煤灰对白云鄂博矿球团粉末结圈行为的影响  

Effect of coal ash on ring-forming behavior of pellets in Bayan Obo ore

作　　者：石颜硕 高晓永 苏龙 白晓光[2] 王永斌[1] 刘培军 柴轶凡 SHI Yanshuo;GAO Xiaoyong;SU Long;BAI Xiaoguang;WANG Yongbin;LIU Peijun;CHAI Yifan(School of Metallurgical Future Technology,Inner Mongolia University of Science and Technology,Baotou 014010,Nei Mongol,China;Inner Mongolia Bao Gang United Steel,Baotou 014010,Nei Mongol,China)

机构地区：[1]内蒙古科技大学冶金未来技术学院,内蒙古包头014010 [2]内蒙古包钢钢联股份有限公司,内蒙古包头014010

出　　处：《钢铁》2025年第2期43-50,118,共9页Iron and Steel

基　　金：中央引导地方科技发展资金资助项目(2024ZY0078);内蒙古自治区高等学校青年科技英才支持计划资助项目(NJYT22060);内蒙古自治区直属高校基本科研业务费资助项目(2022QNJS011,2023XKJX003);内蒙古自治区人才开发基金高层次人才个人项目资助项目(202419)。

摘　　要：链箅机-回转窑是中国主要的氧化球团生产工艺,但回转窑的结圈问题一直制约着球团矿高效低耗的生产。回转窑内结圈程度加剧,对球团品质以及总体产量具有较大的影响,当窑内结圈物增多时,会对设备造成不可逆的影响,甚至引起安全事故。研究了煤灰添加量对白云鄂博矿球团生产过程中回转窑内结圈现象的影响。采用压块、焙烧试验模拟回转窑生产白云鄂博矿球团过程中的结圈物,通过添加不同比例的煤灰来模拟实际生产过程中结圈物生长过程中混入不同量的煤灰,对结圈物的物相组成、固结强度以及显微结构进行分析,揭示煤灰添加量对白云鄂博矿球团粉末结圈行为的影响机制。研究结果表明,不添加煤灰和添加质量分数为1%煤灰的结圈物相比,其变形温度从1345℃降低到1335℃,使结圈物更加容易形成;同时固结强度由2774 N增大至3782 N,增加了结圈物的清理难度。煤灰的加入会导致低熔点液相的生成,一方面低熔点液相会填充在赤铁矿连晶之间从而弥补结圈物的微观结构缺陷,进而增加固结强度;另一方面在高温时低熔点液相中的铁酸盐会与煤灰发生反应,使赤铁矿以再结晶的形式析出,促进赤铁矿的连晶,增加结圈物的固结强度。因此,在球团生产过程中应选用煤灰较低的煤粉进行喷吹,可有效抑制回转窑中的结圈现象。Grate-kiln is the main production process of oxidized pellets in China, the problem of ring formation in rotary kiln has always been an obstacle to the production of pellets with high efficiency and low consumption. The ringing of rotary kiln will destroy the kiln lining and affect the yield and quality of pellets, which will bring great difficulties to the production of pellets. When there are too many ringing objects, it will cause production reduction, shutdown and even more serious safety accidents. The effect of coal ash addition on the ringing phenomenon in the production process of Bayan Obo ore pellets was studied. The briquetting and roasting experiments were used to simulate the formation of pellets in the process of producing Bayan Obo ore pellets in a rotary kiln. By adding different proportions of coal ash, different amounts of coal ash were mixed during the growth of the formation in the actual production process. The phase composition, consolidation strength and microstructure of the agglomerates were analyzed by X-ray diffractometer, field emission scanning electron microscope and energy dispersive X-ray spectrum, and the influence mechanism of coal ash addition on the agglomeration behavior of Bayan Obo powder was revealed.The results show that the deformation temperature of the ring is reduced from 1 345 ℃ to 1 335 ℃ compared with the ring without adding coal ash and adding 1% coal ash(mass fraction), which makes the ring more easily formed. At the same time, the consolidation strength increases from 2 774 N to 3 782 N, which increases the difficulty of cleaning the ring. The addition of coal ash will lead to the formation of liquid phase with low melting point, and the liquid phase with low melting point will be filled between hematite crystals to make up for the microstructure defects of the ring, thereby increasing the consolidation strength. At the same time, the reaction between the liquid phase with low melting point and the coal ash composition at high temperature will promote the cry

关 键 词：回转窑结圈 煤灰 固结强度 赤铁矿连晶 白云鄂博矿 球团 炼铁 双碳 

分 类 号：TF046.6[冶金工程—冶金物理化学]