摘要
铜冶炼渣中砷、铅的经济有效去除是其无害化的关键,而去除效果受限于铁橄榄石结构的影响.本研究提出了一种通过NaOH/Na_(2)CO_(3)碱共解聚耦合酸浸去除铜冶炼渣中砷、铅的环境友好策略,系统优化了影响碱共解聚过程及酸浸过程金属浸出效果的工艺参数,评估了处理后残渣的环境风险,同时通过多项表征手段研究了NaOH/Na_(2)CO_(3)对铜冶炼渣的共解聚机制.结果表明,在碱共解聚最佳条件下,砷浸出率为62.66%,铅几乎没有浸出;在酸浸过程中33.57%的砷和96.55%的铅被进一步浸出;最终,砷、铅的总浸出率分别达到96.23%和96.55%.处理后铜冶炼渣中砷和铅的含量分别从1002.5 mg·kg^(-1)和5343.1 mg·kg^(-1)大幅降低到112.1 mg·kg^(-1)和170.2 mg·kg^(-1),同时,处理后残渣的浸出毒性低于标准限值.XRD、SEM-EDSmapping、FTIR表征结果表明,铜冶炼渣的铁橄榄石相被分解,并暴露出有害成分,经碱共解聚后转化为酸溶形式,促进了后续酸浸效果.碳酸钠的存在拓展了铁橄榄石的解聚途径,为砷和铅提供了新的去除方法,本研究可为铁橄榄石类炉渣的无害化处理提供参考.
The economical and effective removal of As and Pb from copper smelting slags was crucial to its harmless disposal,and the removal efficiency was limited by the fayalite structure.In this work,an eco-friendly strategy for effective removal of As and Pb from copper smelting slags was proposed based on NaOH/Na_(2)CO_(3) alkali co-disaggregation coupled with acid leaching,the process parameters that affect metal leaching efficiency of alkali co-disaggregation and acid leaching process were systematically optimized,the environmental risks of the treated residues were evaluated,and the co-disaggregation mechanism of copper smelting slags by NaOH/Na_(2)CO_(3) was studied through multiple characterization.Under optimal conditions of alkali co-disaggregation,62.66%of As but almost no Pb was leached out.Then during the acid leaching,33.57%of As and 96.55%of Pb were further leached out of copper smelting slags.Finally,the total leaching efficiency of As and Pb reached up to 96.23%and 96.55%,respectively.After treatment,the content of As and Pb in the copper smelting slags was drastically reduced from 1002.5 mg·kg^(-1) and 5343.1 mg·kg^(-1) to 112.1 mg·kg^(-1) and 170.2 mg·kg^(-1),respectively.Moreover,the leaching toxicity of the treated residues was below the standard limit.XRD,SEM-EDS mapping,FTIR results indicated that fayalite in copper smelting slags was decomposed,exposing the harmful ingredients which were converted into acid-soluble forms after alkali co-disaggregation to promote subsequent acid leaching efficiency.The existence of Na_(2)CO_(3) expanded the disaggregation pathway of fayalite,and provided a new removal approach for As and Pb.This work inspired the harmless treatment of fayalite-containing slags.
作者
毛扶林
朱能武
张思海
李飞
马伟文
吴平霄
党志
李心雨
MAO Fulin;ZHU Nengwu;ZHANG Sihai;LI Fei;MA Weiwen;WU Pingxiao;DANG Zhi;LI Xinyu(School of Environment and Energy,South China University of Technology,Guangzhou 510006;The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of Education,Guangzhou 510006;Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling,Guangzhou 510006;Guangdong Environmental Protection Key Laboratory of Solid Waste Treatment and Recycling,Guangzhou 510006)
出处
《环境科学学报》
CAS
CSCD
北大核心
2022年第6期225-236,共12页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.22076048)
国家重点研发计划(No.2019YFC1906900)
广东省科技计划项目(No.2020B121201003,2017A020216013)。
