尾砂固结排放的重金属固化效应研究  

Study on Solidification Effect of Heavy Metal by Tailings Cementation and Discharging Technology

作　　者：侯运炳[1] 刘畅[1,2] 丁鹏初 韩帅 韩冬[1] 张兴 曹曙雄 孙翔 金珠鹏 HOU Yunbing;LIU Chang;DING Pengchu;HAN Shuai;HAN Dong;ZHANG Xing;CAO Shuxiong;SUN Xiang;JING Zhupeng(College of Resources and Safety Eng.,China Univ.of Mining and Technol.(Beijing),Beijing 100083,China;Coal Ming and Designing Dept.Tiandi Sci.and Technol.Co.,Ltd,Beijing 100013,China;Inst.of Mining Eng.,Heilongjiang Univ.of Sci.and Technol.,Harbin 150022,China)

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083 [2]天地科技股份有限公司开采技术事业部,北京100013 [3]黑龙江科技大学矿业工程学院,黑龙江哈尔滨150022

出　　处：《工程科学与技术》2018年第5期231-238,共8页Advanced Engineering Sciences

基　　金：国家自然科学基金资助项目(51674263);中央高校基本科研业务费资助项目(2011YZ02)

摘　　要：为了解决尾砂地面排放的重金属污染和堆排体稳定性的问题,提出采用掺水泥的方法排放尾砂。分析了尾砂排放中污染物来源和重金属迁移原理:尾砂中重金属污染主要通过堆排场浸滤液和排放初期泌出水释放,其迁移动力主要有对流、分子扩散、机械弥散三方面作用。采用电镜扫描研究了尾砂固结过程中微观结构演化规律,发现水泥水化会使固结体结构致密、渗透系数降低。开展了浸滤实验研究固结体在水环境中结构稳定性,研究结果表明,尾砂固结体中水泥掺量较小时遇水会发生崩解;随着水泥掺量增加,固结体抗崩解性能增强;水泥掺量大于3%不易崩解,固结体稳定性提高。单轴抗压强度试验表明,水泥掺量大于4%时固结体强度随水泥掺量急剧增长,说明水泥掺量4%是固结改性的临界掺量,大于此值尾砂排放体发生了改性。通过电感耦合等离子发射光谱仪(ICP-AES)测定了固结体浸滤液中重金属含量并与《地表水环境质量标准》(GB3838-2002)进行了对照。实验表明,添加水泥不会影响泌出水中重金属含量,但会显著降低浸滤液中重金属含量,且随着水泥掺量增加浸滤液中重金属含量减小。当掺量大于3%时,浸滤液中重金属含量急剧减小,达到能够符合国家相关排放的标准。综上可知,重金属的迁移与固结体微观结构、渗透性和抗崩解性能有很大关系,渗透性越好、抗崩解性能越差,浸滤液与水接触程度越大,重金属浸出越多。In order to solve the problems of heavy metal pollution and tailings slope stability,tailings cementation and discharging technology were put forward.The pollutant source and heavy metal migration principle in tailings were analyzed.Results showed that heavy metal is mainly contained in leachate and bleeding water of tailings.Its diffusion depends on convection,molecular diffusion,and mechanical dispersion.The microstructure evolution was studied by electron microscopy and the result showed that the permeability coefficient decrease when cement is used.The cemented tailings soaked experiment was carried out.Results showed that with the increase of cement content,the anti-disintegration of cemented tailings is enhanced.When cement content is larger than 3%,the cemented tailing is no longer disintegration.The compression test also shows that 4%is the criticality content.Heavy metal content determination experimental results show that cement can hardly affect the content of heavy metals in bleeding water,but it can induce a decrease of the heavy metals in leachate water with the increase of cement content.When the cement content exceeds 3%,the amount of heavy metal decreases rapidly which can meet the national emission standards.In conclusion,the migration of heavy metals has a lot to do with the microstructure,permeability and anti-disintegration performance of the emissions.The larger the permeability is and the weaker anti-disintegration performance is,the more heavy metal leaching.

关 键 词：尾砂排放 重金属 微观结构 浸滤液 水泥掺量 

分 类 号：X753[环境科学与工程—环境工程]