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1.
The production and utilization of coal is based on well-proven and widely used technologies. Fly ash, a coal combustion byproduct,
has potential to produce a composite material with controlled and superior properties. The major challenges with the production
of fly ash are in its huge land coverage, adverse impact on environment etc. It puts pressure on the available land particularly
in a densely populated country like India. In India the ash utilization percentage has not been very encouraging in spite
of many attempts. Stabilization of fly ash is one of the methods to transfer the waste material into a safe construction material.
This investigation is a step in that direction. This paper presents the results of an investigation on compressive strength
and bearing ratio characteristics of surface coal mine overburden material and fly ash mixes stabilized with lime for coal
mine haul road construction. Tests were performed with different percentages of lime (2, 3, 6 and 9%). The effects of lime
content and curing period on the bearing ratio and tensile strength characteristics of the stabilized overburden and fly ash
mixes are highlighted. Unconfined compressive strength test results cured for 7, 28 and 56 days are presented to develop correlation
between different tensile strengths and unconfined compressive strength. Empirical models are developed to estimate bearing
ratio and tensile strength of mine overburden–fly ash–quick lime mixtures from unconfined compressive strength test results. 相似文献
2.
Backfilling of mine voids is mandatory to avoid subsequent ground stability problems in the form of subsidence. River sand
and mill tailings have been widely used since a long time as backfilling materials. However, with a strict regulation banning
river sand mining in India, research for developing alternative engineering materials substituting sand has gained importance.
In the present study four fly ash composite materials (FCMs) was developed from the fly ash obtained from a captive thermal
unit of Rourkela Steel Plant (RSP). The main constituent of the composite were fly ash, lime and gypsum. Detailed physical,
and engineering properties were determined for the FCMs. Significant increases in the compressive strength were obtained after
56 days of curing time. A detailed SEM studies was undertaken to account for the increase in strength with time. The fly ash
composite developed from RSP has potential to be used as substitute to sand for backfilling the mine voids. 相似文献
3.
急倾斜厚矿体无间柱上向水平分层充填法采场结构参数的研究 总被引：3，自引：0，他引：3
无间柱连续采矿是一种高效的采矿方法,已成为地下矿山采矿技术发展的大趋势。以某铅锌矿山为例,采用能模拟开挖与充填的三维弹塑性有限元程序,对应用上向水平分层充填无间柱采矿法开采急倾斜厚矿体进行了数值模拟研究,分析了不同的分层高度和超前回采分层数,以及不同的暴露面积条件下采场的稳定性,从而得出合理的采场结构参数,为上向水平分层充填无间柱采矿法在矿山的应用和推广提供一定的依据。 相似文献
4.
由于地下开采形成了大量的采空区,容易发生坍塌事故,尤其对于从地下开采转为露天开采的矿山影响很大,对矿区的安全生产造成隐患,因此对采空区的处理十分重要。针对这一现状,本文研究了一种多层采空区充填井成井工艺,以对多层采空区进行支护处理。通过这种工艺可以减少岩石的移动幅度,防止大面积的地压活动,为矿区的生产和安全提供保障。由于各个矿山的条件不同,采空区的具体位置、形态特征及大小等的不同,对采空区处理方法也不尽相同,本文针对河南省栾川钼矿采空区的特点进行充填井成井工艺的研究与试验。 相似文献
5.
合山煤田是典型的岩溶充水矿床．矿井开采水害严重。煤层的直接顶、底板为碳酸盐岩类,岩溶极为发育,为矿井的直接充水含水层;煤层底部的茅口组为强岩溶含水层,与煤系地层的联系密切,为间接充水含水层;位于煤田两侧的红河水是矿井充水最主要的补给水源。断裂、节理和破碎带等通道是矿井充水的主要通道。通过分析井下突水点的发育特征,认为强岩溶导水带是矿井突水的关键部位,防治矿井水害的重点是切断岩溶导水带,对强导水带进行封堵,防止红水河的侧向补给,对四煤底板灰岩进行加固。总结出地面防治的主要方法为帷幕式、截堵式、堵水点式和地面铺盖式。对井下防治水,提出了有疑必探,先探后掘,设置防水闸门、防水墙,实行分层、分区开采,加强井下排水等防治措施。 相似文献
6.
Because the land requisition and demolishing became difficult more and more, the mining scheme of Luohe iron mine was changed from caving method to filling method. In order to ensure the safety of the residence and the underground tunnel cavern within the mobile belt of the underground mining, the Luohe iron mine did the blasting test on the vertical crater retreat mining method and blasting vibration monitoring. The blasting experiments use common emulsified oil explosives and non-electric initiation system. The way of caved ore adopts the cutting groove and bench side. The NUBOX-6016 intelligent vibration monitor was chosen in the blasting vibration monitoring. Twice experiments on the blasting vibration monitoring were done on the surface or in the underground refuge cavern. The first test select the three monitoring points on the ground and the second select two monitoring points on the ground and a monitoring point in the underground refuge cavern. The blasting vibration monitoring data were conducted by the regression analysis in the Sodev’s empirical formula. The vibration attenuation formula about the underground blasting vibration transmitting in three directions is derived. The blasting test on the vertical crater retreat mining method and the blasting vibration were analyzed. It is estimated if the vibration damage possibly the surface buildings and related facilities of mine. 相似文献
7.
通过对矿区含、隔水层及断层带水文地质特征的分析和井下水文地质现象的观测,认为目前矿井开采煤层较浅,以二1煤顶板直接含水层充水为主,水量不大;但随采掘的延深,煤层下伏的太原组灰岩和奥灰含水层,会在断层的影响下,与其它含水层发生水力联系,对矿井开采形成威胁。根据对矿井充水因素的分析结果,指出目前矿井的充水强度不大,充水通道主要为断层带,在开拓-800m水平时,应注意构造破坏或隔水层薄弱地段,此地段有可能出现奥灰水突入矿井的危险。为防止矿井突水,提出了建立健全地下水观测系统,加强井下钻探和物探工作,重视邻近矿井老窿水监测等矿井水害防治工作建议。 相似文献
8.
煤矿采空区漏风是引发煤火灾害的重要原因,传统充填堵漏材料易干裂,流动性差,成本高,因此研发出有效充填封堵漏风通道的新型材料十分必要。通过单因素变量法,以材料流动度、初凝时间、抗压强度为指标进行配比优选,研发出大掺量粉煤灰无机固化泡沫充填堵漏新材料。同时,利用红外光谱、X射线衍射仪、扫描电镜表征材料的水化过程。结果表明∶基于泡沫均匀度、发泡倍数、半衰期及析水率等参数,优选出十二烷基硫酸钠(SDS)∶辛癸基葡糖苷(APG)=1∶1,黄原胶(XG)∶瓜尔胶(GG)=1∶1的水基泡沫。研发的大掺量粉煤灰无机固化泡沫,其初凝时间与粉煤灰掺量、水灰比、泡沫掺量成正比;流动度与水灰比成正比,与粉煤灰掺量成反比,随泡沫掺量增加先上升后缓慢降低;抗压强度随粉煤灰掺量增加呈先增加后减小趋势,与水灰比和泡沫掺量呈反比关系。综合评价指标确定粉煤灰掺量为60%、水灰比为0.6、泡沫与复合浆液体积比为1∶1时,材料流动度好,为15.9 cm,初凝时间适中,为5 h,抗压强度高,28 d达到1.5 MPa。该材料的水化产物是钙矾石(AFT)以及C-S-H凝胶,由水泥先发生水化反应生成Ca(OH)2,后与粉煤灰反应生... 相似文献
9.
Mining subsidence engineering 总被引：1，自引：0，他引：1
If large, continuous cavities are created underground, as for example in coal mining, the layers of rock over the deposit
generally break and subside. The subsidence can be reduced in amount and severity by filling in, or “stowing,” the mine cavity
with waste material. In the course of subsiding, the land surface deforms into a generally flat, plate-shaped trough, the
edge of which travels ahead of the mine working.
The effects of mining may simultaneously cause a structure to subside, tilt, bend, and be extended or compressed, with extension
and compression sometimes alternating. Areas turned into swamp or placed permanently under groundwater have to be kept drained. 相似文献
10.
露天开采是我国煤矿开采的两大方式之一。与地下开采煤矿类似，露天煤矿在开采过程中同样面临防治水问题，由于我国露天煤矿水害类型相对单一，国内学者鲜有对露天煤矿的水害特征和防治水技术进行深入研究。以我国露天煤矿分布范围为出发点，从充水水源、充水通道、充水强度3方面分析露天煤矿水害特征，得出大气降水、地表水和浅层地下水是主要充水水源；人为开挖形成的直通式通道、强渗透含水层或透水层、垂向导水钻孔、滑坡形成的地表裂缝等是主要充水通道；季节性变化明显、疏排水周期长、排水量大是露天煤矿疏排水主要水害特征的结论。归纳目前我国露天煤矿常用的7种防治水技术，提出露天煤矿由远及近、由上而下、由面至点的立体防治水技术体系。从地下水资源保护和生态环保角度出发，为实现露天煤矿绿色开采和可持续发展，提出以切断补给通道、减小矿坑疏排水量为目的的帷幕截流技术是今后露天煤矿防治水的主要技术方法。 相似文献
11.
吴堡矿区首采地段水文地质特征及矿床充水条件分析 总被引：1，自引：0，他引：1
从鄂尔多斯盆地东部地下水类型、含水岩组等区域水文地质条件入手,对陕北石炭二叠纪煤田吴堡矿区首期开采地段水文地质条件进行了分析。分析表明,区内第四系松散层含水层在首采区虽然分别较广,但水量相对较小,正常情况下与其下含水层贯通的可能性较小,对于煤矿开采影响较小;基岩风化裂隙潜水、太原组灰岩溶隙裂隙及砂岩裂隙承压水及奥陶系灰岩岩溶承压水是煤矿开采中最为主要的突水类型。从矿坑充水水源、充水通道和充水强度角度对首期开采地段进行了矿床充水因素的研究。研究认为,矿井充水水源为煤层顶底板砂岩裂隙水、灰岩裂隙溶隙承压水及奥陶系岩溶承压水;充水通道主要是煤层开采后顶板形成的冒落带和导水裂隙带以及底板受其承压水的影响而产生的破坏带。建议在矿井设计前对首采地段进行三维地震勘探,进一步查明区内断层性质、规模和易发生矿井涌水的部位,为建井设计、矿坑底板的突水和防治提供依据。 相似文献
12.
针对煤层回采顶板垮落法产生的采煤固废堆放量大、长壁胶结充填开采中采充失衡等问题,内蒙古察哈素煤矿31采区采用连采连充巷式胶结充填采煤工艺,采用“隔三采一”的回采方式及“三强一弱”的充填模式。充填材料配比对充填成本与效果具有重要影响,针对原胶结充填材料中水泥消耗大、粉煤灰消纳少的问题,基于泰波理论确定矸石最佳粒径级配系数n为0.5,在此基础上,利用响应面法(RSM)优化材料配比。基于RSM-BBD (Box–Behnken Design)设计13组试验,建立充填体3、7及28 d单轴抗压强度与水泥质量分数X1、粉煤灰质量分数X2、固料质量分数X3及3因素交互作用(水泥与粉煤灰交互作用X1X2、水泥与固料质量分数交互作用X1X3、粉煤灰与固料质量分数交互作用X2X3)的回归模型,模型P值均小于10-4,模型可靠性强。试验结果表明：不仅单一因素对强度影响显著,且各因素的交互作用也对强度有一定的影响。强度随X1与X 相似文献
13.
In the mining environments of the Iberian Pyrite Belt (IPB), the oxidation of sulphide wastes generates acid drainage with high concentrations of SO4, metals and metalloids (Acid Mine Drainage, AMD). These acid and extremely contaminated discharges are drained by the fluvial courses of the Huelva province (SW Spain) which deliver high concentrations of potentially toxic elements into the Gulf of Cádiz. In this work, the oxidation process of mine tailings in the IPB, the generation of AMD and the potential use of coal combustion fly ash as a possible alkaline treatment for neutralization of and metal removal from AMD, was studied in non-saturated column experiments. The laboratory column tests were conducted on a mine residue (71.6 wt% pyrite) with artificial rainfall or irrigation. A non-saturated column filled solely with the pyrite residue leached solutions with an acid pH (approx. 2) and high concentrations of SO4 and metals. These leachates have the same composition as typical AMD, and the oxidation process can be compared with the natural oxidation of mine tailings in the IPB. However, the application of fly ash to the same amount of mine residue in another two non-saturated columns significantly increased the pH and decreased the SO4 and metal concentrations in the leaching solutions. The improvement in the quality of leachates by fly ash addition in the laboratory was so effective that the leachate reached the pre-potability requirements of water for human consumption under EU regulations. The extrapolation of these experiments to the field is a promising solution for the decontamination of the fluvial courses of the IPB, and therefore, the decrease of pollutant loads discharging to the Gulf of Cádiz. 相似文献
14.
地下采煤通常会引起地表严重开裂,甚至发生滑坡、崩塌等地质灾害,采动坡体的稳定性研究一直是工程实际关心的问题。本文以贵州省都匀市煤洞坡采动坡体为例,在斜坡破坏机制分析基础上,采用组合楔形块体原理构建了采动坡体稳定性系数计算方程,并从实验、经验类比、采空率等方面对采动坡体的强度指标进行了综合取值,计算了采动坡体在天然、饱水及裂隙水作用下的安全系数。结果表明:煤洞坡山体是处于稳定状态的,这与坡体上的裂缝位移监测成果是相符的。但在长时间降雨或暴雨情况下,煤洞坡山体稳定性就会逐渐变差,甚至发生滑动; 坡体稳定性安全系数随内摩擦角的降低而降低,随裂隙水充水高度的增加而降低; 一旦后缘块体挤压前缘块体时,就会存在一个安全系数急剧降低的阀值。从裂缝水柱高度与降雨渗入裂缝的雨水量关系出发,建立了裂缝水柱高与降雨量之间关系式。经计算当降雨量(短时间内)超过192mm,斜坡就会失稳。 相似文献
15.
煤岩层对比工作贯穿于整个煤炭地质勘查与矿井生产阶段的全过程,针对近距离、多煤层且构造复杂的矿井生产阶段煤岩层对比困难的问题,以贵州盘县煤田火烧铺煤矿为研究对象,通过对地质勘查资料的分析,结合地面瓦斯勘查钻孔、井下地质调查、瓦斯参数测试工程从地质勘查阶段已经建立的煤岩层对比标志层中提取适应于矿井生产阶段的标志层;结合矿井生产过程中井筒、巷道、工作面及其两巷道、切眼等井巷工程生产揭露资料的宏/微观煤岩、煤质化验、煤层顶底板岩石力学、煤层的光学特征等资料,提炼矿井生产过程中基于开采技术条件的煤岩层对比的标志;综合地质勘查与矿井生产阶段重新构建矿井生产阶段煤岩层综合对比标准体系。研究表明:地质勘查阶段构建的煤岩层对比标志层在矿井生产阶段岩性组合、地球物理测井曲线,高位标志性岩层以及古生物化石层基本上失去了指导意义,而煤层结构、伪顶或低位直接顶板古生物化石层、岩性标志层仍具有指导意义,可以指导实践生产;矿井生产阶段大量的地层倾角数据、宏/微观煤岩组分特征、煤层夹矸岩性,尤其是可见光、热红外等光学特征,煤层瓦斯含量、压力参数,煤层顶底板岩石力学参数等是煤岩层对比的良好标志层;构建的煤岩层综合对比技术体系可以有效地指导煤矿巷道高效掘进、工作面快速回采并识别断层发育特征。研究成果不仅可以指导煤矿井下生产工作而且可以为构造复杂区的煤矿井下工作面智能化开采提供基础地质资料,为煤矿安全、高效、智能化开采提供地质保障技术。 相似文献
16.
17.
Solid backfill mining has apparent technical advantages in extracting coal resource under sensitive surface structures such as buildings and roads; meanwhile, as an effective method of disposing mining wastes, it works well in solving some environmental problems caused by mining activities. In addition, the controlling effect of solid backfill mining is directly related to the compaction characteristic of backfilling materials. The present study aims to modify the backfilling materials by assessing the effect of binders (cement, fly ash, and lime) on the compaction characteristic of granulated gangue backfilling materials. The compaction test was performed with rock mechanic test system equipped with a self-made circular cylinder apparatus. From the results obtained, cement is not the suitable binder for modifying the gangues backfilling materials, while fly ash or lime, when the dosage is up to 20 wt%, is beneficial to the compaction characteristic of backfilling materials. The relationship between strain behavior and micro-structure of backfilling materials was investigated by SEM and the effect of fly ash or lime on the strain behavior of backfilling materials could be associated with its cementation and gap-filling effect. 相似文献
18.
粉煤灰作为路堤填料的动力特性试验研究 总被引：11，自引：2，他引：9
粉煤灰用作路堤填料时,其动力特性是大家较为关注的问题。在扬州电厂粉煤灰动三轴试验的基础上,对影响粉煤灰动强度的若干影响因素进行了分析,对粉煤灰路堤在饱水条件下的抗液化性能进行了探讨。研究结果表明：振次、初始静应力水平、含水量等对粉煤灰的动强度都有显著的影响;粉煤灰路堤在饱水条件下的抗液化性能则与地震动峰值加速度、初始静应力水平等有密切关系。 相似文献
19.
Deka Abhijit Gupt Chandra B. Sekharan Sreedeep 《Geotechnical and Geological Engineering》2021,39(5):3889-3901
Sand-Bentonite mixtures are used in landfill liner application in appropriate proportions. However, effort has been made to replace the sand by some waste materials like fly ash without compromising the required properties for liner construction. In recent years, many studies were carried out to determine the suitability of different fly ashes for using with bentonite based on different geotechnical parameters. On the other hand, limited studies were found in determining the unsaturated characteristics i.e. Water Retention Characteristics Curve (WRCC) of fly ash-bentonite mixes. The determination of WRCC in case of bentonite is very complexed compared to other types of clay soil due to its high shrinkage and swelling characteristics upon drying and wetting. In this study, a combined shrinkage and suction measurement was carried out in fly ash-bentonite mixes to accurately represent the WRCC under drying condition only. The shrinkage measurement was carried out using balloon method and suction measurement was carried out with the help of WP4 dew point potentiameter device. Both the shrinkage and suction results were finally used to obtain the WRCC for the different mixes. Further, the study on the variability of WRCCs for the different mixes indicates that WRCC can be represented by a generalized plot with 20% variation.
相似文献20.
金川二矿区多中段开采曾引起了许多研究焦点,尤其是多中段开采导致的围岩变形和灾变问题最为突出。本文以多年地表监测的结果验证了多中段开采至结束期间并没有造成地表岩体变形的异常或突变。研究认为开挖的地质力学模型内所赋存的岩体应变能是一定值,开挖活动是能量耗散和转移的动态过程。因此,在构造应力影响的开挖力学模型中,不能采用外力边界条件而应采用位移边界条件。小步距开采-充填有利于避免大幅度的岩移发生,矿岩才保持了相对缓慢的低能量释放率的松动、破裂,是矿岩未发生大的灾变失稳的关键因素。最后指出,地表岩移速率大小主要与地下开采速度和采充比有关,在金川二矿地下开采速度和采充比基本保持不变的情况下,地表岩体移动、变形速率不会发生突变现象。 相似文献