D0I:10.13374/j.issn1001053x.1989.06.023 第11卷第6期 北京科技大学学报 Vol.11 No.6 1989年11月 Journal of University of Science and Technology Beijing Nov,1989 Equilibrium between Slag and Molten Iron in the Direct Alloying of Steel with Nb,O:-Bearing Slag' Chen形eiqing(陈伟庆)，Zhou Rongzhang(周荣幸) Lin Zongcai(林宗彩)· ABSTRACT:Equilibrium between slag and molten iron at 1600C was investiga- ted for the direct alloying of steel with Nb2Os-bearing slag.The activity of niobium oxide in the slag was measured.The is in the range of 10-110The is ranged in 109-10-2.Niobium partition decreases with the increase of CSi)%and CaO/SiOa When ato and FeO decrease,niobium partition decre- ases too.Theand the ratio of o to decrease with the incre- ase of slag basicity.The suitable thermodynamic conditions in direct alloying of steel with Nb2Os-bearing slag have been found. KEY WORDS:equilibrium,slag,molten,alloying,Nb2Os The hot metal produced in Baotou,China,contains Nb.After it is treated in oxygen bottom blowing furnace,the slag obtained contains Nb2O.about 5-7%. Now the niobium-bearing slag is reduced to ferro-manganese-niobium in electric arc furnace,which is used as micro-alloying additive for steelmaking.But,if the niobium-bearing slag can be directly used as micro-alloying additive for ste- elmaking the alloying cost will be decreased to about 50%in China.This will be one way of effective use of the niobium containing in the combine iron ores. The equilibrium between slag and Nb-bearing hot metal at 1350C has been studied by the authorst11.The investigation of equilibrium between slag contai- ning Nb and molten iron at 1600C and measurement ofer reported by literaturest41.But,the relations between deoxidation elements in molten iron and niobium partition have not been considered in them.Meanwhile,the composi- tions of slag in the former investigation is different to that in direct alloying Manuscript Received April 11,1989 。·Dept,of Metallurgy 526第 卷第 期 年 月 北 京 科 技 大 学 学 报 。 一 ’ 平 。 夕 陈 伟庆 ， 夕 周 荣章 产尸 ‘， ， 夕 林宗彩 二 。 一 夕邢 〔 〕 。 一 一 。 ， 一 一 一 ‘ 。 · ，， 、 。 万 ， 丫。 ，， 、 一 · 。 一 ， ， 刀 ， ， 。 砂 ， ， ， 。 一 一 一 一 ， 一 ， 一 一 爪 一 一 五 。 ’ ， ‘ · ， 。 ， 二 ， ，日 DOI ：10．13374／j ．issn1001－053x．1989．06．023