重新认识高炉用焦炭与CO2的反应性

简要介绍了现行焦炭反应性试验方法的来源，主要表达焦炭在高炉内进入风口回旋区前抗CO2，气化能力以及反应后的抗粉化能力，是一种规范性试验方法。回顾了国内外对焦炭反应性的认识和变化，20世纪认为反应性表达焦炭在高炉抗CO2，的气化能力，反应性高反应后强度低对高炉生产不利。进入21世纪，新日铁提出反应性只是表达了焦炭的活性，认为提高反应性可以提高高炉反应效率，对高炉生产有利，不同时期认识水平不同认知也会完全相反。通过CO2，含量和反应温度对焦炭反应性影响试验和高炉碳平衡计算，分析了喷吹煤粉高炉内焦炭的行为．确定了焦炭进入风口回旋区前的反应失重率。提出现行国家标准“焦炭反应性及反应后强度试验方法”的反应性表达的是焦炭与CO2，反应的活性，高炉内焦炭反应失重率控制因素是矿石的还原性能和未燃煤粉率，与焦炭实验室测定的反应性无关。

Reappraisal of the reactivity of blast furnace coke with CO2

Abstract：This paper briefly introduced the current coke reactivity test method used in China, which is a standardized method mainly measuring the anti-CO2 gasification property of coke before it enters the raceway of a blast furnace as well as the anti-pulverization property of coke after it reacts with CO2. Knowledge development about coke reactivity in China and foreign countries was reviewed. In the last century, coke reactivity was regarded as an index expressing the anti-CO2 gasification property of coke in a blast furnace. It was considered then that a higher coke reactivity meant a lower coke strength after reaction and was thus unfavorable for blast furnace production. However, in the 21 st century, Nippon Steel put forward that coke reactivity only reflected the activity of coke. The company held the view that the increase in coke reactivity would improve the ~action efficiency in a blast furnace and was thus favorable for blast furnace production. The above two conclusions contradict with each other as the understanding of blast furnace production has progressed with time. This paper also described the calculation of blast furnace carbon balance and the experiments for investigating the effects of CO2 concentration and reaction temperature on coke reactivity. On the basis of the calculation and experiments, the behavior of coke in a blast furnace with coal injection has been analyzed and the reaction weight loss rate of coke before it enters the raceway has been determined. It has been pointed out that in the current national standard,＂Method of determining coke reactivity and coke strength after reaction＂, coke reactivity refers to the activity of coke in the reaction with CO2. The reaction weight loss rate of coke in a blast furnace is mainly affected by the reduction performance of iron ore and the unburned pulverized coal（UPC） rate, and is irrelevant to the coke reactivity measured in labs.