摘要
为资源化利用铁矿选矿过程中产生的大量尾矿,本文以某高塑性选铁尾泥为主要原料,经过改性处理开发尾泥替代膨润土作为球团黏结剂的新技术。试验结果表明:选铁尾泥粒度极细,且富含黏土矿物,小于0.038 mm粒级质量分数为98.79%,高岭石质量分数为27.6%。采用80%选铁尾泥与20%F黏结剂共反应制备改性尾泥,可得到性能优良的黏结剂;改性尾泥的膨胀容由1.9 mL/g提升至18 mL/g。铁精矿的比表面积对生球的质量影响显著。以某弱成球性铁精矿为研究对象,在铁精矿的比表面积为850 cm^(2)/g和最优造球工艺参数下,添加1%的改性尾泥进行造球,生球的落下强度可达11.10次/(0.5 m)、抗压强度可达12.60 N/P、爆裂温度>500℃,优于同条件下3%膨润土用量的生球质量。选铁尾泥在焙烧过程中发生高岭石脱羟基、菱铁矿和方解石分解等反应,影响预热球团的强度,但改性尾泥中少量有机物的燃烧可促进次生赤铁矿的生成,提升球团矿的强度。在预热温度为1050℃、预热时间为16 min,焙烧温度为1220℃、焙烧时间为12 min的条件下,预热球的强度达到466.1 N/P,焙烧球的抗压强度达到2309 N/P,可满足工业应用的要求。
In order to utilize a large amount of tailings generated in the process of tailing mud after beneficiation,a new technology of replacing bentonite as a pellet binder is developed by using high-plastic tailing mud after beneficiation as the main raw material.The results show that the particle size of the tailing mud after beneficiation is very fine and rich in clay minerals,with a particle fraction less than 0.038 mm of 98.79%and a mass fraction of 27.6%of kaolinite.The modified tailings are prepared by co-reaction of 80%tailing mud after beneficiation and 20%F binders,and the binders with excellent performance could be obtained.The expansion capacity of the modified tailing mud is increased from 1.9 mL/g to 18 mL/g.The specific surface area of iron ore concentrate has a significant effect on the quality of fresh pellets.Taking a weakly spheroidizing iron concentrate as the research object,under the specific surface area of the iron concentrate of 850 cm^(2)/g and the optimal pelletizing process parameters,adding 1%modified tailing mud for pelletizing,the fresh pellet falling strength can reach 11.10 times/(0.5 m),the compressive strength can reach 12.60 N/P,and the bursting temperature>500℃,which is better than the fresh pellet mass of 3%bentonite under the same conditions.During the roasting process,kaolinite dehydroxylation,siderite and calcite decomposition occur,which affect the strength of the preheated pellets,but the combustion of a small amount of organic matter in the modified tailings can promote the formation of secondary hematite and improve the strength of the pellets.Under the conditions of preheating temperature of 1050℃,preheating time of 16 min,roasting temperature of 1220℃and roasting time of 12 min,the strength of the preheating ball reaches 466.1 N/P,and the compressive strength of the roasting ball reaches 2309 N/P,which can meet the requirements of industrial applications.
作者
许继龙
张祖刚
张鑫
张津
韦承志
宋锐
XU Jilong;ZHANG Zugang;ZHANG Xin;ZHANG Jin;WEI Chengzhi;SONG Rui(Mining Branch,Nanjing Baodi Meishan Industrial City Development Co.,Ltd.,Nanjing 210039,Jiangsu,China;School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,Hunan,China)
出处
《烧结球团》
北大核心
2025年第3期59-69,共11页
Sintering and Pelletizing
基金
中国科协青年人才托举工程项目(YESS20220533)。
关键词
选铁尾泥
黏结剂
膨胀容
球团
tailing mud after beneficiation
binders
expansion capacity
pellets
