微波外场低温预处理对炼焦煤碳化行为及焦炭冶金性能的影响研究

In order to improve the gas and liquid permeability of stock column and eventually maintain high reduction efficiency in blast furnace, the achievement of excellent metallurgical coke performance in shaft of blast furnace has become the prior task for all ironmaking researchers. In this project, mechanism of coking coal pretreatment with microwave was investigated, by which the pyrolysis and carbonizing mechanism of treated coal and variation pattern of basic and coking property of coal during treatment as well as the variation of law carbon structure regularity will be explored. Consequently, basis for the optimization of coal coking property can be derived; Meanwhile, the variation law of carbon structure, microcrystalline structure, optical structure, microstructure as well as the organic functional group structure will be clarified. The changes in existence of sulfur and mineral matter can be deduced, by which the pyrolysis and coking property of coal can be manipulated. Besides, the relationship between microstructure and reactivity, strength after reaction, resistance for the catalysis from alkali metal will be investigated, by which the catalysis mechanism of mineral and alkali metal on coke reactivity will be revealed and simultaneously the active carbon point can be defined. Based on above research results, the production of metallurgical coke with low reactivity and superior performance can be realized.

提高冶金焦炭在高炉炉身下部高温性能，改善料柱的透气性和透液性，提高高炉煤气的还原效率，已成为炼铁工作者所共同面对的迫切任务。本项目拟通过微波外场对炼焦进行低温预处理，研究微波预处理炼焦煤的裂解和碳化机理，探索微波改质过程对炼焦煤物化性能和焦化性能的影响，揭示炼焦煤碳结构有序性在不同微波改质条件下的演变规律，为炼焦煤结焦性能的优化提供理论基础；明晰改质炼焦煤配合焦化过程中碳结构、微晶结构、光学组织、微观结构、有机官能团结构的形成及演变规律，阐释硫和灰分矿物质赋存状态在碳化过程中变化，调控微波改质条件优化焦炭裂解和碳化反应性能；阐明焦炭微观结构与焦炭气化反应性、反应后强度、抗碱金属催化能力之间的关系，掌握矿物质及碱金属对焦炭气化反应的催化机理，表征气化反应过程中活性碳素基点，为低反应性-高质量焦炭的制备提供基础理论支撑。

焦炭作为高炉炼铁工艺中无法替代的核心燃料，在高炉冶炼过程中发挥着发热剂、还原剂、渗碳剂和料柱骨架等作用。燃料喷吹技术的发展使得焦炭的前三种作用都可以被喷吹煤粉有效地取代。然而，焦炭在高炉内支撑松散物料的骨架作用却无法替代，使得高炉冶炼始终无法摆脱对焦炭的依赖。近年来，高炉大型化使得高炉的工作容积不断扩大，高炉内料柱的高度亦大幅增加，因此对焦炭质量的要求亦不断的提高。与此同时，为了降低铁水冶炼过程的原燃料成本，矿石原料的品位和质量却在不断下降，亦要求焦炭的吨铁消耗量降低，对焦炭质量提出了越来越高的要求。不仅要求焦炭在低温下具有良好的机械性能（耐磨强度和抗碎强度），亦要求焦炭在高温下（1100℃以上）为高炉内的矿石原料创造良好的透气性。. 随着我国钢铁产量的逐年大幅增大，焦炭消耗量也相应地不断随之剧增。虽然我国煤炭资源储量丰富，但可供焦炭冶炼使用的主焦煤稀缺，可供炼焦使用的煤种只占探明总煤储量的27%。主焦煤资源的匮乏导致焦炭价格较为昂贵，同时焦炭冶炼过程对环境的污染也较为严重，巨大的焦炭消耗量必然导致其价格的继续攀升和环境的严重污染。提高焦炭在高炉高温区内的冶金性能，减少铁水冶炼过程中的冶金焦炭消耗，可以通过低成本提高企业在行业中的竞争力，亦可相对缓解主焦煤稀缺和环境污染等方面的问题。. 本项目利用微波外场在低温下对炼焦煤进行辐射改质预处理，研究不同微波功率下炼焦煤样官能管结构和碳素结构随处理时间的变化，同时分析不同改质炼焦煤成焦后焦炭的冶金性能，确定微波外场条件下合理的炼焦煤处理条件。通过合理的微波功率和处理时间优化炼焦煤的结焦性能，从而改善成品焦炭在高炉内对物料的职称作用。