利用铁尾矿制备烧结砖的可行性及烧结固化机理  

Feasibility of using iron tailings to prepare sintering brick and sintering solidification mechanism

作　　者：周伟伦 廖正家 陈涛 宁寻安[1,2] 王逸 谢鸿智[1,2] ZHOU Weilun;LIAO Zhengjia;CHEN Tao;NING Xunan;WANG Yi;XIE Hongzhi(School of Environmental Science and Engineering,Guangdong University of Technology,Guangzhou 510006,China;Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control,Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control,Guangzhou 510006,China;Guangdong Province Dabaoshan Mining Co.,Ltd.,Shaoguan 512127,China)

机构地区：[1]广东工业大学环境科学与工程学院,广州510006 [2]广东省环境催化与健康风险控制重点实验室,环境健康与污染控制研究院,广州510006 [3]广东省大宝山矿业有限公司,韶关512127

出　　处：《环境工程学报》2021年第5期1670-1678,共9页Chinese Journal of Environmental Engineering

基　　金：2017年土壤中央专项资金-大宝山尾矿无害化处理及综合利用前期研究项目(18HK0108)。

摘　　要：针对铁尾矿综合利用率低的问题,利用铁尾矿、粉煤灰、废玻璃制备烧结砖,以提高铁尾矿综合利用率。通过抗压强度、吸水率和重金属浸出3方面评价烧结砖的性能,确定最佳烧结工艺条件;并通过重金属形态分布、孔径分析、XRD和SEM探究烧结砖的固化机理。结果表明,在最佳条件烧结温度为1100℃、铁尾矿、粉煤灰、玻璃配为6∶2∶2的条件下,烧结砖的抗压强度为124 MPa,吸水率为4.6%。最佳条件下烧结砖的Cu、Pb、Zn重金属浸出浓度均低于标准阈值。当烧结温度从900℃上升到1200℃,Cu、Pb和Zn的残渣态占比均有所上升,孔容积从0.019 cm^(3)·g^(-1)下降到了0.001 cm^(3)·g^(-1),平均孔径从22.1 nm下降到了9.3 nm。物相分析结果表明,在烧结过程中,高岭石相和石英相的特征峰降低,莫来石相的特征峰升高。上述结果可以为铁尾矿制备烧结砖提供数据参考。Aiming at the problem of low comprehensive utilization rate of iron tailings,sintering brick was prepared by using iron tailings,fly ash and waste glass to improve the comprehensive utilization rate of iron tailings.The properties of the sintered bricks were evaluated from three aspects:compressive strength,water absorption and heavy metal leaching,and the optimal process conditions were determined.The solidification mechanism of the sintered bricks was investigated by means of heavy metal speciation distribution,pore diameter analysis,XRD and SEM.The results show that under the optimal sintering temperature of 1100℃,iron tailings∶fly ash∶glass is 6∶2∶2,the compressive strength of the bricks and the water absorption rate is124 MPa and 4.6%,respectively.The leaching concentration of Cu,Pb and Zn is all lower than the standard threshold.When the sintering temperature increases from 900℃to 1200℃,the proportion of Cu,Pb and Zn residues increases,the pore volume decreases from 0.019 cm^(3)·g^(-1)to 0.001 cm^(3)·g^(-1),and the average pore diameter decreases from 22.1 nm to 9.3 nm.Phase analysis showed that the characteristic peaks of kaolinite and quartz phases decreased,while those of mullite phases increased during sintering.In addition,it was observed that the internal structure of the sintered bricks tended to densify during sintering.The research can provide theoretical basis for the preparation of sintering brick from iron tailings.

关 键 词：铁尾矿 废玻璃 烧结砖 抗压强度 重金属浸出 

分 类 号：X753[环境科学与工程—环境工程]