Performance Assessment of CO2 Treated Fluxed Iron Oxide Pellets in Basic Oxygen Steel Making Process

Abstract

Lump lime and iron ore are generally used in BOF as flux and cooling material respectively. Owing to high melting point, poor dissolution property, fines generation 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 iron oxide pellets containing waste iron oxides (ϳ70 %) and lime fines (ϳ30 %) were prepared and subsequently strengthened with CO 2 gas treatment. This carbonated fluxed pellets exhibited very good CCS (30 kg/pellet) and DSN (150), suitable for cold handling. The performance of this pellet has been assessed in a laboratory scale bottom blowing converter for its specific use in BOF. The refining characteristic of a liquid bath, prepared with pig iron chips was studied using a laboratory scale bottom blowing converter with three flux conditions namely fluxed pellet plus additional lime, iron ore lump plus lump lime and only lump lime. It has been observed that use of these pellets improves decarburization and dephosphorization, increases the metallic yield, decreases oxygen consumption and reduces foaming. Overall, the developed pellet shows very good application potential in basic oxygen steel making.

A Thermodynamic Model of Phosphorus Distribution Ratio between CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 Slags and Molten Steel during a Top–Bottom Combined Blown Converter Steelmaking Process Based on the Ion and Molecule Coexistence Theory

“…As an important function of converter steelmaking process, the oxidizing dephosphorization of hot metal or molten steel, has been investigated by many researchers [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] since the 1940s, [1,2,9] and many phosphorous distribution ratio prediction models [9][10][11][12][13][14][15][16] have been developed based on some empirical regressions of the measured data, such as Healy's model, [10] Suito's three models, [11,12] Sommerville's model, [9,13] and Balajiva's model. [14] However, the phosphorous distribution ratio models [9][10][11][12][13][14][15][16] are not enough and scarce from the view point of dephosphorization reactions based on metallurgical physicochemistry.…”

Retraction: Representation of Dephosphorization Ability for CaO–Containing Slags Based on the Ion and Molecule Coexistence Theory

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Many studies have been carried out to measure phosphorous distribution between various slags and hot metal since the 1940 s. 1,2,9) However, the measurement of phosphorous distribution between molten slag and hot metal is costly and difficult 11,12) in the operation. It is therefore very necessary to develop a reliable model for predicting phosphorous distribution between molten slag and hot metal.…”

Innovative Development on Agglomeration of Iron Ore Fines and Iron Oxide Wastes

“…This volume expansion helps pellet to decrease the porosity and increase in the compactness. Thus, the transformation of Ca (OH) 2 to CaCO 3 plays a predominant role for strength development of the pellets (Pal et al 2009a(Pal et al , 2010.…”