Study of Soil Seed Banks in Antaibao Opencast Mine

A seed germinating method was used to study soil seed banks in dump sites of the Antaibao opencast mine for soil reclamation and ecological rehabilitation. Based on a richness index, a diversity index and an evenness index, the diversity of species of soil seed banks was studied. As well, the progress of vegetation succession in this thoroughly destroyed ecosystem is discussed and the self-renewal ability of the soil seed banks is analyzed. The results indicate that 1） there are 17 plant species belonging to five families with annuals as the dominant species; 2） the soil seed banks at the dump site show great temporal and spatial heterogeneity and 3） the model of Robinia pseudoacacia x Pinus tabulaeformis × Caragana korshinskii in the anaphase is the best among several reclamation models studied. Therefore, with the extension of reclamation time, the correct choice of a reclamation model is quite helpful for the improvement of the self-renewal ability of soil seed banks and for the stability of the ecosystem, which is very important for land reclamation and ecological rehabilitation of the dump sites of the ATB opencast coal mine.

GPS/GIS based vehicle dispatching for opencast mines

An integrated GPS and GIS based vehicle dispatching system was presented. The system uses GIS technology for the development of digital mine map database and GPS for vehicle positioning. The system consists of five modules: position module incorporated GPS and dead reckoning (DR); a map database structure for displaying and guidance purposes; a routing module based on the map database is able to give out the best route for the vehicles; map matching and route guidance module put the vehicle position to its exact location on the road despite of errors in positioning and map data; and the client-server module allows client exchange information between driver and control centre. The system can be operated in client-server level in which users can request routing and guidance with devices such as hand phone and PDA by communicating their current positions to the server or runs in autonomous mode when users cannot reach the server.

Spatial-temporal variance of reclamation soil physical and chemical character in opencast mine region

In order to study the effects of soil compaction, and soil physical and chemicalcharacteristics after land reclamation, selected lands that were reclaimed after 1, 2, 3, 4,and 5 a, respectively, in the Majiata Mine of the Shendong Open Pit; tested the effects ofsoil compaction; and collected soil samples from 5 different depths, which are 0-7.62,7.62-15.24, 15.24-22.86, 22.86-30.48, and 30.48-38.10 cm, respectively. The resultsshow that: Land reclamation leads to soil compaction. The lowest effect of soil compaction is in the top layer and the highest one at the depth of 20-30 cm; The bulk density of reclaimed soil is higher than that of undisturbed soil; this declines with the reclamation and nearly reaches the level of undisturbed soil after 5-year reclamation;The content of reclaimed soil nutrients is lower than that of undisturbed soil. The lowest one is inthe soil dumping site, which reaches the level of undisturbed soil after 5-year reclamation;The pH value of reclaimed soil is lower than that of undisturbed soil. The highest one isin the soil dumping site; this declines with the reclamation.

Responses of soil stoichiometry and soil enzyme activities in the different distance around opencast coal mine of the Hulun Buir Grassland of China

The objectives of this study were to explore the changes in soil stoichiometry and enzyme activities at different distances from an opencast coal mine in the Hulun Buir Grassland of China. Four transects were established on north and east sides of the opencast coal mining area, and samples were collected at 50 m, 550 m, and 1550 m from the pit on each transect. Control samples were collected from a grassland station 8 km from the opencast coal mining area that was not disturbed by mining. Four replicate soil samples were collected at each point on the four transects. Soil physicochemical properties and enzyme activities were determined, and correlations between soil properties and stoichiometric ratios and enzyme activities were explored using redundancy analysis. The increase in distance from mining did not significantly affect soil properties, although soil urease activity was significantly lower than that of the control area. Soil properties 1550 m from the mine pit were similar to those at the grassland control. In addition, soil total nitrogen had the greatest effect on soil stoichiometry, and soil total potassium had the greatest effect on soil enzyme activities. Coal dust from opencast mining might be the main factor affecting soil stoichiometry and enzyme activities. The results of this study provide direction for the next step in studying the influence of mining areas on soil properties and processes.

Discussion on Land Use Mode Reform in Coal Opencast Mining

The existing land supply mode of opencast mining is"land requisition first,then transfer",which lacks an effective recovery and withdrawal mechanism,and the reclaimed mining land is difficult to withdraw.According to the regular rules of coal opencast mining and the periodic characteristics of land use,this paper puts forward a new mode of temporary land use for coal opencast mining.It is conducive to im-proving the quality and scale of land use and reclamation utilization of opencast coal mining,and is of great significance for exploring and for-mulating reasonable land use policies for mineral resources development projects.

Geochemical and petrological studies of high sulfur coal and overburden from Makum coalfield (Northeast India) towards understanding and mitigation of acid mine drainage

Opencast coal mining produces trash of soil and rock containing various minerals,that are usually dumped nearby the abandoned sites which causes severe environmental concern including the production of acid mine drainage(AMD)through oxidation pyrite minerals.The current study entailed assessing the potential production of AMD from an opencast coal mining region in Northeast part of India.In order to have a comprehensive overview of the AMD problem in Makum coalfield,the physico-chemical,geochemical,and petrological characteristics of the coal and overburden(OB)samples collected from the Makum coalfield(Northeast India)were thoroughly investigated.The maceral compositions reveal that coal features all three groups of macerals(liptinite,vitrinite,and inertinite),with a high concentration of liptinite indicating the coal of perhydrous,thereby rendering it more reactive.Pyrite(FeS_(2))oxidation kinetics were studied by conducting the aqueous leaching experiments of coal and(OB)samples to interpret the chemical weathering under controlled laboratory conditions of various temperature and time periods,and to replicate the actual mine site leaching.Inductively coupled plasma-optical emission spectroscopy(ICP-OES)was operated to detect the disposal of some precarious elements from coal and OB samples to the leachates during our controlled leaching experiment.The Rare earth element(REE)enrichment in the samples shows the anthropogenic incorporation of the REE in the coal and OB.These experiments reveal the change in conductivity,acid producing tendency,total dissolved solid(TDS),total Iron(Fe)and dissolved Sulfate(SO_(4)^(2−))ions on progress of the leaching experiments.Moreover,the discharge of FeS_(2) via atmospheric oxidation in laboratory condition undergoes a significant growth with the rise of temperature of the reaction systems in the environment and follows pseudo first order kinetics.A bio-remediative strategies is also reported in this paper to mitigate AMD water by employing size-segregated powdered limestone and water hyacinth plant in an indigenously developed site-specific prototype station.Apart from neutralisation of AMD water,this eco-friendly AMD remediation strategy demonstrates a reduction in PHEs concentrations in the treated AMD water.

Natural vegetation recovery on waste dump in opencast coalmine area

The changes of vegetation compositions, plant species diversity, species important value and succession of plant community were studied on waste dumps in Haizhou opencast coalmine which is located in the west of Liaoning Province, China (41°41(-42°56( N, 121°1(-122°56(E). Four kinds of terraces with different ages (5, 10, 20 and 40 years) were selected for investigation of plants. Total of 63 species of natural colonized plants were recorded on the waste dump and they belong to 23 families. The main families were Compositae (15 species), Fabaceae (11 species) and Leguminosae (8 species), which accounted for 54.0% of total species and play an important role in natural vegetation recovery in waste dump area. The dominant species on 5-, 10-, 20-, 40-year-old terraces were Tribulus terrestris + Echinochloa hispidula + Salsola collina, Echinochloa hispidula + Artemisia sieversiana + Artemisia scoparia, Echinochloa hispidula + Clinelymus dahuricus + Artemisia scoparia + Artemisia sieversiana + Melilotus officinalis, Clinelymus dahuricus+Phragmites communis + Echinochloa hispidula+ Setaria viridis, respectively. According to the important value of species calculated. It is determined that Tribulus terrestris can act as pioneer species on waste dump and Clinelymus dahuricus, Phragmites communis and Echinochloah hispidula are important dominant species in vegetation restoration in Haizhou opencast coalmine. The study results can provide scientific basis for selecting and disposing appropriately plant species and rehabilitating vegetation on waste dumps of coalmine.

Applying real time seismic monitoring technology for slope stability assessment—An Indian opencast coal mine perspective

This paper outlines the results obtained from real time microseismic monitoring of an opencast coal mine in South India.The objective of the study is to investigate the stress changes within the rockmass along the slope due to underground mine development operation and their impact on the stability of the highwall slope.The installed microseismic systems recorded the seismic triggerings down toà2 moment magnitude.In general,most of the events recorded during the monitoring period are weak in seismic energy.The study adopts a simple and more reliable tool to characterize the seismically active zone for assessing the stability of the highwall in real time.The impact of underground working on the slope is studied on the basis of the seismic event impact contours and seismic clusters.During the monitoring period,it is observed that the intensity of the overall microseismic activity along the slope due to the mine development operations did not cause any adverse impact on the highwall stability.

E24 profile slope stability analysis in Haizhou Opencast Coal Mine of Fuxin

The E24 profile slope analyzed belongs to a series of excavated slopes of the Haizhou Opencast Coal Mine. It seems to be divided into Downslope Part and Upslope Part. Its profile comprises two noticeable coal seams, called the 8# and 9# weak layers, considered as the potential failure surfaces. In consideration of the actual configuration as in the perspective of any modification, assessing the stability of this slope with various profile forms under given conditions, and assessing the risk of instability and quantifying the influence of earthworks or other modifications to the stability of this slope, have constituted the primordial objectives carried out. From assumed potential failure surfaces, any specific profiles and specified slip surfaces are defined. A factor of safety (FoS) is computed for each specified slip surface; the smallest FoS found corresponds to the least favorable slip surface. The safety factor values obtained are compared to the suggested safety factor. Limit equilibrium methods of vertical slices implemented in Slope/W, computer program for slope stability analyses, have been adopted to perform the E24 slope stability analysis. The safety factor values computed with 9# weak layer are lower than for 8#; the factors of safety obtained with Sarma's method are the smallest; more, without groundwater (long term) overall values are greater than those determined under groundwater condition (short term). The lowest safety factor value is found for a profile depending on an adopted earthwork sequence. The E24 profile slope stability analysis shows the instability risk for the deepest weak layer, and also shows the short and long term stability of this slope for the envisaged earth movements. However it demonstrates the existence of instability risk for any earthwork firstly affecting the downslope part.

SICOMINES铜钴矿开采阶段地下水变化规律研究

以刚果(金)SICOMINES铜钴矿为背景,通过分析矿区水文地质条件、矿区1976—2022年地下水流场演变特征和排水数据,对矿区水位变化规律进行深入研究,结果表明地下水动态变化特征是以侧向补给为主、降水为辅;排水以补给量为主、储存量为辅。地下水流动以管道流为主、渗流为辅,含水层之间联系密切,地下水渗透阻力小,坡度缓,连通性好,下部含水层排水能降低不同含水层水位。地下水系统主要由缝、洞构成,存在以空洞为汇集的地下水主径流带,矿区为构造控水。

黄土区排土场复垦初期不同恢复模式下土壤生态化学计量特征

为探究黄土区排土场在复垦初期不同植被恢复模式下土壤的养分状况与限制性,在内蒙古武家塔排土场选取恢复年限3—4 a的苜蓿(Medicago sativa)、沙棘(Hippophae rhamnoides)、大叶槐(Robinia pseudoacacia L.)、刺槐(Robinia pseudoacacia)、竹柳(Bamboo willow)和新疆杨(Populus bolleana)6种植被恢复模式作为研究对象,以新排土为对照,研究其土壤碳氮磷含量与生态化学计量特征及关系。结果表明:不同恢复模式土壤有机碳、全氮和全磷含量分别变化在2.83—4.52 g·kg^(-1)、0.13—0.21 g·kg^(-1)和0.05—0.17 g·kg^(-1),除苜蓿土壤全氮和苜蓿、刺槐土壤全磷外,其余恢复模式下土壤养分含量均高于新排土;其中土壤有机碳在刺槐和苜蓿模式下较高,在沙棘模式下较低,而全氮与全磷均反之,各恢复模式下土壤全磷含量均较低;各恢复模式下土壤有机碳和土壤全氮均呈现出不同程度的表聚现象,而土壤全磷在垂直土层变化不明显。各恢复模式下土壤C/N、C/P和N/P分别变化在13.68—30.69、19.30—106.60和1.13—3.61;苜蓿和刺槐恢复模式下的土壤C/N、C/P和N/P整体表现为高于其他模式且在垂直土层变化差异较大。研究区复垦初期土壤有机碳和全氮整体与土壤各养分及化学计量比紧密相关,土壤C/N、C/P更易受土壤有机碳影响,土壤N/P更易受土壤磷的影响。苜蓿和刺槐恢复模式土壤有机质矿化率低,受磷限制性大,需及时补充磷肥,而新疆杨恢复模式需补充氮肥。

露天煤矿剥离工程施工安全关键技术研究

社会快速发展,对能源需求量越来越大,煤炭开采需求也逐渐提升,露天煤矿剥离工程量也随着增加,为了保证剥离工程的安全和质量,提高剥离效率,需要认真研究、总结。该文通过内蒙古白音华露天煤矿剥离工程介绍施工方法、工艺及关键技术,为类似工程提供相应参考和借鉴。

西南地区露天矿山修复对植被与土壤固碳效应的影响

探究西南地区露天矿山生态修复过程中植被与土壤碳储量变化特征及其固碳潜力,为该地区露天矿山生态修复提供数据支撑。在重庆市铜锣山矿区选取修复后的露天矿坑建立固定样地,在修复后1年、3年和5年开展连续监测,以研究区内典型常绿阔叶林作为参照,在样地中设置样方开展植物群落调查,测定0~10 cm、11~20 cm、21~30 cm土层的有机质、容重、石砾含量,计算不同修复年限植被和土壤碳储量,分析露天矿山修复的植被-土壤系统固碳效应及潜力。结果表明:露天矿山修复后植被-土壤碳密度增加缓慢,修复5年期与1年期未表现出显著差异;修复区植被各组分碳密度表征为地上生物层>根系层>枯落物层;0~10 cm土层有机碳含量和有机碳密度显著大于11~20 cm和21~30 cm土层(P<0.05),具有明显的表层聚集效应;修复后1~5年植被-土壤系统平均固碳速率为0.039 kg/m^(2)·a,固碳速率随演替呈增加趋势,土壤固碳速率为植被的1.8倍。以复垦和植被建设为主的露天矿山人工修复措施可以快速提升修复区植被和土壤碳储量,是增强矿区生态碳汇的有效途径,露天矿山修复固碳潜力较大。

露天煤矿混凝土支护结构的抗压试验研究

为提高露天煤矿混凝土支护结构的安全性,需要分析露天煤矿混凝土支护结构的抗压性能。本文提出露天煤矿混凝土支护结构的抗压试验研究方法,通过分析混凝土支护结构,研究露天煤矿混凝土支护结构的受力情况。在不同养护温度、水灰比和喷射方式下分析了露天煤矿混凝土支护结构的抗压性能。结果表明,混凝土在45℃养护条件下的强度较好;当混凝土支护结构在养护温度过高时,与标准养护环境下的强度值相比处于劣势;随着水灰比的增加使混凝土支护结构在露天煤矿中的抗压强度和孔隙率不断提高;在抗压强度、抗拉强度和抗折强度三个方面,湿喷混凝土均优于干喷混凝土。

Rock fragmentation control in opencast blasting

The blasting operation plays a pivotal role in the overall economics of opencast mines.The blasting subsystem affects all the other associated sub-systems,i.e.loading,transport,crushing and milling operations.Fragmentation control through effective blast design and its effect on productivity are the challenging tasks for practicing blasting engineer due to inadequate knowledge of actual explosive energy released in the borehole,varying initiation practice in blast design and its effect on explosive energy release characteristic.This paper describes the result of a systematic study on the impact of blast design parameters on rock fragmentation at three mines in India.The mines use draglines and shoveledumper combination for removal of overburden.Despite its pivotal role in controlling the overall economics of a mining operation,the expected blasting performance is often judged almost exclusively on the basis of poorly defined parameters such as powder factor and is often qualitative which results in very subjective assessment of blasting performance.Such an approach is very poor substitutes for accurate assessment of explosive and blasting performance.Ninety one blasts were conducted with varying blast designs and charging patterns,and their impacts on the rock fragmentation were documented.A high-speed camera was deployed to record the detonation sequences of the blasts.The efficiency of the loading machines was also correlated with the mean fragment size obtained from the fragmentation analyses.

Prediction of blast-induced flyrock in Indian limestone mines using neural networks

Frequency and scale of the blasting events are increasing to boost limestone production. Mines areapproaching close to inhabited areas due to growing population and limited availability of land resourceswhich has challenged the management to go for safe blasts with special reference to opencast mining.The study aims to predict the distance covered by the flyrock induced by blasting using artificial neuralnetwork （ANN） and multi-variate regression analysis （MVRA） for better assessment. Blast design andgeotechnical parameters, such as linear charge concentration, burden, stemming length, specific charge,unconfined compressive strength （UCS）, and rock quality designation （RQD）, have been selected as inputparameters and flyrock distance used as output parameter. ANN has been trained using 95 datasets ofexperimental blasts conducted in 4 opencast limestone mines in India. Thirty datasets have been used fortesting and validation of trained neural network. Flyrock distances have been predicted by ANN, MVRA,as well as further calculated using motion analysis of flyrock projectiles and compared with the observeddata. Back propagation neural network （BPNN） has been proven to be a superior predictive tool whencompared with MVRA. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

Estimation of carbon sequestration in reclaimed coalmine degraded land dominated by Albizia lebbeck, Dalbergia sissoo and Bambusa arundinacea plantation： a case study from Jharia Coalfields, India

Reclaimed mined lands provide an excellent opportunity to sequester carbon and combat global warming. Carbon sequestration on reclaimed sites depend on age of reclamation, composition of species, geomining conditions （soil characteristics） and prevailing climate. The aims of the present study were to calculate carbon （C）--stock of biomass of 4 years old plantation （dominated by Albizia lebbeck, Dalbergia sissoo and Bambusa arundinacea）, understorey vegetation and litter, soil organic carbon in reclaimed minesoil （RMS） and compare with reference forest site. Allometric equation was used for the estimation of biomass C stock and found 13.0 Mg C ha i （A lebbeck 7.8 Mg C ha-I, D sissoo 3.5 Mg C ha-l and B. arundincea 1.2 Mg C ha-l）, while stock of understorey vegetation was 0.98 Mg C ha-~. In RMS, C stock was 16.3 Mg C ha-1, out of which inorganic C contributed 1.7 g kg-l （8 % of total soil C）, Coal C 8.7 g kg^-1 （43 % of total soil C） and biogenic C 9.8 g kg^-1 （49 % of total soil C）. Total C stock in reclaimed site was calculated as 30.3 Mg C ha^-1（equivalent to 111 Mg CO2 ha-b. The study concluded that （i） coal C is responsible for overestimation of C stock in RMS （ii） Maximun C stock stored in aboveground biomass component and （iii） reclaimed mined lands will take approximately 17 years to reach the level of C stock of reference forest site in dry tropical climate.

面向终身学习的人工智能教育应用研究--欧洲X5GON项目的特征、服务与实践

面对推进全民终身学习的需要,人工智能教育应用展现出其独特的优势,其智能化、自动化和个性化特点可以提供强大的助力。X5GON是欧洲著名的人工智能教育应用项目,它具有根据用户需求进行学习资源推荐、系统透明度高和提供特殊人群服务的特征。为了满足终身学习的需要,X5GON项目能够提供跨国界的高质量翻译、贯穿学习过程的数据分析以及个性化学习资源推荐服务。德国奥斯纳布吕克大学和西班牙瓦伦西亚大学积极参与人工智能教育应用实践,分别依托Opencast发布在线课程和X5GON的翻译技术取得突破。当前,我国正处于推进全民终身学习和建设学习型社会的关键阶段,有必要充分发挥人工智能技术的助力,因而可以学习和借鉴X5GON项目的经验,从翻译服务和数据采集、分析入手,进一步促进我国面向终身学习的人工智能应用的发展。

露天矿区土地复垦适应性管理:内涵解析与框架构建

研究目的:探讨露天矿区土地复垦适应性管理的理论内涵,阐释其主要管理要素与组织框架。研究方法:系统回顾法、类比分析法和逻辑推理法。研究结果:(1)基础铺垫、案例引导、需求倒逼、使命号召4层缘由共同驱动着露天矿区去探索一种与其生态系统内外部机理相适应的土地复垦动态管理模式—适应性管理;(2)矿区土地复垦适应性管理是以矿区土地生态系统健康发展与可持续开发利用为目标,通过监测、评估、反馈、调整等一系列活动,不断探索并认识矿区土地复垦发展过程中的不确定因素及其内在规律,从而促使土地复垦不断适应矿区社会、经济、生态等方面协调发展的管理过程;(3)“目标制定—规划设计—方案执行—监测评估—信息反馈—模式修正”六要素一体构成矿区土地复垦适应性管理的基本组织框架。研究结论:适应性管理具有灵活性、动态性等特征,如果管理者能把握矿区生态系统内部演化机理与外部干扰规律,并借鉴吸收相近领域研究成果经验,那么适应性管理有望成为破解露天矿区土地复垦过程管理难题的有效途径。

粉煤灰、砒砂岩对煤矿排土场土壤水分特性改良的研究

露天煤矿排土场土壤理化特性差直接影响复垦效果,改善土壤水分特性对排土场的复垦具有重要的理论与实践意义。本试验以内蒙古自治区的黑岱沟露天煤矿为对象进行土壤改良试验,将粉煤灰(F)、砒砂岩(S)作为添加物,对排土场土壤(L)进行3种组合处理(LF、LS、LFS)并设置不同的质量比例梯度,试验共设(L3F1、L4F1、L5F1、L1S1、L2S1、L3S1、L4S1、L5S1、L1F1S1、L2F1S1、L3F1S1、L4F1S1、L5F1S1)13种不同质量比的混合处理和(L、F、S)3种对照处理,采用离心机法测定各复配土壤在不同水吸力下的含水量,利用Gardner模型拟合并绘制其水分特征曲线,计算各复配土壤的比水容量、田间持水量、萎蔫系数、有效水含量。结果表明:(1)Gardner模型能够很好地拟合13种复配土壤的水分特征曲线,粉煤灰的添加使排土场土壤中的细土粒含量(黏粒、粉粒)增加了24.11%~37.19%,提高了土壤的持水性和供水性,添加砒砂岩能够改良土壤的持水性但不能改良供水性能。(2)排土场土壤、粉煤灰、砒砂岩质量比为1︰1︰1(L1F1S1)时持水性能最好,较排土场土壤提高了47.6%;排土场土壤、粉煤灰质量比为3︰1(L3F1)时其供水性能最好,较排土场土壤提高了40.23%。(3)LF组合处理和LFS组合处理的田间持水量和有效水含量随着添加物比例的增加而提升,当排土场土壤、粉煤灰质量比为3︰1(L3F1)时田间持水量最大为18.02%,排土场土壤、粉煤灰、砒砂岩质量比为1︰1︰1(L1F1S1)时有效水含量最大为13.1%。综上,粉煤灰、砒砂岩综合利用有利于煤矿排土场土壤水分特性的改良,且复配土壤的黏粒、粉粒含量在30%~35%范围时,土壤的持水供水能力较好,在本试验中三者按1︰1︰1的质量比例进行复配效果最佳。