铁矿球团用有机黏结剂研究进展

Research progress of organic binder for iron ore pellets

随着钢铁行业绿色低碳转型,使用有机黏结剂替代膨润土已经是铁矿球团工序提质降耗的必然趋势。然而,有机黏结剂彻底替代膨润土的技术壁垒仍未突破,严重限制了其在工业生产中的广泛应用。有机黏结剂的黏结效用也是控制球团强度的关键因素,研究其在球团生产中的作用机理对提高球团强度以及开发具有国内知识产权的新型有机黏结剂意义重大。通过总结有机黏结剂在铁矿球团中的研究进展,旨在为其在中国钢铁行业的广泛应用以及新型有机黏结剂的研发工作提供理论指导与试验依据。在介绍理想有机黏结剂分子结构模型的基础上,揭示了4种常见有机黏结剂的结构及特性。重点讨论了黏度和吸水性对有机黏结剂黏结效用的作用机理,有机黏结剂的高黏度特性能够调节球团颗粒间液桥黏滞力大小,从而显著提高生球强度;吸水性是有机黏结剂调控生球自由水含量的重要特性,只有在最佳吸水率下,才能获得强度较高、粒径均匀的生球。总结了有机黏结剂的常见优缺点,其主要优点是微量高效、烧失量大、基本不影响球团铁品位,缺点是生产球团矿缺乏渣相固结而强度不足。分析了优化原料粒度组成、添加含硼化合物及分散剂等强化有机黏结剂球团生产的调控手段,并展望了有机黏结剂未来的发展方向。

With the steel industry′s green,low-carbon transformation,the use of organic binder to replace bentonite has become an unavoidable trend in the iron ore pellet process to improve quality and reduce consumption.However,technical barriers to completely replacing bentonite with organic binders have yet to be overcomed,severely limiting its widespread use in industrial production.The bonding effect of organic binder is also an important factor in controlling pellet strength,and understanding its mechanism of action in pellet production is critical for improving pellet strength and developing new organic binders with domestic intellectual property rights.In order to provide theoretical guidance and direction by summarizing the research progress of organic binders in iron ore pellets.The structures and properties of four common organic binders were revealed based on the introduction of the molecular structure model of ideal organic binders.The effect of viscosity and water absorption on the bonding effectiveness of organic binders was discussed.The high viscosity of organic binders can regulate the size of liquid bridge adhesion between pellets,significantly improving green pellet strength;water absorption is an important property of organic binders to regulate the free water content of green pellets,and only with the best water absorption rate can obtain green pellets with high strength and uniform particle size.The common advantages and disadvantages of organic binders are summarized.The main advantages of organic binders are trace efficiency,high burn-off,and little effect on pellet iron grade,while the main disadvantages are a lack of slag phase consolidation in the production of pellet ore and insufficient strength.Analysing the optimization of raw material particle size composition,the addition of boron-containing compounds and dispersants to strengthen the organic binder pellet production control means,and looking forward to the future development of organic binder direction.