Influence of operational parameters on silicon in hot metal from Corex

Abstract

Quality steel production at low cost demands superior quality of hot metal (HM) with low silicon (Si) and sulphur. High silicon is undesirable for its subsequent treatment during steelmaking, making the process costlier and less productive, hence there have been constant efforts to lower the silicon content in HM. Corex is the only commercially established and proven smelting reduction ironmaking technology alterative to conventional blast furnace (BF) ironmaking. While the mechanism of silicon transfer is largely understood in the BF, the Corex process still requires further operational guidance for its control. A statistical analysis of more than one year plant data has been carried out to understand the parameters influencing the silicon content and to provide directions for its prediction and control. Based on the understanding of the parameters affecting the silicon in HM, regression analysis was carried out and equations have been developed to predict the silicon in Corex HM. The present paper discusses the various parameters involved, the regression output for silicon prediction, its validation and its interrelation with operating parameters. The analysis indicates that high fuel rates due to high moisture, poor metallisation, high volatile matter, high slag volume, high coal fines and low production, along with high basicity and alumina in slag lead to high silicon in HM.

Numerical Analysis on Effect of Additional Gas Injection on Characteristics around Raceway in Melter Gasifier

“…On the other hand, the nitride may be formed on the surface of tuyere under the condition of the high gas temperature, and it could act as a thermal insulating protective film [25]. The production practices of India Jindal [26] and China Baosteel [20] show that when the volume fraction of additional N 2 injection is 8% or more, the number of damaged tuyere decreases effectively and the service life of tuyere is prolonged.…”

Factors Influencing Gas Generation Behaviours of Lump Coal Used in COREX Gasifier

“…Industrial applications have proved that the lump coal quality has a significant impact on stable operation and energy consumption. Kumar [3,4] et al revealed that the quality of lump coal could affect the fuel ratio and Si content in hot metal, and then proposed suitable quality requirements for lump coal used in the COREX process [5,6]. Guo et al found that the metallurgical properties of coal greatly influenced the temperature of hot metal [7,8].…”

Influence of Slag Composition and Temperature on Silicon Distribution between Slag and Hot Metal in the Egyptian Blast Furnace No.III

“…The reduction process is accomplished by further reaction of SiO in the gas phase with the carbon dissolved in the trickling metal droplets passing through the region extending between the bosh and the hearth and gets transferred as silicon to the metal. The reduction of SiO2 to volatile SiO proceeds also by the action of C in the coke, CO or SiC [1][2][3][4][5][6][7].…”