The Thermodynamics and Kinetics of a Nitrogen Reaction in an Electric Arc Furnace Smelting Process
The nitrogen content of electric arc furnace (EAF) steel is much higher than that of basic oxygen furnace (BOF) steel, which cannot meet the requirements of high-grade steel. Most denitrification processes only considered a single smelting condition, which leads to poor denitrification effect. In th...
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MDPI AG
2022-12-01
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| Online Access: | https://www.mdpi.com/1996-1944/16/1/33 |
| _version_ | 1797625393938694144 |
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| author | Fujun Zhang Jingshe Li Wei Liu Aoteng Jiao |
| author_facet | Fujun Zhang Jingshe Li Wei Liu Aoteng Jiao |
| author_sort | Fujun Zhang |
| collection | DOAJ |
| description | The nitrogen content of electric arc furnace (EAF) steel is much higher than that of basic oxygen furnace (BOF) steel, which cannot meet the requirements of high-grade steel. Most denitrification processes only considered a single smelting condition, which leads to poor denitrification effect. In this study, a hot state experiment was conducted to simulate the melting process of EAF steelmaking and to explore the thermodynamic and kinetic constraints of the molten steel nitrogen reaction in the scrap melting, oxygen blowing decarburization, and rapid temperature rise stages. The experimental results showed that the nitrogen reaction in the molten pool during the scrap melting stage was a first-order nitrogen absorption reaction, and the reaction-limiting link was the diffusion of nitrogen atoms in the molten steel. When the carbon content increases to 4.5%, the bath temperature decreases to 1550 °C, and the nitrogen partial pressure decreases to 0.2 <i>P</i><sup>Θ</sup>, the nitrogen saturation solubility decreased to 0.0198%, 0.0318%, and 0.0178%, respectively. At the same time, the rate constants decreased to 0.132 m/min, 0.127 m/min, and 0.141 m/min, respectively. The nitrogen reaction in the oxygen blowing decarburization stage was a secondary denitrification reaction, and the reaction-limiting link was the gas–liquid interface chemical reaction. Argon had better degassing effect. When the argon flow rate increased from 100 mL/min to 300 mL/min, the reaction constant increased by about four times. When the oxygen content of molten steel was 0.0260%, the denitrification rate constant decreased by about 2.5 times. The nitrogen content of liquid steel was higher than 0.045%, and the reaction was a secondary reaction. As the nitrogen content decreased, the reaction rate decreased, and the reaction-limiting link changed from the gas–liquid interface chemical reaction to the joint control of mass transfer and chemical reaction. The oxygen content in the molten steel can not only hinder the chemical reaction of nitrogen at the gas–liquid interface, but also reduce the mass transfer rate of nitrogen atoms in the molten steel. The results provided a theoretical basis for the optimization of nitrogen removal process and further reduction of nitrogen content in liquid steel. |
| first_indexed | 2024-03-11T09:55:56Z |
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| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-11T09:55:56Z |
| publishDate | 2022-12-01 |
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| series | Materials |
| spelling | doaj.art-61a4247954df4e0482647a0ccbec44fa2023-11-16T15:46:04ZengMDPI AGMaterials1996-19442022-12-011613310.3390/ma16010033The Thermodynamics and Kinetics of a Nitrogen Reaction in an Electric Arc Furnace Smelting ProcessFujun Zhang0Jingshe Li1Wei Liu2Aoteng Jiao3State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaState Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, ChinaState Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, ChinaThe nitrogen content of electric arc furnace (EAF) steel is much higher than that of basic oxygen furnace (BOF) steel, which cannot meet the requirements of high-grade steel. Most denitrification processes only considered a single smelting condition, which leads to poor denitrification effect. In this study, a hot state experiment was conducted to simulate the melting process of EAF steelmaking and to explore the thermodynamic and kinetic constraints of the molten steel nitrogen reaction in the scrap melting, oxygen blowing decarburization, and rapid temperature rise stages. The experimental results showed that the nitrogen reaction in the molten pool during the scrap melting stage was a first-order nitrogen absorption reaction, and the reaction-limiting link was the diffusion of nitrogen atoms in the molten steel. When the carbon content increases to 4.5%, the bath temperature decreases to 1550 °C, and the nitrogen partial pressure decreases to 0.2 <i>P</i><sup>Θ</sup>, the nitrogen saturation solubility decreased to 0.0198%, 0.0318%, and 0.0178%, respectively. At the same time, the rate constants decreased to 0.132 m/min, 0.127 m/min, and 0.141 m/min, respectively. The nitrogen reaction in the oxygen blowing decarburization stage was a secondary denitrification reaction, and the reaction-limiting link was the gas–liquid interface chemical reaction. Argon had better degassing effect. When the argon flow rate increased from 100 mL/min to 300 mL/min, the reaction constant increased by about four times. When the oxygen content of molten steel was 0.0260%, the denitrification rate constant decreased by about 2.5 times. The nitrogen content of liquid steel was higher than 0.045%, and the reaction was a secondary reaction. As the nitrogen content decreased, the reaction rate decreased, and the reaction-limiting link changed from the gas–liquid interface chemical reaction to the joint control of mass transfer and chemical reaction. The oxygen content in the molten steel can not only hinder the chemical reaction of nitrogen at the gas–liquid interface, but also reduce the mass transfer rate of nitrogen atoms in the molten steel. The results provided a theoretical basis for the optimization of nitrogen removal process and further reduction of nitrogen content in liquid steel.https://www.mdpi.com/1996-1944/16/1/33electric arc furnace steelmakingthermodynamicsdynamicsrestrictive stepoptimization of denitrification process |
| spellingShingle | Fujun Zhang Jingshe Li Wei Liu Aoteng Jiao The Thermodynamics and Kinetics of a Nitrogen Reaction in an Electric Arc Furnace Smelting Process Materials electric arc furnace steelmaking thermodynamics dynamics restrictive step optimization of denitrification process |
| title | The Thermodynamics and Kinetics of a Nitrogen Reaction in an Electric Arc Furnace Smelting Process |
| title_full | The Thermodynamics and Kinetics of a Nitrogen Reaction in an Electric Arc Furnace Smelting Process |
| title_fullStr | The Thermodynamics and Kinetics of a Nitrogen Reaction in an Electric Arc Furnace Smelting Process |
| title_full_unstemmed | The Thermodynamics and Kinetics of a Nitrogen Reaction in an Electric Arc Furnace Smelting Process |
| title_short | The Thermodynamics and Kinetics of a Nitrogen Reaction in an Electric Arc Furnace Smelting Process |
| title_sort | thermodynamics and kinetics of a nitrogen reaction in an electric arc furnace smelting process |
| topic | electric arc furnace steelmaking thermodynamics dynamics restrictive step optimization of denitrification process |
| url | https://www.mdpi.com/1996-1944/16/1/33 |
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