酸化条件下尾矿砂稳态强度特征研究  

Steady-State Strength Characteristics of Tailing Sand Under Acidification Condition

作　　者：陈文昭 董冠颖 李鑫 王文 CHENG Wenzhao;DONG Guanying;LI Xin;WANG Wen(School of Civil Engineering,University of South China,Hengyang 421000,Hunan,China)

机构地区：[1]南华大学土木工程学院,湖南衡阳421000

出　　处：《中国钼业》2023年第2期50-55,59,共7页China Molybdenum Industry

基　　金：湖南省教育厅重点科研项目(编号:18A252)。

摘　　要：自然环境下尾矿酸化会产生大量的酸性废水,不仅对周边环境造成严重污染,长期作用下还会改变尾矿砂的基本物理力学性质,直接影响尾矿砂的稳态强度。对尾矿砂进行化学浸泡实验,通过控制过氧化氢溶液的用量,模拟不同堆积时期尾矿砂的酸化效果。同时开展SEM扫描电镜试验、颗粒分析试验深入了解酸化前后尾矿砂颗粒微观变化特征以及颗粒级配变化,结合固结不排水三轴压缩试验探究不同酸化程度下尾矿砂稳态强度特征变化规律。试验结果表明,酸化导致尾矿砂不断被腐蚀溶解,尾矿砂整体逐渐细粒化;随着酸化程度的加深,不同围压下尾矿砂的抗剪强度均出现了降低的趋势,尾矿砂的稳态线位置逐渐向下平移;同时尾矿砂的稳态强度也随着酸化程度的加深不断减小,稳态内摩擦角从最初的34.75°减至32.21°。Tailing acidification in natural environment will produce a large amount of acidic wastewater,which not only causes serious pollution to the surrounding environment,but also changes the basic physical and mechanical properties of tailing sand under long-term action,which directly affects the steady-state strength of tailing sand.Chemical soaking experiment of tailing sand was carried out to simulate acidification effect of tailing sand at different accumulation periods by controlling the amount of hydrogen peroxide solution.At the same time,SEM scanning electron microscopy tests and particle analysis tests were carried out to deeply understand the micro-change characteristics and particle distribution changes of tailing sand particles before and after acidification,and combined with consolidation undrained triaxial compression tests to explore the change law of steady-state strength characteristics of tailing sand under different acidification degrees.The test results show that the acidification leads to the tailing sand being corroded and dissolved continually,and the tailing sand is gradually fine-grained.With the deepening of acidification degree,the shear strength of tailing sand decreases under different confining pressures,and the steady-state line position of tailing sand shifts downward gradually.At the same time,the steady-state strength of tailing sand also decreases with the deepening of acidification degree,and the steady-state internal friction angle decreases from the initial 34.75° to 32.21°.

关 键 词：尾矿酸化 颗粒级配 稳态强度 

分 类 号：X936[环境科学与工程—安全科学]