烧结机除尘灰制备纳米氧化铁及其气体传感特性

烧结机机头除尘灰是炼铁过程中产生的高铁含量小颗粒粉末固体废弃物,如何处理机头除尘灰一直是冶金领域的难点问题.鉴于其较高的铁含量,开发了一种以烧结机除尘灰为原料,通过控制还原剂与铁元素的比例,制备高附加值的类球状α-Fe2O3、Fe3O4纳米颗粒以及Fe3O4/Fe2O3纳米复合物的方法.利用多晶X射线衍射仪(XRD)、...

Iron oxide nanoparticles prepared by sinter ash of sintering machine and their gas-sensing performances

Sinter ash of sintering machine is considered as undesirable waste with high iron content during ironmaking processes, and how to deal with sinter ash is always a difficult point in metallurgical field. In this work, we demonstrated a method for preparing high value-added spherical iron oxide nanoparticles by sinter ash. Various iron oxide nanoparticles (e.g. pristine α-Fe₂O₃ and Fe₃O₄ nanoparticles, and Fe₃O₄/Fe₂O₃ nanocomposites) were successfully prepared by controlling the ratio of reducing agent to iron element via a solvothermal process. X-ray powder diffractometer (XRD), X-ray fluorescence spectrometer(XRF), ultraviolet spectrophotometer, field emission scanning electron microscopy(SEM) were used to characterize the materials. The results indicate that pure α-Fe₂O₃, Fe₃O₄ nanoparticles, or different Fe₃O₄/Fe₂O₃ ratio nanocomposites can be gotten by controlling the amount of reducing agent. The sizes of these nanoparticles are uniform and they all have high purity (α-Fe₂O₃, 92.74%; Fe₃O₄, 94.44%), and they are easily prepared and have high repeatability. The gas sensing performance of prepared iron oxide nanoparticles was tested by gas sensor tester. The nano scaled products showed excellent gas sensing performance, especially towards 1-butanol had high sensitivity and unique selectivity. It is found that the optimal working temperature of Fe₃O₄/Fe₂O₃ nanocomposites (100 ℃) is lower than those of α-Fe₂O₃ and Fe₃O₄ nanoparticles by 160 and 100 ℃, respectively. Among the composites, 56/44 Fe₃O₄/Fe₂O₃ nanocomposite shows the highest sensing response (6.33) towards 1-butanol. The preparation of high-added value iron oxide nanoparticles with sintering machine of sinter ash realized the rational utilization of sintering machine ash resource, which has important theoretical and practical significance, and it provides a reference example for treatment of high iron-bearing solid waste in the steel and ironmaking process.