Estimating Radon Flux and Environmental Radiation Dose from Decommissioning Uranium Mill Tailings and Mining Debris

Based on a case study on uranium mine No.765 of China National Nuclear Corporation (CNNC), the paper briefly describes disposal program and effect of decommissioning uranium mine/mill facilities and quantitatively evaluates radon fluxes and doses to man of gaseous airborne pathway from mill tailings and mining debris before and after decommissioning, including annual individual effective dose to critical groups and annual collective effective dose to the population within 80 km region of the facilities.     

细粒含量对尾矿材料液化特性的影响

为了模拟沉积分选后颗粒组成的变化对尾矿材料的动力特性的影响,尾矿筛分后按不同的细粒（颗粒直径小于 0.074 mm）含量制备尾矿试样,并进行了大量的土动力学试验。分析了细颗粒含量对尾矿材料的动力液化特性的影响规律。研究表明,对于铜矿类尾矿坝的尾矿材料,当细颗粒含量占到总量的35 %时其抗液化性能最佳。根据尾矿材料动力特性试验的研究结果,并结合现场的标准贯入试验成果,提出了适用于尾矿材料的细粒含量对标准贯入击数的修正式。该式可以分析不同细粒含量的尾矿材料的抗液化强度,提高尾矿坝液化判别方法的判别准确程度。     

尾矿库下游安全距离预测的探讨

鉴于目前尾矿库下游安全距离没有试验数学模型,导致尾矿库下游的安全距离难以确定。借用泥石流预测数学模型,以探索较为合理的安全距离计算,为尾矿库库址选择、安全评价及主管部门监管提供一种具有一定科学依据的预测计算方法。     

马海盐湖浮选法生产氯化钾排放尾盐中钾资源的强制浸取技术研究

马海盐湖钾资源经过十几年的开发,在生产氯化钾过程中排放了大量的含钾尾盐,随着盐湖钾资源持续的开发,马海盐湖的钾资源已凸显日益枯竭的趋势,为高效利用马海盐湖的钾盐资源,近年来开展了对浮选法生产氯化钾过程所排放的含钾尾盐矿的开发利用技术研究。介绍了采用强制搅拌溶浸技术,溶浸马海盐湖含钾尾矿中钾资源的试验情况及所取得的试验结果,并对试验过程中出现的问题进行了讨论。     

四川拉拉铜矿尾矿中重金属资源和环境意义

尾矿中高含量重金属具有潜在的资源和环境意义。通过分析拉拉铜矿尾矿中的重金属含量及其赋存形式,讨论了尾矿中有价元素的回收利用可能性,并评价了尾矿中重金属的生态风险。结果表明,拉拉铜矿各期尾矿中仅Ⅲ期尾矿的铁、铜、钴具有综合利用价值;各期尾矿中多种重金属元素潜在的生态危害程度轻微,但是各期尾矿中汞的生态危害程度中等,Ⅲ期尾矿中铜的生态危害程度中等。因此,矿区不仅要注意各期尾矿汞对环境的潜在污染,同时也应注意Ⅲ期尾矿铜对环境污染的生态风险。     

中国金属尾矿资源综合利用现状研究

金属矿山尾矿是一种含有微量金属矿物和大量非金属矿物的二次资源,近十年来中国金属矿产开发利用与金属尾矿持续堆积一直呈高速增长状态。经初步估算,仅2011年中国尾矿排放量就达13～14亿吨,但当前我国尾矿综合利用率尚不到10%。为了更有效的开发利用中国尾矿资源,本文在分析尾矿基本特征及十年来中国金属矿产资源开发与尾矿堆积现状的基础上,总结了当前尾矿综合利用两大途径—尾矿再选、尾矿整体利用两个方面的研究现状及取得的一些成绩。提高尾矿资源的综合利用率不仅是当前部分矿山解困的出路之一,而且可以带来长期的经济、社会、环境效益。     

GPS技术在尾矿库安全监测中的应用

本文对地理国情监测的具体案例,某尾矿库监测实施过程中主要技术进行了详细的描述。通过静态GPS测量方法完成了尾矿库控制测量工作,按国家统一坐标系解算了尾矿库基础控制点、监测点等坝体要素的三维坐标,并和尾矿库监测点的原始独立三维坐标进行对照、比较,根据不同高程基准坝体高差变化、尾矿库设计高度等坝体数据进行综合分析,绘制高程标注图。研究结果为尾矿库安全运行提供了准确、可靠的监测数据及相关合理建议。     

Trace metals associated with deep-sea tailings placement at the Batu Hijau copper–gold mine,Sumbawa, Indonesia

The Batu Hijau copper–gold mine on the island of Sumbawa, Indonesia operates a deep-sea tailings placement (DSTP) facility to dispose of the tailings within the offshore Senunu Canyon. The concentrations of trace metals in tailings, waters, and sediments from locations in the vicinity of the DSTP were determined during surveys in 2004 and 2009. In coastal and deep seawater samples from Alas Strait and the South Coast of Sumbawa, the dissolved concentrations of Ag, As, Cd, Cr, Hg, Pb and Zn were in the sub μg/L range. Dissolved copper concentrations ranged from 0.05 to 0.65 μg/L for all depths at these sites. Dissolved copper concentrations were the highest in the bottom-water from within the tailings plume inside Senunu Canyon, with up to 6.5 μg Cu/L measured in close proximity to the tailings discharge. In general, the concentrations of dissolved and particulate metals were similar in 2004 and 2009.     

基于液化流动模型的尾矿坝地震响应分析

针对传统等效线性法对尾矿坝地震响应分析结果与实际情况存在一定的出入的问题,通过振动台模型试验和数值计算结果比对验证数值计算方法的可行性,运用考虑液化后尾矿砂流动特性的孔压上升模型,基于完全非线性动力分析方法,对尾矿坝地震响应进行分析计算,通过对坝顶位移和加速度的监测结果进行分析,得出坝顶的加速度放大系数以及坝顶位移最大值;并由坝体水平方向位移云图、竖直方向位移云图及位移矢量图,判断可能发生局部滑坡的位置;对坝体内液化情况进行判定,得到尾矿坝的地震响应规律,为尾矿坝抗震设计提供一定的理论参考.     

Modeling of self‐desiccation in a cemented backfill structure

After placement of cemented tailings backfill (CTB), which is a mixture of tailings (man‐made soil), water, and binder, into underground mined‐out voids (stopes), the hydration reaction of the binder converts the capillary water into chemically bound water, which results in the reduction of the water content in the pores of the CTB, thereby causing a reduction in the pore‐water pressure in the CTB (self‐desiccation). Self‐desiccation has a significant impact on the pore‐water pressure and effective stress development in CTB and paramount and practical importance for the stability assessment and design of CTB structures and barricades. However, self‐desiccation in CTB structures is complex because it is a function of the multiphysics or coupled (i.e., thermal, hydraulic, mechanical, and chemical) processes that occur in CTB. To understand the self‐desiccation behavior of CTB, an integrated multiphysics model of self‐desiccation is developed in this study, which fully considers the coupled thermal, hydraulic, mechanical, and chemical processes and the consolidation process in CTB. All model coefficients are determined in measurable parameters. Moreover, the predictive ability of the model is verified with extensive case studies. A series of engineering issues are examined with the validated model to investigate the self‐desiccation process in CTB structures with respect to the changes in the mixture recipe, backfilling, and the surrounding rock and curing conditions. The obtained results provide in‐depth insight into the self‐desiccation behavior of CTB structures. The developed multiphysics model is therefore a potential tool for assessing and predicting self‐desiccation in CTB structures.