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。     

南方某离子型稀土矿山的土地复垦

为了更好地开展南方离子型稀土矿山损毁土地的复垦工作,依据土地复垦方案编制规程要求,以某离子型稀土矿山为例,介绍了该类型矿山土地损毁的特点,总结了复垦时序、表土资源剥离和堆存、原地浸矿采场集排水工程、风险金等复垦工程设计特点,并对已损毁土地不同复垦措施进行对比。可以看出,离子型稀土矿山土地复垦方案主要包括拟损毁土地和已损毁土地2大部分。拟损毁土地方面,应结合原地浸矿工艺特点,考虑采场母液渗漏对植物根系和地下水的影响,重视采场集排水工程的修建,增加风险金的提取;已损毁土地方面,应结合矿区废弃地现状,重视已损毁土地损毁特点、程度、面积、立地条件等调查工作。     

发达国家矿地复垦保证金制度及对中国的启示

采矿业是国民经济的支柱产业，但矿产资源的开采也带来了一系列矿山环境问题。发达国家自20世纪70年代就开始制定矿地复垦法律，建立了矿山环境恢复与土地复垦保证金制度。我国矿山环境问题比较严重，而矿山土地复垦资金不足。因此，我国有必要借鉴国外发达国家成熟的矿地复垦立法经验，建立矿山环境治理保证金制度，以恢复矿产资源开采过程中被破坏的土地。     

生态学在露天煤矿排土场生态恢复中的应用

以黑岱沟露天煤矿为例,对矿区工程复垦后土地生物复垦中的土壤改良、植被品种的筛选和植被工艺等理论与技术方面的问题进行了研究。明确了复垦区的土壤性质,运用生态学原理,采取了恰当的土壤改良措施,并有选择地种植了合适的物种,快速地恢复了矿区植被,从而有效地控制了水土流失,改善了矿区的生态环境,也促进了矿区农业、林业、畜牧业的平衡发展。     

Influence of organic amendments and arbuscular mycorrhizal inoculation on plant growth and nutrient uptake in iron ore mine spoils

Trema orientalis L. Blume is able to grow on nutrient-deficient soils and known to be a metal tolerant plant species displaying potential for use in mine restoration programmes. However, reclamation strategies would depend on the plant species used, and physico-chemical status of the spoil that often limits plant growth. This study was directed to determine the efficiency of arbuscular mycorrhizal (AM) species Rhizophagus irregularis and soil organic amendments (farm yard manure [FYM] and vermicompost [VC]), in enhancing growth and nutrient acquisition of T. orientalis in iron ore mine spoil (MS). A pot experiment was conducted using five treatments viz., AM, FYM, FYM and AM, VC, and VC and AM, with pure spoil as the control. Growth parameters, foliar nutrient concentrations and percentage AM root colonisation were determined at the end of 12?months. Addition of FYM and VC altered the chemical properties of spoil, increased pH and macro- and micro-nutrient levels and enhanced plant growth. Growth of T. orientalis was significantly increased by both organic amendments and by AM inoculation over control. AM colonisation increased plant survival in pure spoil and enhanced growth in both pure and amended spoil. High AM colonisation and plant dependency were recorded in pure MS and lower levels in amended spoil. AM colonisation plays a significant role in survival of T. orientalis in hostile iron ore MS environment. T. orientalis transplant success on iron ore mine sites would be greatly increased with VC and R. irregularis amendment.     

平果铝土矿复垦研究与设计

根据平果铝土矿一期工程那塘矿段剥离量特少,粘土底板范围大且土层较厚,岩溶底板范围小,石牙、溶洞发育等具体条件提出了3个各具特征的复垦方案,选定的"平填底板旱式复垦"方案,具有复垦率高、工艺简单、周期短、成本低等特点,经济效益显著,可供复垦设计与施工技术人员参考。     

基于FLAC3D对某铜矿深部开采地压活动规律研究

介绍了地压活动规律对矿山深部开采的重要影响,通过应用FLAC~(3D)软件对某铜矿59#矿体开采过程中的两种工况进行数值模拟计算研究,发现59#矿体在开采至十五中段时,对围岩扰动较小,不会出现顶板大面积冒落的情况;开采对3#采空区稳定性影响最大,对2#采空区稳定性影响最小;废石充填对维护空区稳定有一定作用,但作用不大;随着59#矿体开采深度的不断增加,其对断层的影响程度也逐渐增加;废石充填对断层稳定性影响较小。从而得出随着开采深度的增加,对围岩扰动越来越大,围岩稳定性降低,顶板发生突然冒落的可能性较大,一旦顶板发生突然冒落,井下会出现较大响声和振动,但由于该铜矿采用崩落法开采,采场上部有大量冒落覆岩,顶板突然冒落不会形成冲击地压。     

生物多样性指数在矿山土地复垦中的应用

提出了利用复垦用地结构多样性指数来评价矿区生态恢复状况的方法,并在矸石回填场地上进行了裸矸,覆土、覆件粪,覆棉饼４个处理种植红三叶,柽麻,苜蓿,黑麦草、小冠花及高羊茅等草种的试验。将Ｓｈａｎｎｏｎ指数、Ｓｈａｎｎｏｎ－Ｗｅａｖｅｒ指数和Ｓｉｍｐｓｏｎ指数用于矿山复垦方案的选择与复垦时的植物品种选择,实践证明这种方法是可行的。     

Assessment of the Impact of Irrigation with Low-quality Mine Water on Virgin and Rehabilitated Soils in the Upper Olifants Basin

Low-quality mine water from collieries may be used in large quantities to irrigate agricultural crops on virgin (unmined) and rehabilitated soils in South Africa. Such a use could enhance crop production and allow environmentally sustainable mine water disposal. In this study, the volume and qualities of the runoff from two centre pivots irrigated with moderately saline mine water, as well as their soil water salinities, were monitored and used to determine water and salt balances, using the modified ACRU agrohydrological model, ACRU2000, and its salinity module, ACRUSalinity. At both sites, much of the water evaporated, while a significant part of the salt input either precipitated or remained with the water in the soil horizons. A higher percentage of drainage water (and salinity) were retained as ground water storage and a lower percentage of runoff occurred in the rehabilitated sandy loam soil, while a higher percentage of salts accompanied runoff in the virgin clayey soils. Simulated salt saturation values indicate that many crops could be successfully irrigated at 100% yield potential at either site. Electrical resistivity surveys were carried out at both sites. A general decrease in resistivities with depth in both the virgin and rehabilitated soils reflected the decreasing influence of the mine water used for irrigation with depth and the precipitation of salts in the soils close to the ground surface. The occurrence of a thicker, low-resistivity, near-surface layer near the exit of each pivot area indicates that the water and salt content of the subsurface increased in the direction that the surface and near-surface irrigation water flowed. An erratum to this article can be found at     

基于多方法联合的露天转地下矿山合理覆岩层厚度研究

在露天转地下过程中需人工强制形成覆盖岩层,其对无底柱分段崩落法至关重要,不仅影响矿石回采安全,而且影响矿石回收。因此,研究覆盖岩层厚度对矿山生产具有重要意义。采用理论分析计算及PFC2D数值模拟的手段,对新疆诺尔湖铁矿露天转地下采场覆岩层厚度进行分析研究,确定该矿采场的合理覆盖岩层厚度为40m。     

挑檐式结构无底柱阶段崩落采矿法试验研究

崩落采矿法在实际生产过程中矿石损失贫化较难控制，放矿过程中废石漏斗的形成与破裂是造成矿石损失贫化的主要原因。为延缓放矿过程中废石漏斗的形成和到达放矿口的时间，提出了一种挑檐式结构的无底柱阶段崩落采矿法。该方法以阶段为单位，使得每个下分段都超前其上分段一个挑檐距离，在回采巷道工作面形成挑檐结构，回采工作都在其正上方挑檐结构的遮掩下进行。为验证挑檐结构方案的放矿效果，利用多分段放矿模型进行了挑檐结构下放矿和传统结构下放矿2组物理模拟试验，认为在保持矿石回采率80%的情况下，挑檐结构的矿石贫化率可降低5.3个百分点。在弓长岭井下矿-280~+48 m段4-5号穿脉进行了挑檐结构工业性试验，分别对挑檐结构和原结构进行了9个崩矿步距回采的放矿跟班测定。结果表明：挑檐结构与原结构相比，贫化率可降低3.8个百分点，主要原因是挑檐结构可阻挡顶部覆盖岩石，使其向本分段崩落矿石后方移动，而不出现侧漏现象，提高了纯矿石放出量，矿石贫化减小。上述分析进一步表明：挑檐结构方案施工简单，适用于中等稳定以上矿体地下开采。     

曹庄煤矿自流式似膏体充填工艺研究

 摘要：采用自流式似膏体充填工艺对曹庄煤矿81006工作面进行充填开采,介绍了曹庄煤矿自流式充填系统的构成及充填工艺,最后工作面充填效果进行评价。结果表明：超前巷道顶底板最大移近量为174mm,平均108mm,充填开采有效控制矿压显现强度;充填体内顶底板最大压缩量为104mm,压缩率为5.2%,充填体接顶效果好;充填体内应力逐渐增大,最大应力为15.02MPa,基本与原始应力13.75MPa相等,从采空区开始充填到充填体应力达到原始应力大约需要20天时间,充填密实率好,充填体可以承担覆岩全部重量;充填后,地表几乎没有下沉,地表得到有效保护。     

Changing Surface-Mine Reclamation Practices in Minas Gerais,Brazil

Changing reclamation practices for surface mines in Minas Gerais, Brazil, were examined through visits to several mines and interviews of reclamation specialists, environmental consultants, and regulatory-agency personnel. The quality of reclamation improved consiaderably in the past 13 years due to changes in legal requirements, corporate attitudes, new reaclamation practices, and better application of selected practices. Most experienced reclamation specialists developed techniques well-suited to the specific environmental conditions at their mine. New challenges await as reclamation goals and requirements become more rigorous. On the horizon is long-term, land-use planning as part of mine-closure plans, increased environmental monitoring and mine inspections, and possibly reclamation bonding. On the ground, adoption of topographic-reconstruction practices, complete analyses and use of available topsoil, development of dependable seed sources for wider varieties of plant species, and techniques to insure uniform seed distribution would facilitate continued improvement in reclamation quality. A national reclamation organization would promote reclamation-technology transfer.     

海州露天矿排土场植被重建技术研究

由于农业用地对环境要求相对较高,且需要大量的人力、物力进行管理,多数矿山企业在土地复垦时一般不将种植作物作为其土地用途,而是以管理工作及费用相对较少的林、草种植为主.林草种植在矿山复垦种植中占有相当重要的地位,着重探讨海州露天矿排土场牧草种植的技术途径.     

某金矿岩层移动现场监测及其与工程地质条件关系的研究

某金矿岩层移动和地表变形、沉降比较明显。采用垂直钻孔多点位移计对岩层移动的大小、速率和动态变化过程进行了现场监测 ;通过工程地质调查基本查清了地表古河床、古坑塘的位置和浅部民采未充填采空区的分布。根据现场监测和调查的结果 ,对岩层及地表移动的原因和规律作出了合理的解释 ,为采取有效措施控制岩层及地表移动提供了依据     

Characterisation of overburden waste and industrial waste products for coal mine rehabilitation

Abstract

This study focuses on the creation of artificial soils from waste products, such as overburden, leftover brown coal, fly ash and compost, for rehabilitation of degraded mine sites acknowledging acid mine drainage. It was found that with the increase in the amount of compost from 2 to 2.5 g in artificial soils, there was an increase in the moisture holding capacity and load bearing capacity from 7.47 to 16.5% and 2.5 to 5.7 kN, respectively. Metals leached from artificial soils under different conditions were found to be below standards limits set by USEPA for leachate in the environment.     

Bonding implications of heap leach infiltration rates at Nevada mines

One important factor in determining bonding costs for mine reclamation is the steady-state infiltration rate of the heap leach pad(s). The importance of assessing each mine on a case-by-case basis is demonstrated. Long-term infiltration rates were investigated for 19 Nevada heaps: <2% at <1860?m above mean sea level (amsl) and <3% at >1860?m amsl. A common means of reducing steady-state infiltration rate is the application of a vegetative cover. Cover implementation costs can be optimised by mathematical modelling of precipitation flow through the heap. For the proposed Buffalo Valley mine, the post-closure heap equilibrium flux of ～1?mm/year for a 0.9-, 1.2- or 1.5-m-thick cover was calculated after ～11, 17, and 23?years, respectively, demonstrating that covers >?0.9?m (adequate for successful revegetation) accrue no incremental reduction in infiltration rate. The infiltration rate for this cover thickness (0.6%) was consistent with heaps at similar elevations.     

露天转地下开采覆盖层合理厚度优化研究

眼前山铁矿已经进入到露天开采转向地下开采的过渡阶段,地下开采采用无底柱分段崩落法,该工艺要求露天坑底部应具有一定厚度的覆盖层,以起到挤压爆破和端部放矿的作用.为了既能满足开采要求,同时又能节省工程成本,矿山需要对覆盖层厚度进行优化设计.根据工程地质条件与开采工艺,分别利用室内相似材料试验和PFC2D数值分析方法对不同厚...     

Topsoil and fertilizer effects on ground cover growth on calcareous minesoils

ABSTRACT

We measured canopy cover and aboveground biomass of herbaceous species in four studies for five years (1989–1993) in southeastern Ohio. Three studies compared graded cast overburden, standard graded topsoil (30 era depth), and ripped topsoil. The fourth study lacked the ripped topsoil treatment. In 1997 two studies were seeded with both a standard and a modified mixture of grass and legume species, and two studies used the modified mix only. A nitrogen rate study used 45, 90, or 135 kg/ha of N applied on two occasions, and a phosphorus fertilizer study used rock phosphate amendment at 0, 1120, or 2240 kg/ha and triple superphosphate amendment at 0, 280, or 560 kg/ha. Based on one clipping per year, overall average biomass (Mg/ha dry weight) was slightly greater on standard topsoil (3·34), and ripped topsoil (3·30) than on cast overburden (3·09). Biomass did not differ significantly (p=0·05) on standard topsoil versus cast overburden for 15 of 19 comparisons. Legume biomass (Mg/ha, measured for 3 or 4 years) averaged 0·84 on standard topsoil, 0·75 on ripped topsoil, and 1·16 on cast overburden. In three studies, legume biomass was 50% higher on cast overburden than the topsoils, but differences among the soil surfaces were decreasing by 1993. Nitrogen fertilizer increased ground cover only in the year when fertilizer was applied. Phosphorus fertilizer treatments had no significant effects. Ground cover showed no signs of deterioration during the last measurements in 1993. Observations in 1995 indicated dense canopy cover on all soil surfaces with substantial invasion by goldenrods (Solidago spp.) only on topsoils.     

连续采矿顶板诱导崩落综合技术的研究与应用

对大型矿体的开采,用充填的采矿方法成本较高,对有些矿体的开采不可行,而传统的空场法或崩落法存在资源整体回收率低、后期地压难控制等问题。对此采用我国著名采矿专家古德生院士提出的"以矿段为回采单元、矿段间不留矿柱"的连续开采方式,并相应地用一定的诱导工程崩落处理顶板以释放地压,通过在广西大厂铜坑矿92号矿体的工业试验最终有效地提高了资源的回收率,并用经济安全的工程手段成功控制了大的地压灾害的发生。