二次精煉渣成分對渣中MgO飽和度的影響
Effect of the composition on MgO saturability in secondary metallurgical slag
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摘要: 在二次精煉過程中, 流動性適中且MgO飽和的精煉渣有助于渣鋼傳質, 并可以在一定程度上延長耐火材料的壽命.本研究使用熱力學計算軟件Fact Sage及熱態平衡實驗對酸性精煉渣Ca O-Si O2-Al2O3-MgO四元系中MgO飽和度進行了研究.結果表明:當酸性精煉渣堿度為0.51.8時, 渣中MgO飽和度在2%39%范圍內波動.當堿度增加時, MgO飽和度明顯降低.隨渣中Al2O3含量增加, 在MgO飽和相方鎂石相 (MgO) 和鎂橄欖石相 (2MgO·Si O2) 中MgO飽和度逐漸增加, 在尖晶石相 (MgO·Al2O3) 中逐漸減少.渣中Si O2含量對鈣硅酸鹽中MgO的飽和度有重要影響.此外, 當溫度升高時, MgO飽和度逐漸增加.Abstract: A predominantly liquid and MgO saturated slag is preferred in secondary metallurgical processes.It contributes to the mass transfer in molten steel and the extension of the refractory life.In the present study, the saturability of Mg O in quaternary Ca O-Si O2-Al2O3-MgO system in secondary metallurgical slag with low basicity was investigated by commercial thermodynamic software and laboratory experiments.The result shows that in the basicity (Ca O/Si O2) range of 0.5-1.8, the saturability of MgO fluctuates between2%and 39%and decreases with the increase of basicity.The saturability of MgO increases in the MgO saturated phase periclase (MgO) and forsterite (2MgO·Si O2) and decreases in the MgO saturated phase spinel (MgO·Al2O3) with an increase in Al2O3content.Si O2content has a great effect on the saturability of MgO in lime-silicate slag.Besides, the MgO saturability increases with an increase in temperature.