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为了研究高炉冶炼中焦炭的溶损行为,选用2种不同反应性的焦炭考察焦炭与烧结矿在不同温度下的耦合反应,研究不同温度下焦炭溶损与烧结矿还原的关系。研究结果表明,焦炭溶损和烧结矿还原的耦合反应随着反应温度的升高逐渐加剧,且焦炭反应性提高有利于烧结矿的还原。焦炭溶损率与烧结矿还原度呈正线性相关性,焦炭反应性(CRI)与拟合曲线的斜率k呈反比,而与截距b呈正比,截距可以表征焦炭对烧结矿的初始还原能力。耦合反应后焦炭的光学各向异性指数OTI增大、平均孔径和气孔率大幅增大,反应性较大的焦炭易于在焦炭表面溶损,反应后的孔径较大;而反应性较小的焦炭在反应过程中CO2气体易于扩散至焦炭内部均匀溶蚀各级气孔。 相似文献
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为了研究富氢高炉内焦炭的溶损反应特性,开发了连续进水的全自动焦炭反应性测定装置,分别利用CO2和N2载带不同比例H2O(0%～30%)提供H2O+CO2(H2O和CO2混合气体)和H2O+N2(H2O和N2混合气体)的含水气氛进行焦炭溶损试验,通过红外气体分析仪实时记录出口气体中CO和H2的摩尔分数,研究了焦炭在H2O+CO2气氛下的溶损反应过程以及碳溶反应(C+CO2=2CO)和水煤气反应(C+H2O=CO+H2)的动力学过程。研究表明,随着H2O+CO2混合反应气氛中H2O比例的增加,焦炭的碳素溶损率和溶损速率均逐渐增大,而且水煤气反应的溶损速率逐渐变大、碳素溶损率逐渐升高,但是碳溶反应的溶损速率则逐渐减小、碳素溶损率也逐渐降低,这说明H2O+CO2反应气氛中H2O和CO2同时与焦炭反应存在显著的竞争作用。通过分析碳素溶损率和水蒸气含量线性关系的拟合斜率发现,焦炭在H2O+CO2混合反应气氛中发生的碳溶反应和水煤气反应的斜率均小于单纯单一气氛下的碳溶反应和水煤气反应的斜率,并提出基于斜率差值的抑制因子α表征H2O和CO2对碳溶反应和水煤气反应互相影响程度,CO2对水煤气反应的抑制因子α<sub>CO2/H2O为0.253,H2O对碳溶反应的抑制因子α<sub>H2O/CO2为0.179,α<sub>CO2/H2O为α<sub>H2O/CO2的1.41倍,CO2对水煤气反应的抑制程度强于H2O对碳溶反应的抑制程度。 相似文献
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为了探究富氢高炉内Ca/Fe基高反应性焦炭的溶损反应特性,以CO2（N2）载带不同摩尔比例H2O蒸气（0～30%）进行焦炭溶损实验,通过分析尾气中CO和H2的含量,研究Ca/Fe添加剂对焦炭在H2O+CO2混合气氛下碳溶反应和水煤气反应的影响。研究表明,焦炭在H2O+CO2和H2O+N2两种气氛下的焦炭反应性随H2O蒸气载带率增加呈线性关系,焦炭在H2O+CO2气氛中溶损反应的拟合斜率k值明显小于在H2O+N2气氛中的k值,H2O+CO2混合气氛中H2O和CO2与焦炭反应存在竞争关系。而且基础焦炭（BC）反应性的实验与理论的差值明显小于Ca/Fe基焦炭（BC+Ca、BC+Fe）的差值,表明Ca/Fe添加剂影响了CO2和H2O与焦炭共同反应时的竞争关系。基于两种气氛下速率常数的差异提炼了两个抑制因子\t\t\t\t\t\t\t\t\t\t\t2 (N2) carrier gas with various percentages (0–30%) of H2O vapor, and the effect of Ca/Fe additives on the Boudouard reaction (C + CO2 = 2CO) and water–gas reaction (C + H2O = CO + H2) of cokes in a H2O + CO2 atmosphere was studied by examining the content of CO and H2 in the off-gas. The results demonstrate that the coke reactivity has a positive linear relationship with the percentages of H2O vapor in H2O + CO2 and H2O + N2 atmospheres, and the fitting slope k could be used to characterize the rate constant for the solution loss reaction of cokes in H2O + CO2 and H2O + N2 atmospheres. The k value for the solution loss reaction of the coke in the H2O + CO2 atmosphere is smaller than that of the coke in the H2O + N2 atmosphere, which shows that there is a competition between the reactions of H2O and CO2 with cokes in the H2O + CO2 atmosphere. Furthermore, the experimental reactivities of coke are smaller than their theoretical reactivities in the H2O + CO2 atmosphere, and the difference between the experimental and theoretical reactivities of the basic coke (BC) is less than those of the cokes with Ca/Fe additives (BC + Ca, BC + Fe), which shows that the Ca/Fe additives affect the competitive relationship of the reactions of CO2 and H2O with coke. Two inhibition factors, \t\t\t\t\t\t\t\t\t\t\t相似文献
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