Some Considerations of Copper Removal from Steel by Use of Oxysulfide Systems
It has long been desired to remove tramp elements such as copper and tin from steel, in particular, when ferrous scrap is used for steelmaking. Albeit a number of different approaches have been attempted, however, a satisfactory solution has yet to be found. In the present study a new technology has been investigated, which utilizes a low-melting oxysulfide medium for removal of copper from ferrous scrap. The basic concept of the present approach is that steel scrap containing copper component is melted in the oxysulfide medium, and then metallic iron is induced to precipitate out, leaving most of the copper left in the oxysulfide medium by a proper control of oxygen and sulfur potentials in the system. First, phase equilibria in the Fe-Cu-S ternary system at the Fe-rich corner was experimentally investigated to establish a reliable foundation on fundamental knowledge in the phase relationship of Fe-Cu-S system. Then the two-phase region of solid Fe and liquid solution (Fe-Cu-S) was intensively investigated to quantify the distribution of copper between the phases (LCu = (mass％ Cu)solution/mass％ CuFe.). Effects of temperature and additional elements such as sodium were also investigated. A typical result is that in the Fe-Cu-S system, LCu was found to be about 7 at 1,200°C, and sulfur in the steel was about a few hundred ppm level. Addition of sodium in the sulfide markedly increased LCu, meaning that sodium suppressed copper from moving to the steel. This was attributed to the fact that Na2S decreases the activity coefficient of Cu2S in the sulfide solution. The results obtained through the present study warranted further investigation on the oxysulfide system and develop a conceptual process of copper removal from scrap-using steelmaking.
Fe-Cu-S Phase equilibria Cu removal Ferrous Scrap Tramp element
Sung-Hoon Jung Youn-Bae Kang Jeong-Do Seo Hae-Geon Lee
Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, San 31, Hyoja POSCO Technical Research Laboratories, POSCO, Geodongdong, Pohang, 790-785, Rep. of Korea
国际会议
Ninth International Conference on Molten Slags,Fluxes and Salts(第九届国际熔渣、溶剂与熔盐学术会议 MOLTEN12)
北京
英文
1-9
2012-05-27（万方平台首次上网日期，不代表论文的发表时间）