In order to improve the dephosphorization efficiency of low-basicity converter slag and decrease the consumption of solid CaO,the effect of high Na2O addition(0-15 mass%)on the distribution of P2O5 between solid solut...In order to improve the dephosphorization efficiency of low-basicity converter slag and decrease the consumption of solid CaO,the effect of high Na2O addition(0-15 mass%)on the distribution of P2O5 between solid solution and matrix phase was investigated.The thermodynamic properties of slag samples were calculated by FactSage 7.0 software.Then,the dissolution behavior of phosphorus element from slag was studied.The results show that the mass fraction of 2CaO*SiO2-2CaO*Na2O*P2O5 solid solution increases when the Na2O content is increased in slag.However,the amount of formed solid solution changes little when the Na2O addition is more than 10 mass%.Moreover,the content of Na2O in solid solution would reach saturation when adding 15 mass%Na2O into the slag.With the increase in Na2O content in slag,the distribution ratio of P2O5 between solid solution and matrix phase increases.The values are evidently higher than the results reported in the literature.Meanwhile,the activity of P2O5 in matrix phase and the activity coefficient of P2O5 in solid solution are decreased with increasing the Na2O content in slag.Furthermore,the dissolution ratio of phosphorus in citric acid solution could be improved by adding Na2O into slag,but the increment of dissolution ratio would decrease when the Na2O content exceeds 10 mass%in slag.展开更多
Na2O-Al2O3-SiO2 glass-ceramics doped with Er^3＋ ions were synthesized by the conventional melt quenching technique at a low melting temperature.The samples were characterized by differential scanning calorimetry（DSC...Na2O-Al2O3-SiO2 glass-ceramics doped with Er^3＋ ions were synthesized by the conventional melt quenching technique at a low melting temperature.The samples were characterized by differential scanning calorimetry（DSC）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,UV-vis-NIR scanning spectrophotometry,and fluorescence spectrometry.The results show that the main crystalline phase of glass-ceramics is nepheline.The best heat-treatment process is at 520 ℃ for 2 h.Because the up-conversion luminescence and near infrared luminescence properties of glass doped with Eu^3＋ are studied in detail.展开更多
The recycling rate of rejected electrolytic manganese metal(EMM)scrap can be increased by inhibiting the manganese metal(MM)vaporization during the remelting process with electroslag.However,if the latter is achieved ...The recycling rate of rejected electrolytic manganese metal(EMM)scrap can be increased by inhibiting the manganese metal(MM)vaporization during the remelting process with electroslag.However,if the latter is achieved by reducing the remelting temperature,the desulfurization behavior will deteriorate.Therefore,Na_(2)O-containing electroslag and metallic additive were used to increase the rejected EMM scrap recovery ratio.The respective high-temperature experiment was conducted in a MoSi_(2) electrical resistance furnace filled with fluid argon at 1673 K using five different types of electroslag with the Na_(2)O content ranging from 5.81%to 15.71%.High-purity metallic magnesium and magnesium calcium alloy additives were used as deoxidizers.The addition of Na_(2)O and metallic additives effectively promoted the desulfurization and deoxidization of MM.The removal of sulfur and oxygen by the interaction between Na_(2)O-containing electroslag melt and molten MM with metallic additive was analyzed from the thermodynamic and kinetic standpoints.The effect of Na_(2)O-containing electroslag volatilization on desulfurization and deoxidization was considered.With an increase in Na_(2)O content in the slag,the mass loss rates of Na_(2)O and electroslag rose,as well as the final sulfur partition ratio.If the Na_(2)O content volatilized in the slag melt did not exceed 10.44%,the sulfur removal ratio was increased by high sulfide capacity and CaO activity in all slags due to the addition of Na_(2)O.The rejected EMM scrap deoxidization ratio grew with the increased activity of CaO and reduced activity of Al_(2)O_(3) in the molten slag,caused by the increased Na_(2)O content in the molten slag.The addition of metallic Mg and Mg-Ca alloy indirectly promoted desulfurization and deoxidization by reducing the MnO content in the rejected EMM scrap and growing slag oxidability.The Mg-Ca alloy could also react with dissolved sulfur and oxygen,directly promoting desulfurization and deoxidization processes.The Na_(2)O content in slag should not exceed 10.44%to ensure the high desulfurization and deoxidization abilities,fluidity and low volatilization of slag.展开更多
基金National Natural Science Foundation of China(51604003,51704010)Natural Science Research Project of Anhui Province Universities(KJ20I6A089)Key Laboratory Open Project Fund of Metallurgical Emission Reduction and Resources Recycling(Anhui University of Technology),Ministry of Education(JKF18-02).
文摘In order to improve the dephosphorization efficiency of low-basicity converter slag and decrease the consumption of solid CaO,the effect of high Na2O addition(0-15 mass%)on the distribution of P2O5 between solid solution and matrix phase was investigated.The thermodynamic properties of slag samples were calculated by FactSage 7.0 software.Then,the dissolution behavior of phosphorus element from slag was studied.The results show that the mass fraction of 2CaO*SiO2-2CaO*Na2O*P2O5 solid solution increases when the Na2O content is increased in slag.However,the amount of formed solid solution changes little when the Na2O addition is more than 10 mass%.Moreover,the content of Na2O in solid solution would reach saturation when adding 15 mass%Na2O into the slag.With the increase in Na2O content in slag,the distribution ratio of P2O5 between solid solution and matrix phase increases.The values are evidently higher than the results reported in the literature.Meanwhile,the activity of P2O5 in matrix phase and the activity coefficient of P2O5 in solid solution are decreased with increasing the Na2O content in slag.Furthermore,the dissolution ratio of phosphorus in citric acid solution could be improved by adding Na2O into slag,but the increment of dissolution ratio would decrease when the Na2O content exceeds 10 mass%in slag.
基金Funded by the National High Technology Research and Development Program of China(No.2011AA030204)Key Research Project of Jilin Provincial Science and Technology Department(No.20150204051GX)
文摘Na2O-Al2O3-SiO2 glass-ceramics doped with Er^3＋ ions were synthesized by the conventional melt quenching technique at a low melting temperature.The samples were characterized by differential scanning calorimetry（DSC）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,UV-vis-NIR scanning spectrophotometry,and fluorescence spectrometry.The results show that the main crystalline phase of glass-ceramics is nepheline.The best heat-treatment process is at 520 ℃ for 2 h.Because the up-conversion luminescence and near infrared luminescence properties of glass doped with Eu^3＋ are studied in detail.
基金The authors appreciate the financial support from the National Natural Science Foundation of China(Grant No.51804227).
文摘The recycling rate of rejected electrolytic manganese metal(EMM)scrap can be increased by inhibiting the manganese metal(MM)vaporization during the remelting process with electroslag.However,if the latter is achieved by reducing the remelting temperature,the desulfurization behavior will deteriorate.Therefore,Na_(2)O-containing electroslag and metallic additive were used to increase the rejected EMM scrap recovery ratio.The respective high-temperature experiment was conducted in a MoSi_(2) electrical resistance furnace filled with fluid argon at 1673 K using five different types of electroslag with the Na_(2)O content ranging from 5.81%to 15.71%.High-purity metallic magnesium and magnesium calcium alloy additives were used as deoxidizers.The addition of Na_(2)O and metallic additives effectively promoted the desulfurization and deoxidization of MM.The removal of sulfur and oxygen by the interaction between Na_(2)O-containing electroslag melt and molten MM with metallic additive was analyzed from the thermodynamic and kinetic standpoints.The effect of Na_(2)O-containing electroslag volatilization on desulfurization and deoxidization was considered.With an increase in Na_(2)O content in the slag,the mass loss rates of Na_(2)O and electroslag rose,as well as the final sulfur partition ratio.If the Na_(2)O content volatilized in the slag melt did not exceed 10.44%,the sulfur removal ratio was increased by high sulfide capacity and CaO activity in all slags due to the addition of Na_(2)O.The rejected EMM scrap deoxidization ratio grew with the increased activity of CaO and reduced activity of Al_(2)O_(3) in the molten slag,caused by the increased Na_(2)O content in the molten slag.The addition of metallic Mg and Mg-Ca alloy indirectly promoted desulfurization and deoxidization by reducing the MnO content in the rejected EMM scrap and growing slag oxidability.The Mg-Ca alloy could also react with dissolved sulfur and oxygen,directly promoting desulfurization and deoxidization processes.The Na_(2)O content in slag should not exceed 10.44%to ensure the high desulfurization and deoxidization abilities,fluidity and low volatilization of slag.
