scholarly journals Phosphorus Equilibrium Between Liquid Iron and CaO-SiO2-MgO-Al2O3-FeO-P2O5 Slags: EAF Slags, the Effect of Alumina and New Correlation

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 116 ◽  
Author(s):  
Andre N. Assis ◽  
Mohammed A. Tayeb ◽  
Seetharaman Sridhar ◽  
Richard J. Fruehan
Keyword(s):  
Iron Oxide ◽  
Partition Coefficient ◽  
Calcium Oxide ◽  
Liquid Iron ◽  
Slag Composition ◽  
Iron Ore ◽  
Electric Arc ◽  
Arc Furnace ◽  
Direct Reduced Iron ◽  
New Correlation

The increased use of electric arc furnace (EAF) steelmaking using up to 100% direct reduced iron (DRI) has prompted an interest in better control of phosphorus since iron ore and, consequently, DRI have higher phosphorus and silica compared to scrap. There is limited work reported on slag chemistries corresponding to that in the EAF when DRI is used. In the current research, phosphorus equilibria between molten Fe–P alloys and CaO-SiO2-Al2O3-P2O5-FeO-MgOsaturated slags were investigated. The results indicate that there is a significant decrease in the phosphorus partition coefficient (LP) as alumina in the slag increases. The observed effect of alumina on the phosphorus partition is probably caused by the decrease in the activities of iron oxide and calcium oxide. Finally, an equilibrium correlation for phosphorus partition as a function of slag composition and temperature has been developed. It includes the effect of alumina and silica and is suitable for both oxygen and electric steelmaking-type slags.

scholarly journals Thermodynamic of Liquid Iron Ore Reduction by Hydrogen Thermal Plasma

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1051 ◽  
Author(s):  
Masab Naseri Seftejani ◽  
Johannes Schenk
Keyword(s):  
Iron Oxide ◽  
Liquid Iron ◽  
Thermal Plasma ◽  
Iron Ore ◽  
Hydrogen Plasma ◽  
Reduction Rate ◽  
Plasma Arc ◽  
Ionization Degree ◽  
Reduction Reactions ◽  
Plasma State

The production of iron using hydrogen as a reducing agent is an alternative to conventional iron- and steel-making processes, with an associated decrease in CO2 emissions. Hydrogen plasma smelting reduction (HPSR) of iron ore is the process of using hydrogen in a plasma state to reduce iron oxides. A hydrogen plasma arc is generated between a hollow graphite electrode and liquid iron oxide. In the present study, the thermodynamics of hydrogen thermal plasma and the reduction of iron oxide using hydrogen at plasma temperatures were studied. Thermodynamics calculations show that hydrogen at high temperatures is atomized, ionized, or excited. The Gibbs free energy changes of iron oxide reductions indicate that activated hydrogen particles are stronger reducing agents than molecular hydrogen. Temperature is the main influencing parameter on the atomization and ionization degree of hydrogen particles. Therefore, to increase the hydrogen ionization degree and, consequently, increase of the reduction rate of iron ore particles, the reduction reactions should take place in the plasma arc zone due to the high temperature of the plasma arc in HPSR. Moreover, the solubility of hydrogen in slag and molten metal are studied and the sequence of hematite reduction reactions is presented.

scholarly journals Effect of Direct Reduced Iron on Ferrous Oxide Capacity of Slag in Electric Arc Furnace.

2019 ◽  
Vol 108 (1) ◽  
pp. 64-76
Author(s):  
H. A. Abdelwahed ◽  
M. Shaheen ◽  
G. M. Megahed ◽  
E. Ahmed ◽  
M. Meraikib
Keyword(s):  
Electric Arc Furnace ◽  
Electric Arc ◽  
Ferrous Oxide ◽  
Arc Furnace ◽  
Direct Reduced Iron

scholarly journals Chemical Composition, pH Value, and Points of Zero Charge of High Calcium and High Iron Electric Arc Furnace Slag

2018 ◽  
Vol 7 (3.23) ◽  
pp. 1 ◽  
Author(s):  
Siti Zu Nurain Ahmad ◽  
Hamdan R ◽  
Wan Afnizan Wan Mohamed ◽  
N Othman ◽  
Nur Shaylinda Mohd Zin
Keyword(s):  
Chemical Composition ◽  
Calcium Oxide ◽  
Ferric Oxide ◽  
Ph Value ◽  
Steel Slag ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
High Calcium ◽  
Eaf Slag

Electric arc furnace (EAF) slag as filter media has been extensively used nowadays for wastewater treatment technology. Steel slag was produced as byproduct from steelmaking processes. However, different batches of steel slag production produce different composition. Thus, this study determined the chemical composition, pH value and points of zero charge (PZC) of two different samples of electric arc furnace (EAF) slag; high iron EAF slag (Slag HFe) and high calcium EAF slag (Slag HCa). The steel slag were characterized using X-ray Fluorescence Spectroscopy (XRF) analysis for the chemical composition, extraction with boiling water for pH value, and salt addition method for PZC. Slag HFe was mainly consisted of 38.2% ferric oxide and 20.4% calcium oxide, 10.20 pH value and pH 10.55 for PZC. While for Slag HCa, they were composed of 1.64% ferric oxide and 49.5% calcium oxide of pH value of 11.11 and pH 11.75 for PZC. Therefore, Slag HCa was considered as a more basic species compared to Slag HFe. 

scholarly journals Effect of partially reduced highly fluxed DRI pellets on impurities removal during steelmaking using a laboratory scale EAF

2021 ◽  
pp. 50-50
Author(s):  
R.K. Dishwar ◽  
O.P. Sinha
Keyword(s):  
Reaction Time ◽  
Comparative Study ◽  
Phosphorus Removal ◽  
Sulfur Removal ◽  
Electric Arc ◽  
Pig Iron ◽  
Arc Furnace ◽  
Direct Reduced Iron ◽  
Removal Of Impurities ◽  
Impurities Removal

The present work represents a comparative study on the impurities removal from pig iron melt by addition of partially reduced highly fluxed direct reduced iron (DRI) to make steel in a 2 kg capacity electric arc furnace (EAF). Three types of fluxed DRI (30, 50, 80% Reduction (%R) with similar basicity-8) were used to maintain different level of oxidizing potential on the bath for studying the kinetic behaviour of impurities removal from melt. Results showed that the rate of removal of impurities (i.e. C, Si, Mn, P, S etc.) was increased initially up to 5 minutes of reaction time then decreased afterwards. Phosphorus (~64%), sulfur (~16%) and carbon (~94%) were removed simultaneously up to 25 minutes of reaction time using 30%R fluxed DRI. Similarly, phosphorus (~33%), sulfur (~50%) and carbon (~62%) were removed simultaneously using 50%R fluxed DRI while highly reduced (80%R) flux DRI removed sulfur (~58%), carbon (~56%) with a small fraction of phosphorus (~18%) from pig iron. It was observed in all the cases that silicon (>99%) and manganese (>80%) were removed. From the present study, it can be concluded that ~30%R DRI is favorable for effective phosphorus removal whereas ~80%R is favorable for sulfur removal. The significant removal of impurities could be achieved by charging ~50%R fluxed DRI in the pig iron melt.

scholarly journals A combined hydro-pyrometallurgical process for zinc oxide and iron oxide extraction from electric arc furnace dust waste

2021 ◽  
Vol 945 (1) ◽  
pp. 012027
Author(s):  
Hwang Sheng Lee ◽  
Yao Yi Teo
Keyword(s):  
Zinc Oxide ◽  
Iron Oxide ◽  
Liquid Solution ◽  
Extraction Process ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
Pyrometallurgical Process ◽  
Eaf Dust ◽  
Iron Leaching

Abstract Electric arc furnace (EAF) dust waste is generated during EAF steelmaking process. Zinc and iron which comprise the highest composition in EAF dust are secondary resources for making steel products. They mainly present in the form of stable zinc ferrite (ZnFe2O4), leading to the extraction process difficult. In this study, a combined hydro-pyrometallurgical process was developed to extract both zinc oxide and iron oxide from EAF dust. Initially, hydrometallurgical leaching was used to leach zinc and iron from EAF dust. Results show that 10 M of hydrochloric acid (HCl) at 25°C can achieve zinc and iron leaching of 92% and 91%, respectively. The liquid solution post leaching was subjected to pyrometallurgical process to form Fe2O3 mixture at 250°C while retaining zinc chloride (ZnCl2) as solid residue. Then, the obtained ZnCl2 was treated with sodium hydroxide (NaOH) and nitric acid (HNO3) to form ZnO. The Fe2O3 and ZnO extraction were 2.5 g and 1.5 g, respectively out of 10 g of EAF dust with their respective purity of 87% and 98%. The developed process can provide new insight into recovering zinc oxide and iron oxide simultaneously from EAF dust, thereby paving the way to circular economy development and sustainable steel dust waste management for steel industries.

Utilization of direct reduced iron in an electric arc furnace

1976 ◽  
Vol 15 (1) ◽  
pp. 41-47
Author(s):  
L.M. Kay ◽  
M. Rigaud ◽  
A.H. Marquis
Keyword(s):  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
Direct Reduced Iron

Role of Direct Reduced Iron Fines in Nitrogen Removal from Electric Arc Furnace Steel

2007 ◽  
Vol 78 (8) ◽  
pp. 588-594 ◽  
Author(s):  
J. Pal ◽  
S. Ghosh ◽  
M. C. Goswami ◽  
D. P. Singh ◽  
Manoj Kumar ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
Direct Reduced Iron ◽  
Furnace Steel

scholarly journals Process Improvements for Direct Reduced Iron Melting in the Electric Arc Furnace with Emphasis on Slag Operation

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 402
Author(s):  
Marcus Kirschen ◽  
Thomas Hay ◽  
Thomas Echterhof
Keyword(s):  
Steel Production ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Raw Material ◽  
Steel Scrap ◽  
Process Conditions ◽  
Arc Furnace ◽  
Process Improvements ◽  
Direct Reduced Iron ◽  
Arc Furnaces

Steelmaking based on direct reduced iron (DRI, and its compacted derivative hot briquetted iron, HBI) is an anticipated important global alternative to current steel production based on FeOx reduction in blast furnaces due to its lower specific CO2 emission. The majority of DRI is melted and refined in the electric arc furnace with different process conditions compared to the melting of steel scrap due to its raw material composition being rather different. We provide data and analysis of slag composition of DRI charges vs. steel scrap charges for 16 industrial electric arc furnaces (EAFs). Suggestions for optimized slag operation and resulting process improvements of DRI melting in the EAF are given. A dynamic mass and energy model of the DRI melting in the EAF is introduced to illustrate the implications of the adapted slag operation on the EAF process with DRI charges.

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