Dephosphorization reaction by using multi phase flux
The demand for production of low phosphorus steel has been continuously increasing.During hot metal dephosphorization process,phosphorus is oxidized and removed from molten iron by injecting CaO and FeO,and blowing oxygen from the top of the melt.However,since the operation is carried out at relatively low temperature around 1573 K,the produced CaO–FeO–SiO2 slag contains considerable amount of unreacted solid CaO and thus the utilization efficiency for CaO is not high.It is required to increase the utilization efficiency of solid CaO to reduce the amount of slag from the viewpoint of environmental issues.The present work aims to comprehensively understand the reaction mechanism of solid CaO or 2CaO·SiO2 with the liquid slag,and the formation behavior of solid phase containing P2O5,namely 2CaO·SiO2–3CaO·P2O5 solid solution for the development of the innovative dephosphorization process by using multi phase flux with the utilization of solid phase for refining reaction.Firstly,the reactions between solid CaO or 2CaO·SiO2 and molten CaO–FeO–SiO2–P2O5 slag have been observed at 1573 and 1673 K.The formation behavior of solid phase containing P2O5 has been observed.The phase relationship between solid 2CaO·SiO2–3CaO·P2O5 and liquid slag is quite important for the understanding of the reaction mechanisms.Therefore,the phase relationship and partition behavior of P2O5 between solid and liquid phases have been measured for the CaO–FeO–SiO2–P2O5 system at oxygen partial pressure of 10?8 or 10?10 atm at 1573 or 1673 K.The liquidus and the partition ratio of P2O5 between solid solution and liquid phases has been determined by measuring compositions of all phases after equilibrium by SEM–EDS.From above findings,it has been found that this innovative dephosphorization process with multi phase flux has a possibility to dramatically reduce slag generation amount with maintained dephosphorization ability compared to the conventional process.
Steelmaking Dephosphorization Solid solution Phase diagram Reaction mechanism Multi phase flux
Xu GAO Xiao YANG Hiroyuki MATSUURA Fumitaka TSUKIHASHI
Graduate School of Frontier Sciences,The University of Tokyo,Kashiwa,Chiba 277-8561 Japan Graduate School of Frontier Sciences,The University of Tokyo,Kashiwa,Chiba 277-8561 Japan;Institute
国际会议
Asia Steel International conference 2012(第五届亚洲钢铁大会)
北京
英文
1-6
2012-09-23（万方平台首次上网日期，不代表论文的发表时间）