Runhao Zhang
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Runhao Zhang has a total of 13 co-authors. Here are the top co-authors by number of shared publications:
- Jian Yang
Shanghai University
6 shared publications - Wenkui Yang
State Key Laboratory of Advanced Special Steel, School of Materials Science and Engineering, Shanghai University, Shanghai, P.R. China
6 shared publications - Han Sun
State Key Laboratory of Advanced Special Steel, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
3 shared publications Han Sun
State Key Laboratory of Advanced Special Steel School of Materials Science and Engineering Shanghai University Shanghai 200444 China
2 shared publications- Fubin Gao
HBIS Handan Iron and Steel Group Co., LTD, Handan City, Hebei 056015, China
1 shared publication - Gefan Ye
State Key Laboratory of Advanced Special Steel, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
1 shared publication
Latest Publications
- 28 November 2022
- Published by Wiley in Steel Research International
- Vol. 94 (5)
Comparison of the Prediction of BOF End‐Point Phosphorus Content Among Machine Learning Models and Metallurgical Mechanism Model
The five machine learning models (MLM) of ridge regression, gradient boosting regression (GBR), support vector regression, random forest regression (RFR), convolutional neural network, and a metallurgical mechanism model (MMM) are compared in predicting the end‐point P content in the basic oxygen furnace steelmaking process. The prediction accuracy of MMM is much lower than those of five MLM. The GBR and RFR models have the best performance, with the correlation coefficient values of 0.599 and 0.608, respectively. The smallest mean absolute relative error value of 0.155 and the root mean square error value of 0.00319 are obtained with GBR and RFR, respectively. The values of correlation coefficient after data distribution optimization for all MLM are increased two times higher than before. The second blowing time, lime weight, and oxygen consumption amount are evaluated to have the greatest impacts on the end‐point P content. The end‐point P content decreases with decreasing the second blowing time and with increasing the lime weight and the oxygen consumption amount. The GBR and RFR models are optimized by removing the variables with little impacts on the end‐point P content. The highest prediction accuracy is obtained when 14 variables are remained.
- 28 November 2022
- Published by Wiley in Steel Research International
- Vol. 94 (5)
Comparison of the Prediction of BOF End‐Point Phosphorus Content Among Machine Learning Models and Metallurgical Mechanism Model
The five machine learning models (MLM) of ridge regression, gradient boosting regression (GBR), support vector regression, random forest regression (RFR), convolutional neural network, and a metallurgical mechanism model (MMM) are compared in predicting the end‐point P content in the basic oxygen furnace steelmaking process. The prediction accuracy of MMM is much lower than those of five MLM. The GBR and RFR models have the best performance, with the correlation coefficient values of 0.599 and 0.608, respectively. The smallest mean absolute relative error value of 0.155 and the root mean square error value of 0.00319 are obtained with GBR and RFR, respectively. The values of correlation coefficient after data distribution optimization for all MLM are increased two times higher than before. The second blowing time, lime weight, and oxygen consumption amount are evaluated to have the greatest impacts on the end‐point P content. The end‐point P content decreases with decreasing the second blowing time and with increasing the lime weight and the oxygen consumption amount. The GBR and RFR models are optimized by removing the variables with little impacts on the end‐point P content. The highest prediction accuracy is obtained when 14 variables are remained.
- Open Access
Effect of the Basicity on Mineralogical Phases and Micro-Structure of Dephosphorization Slag in the New Double Slag Converter Steelmaking Process
In the present work, the effect of the basicity at the lower range from 0.98 to 2.13 on dephosphorization of hot metal at 1623 K was studied through high-temperature laboratorial experiments. With the increase of the basicity from 0.98 to 2.13, the P and C contents in hot metal rapidly decrease and increase at first, and then gradually decrease and increase, respectively. From the scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and X-ray diffraction (XRD) results, with the increase of the basicity, the phase containing the high P content changes from the matrix phase into the phosphorus (P)-rich phase. Under the present experimental conditions, the P-rich phase can only be precipitated from the liquid slag when the basicity is higher than 1.55, which is a benefit to the dephosphorization. As the Raman intensity of the P-O-Ca structure unit in the P-rich phase is significantly higher than that of the P-O-Si structure unit, most of the phosphorus in the P-rich phase exists in the P-O-Ca structure unit and a small amount of phosphorus exists in the P-O-Si structure unit. With the increase of the basicity of the dephosphorization slag, the activity coefficient of P2O5, , in the liquid phase decreases, while the basicity in the liquid phase increases.Open AccessEffect of the Basicity on Mineralogical Phases and Micro-Structure of Dephosphorization Slag in the New Double Slag Converter Steelmaking Process
In the present work, the effect of the basicity at the lower range from 0.98 to 2.13 on dephosphorization of hot metal at 1623 K was studied through high-temperature laboratorial experiments. With the increase of the basicity from 0.98 to 2.13, the P and C contents in hot metal rapidly decrease and increase at first, and then gradually decrease and increase, respectively. From the scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and X-ray diffraction (XRD) results, with the increase of the basicity, the phase containing the high P content changes from the matrix phase into the phosphorus (P)-rich phase. Under the present experimental conditions, the P-rich phase can only be precipitated from the liquid slag when the basicity is higher than 1.55, which is a benefit to the dephosphorization. As the Raman intensity of the P-O-Ca structure unit in the P-rich phase is significantly higher than that of the P-O-Si structure unit, most of the phosphorus in the P-rich phase exists in the P-O-Ca structure unit and a small amount of phosphorus exists in the P-O-Si structure unit. With the increase of the basicity of the dephosphorization slag, the activity coefficient of P2O5, , in the liquid phase decreases, while the basicity in the liquid phase increases. - 8 August 2021
- Published by SAGE Publications in Ironmaking & Steelmaking: Processes, Products and Applications
- Vol. 48 (10) , 1277-1290
Kinetic model of dephosphorization in the new double slag converter steelmaking process
The kinetic investigation of the dephosphorization in the new double slag converter steelmaking process was carried out based on the coupled reactions model combining with a heat balance temperature model for the 220-ton industrial experiment. The calculated results of [%C], [%Si], [%P] in the hot metal, and the slag compositions are in good agreement with the experimental results. When the heat balance temperature model is applied, the P prediction results are better rather than those predicted by using the fixed temperatures. The calculated phosphorus distribution ratio increases with the refining time, while the phosphate capacity shows a downward trend due to the decrease in slag basicity and the increase in temperature. The rate-controlling step of the dephosphorization is determined to be the mixed control of the mass transfer of P in the hot metal and P2O5 in the slag. As the initial Si concentration is increased, the interfacial oxygen activity required for starting the dephosphorization is increased, leading to the delay of the dephosphorization start time.
- 8 August 2021
- Published by SAGE Publications in Ironmaking & Steelmaking: Processes, Products and Applications
- Vol. 48 (10) , 1277-1290
Kinetic model of dephosphorization in the new double slag converter steelmaking process
The kinetic investigation of the dephosphorization in the new double slag converter steelmaking process was carried out based on the coupled reactions model combining with a heat balance temperature model for the 220-ton industrial experiment. The calculated results of [%C], [%Si], [%P] in the hot metal, and the slag compositions are in good agreement with the experimental results. When the heat balance temperature model is applied, the P prediction results are better rather than those predicted by using the fixed temperatures. The calculated phosphorus distribution ratio increases with the refining time, while the phosphate capacity shows a downward trend due to the decrease in slag basicity and the increase in temperature. The rate-controlling step of the dephosphorization is determined to be the mixed control of the mass transfer of P in the hot metal and P2O5 in the slag. As the initial Si concentration is increased, the interfacial oxygen activity required for starting the dephosphorization is increased, leading to the delay of the dephosphorization start time.
- 4 August 2021
- Published by Wiley in Steel Research International
- Vol. 92 (11) , 2100256
Kinetics of Dephosphorization at Different Slag Basicities in the Double Slag Converter Steelmaking Process
Combined with the temperature model from heat balance and the lime dissolution model, the dephosphorization kinetic model based on the coupled reaction model for the dephosphorization stage in the double slag converter steelmaking process is developed. Two hundred and twenty ton industrial experiments with the different end slag basicities are also conducted. The calculated values of [%P], [%C], [%Si], and slag basicities are in good agreements with the industrial experiment results at the different basicities. With the progress of dephosphorization, the rate of dephosphorization rises up rapidly at first, then drops down quickly, and increases again. With increasing basicity, the dephosphorization is promoted. When the end basicity is 2.20, the lowest P concentration is 0.0682 mass% with the highest P removal ratio of 51.63%. In the case of maintaining the other parameters to be the same values, with increasing basicity from 1.5 to 2.0, the final P concentration decreases regularly and the final P removal ratio increases from 29.66% to 56.99%. With the progress of dephosphorization, the temperature increases, the volume proportion of solid particles in slag decreases, and the mass transfer resistance in the slag decreases. Based on Pal–Einstein–Roscoe model, the calculated viscosity decreases.
- 4 August 2021
- Published by Wiley in Steel Research International
- Vol. 92 (11) , 2100256
Kinetics of Dephosphorization at Different Slag Basicities in the Double Slag Converter Steelmaking Process
Combined with the temperature model from heat balance and the lime dissolution model, the dephosphorization kinetic model based on the coupled reaction model for the dephosphorization stage in the double slag converter steelmaking process is developed. Two hundred and twenty ton industrial experiments with the different end slag basicities are also conducted. The calculated values of [%P], [%C], [%Si], and slag basicities are in good agreements with the industrial experiment results at the different basicities. With the progress of dephosphorization, the rate of dephosphorization rises up rapidly at first, then drops down quickly, and increases again. With increasing basicity, the dephosphorization is promoted. When the end basicity is 2.20, the lowest P concentration is 0.0682 mass% with the highest P removal ratio of 51.63%. In the case of maintaining the other parameters to be the same values, with increasing basicity from 1.5 to 2.0, the final P concentration decreases regularly and the final P removal ratio increases from 29.66% to 56.99%. With the progress of dephosphorization, the temperature increases, the volume proportion of solid particles in slag decreases, and the mass transfer resistance in the slag decreases. Based on Pal–Einstein–Roscoe model, the calculated viscosity decreases.
- Open Access
Dephosphorization in Double Slag Converter Steelmaking Process at Different Temperatures by Industrial Experiments
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 of the selective oxidation reaction of carbon and phosphorus is 53–80 Pa, and the 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.Open AccessDephosphorization in Double Slag Converter Steelmaking Process at Different Temperatures by Industrial Experiments
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 of the selective oxidation reaction of carbon and phosphorus is 53–80 Pa, and the 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. - Open Access
Effect of the Fe2O3 Addition Amount on Dephosphorization of Hot Metal with Low Basicity Slag by High-Temperature Laboratorial Experiments
In this paper, the influence of the Fe2O3 addition amount on the dephosphorization of hot metal at 1623 K with the slag of the low basicity (CaO/SiO2) of about 1.5 was investigated by using high-temperature laboratorial experiments. With increasing the Fe2O3 addition amount from 5 to 30 g, the contents of [C], [Si], [Mn] and [P] in the hot metal at the end of dephosphorization are decreased and the corresponding removal ratios increase. In dephosphorization slags, the phosphorus mainly exists in the form of the nCa2SiO4–Ca3(PO4)2 solid solution in the phosphorus-rich phase and the value of coefficient n decreases from 20 to 1. Furthermore, the oxygen potential and activity at the interface between the slag and hot metal are increased. When the oxygen potential and the oxygen activity at the interface are greater than 0.72 × 10−12 and 7.1 × 10−3, respectively, the dephosphorization ratio begins to increase rapidly. When the Fe2O3 addition amount is increased to 30 g, the ratio of the Fe2O3 addition amount to theoretical calculation consumption is around 175%, and the dephosphorization ratio reaches the highest value of 83.3%.
Open AccessEffect of the Fe2O3 Addition Amount on Dephosphorization of Hot Metal with Low Basicity Slag by High-Temperature Laboratorial Experiments
In this paper, the influence of the Fe2O3 addition amount on the dephosphorization of hot metal at 1623 K with the slag of the low basicity (CaO/SiO2) of about 1.5 was investigated by using high-temperature laboratorial experiments. With increasing the Fe2O3 addition amount from 5 to 30 g, the contents of [C], [Si], [Mn] and [P] in the hot metal at the end of dephosphorization are decreased and the corresponding removal ratios increase. In dephosphorization slags, the phosphorus mainly exists in the form of the nCa2SiO4–Ca3(PO4)2 solid solution in the phosphorus-rich phase and the value of coefficient n decreases from 20 to 1. Furthermore, the oxygen potential and activity at the interface between the slag and hot metal are increased. When the oxygen potential and the oxygen activity at the interface are greater than 0.72 × 10−12 and 7.1 × 10−3, respectively, the dephosphorization ratio begins to increase rapidly. When the Fe2O3 addition amount is increased to 30 g, the ratio of the Fe2O3 addition amount to theoretical calculation consumption is around 175%, and the dephosphorization ratio reaches the highest value of 83.3%.