Dephosphorization Reaction Mechanism by Using Multi-Phase Flux
To apply solid and liquid coexisting flux (Muti-phase flux) to the hot metal dephosphorization process, the reaction mechanism between solid CaO and slag should be clarified. Therefore, in the present study, solid CaO and FeO<,x>-CaO-SiO<,2>-P<,2>O<,5> slag were reacted at hot metal temperatures. The interface between solid CaO and molten slag were observed and analyzed by SEM/EDS. The CaO-FeO phase was observed adjacent to solid CaO. Next to the CaO-FeO phase, 2CaO·SiO<,2> phase was formed and FeO-CaO-SiO<,2> liquid phase with high FeO content existed adjacent to 2CaO·SiO<,2>. The reaction mechanism between solid CaO and molten slag is discussed based on estimated activities for FeO and CaO in each phase. Then mechanism of the reaction is described as (1) Solid CaO dissolves into the slag and the content of CaO in the melt increases. (2) The CaO and SiO<,2> are consumed to form 2CaO· SiO<,2> in the melt, and the content of FeO in the slag increases. (3) According to the activity gradient of FeO, Fe<2+> diffuses to both solid CaO and bulk slag. (4) CaO-FeO phase is formed beside solid CaO. To reveal the reaction between 2CaO·SiO<,2> and molten slag, 2CaO·SiO<,2> was reacted with FeO<,x>-CaO-SiO<,2>-P<,2> O<,5> slag at 1573K. CaO-SiO<,2>-P<,2>O<,5> phases with high P <,2>O<,5> content were observed within 60s, where the surrounded slag composition was saturated with 2CaO·SiO<,2>. The FeO-CaO- SiO<,2> slag phase without P<,2>O<,5> was identified around CaO- SiO<,2>-P<,2>O<,5> phase. Therefore, if the slag was saturated with 2CaO·SiO<,2>, P<,2>O<,5> in slag around the 2CaO·SiO<,2> particle would diffuse to the 2CaO·SiO<,2> quickly.
solid CaO hot metal dephosphorization multi phase flux
Tasuku HAMANO Hiroyuki MATSUURA Fumitaka TSUKIHASHI
Formerly with Department of Advanced Materials Science, Graduate School of Frontier Sciences, The Un Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of To
国际会议
第十一届中日钢铁技术研讨会(11th China-Japan Symposium on Oron and Steel Technology)
武汉
英文
102-109
2007-10-29（万方平台首次上网日期，不代表论文的发表时间）