Activities of FeO in CaO-SiO2-Al2O3-MgO-FeO slags were determined at 1673 K by electrochemical of the solid electrolyte cell： Mo [Mo＋MoOu[ZrO2（MgO）[Fe＋（CaO-SiO2-Al2O3-MgO-FeO）＋Ag[Fe. The influences of slag com...Activities of FeO in CaO-SiO2-Al2O3-MgO-FeO slags were determined at 1673 K by electrochemical of the solid electrolyte cell： Mo [Mo＋MoOu[ZrO2（MgO）[Fe＋（CaO-SiO2-Al2O3-MgO-FeO）＋Ag[Fe. The influences of slag compositions and basicity on FeO activities were analyzed. The results reveal that, for slags of fixed （%CaO）/（%SiO2） ratio, MgO and Al2O3 content, there was an increase of FeO activities with increase of FeO content. For slags with constant {（%CaO）＋ （%MgO）}/（%SiO2） ratio, fixed FeO and A1203 content, FeO activities decreased when MgO content increased from 5% to 10%, and increased with the increase of MgO content when it was over 10%. The FeO activities increased when （%CaO）/（%SiO2） ratio changed from 1.03 to 1.30 in the slags of constant MgO, FeO and Al2O3 content.展开更多
High-temperature experiments were carried out for the slag systems of“FeO”−SiO_(2)−CaO−Al_(2)O_(3)and“FeO”−SiO_(2)−CaO−MgO at 1200℃and p(O_(2))of 10^(−7)kPa.The equilibrated samples were quenched,and the phase co...High-temperature experiments were carried out for the slag systems of“FeO”−SiO_(2)−CaO−Al_(2)O_(3)and“FeO”−SiO_(2)−CaO−MgO at 1200℃and p(O_(2))of 10^(−7)kPa.The equilibrated samples were quenched,and the phase compositions were measured by electron probe microanalysis(EPMA).A series of pseudo-ternary and pseudo-binary phase diagrams are constructed to demonstrate their applications in copper smelting process and evaluation of the thermodynamic database.Spinel and tridymite are identified to be the major primary phases in the composition range related to the copper smelting slags.It is found that the operating window of the smelting slag is primarily determined by w_(Fe)/w_(SiO_(2))ratio in the slag.Both MgO and Al_(2)O_(3)in the slag reduce the operating window which requires extra fluxing agent to keep the slag to be fully liquid.Complex spinel solid solutions cause inaccurate predictions of the current thermodynamic database.展开更多
文摘为了控制低碳铝镇静钢中Al_(2)O_(3)夹杂物,并提升渣系对Al_(2)O_(3)夹杂物吸附能力,采用FactSage 8.1模拟计算CaO-SiO_(2)-Al_(2)O_(3)-5%MgO-5%FeO渣系的等黏度图和等ΔC/η(ΔC=C_(Al_(2)O_(3))^(s)-C_(Al_(2)O_(3))^(b),η为渣的黏度)值线图。根据模拟计算图选取合适的五元精炼渣做Al_(2)O_(3)的吸附试验,试验研究了Al_(2)O_(3)在CaO-SiO_(2)-Al_(2)O_(3)-5%MgO-5%FeO渣系中的溶解速率,讨论了Al_(2)O_(3)棒浸入深度、直径、转速、渣成分以及温度对Al_(2)O_(3)溶解速率的影响,求解了Al_(2)O_(3)在溶解过程中的活化能。最后,采用场发射扫描电子显微镜(Apreo S HiVac)对氧化铝棒与熔渣接触的界面处进行微区线元素的定性分析。研究结果表明,Al_(2)O_(3)在渣中的溶解速率受诸多因素的影响;溶解速率随氧化铝棒的旋转速度、棒直径、浸入深度和温度的增加而增加;溶解速率也会随着CaO含量的增加而增加,Al_(2)O_(3)和SiO_(2)含量的增加而降低。溶解速率高度依赖于熔渣的黏度,渣的黏度对Al_(2)O_(3)的溶解速率呈负相关,Al_(2)O_(3)的溶解速率与浓度驱动力呈正相关。氧化铝棒溶解于渣系前,会先生成中间相CaO·2Al_(2)O_(3)和CaO·6Al_(2)O_(3),中间相溶解在熔渣中,溶解于渣A中的表观活化能为410.9 kJ/mol。结合溶解速率图与等ΔC/η值线图进行对比,验证了Al_(2)O_(3)在渣中的溶解速率受渣物性的影响。
基金Project supported by the National Natural Science Foundation of China （Grant No.50574036）
文摘Activities of FeO in CaO-SiO2-Al2O3-MgO-FeO slags were determined at 1673 K by electrochemical of the solid electrolyte cell： Mo [Mo＋MoOu[ZrO2（MgO）[Fe＋（CaO-SiO2-Al2O3-MgO-FeO）＋Ag[Fe. The influences of slag compositions and basicity on FeO activities were analyzed. The results reveal that, for slags of fixed （%CaO）/（%SiO2） ratio, MgO and Al2O3 content, there was an increase of FeO activities with increase of FeO content. For slags with constant {（%CaO）＋ （%MgO）}/（%SiO2） ratio, fixed FeO and A1203 content, FeO activities decreased when MgO content increased from 5% to 10%, and increased with the increase of MgO content when it was over 10%. The FeO activities increased when （%CaO）/（%SiO2） ratio changed from 1.03 to 1.30 in the slags of constant MgO, FeO and Al2O3 content.
文摘High-temperature experiments were carried out for the slag systems of“FeO”−SiO_(2)−CaO−Al_(2)O_(3)and“FeO”−SiO_(2)−CaO−MgO at 1200℃and p(O_(2))of 10^(−7)kPa.The equilibrated samples were quenched,and the phase compositions were measured by electron probe microanalysis(EPMA).A series of pseudo-ternary and pseudo-binary phase diagrams are constructed to demonstrate their applications in copper smelting process and evaluation of the thermodynamic database.Spinel and tridymite are identified to be the major primary phases in the composition range related to the copper smelting slags.It is found that the operating window of the smelting slag is primarily determined by w_(Fe)/w_(SiO_(2))ratio in the slag.Both MgO and Al_(2)O_(3)in the slag reduce the operating window which requires extra fluxing agent to keep the slag to be fully liquid.Complex spinel solid solutions cause inaccurate predictions of the current thermodynamic database.
