摘要
为充分发掘有机黏结剂对铁精矿球团质量提升的优点,同时弥补有机复合黏结剂削弱成品球抗压强度的不足,本文将蛭石、羧甲基纤维素钠(有机黏结剂)、膨润土进行复配,探究复合黏结剂对铁精矿球团质量的影响,并借助SEM和热重分析探索蛭石改善成品球强度的机理。试验结果表明:在不复配有机黏结剂,仅仅添加1%的膨润土时,球团的落下强度只有1.5次/(0.5 m),抗压强度为8.2 N/P,爆裂温度为550℃,在预热温度为950℃、焙烧温度为1200℃时成品球的强度为3121 N/P;固定膨润土用量,随着有机黏结剂复配比例增加到0.12%,生球落下强度可提升到8.0次/(0.5 m),抗压强度提升到11.3 N/P,但生球的爆裂温度下降到395℃,成品球强度下降到2465 N/P;加入0.03%蛭石+0.12%有机黏结剂+1%膨润土的复合黏结剂后,球团的质量指标最好,球团落下强度可达到6.5次/(0.5 m),抗压强度为13.4 N/P,爆裂温度为362℃,成品球强度在相同条件下可以提升至2764 N/P。SEM和热重分析结果表明:蛭石膨胀能不断填充球团中的孔隙,在焙烧过程中生成液相,有利于固相扩散晶体长大,降低球团孔隙率,从而提升成品球的抗压强度。
In order to fully explore the advantages of organic binders on the quality improvement of iron concentrate pellets and make up for the shortcomings of organic composite binders in weakening the compressive strength of finished pellets,vermiculite,sodium carboxymethyl cellulose(organic binders)and bentonite are compounded to explore the effect of composite binders on the quality of iron concentrate pellets,and the mechanism of vermiculite to improve the strength of finished balls is explored with the help of SEM and thermogravimetric analysis.The results show that,when only 1%bentonite is added without organic binders,the drop strength of pellets is only 1.5 times/(0.5 m),the compressive strength is 8.2 N/P,the burst temperature is 550℃,and the strength of finished pellets is 3121 N/P when the preheating temperature is 950℃and the roasting temperature is 1200℃.When the amount of bentonite is fixed,with the increase of the proportion of organic binder to 0.12%,the drop strength of green pellets can be increased to 8.0 times/(0.5 m),and the compressive strength can be increased to 11.3 N/P,but the bursting temperature of green pellets can be reduced to 395℃,and the strength of finished pellets can be reduced to 2465 N/P;After adding 0.03%vermiculite+0.12%organic binders+1%bentonite,the quality index of pellets is the best,the dropping strength of pellets can reach 6.5 times/(0.5 m),the compressive strength is 13.4 N/P,and the bursting temperature is 362℃.The strength of finished pellets can be increased to 2764 N/P under the same conditions.The results of SEM and thermogravimetric analysis show that the expansion of vermiculite can continuously expand and fill the pores in the pellets,and form a liquid phase during the roasting process,which is conducive to the growth of solid-phase diffusion crystals,reduce the porosity of the pellets,and improve the compressive strength of the finished pellets.
作者
岳志玲
杨大兵
胡明欣
王炜
YUE Zhiling;YANG Dabing;HU Minxin;WANG Wei(Wuhan University of Science and Technology School of Resources and Environmental Engineering,Wuhan 430081,Hubei,China;Wuhan University of Science and Technology Hubei Province Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources,Wuhan 430081,Hubei,China;Wuhan University of Science and Technology Institute of Materials and Metallurgy,Wuhan 430081,Hubei,China)
出处
《烧结球团》
北大核心
2024年第2期31-37,共7页
Sintering and Pelletizing
基金
国家自然科学基金资助项目(51974212)。
关键词
羧甲基纤维素钠
蛭石
复合黏结剂
球团质量
抗压强度
sodium carboxymethyl cellulose(CMC)
vermiculite
composite binder
pellets quality
compressive strength
作者简介
岳志玲(1998-),女,硕士研究生,从事铁矿黏结剂方面的研究;通信作者:杨大兵(1965-),男,教授,从事矿物加工、铁矿球团黏结剂方面的研究。
