Effects of slag composition and additive type on desulfurization of rejected electrolytic manganese metal scrap by Na2O-containing electroslag  

作　　者：Ru Lu Guang-qiang Li Chang Liu Yun-ming Gao Yu-fei Chen Qiang Wang 

机构地区：[1]The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan,430081,Hubei,China [2]Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan,430081,Hubei,China [3]Hubei Rising Technology Co.,Ltd.,Huangshi,435000,Hubei,China

出　　处：《Journal of Iron and Steel Research International》2021年第12期1515-1529,共15页

基　　金：The authors appreciate the financial support from the National Natural Science Foundation of China(Grant No.51804227).

摘　　要：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 shoul

关 键 词：Rejected electrolytic manganese metal DESULFURIZATION DEOXIDIZATION Additive Na2O content Thermodynamic 

分 类 号：TF769.4[冶金工程—钢铁冶金]