Solid-state reduction kinetics and mechanism of pre-oxidized vanadium-titanium magnetite concentrate  

预氧化钒钛磁铁精矿的固态还原动力学及其机理(英文)

作　　者：刘水石[1] 郭宇峰[1] 邱冠周[1] 姜涛[1] 陈凤[1] 

机构地区：[1]中南大学 资源加工与生物工程学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第10期3372-3377,共6页中国有色金属学报（英文版）

基　　金：Project(NCET-10-0834)supported by the Program for New Century Excellent Talents in University,China

摘　　要：The solid-state reduction kinetics of pre-oxidized vanadium-titanium magnetite concentrate was studied. The phase and microstructure of the reduction product were characterized by XRD, SEM and EDS methods, based on which the mechanism of the solid-state reduction was investigated. The results showed that using coal as reductant at 950-1100 °C, the solid-state reduction of the pre-oxidized vanadium-titanium magnetite concentrate was controlled by interface chemical reaction and the apparent activation energy was 67.719 k J/mol. The mineral phase transformation during the reduction process can be described as follows： pre-oxidized vanadium-titanium magnetite concentrate → ulvospinel → ilmenite → Fe Ti2O5 →（FenTi1-n）Ti2O5. M3O5-type（M can be Fe, Ti, Mg, Mn, etc） solid solutions would be formed during the reduction process of the pre-oxidized vanadium-titanium magnetite concentrate at 1050 °C for 60 min. The poor reducibility of iron in M3O5 solid solutions is the main reason to limit the reduction property of pre-oxidized vanadium-titanium magnetite concentrate.研究预氧化钒钛磁铁精矿固态还原反应的动力学,采用XRD、SEM和EDS等手段研究还原产物的显微结构和物相变化,在此基础上,对其固态还原机理进行研究。结果表明：以煤为还原剂,在还原温度为950~1100°C时,预氧化钒钛磁铁精矿的固态还原受界面化学反应控制,反应的表观活化能为67.719 k J/mol;预氧化钒钛磁铁精矿的还原历程可描述为：预氧化钒钛磁铁精矿→钛铁晶石→钛铁矿→亚铁板钛矿（Fe Ti2O5）→（FenTi1-n）Ti2O5。预氧化钒钛磁铁精矿在1050°C还原60 min后,还原产物中会形成M3O5型（M为Fe、Ti、Mg、Mn等）固溶体,存在于M3O5固溶体中铁的难还原性是限制预氧化钒钛磁铁矿还原的主要原因。

关 键 词：vanadium-titanium magnetite solid-state reduction reduction kinetics reduction process 

分 类 号：TD95[矿业工程—选矿]