CO氣氛下CaO對鐵晶須生長影響的原位觀察和機理研究

In situ observation and mechanism research of the influence of CaO on the growth of iron whiskers under CO atmosphere

摘要: 利用光學體視顯微鏡和高溫熱臺對CO氣體還原Fe₂O₃過程進行原位觀察,并結合掃描電鏡、能譜和紅外光譜分析,研究摻入CaO對還原過程中鐵晶須生成和生長機理的影響.實驗結果表明:鐵晶須是在實現FeO→Fe轉變時形成和不斷生長的;CaO對氧化鐵的還原有抑制作用,當摻入CaO質量分數 ≥ 8%時,沒有鐵晶須生成和生長.因此,可以通過控制CaO摻入量的方式抑制鐵晶須的生成和生長,進而減少礦粉顆粒團聚的發生.

Abstract: The influences of CaO on the formation and growth of iron whiskers and their mechanism in the reduction of iron oxide under CO atmosphere were studied.In situ observations on the development of iron whiskers were carried out using a stereo optical microscope and a hot stage under CO atmosphere.The reduced samples were analyzed by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS) and Fourier transform infrared spectroscopy(FTIR).It is indicated that the formation and growth of iron whiskers proceed in the stage of FeO being reduced to Fe and CaO has a negative effect on the reduction of iron oxide.When the mass fraction of CaO mixing into the sample is more than 8%,iron whiskers can not be observed.Therefore,controlling the amount of CaO mixing into the sample can inhibit the formation and growth of iron whiskers and reduce ore grain agglomeration.