Water quality impacts from waste rock at a Carlin-type gold mine,Elko County,Nevada

Changes in water quality in the North Fork of the Humboldt River, Nevada are caused by weathering of waste rock from an inactive Carlin-type gold mine. Review of historical water-quality data, monthly water sampling, and continuous monitoring of water-quality parameters were used to quantify these impacts. River water pH, which ranged between 7 and 8, did not show statistically significant variation from upstream of the mine to downstream. Several constituents, most notably sulfate, calcium, and magnesium, showed statistically significant increases in dissolved-ion concentrations. These data, along with geochemical modeling, suggest that oxidation of sulfide minerals and in situ acid neutralization by carbonate host rocks are occurring. Large increases in dissolved-ion concentrations were observed twice a year—during spring snow melt and the onset of the winter precipitation season. These spikes are likely caused by flushing of pore waters that have reacted with waste rock during months-long periods when shallow groundwater recharge is not occurring.     

Treatment of a potential soil capping for open-cut mines (Part 1): Influence of prior management on responses to a phyto-organic amendment

Extraction of mineral ores, and some projects in engineering geology commonly entail removal of large tracts of valuable topsoil called overburden. A potential mine overburden capping material from an Alfisol with different management histories was treated to assess its physical responses to phyto-organic amendments during storage. Although there were small inceases in hydraulic conductivity, phyto-organic amendments did not greatly improve the physical properties of the Alfisol which had previously been cultivated for several years, as changes in stability and water retention were generally not statistically significant. However, very substantial increases of stability (about 25%) and water retention about 40%) occurred in the same soil which had previously been under a long-term permanent pasture regime. As topsoils can quickly deteriorate when removed and stored, prior soil management should be taken into account where topsoil is to be removed and replaced as a capping after operations such as ore extraction.     

矿山土地破坏程度评价--以攀枝花市花山煤矿为例

土地破坏程度评价对指导矿山土地复垦和生态重建具有指导意义。应用模糊数学综合评价方法对花山煤矿土地破坏程度进行评价。介绍了模糊数学评价的原理、方法和评价程序,确定了各种破坏类型土地的破坏程度评价因子、因子权重及评价等级。根据土地破坏类型,花山煤矿破坏土地可划分为两大类六单元。各单元分别建立起土地破坏程度评价的模糊评价矩阵,最终评价得出花山煤矿土地破坏程度综合评价结果为:江边排矸场为重度破坏,C区排矸场为中度破坏,地表塌陷区、水泥厂排矸场、金塘湾排矸场、沿江沟排矸场为轻度破坏。     

河南平煤四矿煤矸石山自燃爆炸成因及防治分析

2005年5月15日、16日,平煤集团四矿矸石山先后发生两次自燃爆炸灾害,8人遇难,122人受伤,造成生命财产的重大损失。论文首先介绍了平煤集团四矿煤矸石的物质组成,分析其致灾原因:高含硫煤矸石的存在是引起煤矸石山自燃的决定因素;煤矸石的堆积方式以及有效的粒径组成在一定程度上决定了煤矸石的透气性,是引起煤矸石山自燃的促进条件;突发降雨是本次灾害的主要导火索。在燃料含量一定,清除比较困难,燃烧已开始并还在不断堆积矸石的情况下,降温和隔氧显得尤为重要。针对本矸石山的实际情况,提出了采用注浆法为主,辅以高温区域表面喷射浆液、挖掘沟槽、表面覆盖等灭火方法;对今后避免矸石山自燃进行了展望。     

模糊神经网络在矿震预测中的应用

矿震同天然地震一样会给矿山生产及人身安全等带来重大灾难。也是目前尚不能准确预测的矿山灾害现象之一。根据现有的研究成果可知，矿震是一个多输入、多干扰、单输出的复杂系统。由于干扰项的存在，使利用建模、神经网络等手段对系统进行预测时会导致很大误差。模糊神经网络系统在建立对象输入、输出关系时与传统数学方法不同。即可以建立在无模型基础上，并利用其较强的学习训练特性，自动获取对象的输入、输出关系表达；可以将专家的评价语言作为系统的干扰项引入。这在一定程度上缓解了人为因素对预测结果的影响，且平滑了观测数据的随机性。文章利用改进的模糊神经网络及抚顺老虎台矿的矿震资料，对矿震最大震级的预测方法进行了探索。‘初步探讨了改进的模糊神经网络在矿震预测中的应用。得出在运用模糊神经网络进行预测时，为减小预测误差，应综合多种因素并提高专家评判语言的精确度的结论。指出在建立矿震系统预测模型时，利用干扰项将人为因素引入系统是必需的。通过实际应用证明其可行性。     

Groundwater Inflow Controls Acidity Fluxes in an Iron Rich and Acidic Lake

To ascertain the influence of hydrological boundary conditions on acidity fluxes in lakes influenced by acid mine drainage, acidity budgets were developed for two sediments in areas of differential groundwater inflow (approx. 1 L m^?2 d^?1 and 10 L m^?2 d^?1). In both sediments iron was deposited as schwertmannite leading to iron(III) enriched sediments (3.9…6.2 mmol g^?1, referred to dry weight). Compared to the surface water, the inflowing groundwater had higher pH (4.5 vs. 3), ferrous iron (6…20 mmol L^?1 vs. 0.8…2.0 mmol L^?1), and sulfate (5…60 mmol L^?1 vs. 8…13 mmol L^?1) concentrations. The inflow changed the sediment pore water chemistry and triggered a further increase in pH to above 5.5. In both sediments acidity generation in the surface water (10…30 mol m^?2 a^?1) strongly prevailed over acidity consumption in the sediments (> ?0.6 mol m^?2 a^?1). With advective groundwater inflow, however, more acidity was consumed due to TRIS formation (?0.12 mol m^?2 a^?1 vs. ?0.017 mol m^?2 a^?1), iron carbonate burial (upper estimate: ?0.14 mol m^?2 a^?1 vs. ?0.022 mol m^?2 a^?1), and unspecific ferrous iron retention (?0.39 mol m^?2 a^?1 vs. ?0.08 mol m^?2 a^?1). Also, less acidity was generated due to schwertmannite transformation (?2.4 mol m^?2 a^?1 vs. ?0.11 mol m^?2 a^?1). The acidity balance of internal processes in the sediment with groundwater inflow was negative, whereas it was positive in the other sediment. The study demonstrates that in acidic and iron rich lakes the hydrological boundary conditions strongly affect geochemical processes as subsumed in acidity fluxes.     

关于阜新矿震活动的初步研究

本文依据地震学分析预报方法，对1990～2004年阜新矿震资料进行了统计分析。结果认为，矿震活动主要由煤矿开采引起，同时与区域构造也有一定的关联。适当地选择地震活动性参数来描述矿震的活动特征，对监测区域地震活动有一定帮助。     

滇东磷块岩及工业磷矿床成因

滇东地区存在两套含磷岩系，十个磷块岩层位，可归纳为三类成因、四个工业磷矿层，进一步划分为四个沉积阶段、四个工业磷矿床成矿区。其中，研究较深的中谊村段磷矿，是由成矿地质背景和环境因素控制的八种主要成矿作用和四个成矿富集阶段多重反复叠加形成的生物沉积磷块岩矿床。     

矿山地震能量极值分布的研究及其应用

将冈贝尔I型极值分布应用于矿山地震能量分布规律的研究，结合前人的研究成果，推导了能量极值分布函数的表达式，给出了其参数确定方法。在简要介绍老虎台矿矿山地震活动的构造及物理背景后，结合老虎台矿矿震实际，介绍了如何将能量极值分布用于强矿山地震事件的预测。结果表明，用这种方法预测的月最大矿震能量的概率分布与实际记录的矿震月最大能量分布一致。最后应用该法预测了老虎台矿未来几年内强矿震事件发生的概率。     

富家坞矿区露采边坡垮塌的原因分析及治理措施

江西富家坞矿区露采基建剥离工程于1991年底开始施工，6年以后，于1997年11月发生露采边坡大垮塌，导致即将竣工投产的“坑改露”工程彻底失败。本文研究分析了造成该矿区露采边坡垮塌的主要原因，针对露采边坡垮塌后的现状，提出了今后恢复生产的治理措施。对以后类似工程的设计及生产矿山有一定的参考价值。