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题名	多孔铁矿石球团还原动力学及其数学模型
作者	陈宇飞
学位类别	硕士
答辩日期	1986-06-30
授予单位	中国科学院研究生院
导师	张宗诚
中文摘要	孔隙性固体与气体的反应是一类重要反应。多孔铁矿石球团的孔隙特性及反应的多级性，使得还原反应非常复杂并且具有一定的代表性，因此，进行还原动力学的研究并建立还原过程的数学模型具有重要意义。本文通过添加锯末，球团焙烧获得了不同孔隙度的球团；通过观察还原球团样品剖面，论证了多孔球团还原进行的型式；通过控制还原气氛，实现铁矿石球团的逐段还原，求出了各阶段的反应速度常数及反应活化能，并得到了有效扩散系数对孔隙度的函数关系。由此，研究了孔隙度对铁矿石球团还原性能及还原反应进行方式的影响。系统研究了单界面未反应核模型，三界面模型，两阶段模型，微颗粒模型，多级区域反应模型，具有变结构参数的多级区域反应模型和多阶段反应模型等七个模型，并编制了求解模型的计算机程序及用单纯形法进行模型参数优化程序。通过将模型结果与实验结果的比较，研究了各模型对于多孔铁矿石球团还原的适用性及各模型之间的联系与适用条件。此外，本文还研究了还原过程中球团有关结构参数的变化规律，说明了考虑固相结构参数变化的重要性，提出了具有变结构参数的多阶段反应模型。
英文摘要	In this thesis, porous pellets have been obtained by burning away the combustible material (saw wood dust) which has previously been mixed in the pellets so as to leave pores behind. By means of examining the partially reduced samples both macroscopically and microscopically, the manner by which the reduction of porous hematite pellet proceeds has been determined. A series of step-wise reduction experiments was carried out by CO-CO2 mixtures of appropriate compositions. Experimental data for each reduction step were analyzed on the basis of mixed control kinetics. Expressions for chemical-reaction rate constants and effective diffusivities are presented as functions of porosity, respectively. thus the dominant diffusion zone can be identified. Seven frequently used gas-solid non-catalytic reaction models have been systematically researched, their applicability to porous pellets have been discussed. Moreover, the effects of pellet porosity on the reducibility of the one material and non-topo-chemical behavior have been observed. Finally, a mathematical model which describes local changes in porosity and effective diffusivity accompanying the reduction process is presented. The results of these investigations indicate clearly that the variations in structural parameters, such as porosity and labyrinth factor, are a function of the structure of original oxide, the step of reduction reaction and the degree of reduction. It is important that the effect of structural changes of pellets on reduction rate is taken into account.
语种	中文
公开日期	2013-09-27
页码	91
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/2050]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	陈宇飞. 多孔铁矿石球团还原动力学及其数学模型[D]. 中国科学院研究生院. 1986.

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