摘要
黏结剂在散体物料制球中具有重要的桥联作用与团聚作用,能改善球团的烧结性能。本文主要介绍了粉料制球黏结剂的种类、各类黏结剂的桥联与黏结作用机理,以及应用于冶炼尾渣、高炉烟灰、矿山尾矿等粉体物料的球团工艺情况。膨润土遇水后迅速高度分散成单体填充在散粒物料的空隙中,降低了球团孔隙率,同时产生的吸附水层能使球团受到冲击时产生塑性形变不易碎裂,进而提高球团强度;水泥与水混合后会发生水化反应和结晶硬化而固结;水玻璃在颗粒表面包裹一薄层水玻璃膜,颗粒之间通过黏结膜连接,固化后提高球团强度;有机黏结剂中的基团可以改善物料表面的亲水性,增强颗粒间的相互作用。膨润土作为球团中常见而广泛应用的无机黏结剂,用量过大导致球团品位降低和渣量增加,可通过膨润土的钠化、润磨、高压辊磨、有机黏结剂替代部分膨润土及有机黏结剂的改性等手段来降低膨润土的用量;有机黏结剂虽不会降低球团品位,但相比于无机黏结剂价格较高,球团机械强度低,难以大规模投入实际生产;复合黏结剂集合了前两者的优点,综合性能较好,应用前景广阔。
Binder plays an important role in bridging and agglomeration in the pelletizing of bulk materials,which can improve the sintering performance of pellet.The types of powder pelletizing binders,the bridging and bonding mechanism of each binder,and the pelletizing process of various powder materials such as smelting tailings,blast furnace soot,and mine tailings were focus on describing in the paper.After contacting water,bentonite is quickly dispersed into monomer and filled in the void of iron ore powder,which reduces the porosity of the pellets.Meanwhile,the generated adsorbed water layer can make the pellets cause plastic deformation when under impact and avoid fragmentation,thus improving the strength of the pellets.When cement is mixed with water,hydration reaction and crystallization hardening and consolidation will occur.The surface of particles is wrapped around with a thin layer of sodium silicate film,and the particles are connected by sodium silicate film to improve the strength of pellets after curing.The functional group in the organic binder improve the hydrophilicity of the material surface and enhance the interaction between particles.Bentonite is a common and widely used inorganic binder in pellets.Excessive dosage leads to a decrease in pellet grade and an increase in slag content.Part of bentonite and modification of organic binders can be used to reduce the amount of bentonite.Although organic binders will not reduce the grade of pellets,they are expensive compared to inorganic binders,and the mechanical strength of pellets is low,making it difficult to put into practical production on a large scale.The composite binder combines the advantages of the former two binders,with good comprehensive performance and great application prospects.
作者
罗立群
刘成
叶远林
雷严明
LUO Liqun;LIU Cheng;YE Yuanlin;LEI Yanming(School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China;Key Laboratory of Mineral Resources Processing and Environment in Hubei Province,Wuhan 430070,China)
出处
《中国矿业》
2022年第12期79-87,共9页
China Mining Magazine
基金
国家自然科学基金项目资助(编号:51874219)。
