球磨预处理强化铜冶炼烟灰中砷与有价金属高效分离  

Selective leaching of arsenic and valuable metals in copper smelting soot strengthened by ball milling pretreatment

作　　者：胡中求 瞿军 郭莉 马文博[1,2] 胡楠 占伟 杜冬云 HU Zhong-qiu;QU Jun;GUO Li;MA Wen-bo;HU Nan;ZHAN Wei;DU Dong-yun(Hubei Province Engineering Research Center for Control and Treatment of Heavy Metal Pollution,College of Resources and Environmental Science,South-Central University for Nationalities,Wuhan 430074,China;Key Laboratory of Catalysis Conversion and Energy Materials Chemistry,Ministry of Education,South-Central University for Nationalities,Wuhan 430074,China)

机构地区：[1]中南民族大学资源与环境学院湖北省重金属污染防治工程技术研究中心,武汉430074 [2]中南民族大学催化转化与能源材料教育部重点实验室,武汉430074

出　　处：《中国有色金属学报》2020年第8期1915-1924,共10页The Chinese Journal of Nonferrous Metals

基　　金：国家科技支撑计划项目(2015BAB01B03);中南民族大学中央高校项目(CZT18022)。

摘　　要：探究了球磨预处理铜冶炼烟灰中As与有价金属的高效分离,并对比研究球磨及碱性介质中球磨预处理对烟灰中As分离浸出效果影响。结果表明:单独采用球磨预处理会抑制烟灰中As的浸出,与未球磨烟灰相比,浸出率由56.01%降至32.85%;而碱性介质的加入可显著提高As浸出率,浸出率则由56.01%升至78.52%,最优工艺参数为:NaOH与烟灰质量比(mNaOH:mAsh)=0.5:1、球磨活化60 min(碱性介质下球磨预处理(50±5) min后,投加入一定量的乙醇研磨(10±5) min)、转速600 r/min。另外,采用该方法处理后,烟灰中Cu、Zn、Pb、Cd基本未被浸出,且浸出残余固体物中As含量由5.74%降低至0.13%。SEM和粒径分析表明:球磨可使颗粒表面产生缺陷,减小烟灰粒度,增大反应比表面积,促进界面传质,提高As浸出率。XRD和XPS结果表明:球磨过程中局域产生高温高压,诱导固-固反应,As2O3等与Na OH反应转化为可溶性的砷酸盐,部分PbSO4在局部高温下最终分解为PbO,进一步强化浸出过程中As与有价金属的高效分离,该方法为烟灰无害化及资源化的利用提供了理论依据。The high-efficiency separation of arsenic and valuable metals in copper smelting soot strengthened by the ball milling pretreatment were investigated.The results show that the ball milling pretreatment alone can inhibit the leaching of As in soot.Compared with the unmilled soot,the leaching efficiency is reduced from 56.01%to 32.85%.However,the addition of NaOH can significantly increase the As leaching efficiency from 56.01%to 78.52%.The optimal process parameters are as follows:the mass ratio of NaOH to ash(mNaOH:mAsh)of 0.5:1,activation time of ball mill of 60 min(after ball milling pretreatment for(50±5)min in alkaline medium,and then milling with ethanol in sequence),the rotation speed of 600 r/min.Besides,Cu,Zn,Pb and Cd in the soot is basically not leached after treatment by this method,and the As content in the leaching residual solid is reduced from 5.74%to 0.13%.The SEM and particle size analysis show that ball milling can create defects on the surface of the particles,reduce the particle size of the soot,increase the specific surface area of the reaction and promote the mass transfer of the interface.Therefore,the leaching efficiency of As is dramatically enhanced.The results of XRD and XPS show that high temperature and high pressure are generated in the specific area during the ball milling process,inducing the solid-solid reaction:the oxidation state of As2O3 after reacting with NaOH converges into soluble arsenate,finally.And decomposition of parts of PbSO4 into PbO in a local high temperature environment,which further enhances the efficient separation of As and valuable metals during the leaching process.This study provides a theoretical basis for the harmlessness,and the resource utilization of arsenic-containing materials is produced by copper smelting industry.

关 键 词：铜冶炼烟灰 球磨 化学反应 活化 界面传质 选择性浸出 

分 类 号：X756[环境科学与工程—环境工程]