Kinetics study on oxidation of iron ore concentrate
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摘要: 通過恒溫和均勻升溫實驗,采用大載荷熱重分析儀研究了鐵精粉氧化過程動力學.結果表明:均勻升溫過程中,鐵精粉氧化的主要控制環節變化是外擴散型→內擴散型→外擴散型,氧化結束后,部分Fe2O3發生分解反應生成Fe3O4和O2,使得TG曲線質量變化率減小;等溫實驗也證明了氧化主體部分的控制環節是內擴散,其表觀活化能為26.193kJ·mol-1;鐵精粉氧化過程促進了鈦元素富集,改變了產物的微觀結構.Abstract: Isothermal and uniform temperature-rise experiments were done to study the oxidation kinetics of iron ore concentrate with a TG instrument. The results indicated that the major control unit of the oxidation process changed from out-diffusion to inner-diffusion, and out-diffusion finally during uniform temperature rise. After oxidation, partial hematite decomposed into magnetite and oxygen; as a result, the mass change ratio on the TG curve gradually decreases. The isothermal experiment also proves that the main step is inner-diffusion and the apparent activation energy of oxidation is 26.193 kJ·mol-1. Oxidation of iron ore concentrate accelerates titanium enrichment and changes the microstructure of oxidized products.
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Key words:
- iron ore concentrate /
- oxidation /
- reaction kinetics /
- titanium /
- diffusion
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