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您的检索式：作者名="Beuria P.C."
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| 1 | Study on kinetics of thermal decomposition of low LOI goethetic hematite iron ore显示文摘In the present study, the kinetics of thermal decomposition of hydrated minerals associated in natural hematite iron ores has been investigated in a fixed bed system using isothermal methods of kinetic analysis. Hydrated minerals in these hematite iron ores are kaolinite, gibbsite and goethite, which contribute to the loss on ignition(LOI) during thermal decomposition. Experiments in fixed bed have been carried out at variable bed depth(16, 32, 48 and 64 mm),temperature(400-1200 ℃) and residence time(30,45, 60 and 75 min) for iron ore samples. It is observed that beyond a certain critical bed depth(16 mm), 100% removal of LOI is not found possible even at higher temperature and higher residence time. Most of the solid-state reactions of isothermal kinetic analysis have been used to analyze the reaction mechanism. The raw data are modified to yield fraction reacted 'α' versus time and used for developing various forms of 'α' functions.f(α) is the inverse of first derivative of g(α) with respect to α. The study demonstrates that decomposition of hydrated mineral in hematite follows the chemical kinetics.The estimated activation energy values in all the experimental situations are found to high, of the order of 60 kJ/mol, reinstating that the reactions are indeed controlled by moving phase boundary and random nucleation. | Beuria P.C. Biswal S.K. Mishra B.K. Roy G.G. | 2017 | International Journal of Mining Science and Technology2017，27，6： | 3 |
| 2 | Kinetics of thermal decomposition of hydrated minerals associated with hematite ore in a fluidized bed reactor显示文摘The kinetics of removal of loss on ignition(LOI) by thermal decomposition of hydrated minerals present in natural iron ores(i.e.,kaolinite,gibbsite,and goethite) was investigated in a laboratory-scale vertical fluidized bed reactor(FBR) using isothermal methods of kinetic analysis.Experiments in the FBR in batch processes were carried out at different temperatures(300 to 1200°C) and residence time(1 to 30 min) for four different iron ore samples with various LOIs(2.34wt% to 9.83wt%).The operating velocity was maintained in the range from 1.2 to 1.4 times the minimum fluidization velocity(Umf).We observed that,below a certain critical temperature,the FBR did not effectively reduce the LOI to a desired level even with increased residence time.The results of this study indicate that the LOI level could be reduced by 90% within 1 min of residence time at 1100°C.The kinetics for low-LOI samples(<6wt%) indicates two different reaction mechanisms in two temperature regimes.At lower temperatures(300 to 700°C),the kinetics is characterized by a lower activation energy(diffusion-controlled physical moisture removal),followed by a higher activation energy(chemically controlled removal of LOI).In the case of high-LOI samples,three different kinetics mechanisms prevail at different temperature regimes.At temperature up to 450°C,diffusion kinetics prevails(removal of physical moisture);at temperature from 450 to 650°C,chemical kinetics dominates during removal of matrix moisture.At temperatures greater than 650°C,nucleation and growth begins to influence the rate of removal of LOI. | P.C. Beuria S.K. Biswal B.K. Mishra G.G. Roy | 2017 | International Journal of Minerals,Metallurgy and Materials2017，24，3： | 0 |
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