scholarly journals New trends in basic oxygen furnace dephosphorization

2020 ◽  
Vol 56 (1) ◽  
pp. 1-10
Author(s):  
E. Keskinkilic
Keyword(s):  
Phosphorus Removal ◽  
Basic Oxygen Furnace ◽  
Converter Steelmaking ◽  
Hot Metal ◽  
Basic Oxygen ◽  
P Content ◽  
Low Phosphorus ◽  
Unique Method ◽  
Dephosphorization Slag ◽  
Double Slag

Except for special grades of steel where it is used as an alloying element, phosphorus is regarded as an impurity that must be removed. Considering the conventional integrated iron and steelmaking, there are primarily two processes for phosphorus removal. The first is a hot metal dephosphorization (DeP) process that is applied to a blast furnace for hot metal before the steelmaking process. The second is the basic oxygen furnace steelmaking (BOS), a unique method primarily used for steelmaking, with the exception of stainless steels. Hot metal phosphorus content has a direct impact on BOS. An increase of phosphorus in hot metal is mainly related to the use of high P2O5 containing iron ores. In the current literature review, new trends of phosphorus removal in converter steelmaking are outlined. The double-slag practice was reported to be successful when hot metal P content was larger than 0.100%. It was indicated that the tapping temperature was critical for the production of low-phosphorus grades for which maximum allowable P content was 0.007% and that high tapping temperatures should be avoided. The tap-to-tap time for the double-slag process was slightly longer than the conventional converter steelmaking. It was further reported that the double-slag practice would be more economical than an establishment of a separate hot metal dephosphorization unit, if low-phosphorus grades did not have a significant share in the product mix of a steelmaking company. Endpoint phosphorus prediction was one of the important recent trends of converter steelmaking. A mixed injection of CO2-O2 to a basic oxygen furnace was applied to enhance dephosphorization, and promising results were reported. Unfortunately, a successful process for recycling of BOS dephosphorization slag has not been reported yet.

scholarly journals Dephosphorization by Double-Slag Process in Converter Steelmaking

2018 ◽  
Vol 37 (7) ◽  
pp. 625-633
Author(s):  
Yang Wang ◽  
Shufeng Yang ◽  
Jingshe Li ◽  
Jie Feng ◽  
Feng Wang
Keyword(s):  
Production Efficiency ◽  
Smelting Process ◽  
Converter Steelmaking ◽  
Steelmaking Process ◽  
Key Factors ◽  
Iron Slag ◽  
Low Phosphorus ◽  
Dephosphorization Slag ◽  
Phosphorus Steel ◽  
Double Slag

AbstractThe double-slag converter steelmaking process can smelt low- and ultra-low-phosphorus steel and reduce lime and dolomite consumption and the amount of final slag simultaneously. Industrial steelmaking tests on a 150-metric ton converter at the Tangsteel Company were carried out to study this principle and its effect on the dephosphorization ratio and material consumption. The results showed that low-temperature stage could be used with a reduced amount of slag in the double-slag steelmaking process to achieve rapid and efficient dephosphorization. A low-basicity slag (~1.5–2.0) in the dephosphorization stage is required in double-slag process. The dephosphorization ratio reached a maximum of 71 % when the slag basicity was 1.7. The end-point phosphorus content after the smelting process was reduced from an average of 0.018 mass% to an average of 0.011 mass% and the dephosphorization efficiency increased by more than 6 %. The dephosphorization slag could be poured out rapidly when the FeO content was controlled at ~16–20 mass% in the double-slag smelting process. Based on key factors such as an efficient dephosphorization and a rapid iron–slag separation, the production efficiency was improved and the smelting cycle increased by only four minutes over the conventional process.

scholarly journals Dephosphorization in Double Slag Converter Steelmaking Process at Different Temperatures by Industrial Experiments

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1030
Author(s):  
Han Sun ◽  
Jian Yang ◽  
Xinwu Lu ◽  
Wanshan Liu ◽  
Gefan Ye ◽  
...  
Keyword(s):  
Dynamic Equilibrium ◽  
Converter Steelmaking ◽  
Steelmaking Process ◽  
Hot Metal ◽  
Experimental Conditions ◽  
Rich Phase ◽  
Temperature Range ◽  
Industrial Experiments ◽  
Dephosphorization Slag ◽  
Double Slag

In the present work, the effect of dephosphorization endpoint temperature on the dephosphorization of hot metal was studied for the double slag converter steelmaking process under the conditions of low temperature and low basicity by the industrial experiments. In the temperature range of 1350–1450 °C, with an increasing dephosphorization endpoint temperature, the dephosphorization ratio and phosphorus distribution ratio first increase and then decrease. The phosphorus content in hot metal first decreases and then increases at the end of dephosphorization. At the dephosphorization temperature range of 1385–1410 °C, the dephosphorization ratio is higher than 55%, the P2O5 content in the dephosphorization slag is 3.93–4.17%, the logLP value is 1.76–2.09, the value of PCOP-C of the selective oxidation reaction of carbon and phosphorus is 53–80 Pa, and the aFeO value is 0.284–0.312. The path of phosphorus in hot metal entering the P-rich phase of dephosphorization slag can be reasonably inferred as: hot metal → Fe-rich phase → P-rich phase. Under the present industrial experimental conditions, the dephosphorization and rephosphorization reactions are in dynamic equilibrium at 1413 °C. Considering the experimental results and thermodynamic calculation results of industrial experiments by the double slag dephosphorization process, the optimal temperature range for intermediate deslagging is about 1400–1420 °C.

scholarly journals The Potential of Recycling the High-Zinc Fraction of Upgraded BF Sludge to the Desulfurization Plant and Basic Oxygen Furnace

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1057 ◽  
Author(s):  
Anton Andersson ◽  
Mats Andersson ◽  
Elsayed Mousa ◽  
Adeline Kullerstedt ◽  
Hesham Ahmed ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Reduction Rate ◽  
Basic Oxygen Furnace ◽  
Plant Residues ◽  
Hot Metal ◽  
Smelting Reduction ◽  
Basic Oxygen ◽  
High Zinc ◽  
Endothermic Reactions ◽  
Recycling Potential

In ore-based steelmaking, blast furnace (BF) dust is generally recycled to the BF via the sinter or cold-bonded briquettes and injection. In order to recycle the BF sludge to the BF, the sludge has to be upgraded, removing zinc. The literature reports cases of recycling the low-zinc fraction of upgraded BF sludge to the BF. However, research towards recycling of the high-zinc fraction of BF sludge within the ore-based steel plant is limited. In the present paper, the high-zinc fraction of tornado-treated BF sludge was incorporated in self-reducing cold-bonded briquettes and pellets. Each type of agglomerate was individually subjected to technical-scale smelting reduction experiments aiming to study the feasibility of recycling in-plant residues to the hot metal (HM) desulfurization (deS) plant. The endothermic reactions within the briquettes decreased the heating and reduction rate leaving the briquettes unreduced and unmelted. The pellets were completely reduced within eight minutes of contact with HM but still showed melt-in problems. Cold-bonded briquettes, without BF sludge, were charged in industrial-scale trials to study the recycling potential to the HM deS plant and basic oxygen furnace (BOF). The trials illustrated a potential for the complete recycling of the high-zinc fraction of BF sludge. However, further studies were identified to be required to verify these results.

Optimization Studies of Hot Metal Desulphurized and Basic Oxygen Furnace Slags in Sinter Making at JSW Steel Limited

2017 ◽  
Vol V6 (09) ◽  
Author(s):  
Sharanappa Kalshetty ◽  
Rudramuniappa MV ◽  
Ratnakar Bonda ◽  
VR Sekhar ◽  
Keyword(s):  
Basic Oxygen Furnace ◽  
Hot Metal ◽  
Basic Oxygen

Investigation of the phosphorus removal capacities of basic oxygen furnace slag under variable conditions

2015 ◽  
Vol 37 (10) ◽  
pp. 1257-1264 ◽  
Author(s):  
Chong Han ◽  
Zhen Wang ◽  
Wangjin Yang ◽  
Qianqian Wu ◽  
He Yang ◽  
...  
Keyword(s):  
Phosphorus Removal ◽  
Basic Oxygen Furnace ◽  
Basic Oxygen ◽  
Basic Oxygen Furnace Slag ◽  
Furnace Slag

Effects of pH on phosphorus removal capacities of basic oxygen furnace slag

2016 ◽  
Vol 89 ◽  
pp. 1-6 ◽  
Author(s):  
Chong Han ◽  
Zhen Wang ◽  
Wangjin Yang ◽  
Qianqian Wu ◽  
He Yang ◽  
...  
Keyword(s):  
Phosphorus Removal ◽  
Basic Oxygen Furnace ◽  
Basic Oxygen ◽  
Effects Of Ph ◽  
Basic Oxygen Furnace Slag ◽  
Furnace Slag

scholarly journals Kinetics Behavior of Iron Oxide Formation under the Condition of Oxygen Top Blowing for Dephosphorization of Hot Metal in the Basic Oxygen Furnace

2009 ◽  
Vol 95 (3) ◽  
pp. 207-216 ◽  
Author(s):  
Akitoshi Matsui ◽  
Seiji Nabeshima ◽  
Hidetoshi Matsuno ◽  
Naoki Kikuchi ◽  
Yasuo Kishimoto
Keyword(s):  
Iron Oxide ◽  
Basic Oxygen Furnace ◽  
Hot Metal ◽  
Oxide Formation ◽  
Basic Oxygen

Evaluation of the role of inherent Ca2+ in phosphorus removal from wastewater system

2015 ◽  
Vol 73 (7) ◽  
pp. 1644-1651 ◽  
Author(s):  
Chong Han ◽  
Zhen Wang ◽  
Qianqian Wu ◽  
Wangjin Yang ◽  
He Yang ◽  
...  
Keyword(s):  
Phosphorus Removal ◽  
Energy Dispersive Spectrometer ◽  
Basic Oxygen Furnace ◽  
Basic Oxygen ◽  
Batch Tests ◽  
Infrared Spectrophotometer ◽  
Ft Ir ◽  
Basic Oxygen Furnace Slag ◽  
Furnace Slag

The role of inherent Ca2+ in phosphorus removal from wastewater was evaluated by batch tests. Precipitates were characterized by an X-ray diffractometer (XRD), Fourier transform infrared spectrophotometer (FT-IR) and scanning electron microscope with an energy dispersive spectrometer (EDS) system. Effects of inherent Ca2+ on phosphorus removal through basic oxygen furnace slag (BOFS) were also analyzed. The results show that upon adjusting the pH to higher than 7.0, inherent Ca2+ can remove phosphorus from wastewater and form Ca-P precipitates. Residual phosphorus exhibited a linear decreasing trend with increasing the pH from 7.0 to 10.0 and then remained unchanged at higher pH than 10.0. EDS determined that the precipitates contained the elements Ca, P and O. FT-IR spectra demonstrated that the functional groups of precipitates involved PO43−, OH− and CO32−. XRD indicated that the precipitates may consist of CaCO3 and some Ca-P phosphates such as CaHPO4, Ca4H(PO4)3, Ca3(PO4)2, and Ca5(PO4)3(OH). During the removal process of phosphorus by BOFS, due to the presence of inherent Ca2+ in wastewater, the removal efficiency and rate of phosphorus increased by 15.5% and by a factor of about 3.0, respectively.

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