Study On The Basic Performance Of Blast Furnace Slag Under The Baotou Steel Condition Of Raw Materials

With the great progress of Baotou Steel's Beneficiation Technology,the proportion of foreign purchased ore and imported ore in the blast furnace raw materials has an increase,which greatly cut down the content of F,K,and Na in the blast furnace slag,while the content of Al₂O₃has been greatly improved to some extent,which changes the composition of the blast furnace slag and the performance.Therefore,it is very necessary to study the properties of Baotou Steel's blast furnace slag under raw material conditions.Based on the slag of No.7 Blast Furnace of Baotou Steel,the method that combining experiments and thermodynamic calculations is used to study the change of slag chemical composition to its viscosity,melting temperature,reflow temperature range,thermal stability,and the influence of chemical stability,heat enthalpy and desulfurization and binary alkalinity remove of slag by single-factor experiment.Through orthogonal experiments,the influence of slag composition on the viscosity is studied,the content of MgO,Al₂O₃ and the best controlled range of MgO/Al₂O₃ is confirmed,the slag performance is optimized.The research indicates:When the binary alkalinity is 1.1¹.4,the trend of melting temperature is small,and when the reflow range is 2.33?⁴.6?,the slag has good chemical stability,and when the thermal stability of the slag is 0.019 Pa·S/10?⁰.022 Pa·S/10?,the viscosity of slag is low,and it has good fluidity.When MgO content is in the range of 10%¹4%,the melting temperature of the slag rises,and the softening interval decreases,and the viscosity of the slag is continuously decreasing.When thermal stability of the slag is 0.020 Pa·S/10?⁰.024 Pa·S/10?,it has good fluidity and stability.When Al₂O₃ content is in the range of8%¹7%,the melting temperature of the slag continues to increase,the softening interval decreases,and the viscosity of the slag decreases.When the thermal stability of the slag is 0.020Pa·S/10?⁰.026 Pa·S/10?and Al₂O₃ content is 15%,the viscosity of slag is the lowest,and it has good fluidity and stability.MgO/Al₂O₃ is in the range of 0.4⁰.8,the liquidus temperature and viscosity decrease first and then increase,the thermal stability is 0.020 Pa·S/10?⁰.029Pa·S/10?,when MgO/Al₂O₃ is 0.5,the viscosity of slag is the lowest,and it has good fluidity.Through the orthogonal test with three factors and four levels,it reveals that the binary alkalinity has the greatest influence on the viscosity of slag.The content of MgO and Al₂O₃ has the same influence on the viscosity of slag.The regularity of slag heat enthalpy is studied when alkalinity?MgO content and Al₂O₃ content in 1.1¹.3?8%¹2%and 10%¹6%respectively in the method combining experiment with calculation.Desulfurization and binary alkalinity removal experiments are carried out when the binary alkalinity is between 1.1 and 1.4.It is beneficial to the desulfurization of slag and not conducive to binary alkalinity removal of slag as the binary alkalinity increasing.Adjusting the alkalinity of the slag after it is completed to 1.15 and the MgO content is 12%,the Al₂O₃ content is 15%as well.Carrying out the desulfurization and alkali remove experiments,the ability of desulfurization and alkali remove is increased by 51%and 9%respectively compared with the current slag.