改进分段尝试法研究焦炭气化反应动力学

焦炭作为高炉炼铁的主要燃料,对高炉的正常运行以及高效冶炼发挥着至关重要的作用.伴随着现代高炉大型智能化的发展趋势,面对资源的不断消耗,用于冶炼优质冶金焦的原料逐渐减少,低质冶金焦引起了冶金工作者越来越多的关注.在测定高炉使用的焦炭基础理化特性后,通过对不同升温速率下不同质量焦炭与CO2的气化反应试验,采用分段尝试法建立...

Kinetics of coke gasification reaction process by improved segmentation attempt method

As the main fuel of blast furnace ironmaking, coke plays a vital role in the normal operation of blast furnace and efficient smelting. With the development trend of large-scale intelligence of modern blast furnace and the continuous consumption of resources, the raw materials used to smelt high-quality metallurgical coke are gradually reduced. Low-quality metallurgical coke has attracted more and more attention of metallurgical workers. After determining the basic physical and chemical properties of coke in blast furnaces, the kinetics of different quality coke and CO₂ gasification reaction processes under different heating rates were studied using the segmentation attempt method. The control mechanism of coke gasification reaction process was studied, which could be divided into two stages, the chemical reaction rate control in the early stage and the diffusion mass transfer rate control in the later stage. A two-stage speed control model was used to fit the gasification reaction process data, and then an unreacted shrinking core model for the chemical reaction rate control in the early stage and a shrinking core model for the diffusion mass transfer rate control in the later stage were established respectively. The conversion points, chemical reaction rate constant and mass transfer coefficient of the two control rates in reaction process were determined. Considering that the chemical reaction rate was nearly three orders of magnitude higher than the diffusion control rate, according to the irreversible thermodynamic phenomenological equation, the interference effect of chemical reaction process on the internal diffusion rate control process in the later stage of gasification reaction process was studied, and the valence coefficient in the phenomenological equation was determined. The latter diffusion speed control equation was modified, segmentation attempt method which was suitable for metallurgical reaction engineering to study reaction process kinetics was improved and its accuracy was further increased.