کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1629754 1006158 2009 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of Size of Hematite Powder on Its Reduction Kinetics by H2 at Low Temperature
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
Influence of Size of Hematite Powder on Its Reduction Kinetics by H2 at Low Temperature
چکیده انگلیسی
The reduction kinetics and mechanisms of hematite ore with various particle sizes with hydrogen at low temperature were studied using the thermogravimetric analysis. At the same temperature, after the particle size of powder decreases from 107.5 μm to 2.0 μm, the surface area of the powder and the contact area between the powder and gas increase, which makes the reduction process of hematite accelerate by about 8 times, and the apparent activation energy of the reduction reaction drops to 36.9 kJ/mol from 78.3 kJ/mol because the activity of ore powder is improved by refining gradually. With the same reaction rate, the reaction temperature of 6.5 μm powder decreases by about 80 °C compared with that of 107.5 μm powder. Thinner diffusion layer can also accelerate the reaction owing to powder refining. The higher the temperature, the greater is the peak of the reduction rate; at the same temperature, the greater the particle size, the smaller is the peak value of the reduction rate; both inner diffusion and interface chemical reaction play an important role in the whole reaction process.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Iron and Steel Research, International - Volume 16, Issue 5, September 2009, Pages 07-11
نویسندگان
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