摘要
细粒级铁精矿球团化有助于增加低品位矿藏的开发及工业应用力度,稳定和拓展国内铁矿供应来源。使用消石灰作为球团的黏结剂与助熔剂,对球团生产提质降耗与节能减排具有重要意义。首次介绍了消石灰配比对细粒级铁精矿生球质量及干燥特性与预热焙烧球强度的影响,试验结果表明,消石灰配比的增加会提高细粒级铁精矿生球的落下和抗压强度,在4%配比时生球落下强度为3.55次/0.5 m,生球的抗压强度均大于11 N,生球爆裂温度先升高后降低,最高为360℃;不同消石灰配比对细粒级铁精矿的干燥特性影响较小,干燥温度和干燥风速则对生球干燥特性有显著影响,Weibull和Dincer模型拟合的结果与试验结果基本一致,模型较为有效,拟合结果表明生球的干燥速率受内外部水分扩散共同控制,干燥温度和干燥风速的增加会导致生球干燥温度分布趋向不均匀,生球干燥活化能值为9977.30 J/(mol·K);随着消石灰配比增加,细粒级铁精矿预热球强度始终增加,焙烧球抗压强度则先增加后降低,在配比为4%时达到最大值,为3800 N。细粒级铁精矿配加4%~6%(质量分数)消石灰较为适宜,该配比下可以获得生球和预热焙烧球强度均符合工业需求的球团;消石灰与细粒级铁精矿制备球团的生球干燥特性研究可为通过干燥设备选择和干燥条件优化来减轻生球干燥破裂现象提供理论支持。
The pelletization of fine-grained iron ore concentrates helps to increase the development and industrial application of low-grade deposits and stabilize and expand the domestic iron ore supply sources.The use of lime hydrate as a binder and flux for pellets is of great significance to the pellet production in terms of quality improvement and consumption reduction,energy saving and emission reduction.The effect of lime hydrate ratio on the quality and drying characteristics of fine iron ore concentrate green pellets and the strength of preheated roasted pellets is introduced for the first time.The test results show that the increase of lime hydrate ratio will improve the falling and compressive strength of fine iron ore concentrate green pellets.The results of fitting Weibull and Dincer model are basically consistent with the experimental results,and the model is more effective.The fitting results show that the drying rate of green pellets is jointly controlled by internal and external moisture diffusion,and the increase of drying temperature and drying air speed will lead to the drying temperature distribution of green pellets tends to be uneven,and the activation energy value of green pellets is 9977.30 J/(mol·K),the strength of preheated pellets of fine-grained iron ore concentrate always increases with the increase of lime hydrate ratio,and the compressive strength of roasted pellets increases first and then decreases,reaching the maximum value of 3800 N at the ratio of 4%.The pellets of pellets prepared from lime hydrate and fine-grained iron ore concentrate with 4%-6%lime hydrate are suitable to obtain pellets with the strength of green pellets and preheated roasted pellets that meet the industrial requirements,the study on the drying characteristics of raw pellets prepared from lime hydrate and fine-grained iron ore concentrate can provide theoretical support to reduce the drying breakage of raw pellets through the selection of drying equipment and optimization of drying conditions.
作者
从俊强
温宝良
李家新
张晓萍
杨佳龙
CONG Jun-qiang;WEN Bao-liang;LI Jia-xin;ZHANG Xiao-ping;YANG Jia-long(School of Metallurgical Engineering,Anhui University of Technology,Maanshan 243032,Anhui,China;Maanshan Iron and Steel Co.,Ltd.,Maanshan 243003,Anhui,China)
出处
《钢铁》
CAS
CSCD
北大核心
2023年第5期20-30,共11页
Iron and Steel
基金
国家自然科学基金青年基金资助项目(52204330)。
关键词
消石灰
细粒级铁精矿
生球质量
干燥特性
预热焙烧
lime hydrate
fine-grained iron ore concentrate
green pellet quality
drying characteristics
preheating and roasting
