phase within the ore or agglomerate, a phenomenon referred to as exudation, is intricately complex and strongly tied to the chemical composition of the burden material. Despite the challenges in replicating the conditions of the softening and melting zone at a laboratory scale, numerous studies have endeavored to establish a correlation between these chemical characteristics of the burden and its metallurgical properties. Through an extensive series of pellet tests, an investigation was conducted to determine such correlations taking into consideration the VALE’s Ferrous Technology Center database. The findings revealed that quaternary basicity serves as the most accurate predictor variable for describing the softening and melting properties of the pellets. This study supports the existing literature, suggesting that burdens with higher basicity exhibit a higher softening temperature and, consequently, a greater degree of indirect reduction. Conversely, more acidic pellets demonstrated a lower softening temperature, coupled with an extended softening interval. In conclusion, it was discovered that burdens with higher basicity also yielded lower maximum pressure values and pressure drop areas.
Keywords
Referências
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Submetido em:
22/09/2022
Aceito em:
12/08/2024
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