高喷煤比条件下焦炭在高炉内热强度变化规律及机理研究

With the development of blast furnace with large scale and high spray of pulverized coal, the real conditions of coke in furnace have changed greatly. More and more questions are raised about the rationality of CRI/CSR simulation for coke. It is reported that the correlation between the strength of coke and CRI/CSR was not clear and even some contrary results were found. In this project, the strength of coke will be studied under a series of simulating conditions of different coal injection rates. The reaction conditions of coke will be determined by combing the experiences of formers, the production data of manufacturer and the simulation of computer. The injection rate of coal is simulated comprehensively from zero to 250kg/t. The strength after reaction of coke will be focused. A series of similar and differentiated kinetic models of coke solution reaction is the major objective to achieve and also the models may be used to explain the regulation of coke strength. The results of this project may lead to a deep understanding for coke solution in furnace, and provide a theoretical basis for control of coke quality in modern furnace with high spray of pulverized coal.

随着现代高炉大型化的发展及高喷煤技术的应用，焦炭在高炉内的负荷发生了很大变化。人们对传统焦炭CRI/CSR测试指标模拟性不足的质疑不断增多，已经有人通过试验发现高炉实际焦炭热强度与标准CRI/CSR指标没有关联性，甚至发现焦炭热强度性质会在高炉内发生CRI/CSR测试结果序列逆转。本项目提出在更接近现代高炉实际的情况下，模拟系列喷煤比条件升温过程与CO2气氛组成条件，研究焦炭热强度变化规律，并通过碳溶损反应的研究解释内在机理。通过借鉴前人经验、分析生产数据并结合数值模拟的方法确定试验条件，进行系统而全面地模拟全焦到喷煤250kg/t水平试验研究。着重研究在系列条件下焦炭热强度性质变化行为，建立类似而有区别的、基于煤种的焦炭碳溶反应动力学模型，明晰焦炭热强度变化规律内在机理。研究结果可望提高对焦炭在高炉内消耗过程的认识水平，为高喷煤比条件下焦炭质量的控制提供理论依据。

随着现代高炉大型化的发展及高喷煤技术的应用，焦炭在高炉内的负荷发生了很大变化，人们对传统焦炭CRI/CSR测试指标模拟性不足的质疑不断增多。本项目在更接近现代高炉实际的情况下，模拟系列喷煤比操作升温过程与CO2气氛组成条件，研究焦炭热强度变化规律。通过对多种单种煤焦炭、配合煤焦炭及生产焦的试验研究发现，国标法对于评价焦炭在高炉中的质量存在的模拟性不足且差距较大。在国标测试条件下CSR相差较大的气煤焦和焦煤焦经模拟高炉条件反应后，其反应后强度的差距明显缩小，甚至发生了逆转。发生以上问题的根本原因在于，在模拟高炉条件下，焦炭中不同组织结构的反应性在不同模拟高炉条件下与标准反应条件下有较大差异。大多数焦炭的各向同性结构构的反应性显著降低，而大部分各向异性结构的反应性增加。焦炭的各向同性组织的反应性在国标条件下普遍高于各向异性，在模拟高炉条件下，两者反应性的差距有所减小，甚至出现逆转。当焦炭的各向同性组织含量达到一定百分比后，模拟高炉条件下的反应后强度会高于国标条件。在保证生产焦冷强度及国标条件下反应后强度无明显下降的前提下，适当提高1/3焦煤和气煤在配煤中的比例，可以有效提高焦炭在模拟高炉条件下的反应后强度。