预氧化强化印尼海砂矿还原分离及机理研究

Mechanism for Reduction⁃Separation of Indonesia Iron Sand Intensified by Pre⁃oxidation Treatment

以印尼某海砂矿为研究对象,采用光学显微镜、SEM⁃EDS、X射线衍射等分析测试手段,研究了预氧化对海砂矿原料特性及其固态还原分离行为的影响。结果表明,海砂矿结构致密、组元分布相对均匀;预氧化破坏了其致密状态,形成疏松多孔结构,促进了钛磁铁矿和钛铁矿物相向钛赤铁矿和铁板钛矿的转变,同时使V、Ti局部预富集,有助于改善海砂矿还原分离性能。海砂矿经1100℃预氧化90 min后,在C/Fe比0.6、还原温度1350℃、还原时间60 min条件下还原,可获得金属化率93.87%的还原产物,还原产物经磨选分离可获得Fe品位90.90%、回收率93.47%的磁性产物以及TiO_(2)品位32.10%和回收率91.51%、V_(2)O_(5)品位2.04%和回收率91.04%的非磁性产物。

With a kind of typical Indonesia iron sand taken in the research,the effects of pre⁃oxidation treatment on the properties of iron⁃sand materials and their solid⁃state reduction and separation behavior were studied with optical microscope,SEM⁃EDS and X⁃ray diffraction.Results show that the iron sand has a dense structure,with relatively uniform distribution of compositions.Pre⁃oxidation destroys its dense structure and forms a loose porous structure,thus promoting the transformation of titanomagnetite and ilmenite mineral phases into ilmenite and brookite.In the meantime,the local pre⁃enrichment of V and Ti is conducive to the improvement of its reduction and separation performance.The iron sand is pre⁃oxidized at 1100℃for 90 min,and reduced with C/Fe ratio of 0.6,at 1350℃for 60 min,leading to a reduced product with a metallization rate of 93.87%.After further grinding and separation processes,a magnetic product grading 90.90%Fe can be finally reclaimed at 93.47%recovery,and a non⁃magnetic product is obtained grading 32.10%TiO_(2) and 2.04%V_(2)O_(5),with recoveries of 91.51%and 91.04%,respectively.