用扫描电镜的背散射电子像分析转炉钢渣中的矿物相

Analysis of Mineral Phase of Converter Steel Slag by Backscattered Electron Images of SEM

利用扫描电镜的背散射电子像(SEM)和X射线能谱分析(EDXA),并结合X射线衍射(XRD)方法对3种钢厂转炉钢渣的矿物组成和微观形貌特征进行了系统分析。结果表明,在扫描电镜的背散射电子像中,钢渣中的各矿物相清晰可辨,C_2S呈黑色圆粒状和树叶状,C_3S呈黑色六方板状,铁酸二钙呈灰色无定形状,镁铁相呈白色圆粒状或不规则形貌;钢渣的主要矿物为C_2S、铁酸二钙及镁铁相固溶体(RO相),还含有少量的C_3S、f-CaO和MgO;同时还发现铁酸二钙固溶相的典型组成是Ca_2(Al,Fe)_2O_5,镁铁固溶相的代表性组成是MgO·2FeO。这为钢渣的矿物鉴别提供了有效的分析手段。

The mineral composition and mierostructure characteristics of converter steel slag samples from 3 steel plants are analyzed using X-ray diffraction （XRD） and the backscattered electron images of scanning electron microscopy （SEM） with energy dispersive X-ray analysis （EDXA）. The experimental result shows that the microstructure morphologies of mineral phases are plainly discernible in the backscattered electron images of SEM. The morphology of C2 S in converter steel slag is darkly round or leaf shape, C3 S is darkly hexagonal, and the phase of gray dicaleiurn ferrite and bright MgO-FeO both are irregular. The main phases in the steel slag are C2S, dicalcium ferrite and MgO-FeO solid solution, and the minor minerals are C2S, f-CaO and MgO. It is found that the representative composition of the dicalcium ferrite phase is Ca2 （A1, Fe）2O5, and representative composition of MgO-FeO solid solution is MgO · 2FeO. It provides effective analysis approach for mineral identification of converter steel slag.