Specifics of Internal Overburden Dumping in Open Pit Mining

Journal of Mining Science - The authors discuss the application ranges of internal overburden dumping open pit mining. Specifics of internal overburden dumping on gently and steeply dipping beds is...     

Stripping with direct dumping in Kuzbass open pit mines: The current state and prospects

The analytical results are given for application of stripping with direct dumping in open pit mines in Kuzbass. It is emphasized that this most productive and the least power-consuming technology loses its weight in the overall content of overburden stripping. The authors propose a method to determine rational boundaries for application area of stripping with direct dumping using slice re-excavation coefficient. The scope of the discussion comprises potential trends of the technology and use of draglines towards enhancement of open pit mining efficiency.     

露天转地下崩落法采矿覆盖层渗流量影响因素分析

露天转地下崩落法采矿时露天坑覆盖层渗流量的大小关系到井下回采放矿的安全。通过分析矿区降雨强度、露天坑汇水面积以及覆盖层本身的结构特性,研究这些因素与露天坑覆盖层渗流量的关系,对减小井下水量,确保采矿安全意义重大。     

露天矿排岩收费条件下排岩方式的优选

排岩收费政策直接影响到采矿成本,因此就有可能影响到采矿设计中的各个环节。为此,以白云鄂博铁矿为例,重点讨论排岩收费政策对排岩工艺的影响。研究结果表明,排岩收费政策对采场内排岩与采场外排岩等排岩方式的选择有直接影响;在排岩运输方式的选择上,排岩收费政策至少在眼下还无力影响铁路和公路运输之间的选择,而在胶带运输排岩和铁路运输排岩这两个方案的选择中,是否实行排岩收费政策将是一个不可忽视的因素。实行排岩收费政策将促使采场内排岩等绿色排岩方式和胶带运输排岩等绿色排岩工艺得到更广泛的应用,给露天矿的排岩工艺带来崭新的变革。     

Calculating stability of overburden dumps on weak bases

The scope of the discussion covers the issues of open pit mining efficiency and safety with dry overburden dumping over sludge base. The stress analysis of a dump at Kedrovsky Open Pit Mine uses finite element modeling of linearly deformable medium based on geotechnical, surveying and hydromechanical data. The modeling produces the field of displacements of the dump and its base and the distribution of the Mohr–Coulomb strength criterion. The sludge base breakout-hazardous areas are revealed, and the displacements of the growing dump are predicted. The developed model enables operational forecasting of strength loss at dumps.     

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。     

Regime of Internal Dump Formation in Mining Sloping Deposits

Mathematical models of the dynamics of working- and dump-zone development in an open pit are considered. The dependence of the volume of overburden that may be sent to the internal dump on the parameters of the open pit and its first block is established. The influence of the dump-filling regime on the transport costs in overburden storage is investigated.     

倾斜煤层窄长形露天矿横采内排分期境界优化

为了使采用横采内排开采程序的倾斜煤层窄长形露天矿开采境界最优化,依据露天开采原理,提出一种分时期优化境界的方法。该方法依据剥离物流向流量的变化,将其矿山工程划分为3个时期,即:全部外排期、部分内排期、全部内排期;通过构建各时期剥、采、排工程位置模型,分析了开采过程中不同时期剥离物流向流量的变化对经济合理剥采比的影响,揭示了经济合理剥采比与内排工作线推进度的关系,构建了各煤、岩层边帮厚度拟合函数,阐释了采用循环判断方式确定剖面最优边帮位置的方法,给出了分期境界优化的原则、适用条件及优化模型。将此方法运用于神新能源黑山露天煤矿,结果表明:经济合理剥采比由8.06 m~3/t逐期增加至10.54 m~3/t,较原设计境界经济可采储量增加44.95 Mt,服务年限增加4.26 a,实现了露天开采经济效益最大化。     

Fragmentation systems design in surface mines: An expert system application

ABSTRACT

Mining Engineers in charge of open pit mine planning very often face decision making situations dealing with the selection of the most economical method for the removal of overburden. Ripping versus conventional drilling and blasting are the options considered. The choice of a particular overburden removal method depends upon the physicomechanical properties of the overburden material as well as the various cost factors involved in the process. The analysis of technoeconomical factors, related to different methods of overburden removal in surface mines, needs detailed study and investigation by a technical expert. The expert system “FRAGMENTATION” has been developed to help and expedite the decision making process involving the selection of overburden removal method in surface mines. Furthermore, this expert system can be used for detailed design of overburden removal in open pit mines, specifically for determining charge geometry placement and cost analysis     

露天采坑改建尾矿库关键技术探讨

采坑改建为尾矿库是采矿坑综合利用方法之一。系统阐述了采坑改建尾矿库的关键技术,涉及到尾矿库容积确定,尾矿库边坡安全稳定,尾矿库排洪、回水系统的安全可靠性,坑内尾矿排放安全位置确定等方面,为采坑改建尾矿库工程项目的实施提供值得借鉴的方法并起到指导性的作用。     

胶带机排土带宽度的参数优化

分析胶带排土机排土带宽参数特征, 提出用稳定性分析方法确定排土带宽度的优化模型, 通过无约束优化法计算排土带宽度的最优值, 并应用于南芬露天矿胶带机排土过程计算, 结果表明, 与设计值相比可提高排土机综合工作效率5%以上。     

Efficiency of cyclical-and-continuous method in open pit mining

The article reviews in brief application of cyclical-and-continuous method in the conveyor-andtruck haulage in open pit mines. Consumption of materials and power is evaluated as a function of mined rock haulage volumes and depth of crush-and-reload station position in an open pit mine. The change in capital and operational cost to transport ore and hard overburden is studied at varied distances from a crushand- reload station in open pit to a surface receiving station. Efficiency of the conveyor-and-truck haulage using cyclical-and-continuous method is evaluated. In terms of deep and large mineral deposits, the authors substantiate positions for crush-and-reload stations in large open pit mines.     

Comparison of tripper-spreader combinations

ABSTRACT

In future, the volume of overburden to be dumped will further increase as mining operations have to go down to greater and greater depths in order to expose the mineral deposits to be extracted in open pit mining.

For this reason, the selection of the correct spreading system is becoming increasingly important. Thus, an optimal tripper-spreader combination has to be selected with regard to the actual dumping procedure and the geometry of the dump crosssection.

In order to guarantee economical mining of mineral deposits, despite the increasing costs of overburden removal, the machine system selected must also be examined with regard to its costs, operational safety and availability.

Because of the complexity of the subject matter and the limited size of this paper, this is a contribution only to give a brief overview of the machines more commonly combined as systems and to present their most significant features in terms of type, method of operation, mass and cost effectiveness.     

庙沟铁矿排土方案的改进

通过对原排土场设计方案及存在问题的分析,提出其改进方案,确保岩土从露天采场到排土场的流向科学合理,达到岩土运输功和排弃费用最低.     

大红山铁矿400 m以上坑采对露采的影响

地下崩落法采矿破坏了采场上覆岩层的应力平衡状态,引起地表变形和岩层移动,影响到地表构筑物的安全使用与保护问题。深部矿体采用崩落法开采,将会影响到地表露天采场境界的稳定。采用FLAC3D数值模拟的方法来研究深部矿体开采后对露采境界的影响。模拟分析表明：按照65°移动角计算,预留保安矿柱,400 m水平以上南部矿体开挖后,并未影响到露采境界,露天工程整体稳定。但是不预留保安矿柱, 400 m以上矿体全部开挖后,影响到了A34线以西的露采境界。研究结果为地表露天矿的设计和安全生产提供了指导性的依据。     

露天边帮煤井工长壁综放开采工作面顶板压力计算

受露天矿剥离和内排回填的影响,采用井工长壁采煤法回采露天矿边帮煤的采煤工作面的顶板结构、覆岩活动规律、矿山压力显现规律与常规井工矿井地层条件下的工作面相比存在显著差别,因此,顶板压力计算方法也需要根据露天矿边帮煤特殊的顶板覆岩结构特点和应力场环境进行理论和实验研究。以黑岱沟露天矿一采区西帮和南帮煤为研究对象,分析其边帮煤层顶板覆岩结构特点。对于经过内排回填,且剥离较多的低台阶处煤层仅保留较薄且强度较低的基岩顶板,其上覆盖厚层的松散排土。这种软弱薄基岩厚松散覆盖层的顶板本质上不存在关键层,露天矿台阶下保留的软弱薄基岩仅仅作为井工长壁工作面的直接顶提供有限的保护作用。由于厚层的松散排土载荷作用,软弱薄基岩的破碎也较为严重。按照传统的矿山压力理论,这种不存在关键层的软弱薄基岩厚覆盖层的顶板压力应当按照支架上方全部岩层重量进行计算。然而,根据相似材料实验结果显示,支架实际受压比其上方岩层重量小得多。实验证明在没有关键层的顶板岩层中仍然存在某种保护结构。根据实验观察和矿山压力理论分析,结合放矿理论,提出了软弱薄基岩厚覆盖层的椭球拱结构和直接顶自承能力相结合混合力学模型。在露天矿边帮下煤层还存在另一种未进行内排回填的薄基岩无覆盖层的顶板覆岩类型。对于这种顶板覆岩类型,提出了薄基岩无覆盖层的台阶式悬臂梁结构和直接顶自承能力的混合力学模型。本文总结了露天矿边帮煤层3种顶板覆岩类型,推导建立了露天边帮煤井工长壁开采工作面3种顶板结构条件下的顶板压力计算解析公式。按照软弱薄基岩厚覆盖层的椭球拱结构和直接顶自承能力相结合混合力学模型计算的顶板压力与相似材料实验结果相吻合。考虑了直接顶自承能力计算的顶板压力比传统不考虑直接顶自承能力的顶板压力小约14%。采用实验和理论分析方法,对露天边帮煤井工长壁工作面开采过程顶板垮落、覆岩活动,顶板压力计算等矿山压力问题进行了系统研究。     

Methodological basis for calculating parameters of direct dumping flowsheets in open pit mining of gently dipping coal beds

Under discussion are the direct dumping flowsheets applied to remove lower overburden layers at coal series deposits in Kuzbass. The authors present the calculation procedure for the parameters of overburden excavation and re-excavation flowsheets using draglines. It is found how the re-excavation coefficient depends on the place and level of the dragline site. The recommendations on selecting the dragline route in internal dumping are made. The main trends toward expanding the area of application of the direct dumping technology are identified.     

深凹露天坑排尾砂后地下采区稳定性分析

鲁南矿业王峪矿段深凹露天矿闭坑后,由于矿区尾矿库的库容不足,提出了露天坑底部排放尾砂的工艺。通过ABAQUS大型有限元数值软件,模拟了露天坑采结束-坑底干排尾砂-露天转地下第一阶段采矿全过程,分析了露天边坡位移变化趋势以及露天转地下采区的应力分布情况,得出结论：露天坑底排尾砂后地下开采区域应力场没有明显的增加,同时围岩体的塑性区域没有贯通;原露天边坡的水平与竖直位移均在可控范围内。并针对露天转地下过程中坑底积水情况,提出了工程上的防排渗措施,具有较好的工程参考价值。     

露天矿区景观恢复与整治措施探讨

露天采矿破坏植被、土壤和上覆岩层,形成露天采场、排土场、尾矿库、工业场地等类型的景观混乱与破坏,如何有效治理和恢复矿区景观是亟待解决的问题。通过分析露天矿区重点景观受损区的类型、特点,及其对土地与生态环境的影响,探讨了露天矿区景观恢复原则与技术思路,并从地质环境综合治理和露天矿景观功能分区恢复2方面提出恢复的技术措施,为露天矿区景观恢复提供依据。     

浅析采空区塌陷爆破设计方案的选择

在露天煤矿的开采中,前期经过小煤窑开采破坏所形成的采空区给露天煤矿的正常开采带来了很大的危害,采用何种有效的爆破方式使其上部的覆盖层由地表塌陷填实采空区,将对露天煤矿的后续开采安全影响极大。本文通过铁长沟露天煤矿采空区塌陷爆破实例进行分析和解释。