铁铝尖晶石制备的方法研究

发布时间：2018-05-30 18:47

  本文选题：铁铝尖晶石 + 烧结法　； 参考：《太原理工大学》2015年硕士论文

【摘要】：随着新型干法水泥生产技术的出现，水泥窑对耐火砖的要求越来越高，特别是工作环境最为恶劣的水泥回转窑烧成带对耐火材料的要求更为苛刻。镁铬砖是回转窑烧成带的传统耐火材料，但在使用过程中Cr3+会变为有毒的Cr6+，污染环境及水源并对人畜造成伤害。镁铁铝尖晶石砖作为镁铬砖的代替品，具有良好的挂窑皮性能、抗侵蚀性和抗磨损性，是一种理想的水泥回转窑用耐火材料。铁铝尖晶石是镁铁铝尖晶石砖中不可缺少的重要组成，但天然存在的铁铝尖晶石很少，需要人工合成。因此合成铁铝尖晶石对制备镁铁铝尖晶石砖至关重要。 本文通过烧结法和熔盐法分别以氧化铝粉和氧化铁粉、高铁铝土矿和氧化铁粉为原料，制备了铁铝尖晶石。烧结法使用的还原剂为石墨粉，，熔盐法分别使用了石墨粉和葡萄糖作为还原剂。通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）和正置金相显微镜等方法对烧结样品的物相组成和微观形貌进行了分析，研究了煅烧温度、煅烧气氛、还原剂添加量和还原剂种类等因素对烧结产物的影响，研究结果表明： （1）以氧化铝粉和氧化铁粉为原料，以石墨粉为还原剂，采用烧结法在氮气气氛下1450℃以上时可以合成铁铝尖晶石，并且随着温度升高，合成的铁铝尖晶石结晶程度越来越好。 （2）熔盐法合成铁铝尖晶石时，以氧化铁粉和氧化铝粉为原料，石墨粉为还原剂时，熔盐法合成铁铝尖晶石的最佳条件为空气气氛下1100℃煅烧3h；使用葡萄糖为还原剂时，熔盐法合成铁铝尖晶石的最适宜的条件是：温度为1000℃，熔盐量为m(原料):m(NaCl)=1:1，还原剂加入量为13.5%。 （3）熔盐法可以在较温和的条件下合成铁铝尖晶石，将合成温度降低到了1000℃，并且葡萄糖比石墨更适合作还原剂。 （4）以高铁铝土矿为原料，石墨粉为还原剂，采用烧结法在氮气气氛下1550℃合成了铁铝尖晶石。
[Abstract]:With the emergence of new dry cement production technology, the requirement of refractory brick in cement kiln is more and more high, especially the firing belt of cement rotary kiln, which has the worst working environment, is more demanding on refractory material. Magnesia chrome brick is a traditional refractory material of rotary kiln firing zone, but during the process of use, Cr3 will become toxic Cr6, pollute the environment and water source and cause harm to human and animal. Mg-Fe-Al spinel brick is an ideal refractory for cement rotary kiln because of its good property of hanging kiln skin corrosion resistance and wear resistance as a substitute for magnesia-chrome brick. Fe-Al spinel is an indispensable component of magnesia-Fe-Al spinel brick, but there are few iron-aluminum spinel in nature, which need to be synthesized artificially. Therefore, the synthesis of Fe-Al spinel is very important to the preparation of Mg-Fe-Al spinel brick. In this paper, Fe-Al spinel was prepared by sintering method and molten salt method using alumina powder and ferric oxide powder, ferric bauxite and ferric oxide powder respectively as raw materials. The reducing agent used in the sintering process is graphite powder, and the molten salt method uses graphite powder and glucose as reducing agents respectively. The phase composition and microstructure of sintered samples were analyzed by means of X-ray diffractometer, scanning electron microscope (SEM) and positive metallographic microscope (SEM). The calcination temperature and atmosphere were studied. The effects of the amount of reducing agent and the type of reductant on the sintered product were studied. 1) Iron-aluminum spinel can be synthesized by sintering with alumina powder and iron oxide powder as raw materials and graphite powder as reducing agent under nitrogen atmosphere above 1450 鈩

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