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烧结过程中Pb元素的迁移规律及控制措施

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为了明确烧结过程中Pb的迁移规律,以某钢铁企业烧结机为研究对象,采用离子色谱法作为检测手段,分析Pb的收支平衡;结合热力学分析,得出Pb在烧结工序内的反应行为以及不同烧结温度时的平衡相组分变化特征,进而提出预防Pb超标的技术控制措施.结果表明,混匀矿和烧结矿分别占据了 Pb收入项中96.16%和Pb支出项中的79.82%.该企业烧结工序Pb的脱除率为20.18%.此外烧结工序Pb负荷为0.06 kg/t,烟气排放因子为1.22 g/t.在烧结过程中大部分含Pb化合物会发生反应,导致含Pb物料产生物相转变;在企业当前物料条件下,Pb在原料中主要以PbS形式存在,在烧结过程温度低于740 ℃时,Pb主要以PbSO4形式存在于烧结矿中,而PbCl2以气态方式进入烟气被脱除;温度升高至1 300 ℃过程中,PbSO4转变为PbSiO3和Pb单质,在1 300 ℃以上进一步转变为气态PbO被脱除.在现有条件下,控制含Pb固废物料的利用比例,并提升固废物料与铁矿粉的混匀效果以稳定烧结矿中Pb含量、改进除尘设备来促进挥发性含Pb物质排出是控制Pb危害的重要途径.
Migration law and control measures of Pb element in sintering process
To clarify the migration law of Pb during sintering process,the sinter machine in a steel company was taken as the research object.The balance state of Pb was studied by the ion chromatography.The reaction behavior of Pb in the sintering process and the change characteristics of equilibrium phase composition at different sintering temperatures were obtained with thermodynamic analysis,and then the control method to defend Pb from exceeding the standard was brought.The results show that blending ore provides 96.16%of the Pb source,while sintering ore accounts for 79.82%of Pb expenditure.The removal rate of Pb in the sintering process is 20.18%.In addition,the Pb load in the sintering process is 0.06 kg/t,and the sintering flue gas emission factor is 1.22 g/t crude steel.During the sintering process,most of the Pb-containing compounds will be reacted,leading to the Pb-containing ma-terials to produce phase transformation.Pb in the raw material mainly exists as PbS.When the temperature of sinte-ring process is lower than 740 ℃,Pb mainly exists as PbSO4 in the sintering ore,while PbCl2 is in a gaseous state into the flue gas to be removed.PbSO4 is transformed to PbSiO3 and Pb monomers during the temperature increases to 1 300 ℃.It is further transformed into gaseous PbO to be removed above 1 300 ℃.In addition,under the exist-ing conditions,controling the utilization ratio of solid waste materials containing Pb,and improving the mixing effect of solid waste materials and iron ore powder to stabilize the Pb content in sinter and improving the dust removal equipment to promote the discharge of volatile Pb-containing substances are important ways to control Pb hazards.

sinteringlead elementmigration behaviorlead equilibrium distributioncontrol measure

李嘉雨、张朝晖、李红红、郭胜兰、折媛、邢相栋

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西安建筑科技大学冶金工程学院,陕西西安 710055

宝钢湛江钢铁有限公司,广东湛江 524072

烧结 铅元素 迁移行为 铅平衡 控制措施

国家自然科学基金陕西省创新能力支撑计划陕西省教育厅重点实验室科学研究项目

521743252023-CX-TD-5320JS072

2024

中国冶金
中国金属学会

中国冶金

CSTPCD北大核心
影响因子:0.907
ISSN:1006-9356
年,卷(期):2024.34(6)