Removal kinetics of phosphorus through use of basic oxygen furnace slag（BOF-slag）was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-s...Removal kinetics of phosphorus through use of basic oxygen furnace slag（BOF-slag）was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial p H, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant（kobs） significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial p H, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage.A linear dependence of kobson total removed phosphorus（TRP） was established with kobs=（3.51 ± 0.11） × 10^-4× TRP. Finally, it was suggested that the Langmuir–Rideal（L–R）or Langmuir–Hinshelwood（L–H） mechanism may be used to describe the removal process of phosphorus using BOF-slag.展开更多
Double slag process was adopted to produce low-phosphorus steel from middle-phosphorus hot metal.To achieve a stable dephosphorization operation,conventional process was modified as follows：the blowing time was exten...Double slag process was adopted to produce low-phosphorus steel from middle-phosphorus hot metal.To achieve a stable dephosphorization operation,conventional process was modified as follows：the blowing time was extended by approximately 1min by reducing the oxygen supply flow rate;calcium ferrite pellets were added to adjust the slag composition and viscosity;the dumping temperature was lowered by 30-50°C by the addition of calcium ferrite pellets during the double slag process to prevent phosphorus in the slag from returning to the molten steel;and the bottom-blown gas flow was increased during the blowing process.For 40 heats of comparative experiments,the rate of dephosphorization reached 91% and ranged between 87% and 95%;the phosphorus,sulfur,manganese,and oxygen contents calculated according to the compositions of molten steel and slag as well as the temperature of molten steel at the end-point of the basic oxygen furnace process were similar to the equilibrium values for the reaction between the slag and the steel.Less free calcium oxide and metallic iron were present in the final slag,and the surface of the slag mineral phase was smooth,clear,and well developed,which showed that the slag exhibited better melting effects than that produced using the conventional slag process.A steady phosphorus capacity in the slag and stable dephosphorization effects were achieved.展开更多
基金financially supported by the Fundamental Research Fund for the Central Universities (No. N130302004)the National Natural Science Foundation of China (No. U1360204)
文摘Removal kinetics of phosphorus through use of basic oxygen furnace slag（BOF-slag）was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial p H, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant（kobs） significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial p H, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage.A linear dependence of kobson total removed phosphorus（TRP） was established with kobs=（3.51 ± 0.11） × 10^-4× TRP. Finally, it was suggested that the Langmuir–Rideal（L–R）or Langmuir–Hinshelwood（L–H） mechanism may be used to describe the removal process of phosphorus using BOF-slag.
基金financially supported by the Beijing Natural Science Foundation of China(No.2172057)
文摘Double slag process was adopted to produce low-phosphorus steel from middle-phosphorus hot metal.To achieve a stable dephosphorization operation,conventional process was modified as follows：the blowing time was extended by approximately 1min by reducing the oxygen supply flow rate;calcium ferrite pellets were added to adjust the slag composition and viscosity;the dumping temperature was lowered by 30-50°C by the addition of calcium ferrite pellets during the double slag process to prevent phosphorus in the slag from returning to the molten steel;and the bottom-blown gas flow was increased during the blowing process.For 40 heats of comparative experiments,the rate of dephosphorization reached 91% and ranged between 87% and 95%;the phosphorus,sulfur,manganese,and oxygen contents calculated according to the compositions of molten steel and slag as well as the temperature of molten steel at the end-point of the basic oxygen furnace process were similar to the equilibrium values for the reaction between the slag and the steel.Less free calcium oxide and metallic iron were present in the final slag,and the surface of the slag mineral phase was smooth,clear,and well developed,which showed that the slag exhibited better melting effects than that produced using the conventional slag process.A steady phosphorus capacity in the slag and stable dephosphorization effects were achieved.
