Mining Science and Technology (China)最新文献

{"title":"Modeling seismic wave propagation in a coal-bearing porous medium by a staggered-grid finite difference method","authors":"Zou Guangui,&nbsp;Peng Suping,&nbsp;Yin Caiyun,&nbsp;Deng Xiaojuan,&nbsp;Chen Fengying,&nbsp;Xu Yanyong","doi":"10.1016/j.mstc.2011.03.002","DOIUrl":"10.1016/j.mstc.2011.03.002","url":null,"abstract":"<div><p>A staggered-grid finite difference method is used to model seismic wave records in a coal bearing, porous medium. The variables analyzed include the order of the difference calculations, the use of a perfect match layer to provide absorbing boundary conditions, the source location, the stability conditions, and dispersion in the medium. The results show that the location of the first derivative of the dynamic variable with respect to space is coincident with the location of the first derivative of the kinematic variable with respect to time. Outgoing waves are effectively absorbed and reflection at the boundary is very weak when more than 20 perfect match layer cells are used. Biot theory considers the liquid phase to be homogeneous so the ratio of liquid to solid exposure of the seismic source depends upon the medium porosity. Numerical dispersion and generation of false frequencies is reduced by increasing the accuracy of the difference calculations and by reducing the grid size and time step. Temporal second order accuracy, a tenth order spatial accuracy, and a wavelength over more than ten grid points gave acceptable numerical results. Larger grid step sizes in the lateral direction and smaller grid sizes in the vertical direction allow control of dispersion when the medium is a low speed body. This provides a useful way to simulate seismic waves in a porous coal bearing medium.</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 5","pages":"Pages 727-731"},"PeriodicalIF":0.0,"publicationDate":"2011-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.03.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81224842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An experimental study of pyrite bio-leaching as a way to control spontaneous combustion","authors":"Yin Shenghua ,&nbsp;Wu Aixiang ,&nbsp;Liu Jinzhi ,&nbsp;Huang Mingqing ,&nbsp;Wang Hongjiang","doi":"10.1016/j.mstc.2011.06.009","DOIUrl":"10.1016/j.mstc.2011.06.009","url":null,"abstract":"<div><p>Bio-leaching of pyrite by native strains of acidophilic bacteria was examined by laboratory scale tests. Three groups of batch trials in agitated flasks and three continuous column leaching tests were performed. The leaching ability and efficiency of native bacteria was greatly improved by adaptation of the bacteria to the test conditions. These cultivated bacteria were then used for the leaching process. The changes in solution pH, Eh, Fe²⁺ concentration, and sulfate ion concentration were monitored throughout the tests. A portion of the pyritic sulfur is transformed into soluble sulfate ion. The desulfurization ratio of 42.6% was obtained in a flask shaking test and a ratio of 39.4% was obtained during column leaching. A weight gain test was performed on leached and unleached samples by exposing the samples to humid air for several days. A smaller weight gain of the bio-leached samples indicates that removing sulfur from the sulphide ore helps reduce its oxidation rate and the potential for spontaneous combustion.</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 4","pages":"Pages 513-517"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.06.009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78936496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rare earth element geochemistry of groundwater from a deep seated sandstone aquifer, northern Anhui province, China","authors":"Gui Herong ,&nbsp;Sun Linhua ,&nbsp;Chen Luwang ,&nbsp;Chen Song","doi":"10.1016/j.mstc.2011.06.003","DOIUrl":"10.1016/j.mstc.2011.06.003","url":null,"abstract":"<div><p>Deep coal mines in northern Anhui province, China, provide opportunities for tracing the distribution and fractionation of rare earth elements (REEs) in deep seated environments. Major ions, as well as REE concentrations were measured in groundwater from a sandstone aquifer located between –400 and –280<!--> <!-->m. Our results indicate that this groundwater consists of Cl·HCO₃-Na or Cl·CO₃-Na water types with warm temperature (30.1–31.4<!--> <!-->°C), circumneutral pH (7.27–8.61) and high levels of total dissolved solids (TDS<!--> <!-->=<!--> <!-->1306–2165<!--> <!-->mg/L). Concentrations of REEs in groundwater are high as expressed by their Nd concentrations (0.0086–0.018<!--> <!-->μg/L). Except for weak heavy REEs (HREE) enrichment relative to light REEs (LREE), the similarity of REE distribution patterns between groundwater and aquifer rock indicate that enrichment of REEs is considered to be controlled by aquifer rock, as well as by their minerals, whereas the fractionation of REEs is controlled by HREE enriched minerals and, to a lesser extent, by inorganic REE complexes. Ce anomalies normalized to Post Archean Average Shale (PAAS) and aquifer rock are weak, which probably reflect the contribution of reduced conditions in combination with pH, rather than a signature of aquifer rock.</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 4","pages":"Pages 477-482"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.06.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79783143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coal mining GPS subsidence monitoring technology and its application","authors":"Wang Jian ,&nbsp;Peng Xiangguo ,&nbsp;Xu Chang hui","doi":"10.1016/j.mstc.2011.06.001","DOIUrl":"10.1016/j.mstc.2011.06.001","url":null,"abstract":"<div><p>We proved theoretically that geodetic height, measured with Global Positioning System (GPS), can be applied directly to monitor coal mine subsidence. Based on a Support Vector Machine (SVM) model, we built a regional geoid model with a Gaussian Radial Basis Function (RBF) and the technical scheme for GPS coal mine subsidence monitoring is presented to provide subsidence information for updating the regional Digital Elevation Model (DEM). The theory proposed was applied to monitor mining subsidence in an Inner Mongolia coal mine in China. The scheme established an accurate GPS reference network and a comprehensive leveling conjunction provided the normal height of all GPS control points. According to the case study, the SVM model to establish geoid-model is better than a polynomial fit or a Genetic Algorithm based Back Propagation (GA-BP) neural network. GPS-RTK measurements of coal mine subsidence information can be quickly acquired for updating the DEM.</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 4","pages":"Pages 463-467"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.06.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73527346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution characteristic and geological significance of rare earth elements in Lopingian mudstone of Permian, Panxian county, Guizhou province","authors":"Shao Yubao ,&nbsp;Guo Yinghai ,&nbsp;Qin Yong ,&nbsp;Shen Yulin ,&nbsp;Tian Li","doi":"10.1016/j.mstc.2011.06.002","DOIUrl":"10.1016/j.mstc.2011.06.002","url":null,"abstract":"<div><p>In order to discuss the geochemical characteristic of REEs (rare earth elements) and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian (Late Permian) mudstone samples in Panxian county, carrying out ICP-MS and XRD analysis. The results show that the amount of REEs (185.56–729.46<!--> <!-->×<!--> <!-->10⁻⁶) is high. The ratios of <em>w</em>(LREE)/<em>w</em>(HREE) (6.84–13.86) and <em>w</em>(La)<em>_N</em>/<em>w</em>(Yb)<em>_N</em> (1.01–3.02) show clear differentiation of LREEs and HREEs. ΣREE has a significantly or critically positive correlation with lithophile elements Th, Nb, Ta, Ti, Ga, Sc, Cs, Zr, Hf, Sr, Be and chalcophile element Zn, a critically negative correlation with siderophile element Fe and a slightly positive correlation with illite, illite smectite mixed layers and siderite. REEs originate mainly from terrigenous minerals, in an inorganic phase. Source rocks of our samples consist of Emeishan basalt and a small part of sedimentary rocks, as suggested by the distribution patterns of REEs and <em>w</em>(∑REE)–<em>w</em>(La)/<em>w</em>(Yb) diagram. Moreover, abnormal surfaces near the sequence boundaries (SB2, SB3, SB4) are related with the boundaries, identified by geochemical characteristics of the REEs, such as ∑REE, <em>w</em>(LREE)/<em>w</em>(HREE), Eu/Eu^∗ and Ce_anom.</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 4","pages":"Pages 469-476"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.06.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81386259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study and application of monitoring plane displacement of a similarity model based on time-series images","authors":"Xu Jiankun ,&nbsp;Wang Enyuan ,&nbsp;Li Zhonghui ,&nbsp;Wang Chao","doi":"10.1016/j.mstc.2011.06.007","DOIUrl":"10.1016/j.mstc.2011.06.007","url":null,"abstract":"<div><p>In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests, such as inadequate real-time monitoring and more manual intervention, an effective monitoring method was proposed in this study, and the major steps of the monitoring method include: firstly, time-series images of the similarity model in the test were obtained by a camera, and secondly, measuring points marked as artificial targets were automatically tracked and recognized from time-series images. Finally, the real-time plane displacement field was calculated by the fixed magnification between objects and images under the specific conditions. And then the application device of the method was designed and tested. At the same time, a sub-pixel location method and a distortion error model were used to improve the measuring accuracy. The results indicate that this method may record the entire test, especially the detailed non-uniform deformation and sudden deformation. Compared with traditional methods this method has a number of advantages, such as greater measurement accuracy and reliability, less manual intervention, higher automation, strong practical properties, much more measurement information and so on.</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 4","pages":"Pages 501-505"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.06.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73273732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Ni(NO3)2 in the preparation of a magnetic coal-based activated carbon","authors":"Zhang Jun,&nbsp;Xie Qiang,&nbsp;Liu Juan,&nbsp;Yang Mingshun,&nbsp;Yao Xing","doi":"10.1016/j.mstc.2011.01.003","DOIUrl":"10.1016/j.mstc.2011.01.003","url":null,"abstract":"<div><p>The role of Ni(NO₃)₂ in the preparation of a magnetic activated carbon is reported in this paper. Magnetic coal-based activated carbons (MCAC) were prepared from Taixi anthracite with low ash content in the presence of Ni(NO₃)₂. The MCAC materials were characterized by a vibrating sample magnetometer (VSM), X-ray diffraction (XRD), a scanning electric microscope (SEM), and by N₂ adsorption. The cylindrical precursors and derived char were also subjected to thermogravimetric analysis to compare their behavior of weight losses during carbonization. The results show that MCAC has a larger surface area (1074<!--> <!-->m²/g) and a higher pore volume (0.5792<!--> <!-->cm³/g) with enhanced mesopore ratio (by about 10%). It also has a high saturation magnetization (1.6749<!--> <!-->emu/g) and low coercivity (43.26 Oe), which allows the material to be magnetically separated. The MCAC is easily magnetized because the nickel salt is converted into Ni during carbonization and activation. Metallic Ni has a strong magnetism on account of electrostatic interaction. Added Ni(NO₃)₂ catalyzes the carbonization and activation process by accelerating burn off of the carbon, which contributes to the development of mesopores and macropores in the activated carbon.</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 4","pages":"Pages 599-603"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.01.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73212463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical characteristics of illite clay rocks from the Shihezi Formation in the Hanxing mining area and its sedimentary environment","authors":"Xu Bohui ,&nbsp;Ding Shuli ,&nbsp;Wang Yu ,&nbsp;Liu Qinfu","doi":"10.1016/j.mstc.2011.06.006","DOIUrl":"10.1016/j.mstc.2011.06.006","url":null,"abstract":"<div><p>We studied the geochemical characteristics of illite clay rocks and their importance from the Shihezi Formation of Late Permian in the Hanxing mining area by means of ICP-MS and sequential X-ray fluorescence spectrometry. The results show that the amount of SiO₂ is between 53.37% and 61.58% (by weight) and that of Al₂O₃ 22.40% and 31.31% (by weight). The ratio of SiO₂/Al₂O₃ lies between 1.71 and 2.75. The amount of K₂O ranges from 1.11% to 2.56% (by weight). The amounts of Fe and Ti are higher than the theoretical values in illite clay rock would indicate. The amounts of some trace elements, such as Ga, As, Ba, Cu, Th and U are higher than their Clark values, while that of another 23 trace elements are found to be close to their Clark values. The amounts of REE range from 22.59 to 570.54<!--> <!-->μg/g, with an average of 163.23<!--> <!-->μg/g. The ratios of LREE/HREE range from 5.41 to 21.82, with an average of 8.87. These characteristics show that LREE are much richer in content than HREE. The REE distribution patterns of our samples were characterized by clearly negative Ce and Eu anomalies. We analyzed the sedimentary environment of the Hanxing mining area in Late Permian by the characteristic element ratio method. The ratios of Mn/Fe range from 0 to 0.0168, which are lower than those in a marine sedimentary environment. The ratios of Sr/Ba (0.20–0.41) are less than 1. These are all indications that the sediments of the Hanxing mining area in Late Permian form largely a continental sedimentary environment. The sedimentary water is freshwater, a conclusion reached on the basis of the ratios of Th/U (2.66–6.62) and of Ca/(Ca<!--> <!-->+<!--> <!-->Fe) (0.01–0.059); the average ratio of Fe²⁺/Fe³⁺ is 4.8. The sedimentary water condition is weakly acidic and weakly oxidative-weakly reductive, a conclusion reached on the basis of ratios of Fe²⁺/Fe³⁺ (4.8) and of Ce_anom (−0.08).</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 4","pages":"Pages 495-500"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.06.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79877458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A method for detecting miners based on helmets detection in underground coal mine videos","authors":"Cai Limei,&nbsp;Qian Jiansheng","doi":"10.1016/j.mstc.2011.06.016","DOIUrl":"10.1016/j.mstc.2011.06.016","url":null,"abstract":"<div><p>In order to monitor dangerous areas in coal mines automatically, we propose to detect helmets from underground coal mine videos for detecting miners. This method can overcome the impact of similarity between the targets and their background. We constructed standard images of helmets, extracted four directional features, modeled the distribution of these features using a Gaussian function and separated local images of frames into helmet and non-helmet classes. Out experimental results show that this method can detect helmets effectively. The detection rate was 83.7%.</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 4","pages":"Pages 553-556"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.06.016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85884973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Suitable layout of gate roads related to slice mining in an ultra-thick unstable coal seam","authors":"Fan Gangwei ,&nbsp;Zhang Dongsheng ,&nbsp;Zhou Lei","doi":"10.1016/j.mstc.2011.06.017","DOIUrl":"10.1016/j.mstc.2011.06.017","url":null,"abstract":"<div><p>We determined a suitable gate road layout in slice mining in an ultra-thick unstable coal seam, using theoretical analysis and numerical calculations. Based on plasticity theory in terms of limiting equilibrium, the width of chain pillar in the upper slice was calculated to be 18<!--> <!-->m. The stress distribution in the chain pillar after the upper slice was mined out was described with numerical simulation. The extent of the effect of stress on the upper chain pillar on the lower solid coal was obtained on the basis of an elastic solution of a distributed force loaded on a half-plane. Three layout designs for lower gate roads were proposed and a stability factor was introduced to analyze the stability of the lower pillar with numerical calculation. Gate road translation was determined as the most suitable layout method, which maximizes the extraction rate on the basis of the pillar stability.</p></div>","PeriodicalId":100930,"journal":{"name":"Mining Science and Technology (China)","volume":"21 4","pages":"Pages 563-566"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mstc.2011.06.017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76618990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}