Phase Equilibrium for the CaO-SiO_2-FeO-P_2O_5 System at 1673K for Dephosphorization With Multi Phase Flux

作     者：Hiroyuki MATSUURA Fumitaka TSUKIHASHI 

作者机构：Graduate School of Frontier Sciences The University of Tokyo Kashiwa Chiba 277-8561 Japan 

出 版 物：《Journal of Iron and Steel Research International》 (国际钢铁研究杂志)

年 卷 期：2011年第18卷第S2期

页      面：84-86页

核心收录：

学科分类：080602[工学-钢铁冶金] 08[工学] 0806[工学-冶金工程] 

主　　题：steelmaking dephosphorization multi phase flux thermodynamics phase diagram 

摘      要：Development of the efficient hot metal dephosphorization processes during steelmaking process is one of the most essential topics for the production of high grade clean steels. Since the formation of solid solution composed of tricalcium phosphate and dicalcium silicate could obtain a considerable mass transfer of phosphorus from liquid slag into solid phase during hot metal dephosphorization, itcould obviously sustain a high phosphatecapacityof theliquid slag without huge consumption of lime or addition of fluxes, such as fluorite. The above outlines are the main idea of multi phase flux dephosphorization. For the last few decades, many studies have been done towards the scientific principles and the commercial utilization of this technique. However, the reaction mechanism by using multi phase fluxes remains unclear even by now due tolack of evidence. Based on those previous works, providing a reliable and available phase diagram for the fundamental understanding of the reaction mechanism of multi phase flux dephosphorization has become the main purpose of present research. As well known, the CaO-SiO2-FeO-P2O5 slag is the main component of current steelmaking process. Hence the CaO-SiO2-FeO-P2O5 system at equilibrium has been studied at 1673K with low oxygen partial pressure. The solid phase coexisting with liquid flux is approved to be the solid solution composed of CaO, SiO2 and P2O5. Phosphorus distributes mainly in solid solution rather than liquid phase.