Prediction of soil erosion from waste dumps of opencast mines and evaluation of their impacts on the environment

The volume of mine waste rock generated, including tailings from mineral processing activities, is one of the main pollution concerns in the mining industry in general. In the State of Goa (India), the waste rock management is becoming increasingly difficult due to acute space shortage consequent to expanding mining activities. These waste rocks contain acid producing sulphides and high concentrations of heavy metals. In the Goa region, the agricultural fields, nallahs, river beds and creeks are prone to heavy siltation/sediment deposition, which results from soil erosion due to the heavy rainfall this region receives. In view of this erosion and consequent degradation of surrounding environment, this article seeks to estimate the amounts of soil erosion from mine waste rock dumps using the RUSLE model and evaluates the impacts of erosion on the local environment. Based on data interpretation and RUSLE analysis, the trends in soil loss were established under various geo-environmental conditions, such as different slope angles and lengths. This provides a sound basis to plan and implement sound environmental management practices for mine waste rock in the mines of Goa, India.     

复合煤层露天矿下部煤层开采境界优化

通过理论分析与计算,研究近水平复合煤层露天矿剥、采、排程序对经济剥采比的影响,提出了复合煤层露天矿下部煤层开采境界的优化方法。分析了露天矿经济剥采比的影响因素,建立了复合煤层露天矿剥、采、排工程位置模型,构建了下部煤层及其覆盖物厚度拟合函数,揭示了下部煤层开采境界与开采成本的关系,研究开采下部煤层经济剥采比的优化确定方法。在神华宝日希勒露天煤矿进行了实践,结果表明:此方法能够使近水平复合煤层露天矿下部煤层得到经济合理地回采,实现矿床开采的经济效益最大化。     

露天矿排土场堆置参数优化

设计合理的排土场堆置参数可以达到降低露天矿的排岩成本并保持排土场的稳定性的目的。在建立通用的堆置参数优化的多目标规划模型基础上,结合国内某露天矿实际情况,首先确立单排岩台阶稳定性、总排土场的稳定性与堆置参数的关系,之后在考虑碎岩的运输过程及排土场随排弃任务推进的空间几何演化规律下,建立排岩工作的运输成本及管理费用与堆置参数的函数关系表达式,从而得到该矿以排土场稳定性及排岩成本为优化目标的排土场堆置参数优选模型;对该模型求解得到最佳的排土场堆置参数：台阶数目为4,平盘宽度取最小平盘宽度57 m,单个排岩台阶高度30 m,排土场总堆置高度为120 m,排土场边坡角为26°,该结果与矿山实际情况相符合。     

Revaluing mine waste rock for carbon capture and storage

Many mining wastes, especially those from the metal mining industry, have traditionally been treated as a matter of little or no value and in practice a cost burden. Some wastes, because of their reactivity characteristics, have emergent values that go beyond purely economic and into the environmentally beneficial realm. This article discusses the changing paradigm of mine waste management. Such fundamental parameters, such as cut-off grade and strip ratio, are positively impacted by the revaluation of waste rock material. Mine rock waste can now be seen as a commodity of value similar to the underlying ore being mined, which influences the economic performance of suitable projects. This valuable material can be used for industrial purposes including acid neutralisation as well as the capture and long-term disposal of anthropogenic carbon dioxide. The Turnagain Nickel project, located in Northern British Columbia, serves as an example of how waste rock material can become an important matrix for carbon capture and sequestration and how a project can benefit economically from it. By producing material that has emergent economic value as well as carbon capture and sequestration capabilities, the sequestration matrix producer is a beneficiary of new carbon credits that have a market value and is looked upon favourably by regulatory authorities and affected stakeholders.     

大型深凹露天矿高效运输系统综合技术研究

运输占大型露天矿生产总成本的50％左右，传统的汽车、铁路及其联合运输方式已不能适应深凹露天矿的运输要求，汽车一胶带半连续运输工艺是深凹露天矿最有发展前途的运输方式之一。本文以水厂铁矿为依托工程，研究了汽车-胶带半连续运输系统的设备选型及最佳配套技术、运输线路布设优化、胶带排土工艺及参数优化、系统可靠性分析、坑内单线陡坡联络道技术及系统高效运行保障技术等。分析了水厂铁矿建立-套汽车-胶带矿石运输系统和两套汽车-胶带排岩运输系统后可获得的经济效益。     

露天矿排土规划CAD软件包设计研究

针对露天矿排土规划的特点，利用CAD技术提出了一整套计算排土场容积和排土征地面积的可行算法，并形成软件包，该算法可为露天矿长远规划提供决策依据。     

内排土在河北赵店子铁矿的应用

河北赵店子铁矿根据其矿床开采条件，采用分期开采方案，从而有计划的创造条件，实施部分剥离内排土，减少了排土场占地，保护了生态环境，本文介绍了分期开采的具体方案、内排土的工艺及内排土场的管理，并对该矿的内排土进行了评价。     

近水平露天矿内排重复剥离量及留沟深度

分析了近水平露天矿分区开采中全压帮、半压帮及全留沟内排方式的特点,并得出了在全压帮和半压帮内排条件下计算重复剥离量的公式。运用露天采矿学的基本原理,根据矿山内排端帮单双环运输的运距,建立了以留沟深度为基本变量的经济效益数学模型,推导出留沟深度的效益函数,使压帮内排的经济效益实现最大化。最后分析了影响最佳留沟深度的因素,得出对于近水平缓倾斜露天矿田内排,开采深度、坑底宽度和端帮边坡角对最佳留沟深度影响较大。     

Valorization of acid mine drainage treatment sludge as remediation component to control acid generation from mine wastes,part 2: Field experimentation

The possibility of using acid mine drainage (AMD) treatment sludge as a cover component to control AMD generation from mine wastes was investigated through laboratory characterization and kinetic column testing (companion paper). The results showed that mixtures of sludge and waste rock, and sludge and tailings, may be integrated in an AMD prevention and control strategy at Doyon mine site (northwestern Quebec, Canada). In order to further investigate these scenarios in realistic climatic conditions, instrumented field test cells were installed on site to evaluate the performance of the mixtures to control AMD generation from tailings and waste rock under natural field conditions. The main findings from two seasons of monitoring are presented in the paper. The waste rock-sludge mixture placed over waste rock was able to reduce the generation of AMD from the waste rock, therefore confirming lab results, and was able to produce a neutral effluent with low concentrations of dissolved metals. The tailings-sludge mixture placed over tailings, with an evaporation protection layer, maintained a high volumetric water content and reduced sulphide oxidation from the tailings as exhibited by a neutral effluent. Monitoring of the field cells will continue to provide valuable information on the possible sludge valorization options.     

Oil sands mine planning and waste management using mixed integer goal programming

Strategic mine planning and waste management are an important aspect of surface mining operations. Recent environmental and regulatory requirements make waste management an integral part of mine planning in the oil sands industry. The research problem here is determining the order of extraction of ore, dyke material and waste to be removed from a predefined ultimate pit limit over the mine life that maximises the net present value of the operation. We have developed, implemented, and tested a proposed mixed integer goal programming theoretical framework for oil sands open pit production scheduling with multiple material types. The formulation uses binary integer variables to control mining precedence and continuous variables to control mining of ore and dyke material. There are also goal deviational variables and penalty costs and priorities that must be set up by the planner. The optimisation model was implemented in TOMLAB/CPLEX environment. The developed model proved to be able to generate a uniform schedule for ore and dyke material. This is in line with recent regulatory requirements by Alberta Energy Resources and Conservation Board (Directive 074) which requires oil sands mining companies to develop life of mine plans which ties in to their in-pit tailings disposal strategy. It also provides a practical mining sequence that is consistent with mining oil sands deposit. Similarly, tradeoffs between achieving a goal and maximising NPV can be made.     

Prediction of Minerals Producing Acid Mine Drainage Using a Computer-Assisted Thermodynamic Chemical Equilibrium Model

Methods such as optical microscopy, electron microscopy, and X-ray diffraction are sometimes used to identify minerals involved in the production of acid mine drainage (AMD). A simpler method to identify the minerals without losing accuracy would decrease costs. This paper presents an overview of the important oxidation reactions of sulphide minerals and related chemical components produced by these oxidation reactions. A methodology for predicting the minerals producing AMD using MINTEQ is also discussed. This method can be used in conjunction with analytical techniques to characterize AMD for a specific site. While it does not replace analytical tests, it can decrease the number and frequency of these expensive tests. The model has been validated with data from the Wolverine coal mine in northeastern BC, Canada.     

我国煤矿岩巷快速掘进技术现状及展望

为了提高我国煤矿岩巷的掘进速度和机械化水平,扭转采掘失调局面,介绍了目前我国煤矿3种机械化作业线的技术现状及特点,借鉴国外经验分析了岩巷快速掘进的技术趋势,研究提出了2种岩巷快速掘进机械化作业线,即液压钻车配侧卸装岩机和掘进机配梭式矿车、带式输送机,并对2种作业线的优缺点及适用条件进行了分析,指出了岩巷快速掘进应优先发展第1种钻爆法岩巷机械化快速作业线,研究其施工工艺及技术装备问题,解决国内岩巷掘进施工中的普遍性问题。     

Valorisation of acid mine drainage treatment sludge as remediation component to control acid generation from mine wastes,part 1: Material characterization and laboratory kinetic testing

In operating mines, acid mine drainage (AMD) is often treated using lime treatment. This process generates a significant amount of sludge that contains metal hydroxide precipitates, gypsum, and unreacted lime. The sludge may have interesting geotechnical and geochemical properties to be used as a part of covers (oxygen barriers) to prevent AMD generation from waste rocks and tailings. The main results of a project aiming to evaluate the use of sludge from the Doyon mine site (Canada) as a material in mine site rehabilitation are presented. The first part of the project involved detailed characterization of sludge, waste rock, and tailings samples. Then, laboratory column leaching tests were performed to evaluate the performance of the mixtures to control AMD produced by tailings and waste rocks. It was found that a sludge–waste rock mixture placed over waste rock reduces the metal loads in the column effluent, which remained acidic, as well as a mixture of sludge and tailings deposited over tailings can reduce metal content in effluents from tailings.     

司家营铁矿项目建设及采选系统介绍

介绍了河北钢铁集团矿业有限公司司家营铁矿自然概况、资源分布及项目规划建设情况,重点介绍了司家营铁矿一期工程采矿工艺、选矿工艺,供水、供电等公辅设施,以及废石填海造地、尾矿库易址采煤沉陷坑等情况。     

新疆准东露天煤矿单一巨厚煤层复合边坡空间形态优化

针对单一巨厚煤层露天矿土-岩复合边坡稳定性及空间形态问题,以新疆准东露天矿为工程背景,采用刚体极限平衡和FLAC3D数值模拟相结合的方法,研究了露天矿复合边坡的稳定性及空间形态,分析了复合边坡的潜在滑动模式及稳定性规律,确定了采场与排土场的最大安全距离。研究结果表明:新疆准东露天矿采场最终边坡角为34°,排土场边坡角为23°,排土场与采场安全距离为150 m时满足安全性与经济性要求;单一巨厚煤层露天矿土-岩复合边坡的滑坡模式为沿排弃物内部的圆弧滑动和以坡体出露弱层面为底界面的组合滑动;在岩体自身重力作用下,单一巨厚煤层露天矿土—岩复合边坡破坏形式为拉张—剪切复合型。     

Warning Signs to Geotechnical Failure of Mining Structures

Mining structures, such as open pits and underground mines, tailings dams and waste rock dumps, under stress can suffer geotechnical damage and fail. Studies were carried out on large scale failures in a form of rock mass collapse (collapse of an open pit slope and a surface crown pillar), seismic events (rockburst and gas outbursts), mine inundation, and waste rock material instability (tailings dams and waste rock dumps).

The case studies revealed that geotechnical failure of mining structures were preceded by warning signs like indicators and precursors and that the failures were triggered by external factors like rainfalls or mine blasting. For large scale geotechnical failures, the initial precursors were present months or even years before failure. During the period from the initiation of structural damage to the final failure many various types of precursors were commonly reported and the number and scale of precursors increased towards impending failure. In a number of cases it was found that large scale geotechnical failures were preceded by a succession of small scale failures.     

Geophysical Diagnosis of Diversion Channel Infiltration in a Uranium Waste Rock Pile

The Osamu Utsumi mine was the first to economically mine uranium ore in Brazil. During its operation, a river valley was buried for the construction of the waste rock pile. The original stream was diverted to the northwest side of the pile and has since flowed into a diversion channel devoid of basal waterproofing, while an acid mine drainage (AMD) source flows at the base of this waste rock pile. This research aims to evaluate the possible relationship between water infiltration of the diversion channel and the AMD resurgence at the base of the pile using electrical resistivity tomography and induced polarization. 2D inversion models and pseudo-3D maps allowed the recognition of low resistivity zones (<?100 Ω·m) with high chargeability areas (10 mV/V). Some of these low-resistivity areas have been interpreted as infiltration zones in segments of the diversion channel into the pile, and in one of them, the flow intercepts a high chargeability area interpreted as a sulfide-rich zone that is expected to contribute to AMD at the base of the pile. Understanding the hydrogeochemical process will help select effective actions to mitigate the generation of AMD at the mine, which is currently in the decommissioning phase.

     

露天采矿活动对生态脆弱区水资源的影响及其对策

 随着西部地区煤炭开采活动强度的不断增大,西部地区水资源的短缺与煤炭开采活动对环境的破坏之间的矛盾越来越突出。为实现煤炭开采地区的可持续发展,通过对地下水系统的分析,结合地下水运动的规律,提出了针对露天矿的保水开采方法,即能够实现内排的露天矿通过重构关键地层技术实现地下水系统的重构与恢复,不能够实现内排的露天矿通过重建地下水补给区的办法恢复地下水系统。最后针对水资源保护的目标,对排土工艺做了适当的调整。     

地下矿山无废开采和灾害控制技术的现状与发展对策

回顾了国内地下矿山无废开采和灾害控制技术的现状和取得的技术研究成果,分析了当前国内在开采矿产资源中存在的主要问题,以及这些问题对诱发矿山地质灾害和污染环境的影响。最后提出了以地下矿山无废开采和灾害控制技术为研究对象,在地下矿山无废开采方法及工艺技术、地下矿山废石与尾矿混合充填料充填技术、地下矿山采场稳定性及岩层控制技术、地下矿山地面沉降塌陷灾害预警系统等领域开展技术研究。     

清洁化无废矿山采矿工艺设计实践

在ENFI承担的云南驰宏公司深部资源矿山的开采设计中,采用了以全尾砂、水淬渣、废石和水泥为原料的膏体泵送充填采矿工艺,提出了将该矿建成尾砂不进库、废石不出坑的清洁化无废开采矿山的目标。