Formation mechanism of Ca3TiFe2O8 in a CaO-TiO2 -Fe2O3 system
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摘要: 釩鈦磁鐵礦是燒結礦重要的原料之一,Ca3TiFe2O8作為釩鈦燒結礦中礦物被發現之后,其生成機理尚不明確.本文采用X射線衍射分析、元素能譜分析和TG-DSC分析相結合的方法,研究了Ca3TiFe2O8的生成機理以及不同溫度、CaO與TiO2含量下Ca3TiFe2O8的生成規律.實驗結果表明,Ca3TiFe2O8由Ca2 Fe2O5和CaTiO3反應生成,即CaO和Fe2O3反應生成Ca2 Fe2O5;其后,與CaTiO3反應生成Ca3TiFe2O8.反應時間越長,Ca3TiFe2O8的生成量越大,但反應溫度對Ca3TiFe2O8生成的影響并不明顯.另外,還發現CaO含量越高,Ca3TiFe2O8越易于生成,而且等摩爾Fe2O3和CaO下只要存在TiO2,就會有Ca3TiFe2O8生成.
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關鍵詞:
- 釩鈦磁鐵礦 /
- 燒結 /
- Ca3TiFe2O8 /
- 生成機理 /
- 生成規律
Abstract: Vanadium-titanium magnetite is one of the important raw materials for iron making in a blast furnace. Ca3TiFe2O8, which is a mineral of vanadium-titanium sinter, was discovered to form during the process; however, its formation mechanism is not clear. In this work, an X-ray diffraction analysis, an elemental spectroscopy, and a TG-DSC were employed to investigate the formation mechanism of Ca3TiFe2O8 and the formation law at different temperatures and at CaO and TiO2 contents in the CaO-TiO2 -Fe2O3 system. The formation mechanism of Ca3TiFe2O8 is clarified:CaO reacts with Fe2O3 to form Ca2 Fe2O5, and then continues to react with the CaTiO3 to form Ca3TiFe2O8. The longer the reaction time, the greater is the amount of Ca3TiFe2O8 formed. However, the effect of temperature on the formation of Ca3TiFe2O8 is not obvious. It is found that high CaO content contributes to the formation of Ca3TiFe2O8. Further, so long as TiO2 is present, Ca3TiFe2O8 is formed under the condition of equal molar concentration Fe2O3 and CaO.-
Key words:
- vanadium and titanium magnetite /
- sintering /
- Ca3TiFe2O8 /
- formation mechanism /
- formation law
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參考文獻
[8] Verein Deutscher Eisenhüttenleute. Slag Atlas. 2nd Ed. Dusseldorf:Verlag Stahleisen GmbH, 1995 [9] Prasanna T R S, Navrotsky A. Energetics in the brownmilleriteperovskite pseudobinary Ca2Fe2O5-CaTiO3. J Mater Res, 1994, 9(12):3121 [10] Rodriguez-Carvajal J, Vallet-Regi M, Calbet J M G. Perovskite threefold superlattices:a structure determination of the A3M3O8 phase. Mater Res Bull, 1989, 24(4):423 [11] Grenier J C, Darriet J, Pouchard M, et al. Mise en evidence d' une nouvelle famille de phases de type perovskite lacunaire ordonnee de formule A3M3O8 (AMO2,67). Mater Res Bull, 1976, 11(10):1219 -

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