摘要
为研究粉煤灰淋滤过程中微量有害元素的迁移特性及钝化剂对元素的钝化效果,以某煤化工基地原煤与粉煤灰为试验原料,以砷和铅为研究对象,利用逐级化学提取研究了元素的赋存形态;在淋滤试验中研究了pH和淋滤时间对元素迁移的影响;在钝化试验中研究了腐植酸和沸石对元素的钝化效果。结果表明,砷和铅在原煤中赋存形态主要是不溶态、有机质结合态及铁锰氧化物结合态,而在粉煤灰中主要是不溶态。以风险评价指数法评价的表明原煤中砷、铅和粉煤灰中砷属于低风险范围。砷和铅在粉煤灰中以不溶态为主的赋存形态使其相对于在原煤中有较低的最大迁移率、阶段迁移率和迁移强度均低于其在原煤的主要原因。腐植酸和沸石对粉煤灰中砷和铅钝化效果明显,且钝化剂用量越大,其迁移率越低;腐植酸比沸石对砷有更好的钝化效果,2种钝化剂对铅的钝化效果相似。
In order to study the migration characteristic of trace harmful elements during the leachingprocess of flyash and the immobilization effect of immobilization agents on elements,the arsenic and lead ofraw coal and fly ash from a certaincoal chemical base were selected as research objects,sequential chemical extraction was usedto study the modes of occurrence of elements.The effects of pH and leaching time on element migration were studied in the leaching experiment.Finally,humic acid and zeolite were selected to studytheir immobilization effects on elements in fly ash.The results show that the insoluble mode was themain mode of occurrence of arsenic and lead in fly ash,while the insoluble mode,organic-bound mode andFe-Mn oxide-bound mode were their main modes of occurrence in raw coal.The risk assessment code methodindicated that arsenic and lead in raw coal and arsenic in fly ash were in the low-risk range.Themain reason why the maximum migration ratio,stage migration ratio and migration intensity of arsenic and lead in fly ash were lower than those in raw coal was that the due to insoluble mode was their main mode of occurrence in fly ash.Humic acid andzeolite had anobvious immobilization effect on arsenicand lead in fly ash,and the larger the amount of the agent,the lower their migration ratio.Humicacid had a better immobilization effect on arsenic than zeolite,while the two agents had a similarimmobilization effect on lead.
作者
王晓兵
李浩
曲文涛
周玲妹
WANG Xiaobing;LI Hao;QU Wentao;ZHOU Lingmei(Kunlun Digital Technology Co.,Lt.,Beijing 102206,China;School of Chemistry and Environmental Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)
出处
《洁净煤技术》
CAS
CSCD
北大核心
2024年第S02期197-205,共9页
Clean Coal Technology
基金
中国矿业大学(北京)越崎青年学者资助计划(2020QN10)
关键词
粉煤灰
微量有害元素
赋存形态
迁移
钝化
flyash
trace harmful elements
mode of occurrence
migration
immobilization
作者简介
王晓兵(1990—),男,山东潍坊人,中级工程师,博士。E-mail:wangxiaobing02@cnpc.com.cn;通讯作者:周玲妹(1986—),女,安徽宿州人,副教授,博士。E-mail:201506@cumtb.edu.cn
