转炉脱磷渣物相结构对脱磷的影响

通过采用热力学软件 Factsage 6.4、SEM、EDS、XRD,并结合红外和拉曼实验手段分析研究了一次倒渣和终点炉渣物相结构.结果表明：一倒渣和终渣的黏度均随着温度的升高而降低.温度相同时,一倒渣的黏度较高,但熔点低于终渣.低温时形成的液相较多,更有利于脱磷反应的进行.炉渣 Si、Ca、P 元素富集的区域,形成的矿相主要为2CaO?SiO2-3CaO?P2 O5固溶体相,对脱磷较为有利；而 Fe、Mn、Mg 和 O 元素富集的区域,形成的物相主要为铁氧化物和RO相,炉渣脱磷能力脱磷较差.红外和拉曼分析结果表明：一倒渣和终渣都形成SiO4四面体单元,一倒渣主要以Si-O-Si键为主,而终渣主要以P-O-P键为主.硅酸盐网状结构单元结构越多,对脱磷越有利.

Effect of phase structure of converter dephosphorization slag on dephosphorization

The phase structures of dephosphorization slag at the first deslagging and final slag were investigated by Factsage 6.4 software,SEM,EDS,XRD,Fourier transformation infrared (FTIR)and Raman spectral spectros-copy analysis.The results show that the first deslagging viscosity and final slag viscosity decrease with increasing temperature.The first deslagging viscosity is higher than that of the final slag at the same temperature;whereas, the melting point of the first deslagging slag is lower.The more the liquid phase forms in low temperature,the better it will be for the dephosphorization reaction.The slag composition which is favorable for enriching Si,Ca and P in the area where the main mineralogical structure is solid solution phases of 2CaO?SiO2-3CaO?P2 O5 has good dephosphorization ability,while the composition which is favorable for enriching Fe,Mn,Mg and O in the area where the main mineralogical structure is phase of iron oxides and RO shows poor dephosphorization ability. The results of FTIR and Raman spectral spectroscopy analysis indicate that it mainly contains [SiO4 ]tetrahedra for the first deslagging and final slag.The Si-O-Si band is mainly formed in dephosphorization slag at the first deslagging,while P-O-P band is mainly formed in the final slag.The more network structure units of silicate exist in slag,the better it will be for slag dephosphorization ability.