国内超高碱度烧结矿生产实践及发展趋势

Production practice and development trend of iron ore sinter with ultra-high basicity

为了响应国家碳达峰碳中和号召,钢铁企业对于生产节能减排的要求也越来越高,烧结工艺由于在生产过程中固废排放量巨大,因此常常面临限产而导致的烧结产能不足等问题。国内外生产实践表明,高炉高比例球团冶炼具有燃料比低、渣量少等优点,且球团矿性能优良、生产过程更为环保,具有很好的应用前景。为了配合高球比炉料结构的应用,同时避免由于环保限产引起的烧结矿产能不足等问题,国内诸多钢铁企业针对超高碱度烧结矿开展研究。首先从烧结过程和矿物组成变化两个方面对超高碱度烧结矿成矿机理与质量之间的关系进行研究,发现烧结矿碱度在2.10~2.80范围内,随着碱度的升高,矿物主要黏结相逐渐向铁酸钙系黏结相转变,矿物组成逐渐平稳,而碱度大于2.80后黏结相中玻璃质和裂纹逐渐增加,严重影响烧结矿质量。随后对国内典型钢铁企业超高碱度烧结矿生产概况进行了调研分析,并结合矿物学基本原理明确了超高碱度烧结矿与其经济技术指标间的耦合关系。最终提炼出钢铁企业在生产超高碱度烧结矿中出现的问题,基于烧结工艺、矿物学原理及实践经验,探讨了问题的产生原因并提出了相应的解决建议。

In order to meet the national call for carbon peak carbon neutralization,iron and steel enterprises have higher and higher requirements for energy saving and emission reduction in production.Due to the huge solid waste emissions in the production process,sintering process is often faced with problems such as insufficient sintering capacity caused by production limit.The world production practice shows that high proportion pellet smelting in blast furnace has the advantages of low fuel ratio and less slag amount.At the same time,it has brought development prospects due to the excellent pellet performance and more environmental-friendly production process.In order to cooperate with the application of a high proportion of pellet charge structure and avoid problems such as insufficient sinter production capacity due to limited production because of environmental protection,many domestic steel companieshave launched ultra-high basicity sinter production explores.Firstly,this article studies the relationship between mineralization mechanism and quality of ultra-high basicity sinter from two aspects of sintering process and mineral composition change,and finds that the basicity of sinter is in the range of 2.10-2.80.With the increase of basicity,the main mineral bonding phase gradually changes to calcium ferrite bonding phase,and the mineral composition gradually becomes stable.When the basicity exceeds 2.80,the vitreous and cracks in the bond phase gradually increase,which seriously affects the quality of sinter.Then this article summarizes the production profile and technical and economic indicators of ultra-high basicity sinter in typical domestic steel enterprises.The sintering process and mineralization mechanism of ultra-high basicity sintered ore were clarified based on the practice and the principles of mineralogy.Finally,the problems in the production of ultra-high basicity sinter in iron and steel enterprises are summarized.Based on sintering process,mineralization mechanism and previous practical experience,the causes of the problems are discussed,and corresponding solutions are proposed.