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Characteristics of heavy metals in soil of lead-zinc mining areas and changes of antioxidant enzyme systems in maize leaf under Pb stress

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International Journal of Coal Science & Technology 2022年第6期9卷 178-185页

作者： Ranran Jiang Ping Liu Yongjian He Yanru Cao Xiuli Hou College of Agronomy and Life Sciences Kunming University650214 KunmingChina Yunnan Phosphate Chemical group limited company KunmingChina

Pb,Cu,Cd,Zn content of soil in mining areas and abandoned land,flats of the Pijiang River and farmlands were inves-tigated.On this basis of soil heavy metal pollution,the changes of antioxidant enzyme system in maize(Qiandan 88)under different Pb concentrations(0,20,40,60,80,100,150,200,500,1000,2000,3000 mg/L)stress were studied.The results show that the content of Pb,Cu,Cd,and Zn in soil is the highest in mining areas and abandoned land,followed by flats of the Pijiang River>farmlands,and that the variation range of Pb,Cu,Cd in mining areas and abandoned land are 106.40-2564.72,14.83-490.88,22.57-712.77 mg/kg,respectively,which are higher than that of the other land use types.When maize is under stress of 20-500 mg/L Pb concentration,T-SOD activity of maize leaves increase with the increase of Pb concentration and the highest value is 50.21 U/mg prot,but under Pb concentration>1000 mg/L stress,T-SOD activity of maize leaves decrease gradually.The activity of POD decreases with the increases of Pb concentra-tion,and the lowest POD activity of leaves in maize with the value of 93.24 U/mg prot is appeared in Pb 1000 mg/L concentration treatment group.MDA content in leaves of maize increases with the increase of the Pb concentration and the highest value is 101.98 nmol/mg prot,then the content of MDA decreases gradually when the Pb concentration is more than 500 mg/L,which indicates that the membrane lipid peroxidation of maize leaves under high concentration of Pb stress is serious and leads to the cell damage.

关键词： Heavy metal pollution Pb stress Maize Antioxidant enzyme system

Assessment of landslide susceptibility using DBSCAN-AHD and LD-EV methods

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Journal of Mountain Science 2022年第1期19卷 184-197页

作者： MAO Yi-min MWAKAPESA Deborah S LI Yi-can XU Kai-bin NANEHKARAN Yaser A ZHANG Mao-sheng School of Information Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Key Laboratory for Geo-hazards in Loess Area Xi’an 710054China Northwest Nonferrous Geological mining group limited company Xi’an 710054China

Landslide susceptibility assessment plays a vital role in understanding landslide information in advance and taking preventive as well as control measures. The need to initially specify the number of clusters, difficulty in handling noise and quantifying rainfall data, limits the application of traditional clustering models in landslide susceptibility assessment which then lowers their performance accuracy. Thus, to overcome these limitations, this study proposed an improved clustering algorithm titled the DBSCAN-AHD algorithm, which combines the traditional DBSCAN(Density Based Spatial Clustering of Application with Noise) algorithm and an Adaptive Hausdorff Distance(AHD) for landslide susceptibility modeling. Firstly, AHD was introduced to the traditional DBSCAN to quantify rainfall. Then,the DBSCAN-AHD grouped the mapping units with similar topology and geology characteristics into subclasses without specifying the number of clusters in advance for its ability to handle noise in the data.Furthermore, the LD-EV(landslide density or eigenvalues) approach was introduced to obtain the susceptibility levels using K-means algorithm. Finally,to verify the model’s performance, statistical indices and the area under the curve(AUC) were applied and compared to the traditional DBSCAN, KPSO, Kmeans and Hierarchical Clustering algorithms,whereby, the proposed model outperformed the others. Also, the obtained susceptibility map can provide references in taking relevant preventive and control measures.

关键词： Landslide susceptibility DBSCAN Machine learning algorithm Uncertain data Clustering algorithm

A novel robust AE/MS source location method using optimized M-estimate consensus sample

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International Journal of mining Science and Technology 2022年第4期32卷 779-791页

作者： Yichao Rui Zilong Zhou Xin Cai Riyan Lan Congcong Zhao School of Resources and Safety Engineering Central South UniversityChangsha 410083China Guangxi Xinfazhan Communication group company limited Nanning 530029China

Due to the complexity of the real engineering environment, the arrival measurement inevitably contains outliers and leads to serious location errors. In order to eliminate the influence of the outliers effectively,this paper proposes a novel robust AE/MS source localization method using optimized M-estimate consensus sample. First, a sample subset is selected from the entire arrival set to obtain fitting model and its parameters. Second, consensus set is determined by checking the arrivals with the fitting model instantiated by the estimated model parameters. Third, optimization process is performed to further optimize the consensus set. The above steps are iterated, and the final source coordinates are obtained by using all the elements in the optimal consensus set. The novel method is validated by a pencil-lead breaks experiment. The results indicate that the novel method has better location accuracy of less than 5 mm compared to existing methods, regardless of the presence or absence of outliers. With the increase of outlier scale and outlier ratio, the location result of the proposed method is always more stable and accurate than that of the existing methods. Mine blasting experiments further demonstrate that the new method holds good prospects for engineering applications.

关键词： Microseismic source Acoustic emission Source localization Outliers Consensus sample

Feasibility analysis of gob-side entry retaining on a working face in a steep coal seam

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International Journal of mining Science and Technology 2014年第4期24卷 499-503页

作者： Deng Yuehua Wang Shouquan Sichuan Coal Industry group limited Liability company

Based on the decline in exploitation of coal resources, steep coal seam mining and mining face tensions continue to explore the feasibility analysis of steeply inclined faces in the gob. One of the key factors in utilizing the technology of gob-side entry retaining in steep coal seams is to safely and effectively prevent caving rock blocks from rushing into the gob-side entry by sliding downwards along levels. Using theoretical analysis and field methods, we numerically simulated the mining process on a fully-mechanized face in a steep coal seam. The stress and deformation process of roof strata has been analyzed, and the difficulty of utilizing the technology is considered and combined with practice in a steep working face in Lvshuidong mine. The feasibility of utilizing the technology of gob-side entry retaining in a steep coal seam has been recognised. We propose that roadways along the left lane offshoot body use a speciallymade reinforced steel dense net to build a dense rock face at the lower head. The results show that the lane offshoot branch creates effective roof control, safe conditions for roadway construction workers, and practical application of steeply inclined gob.

关键词：急倾斜煤层开采综采工作面采空区侧煤炭资源开采过程数值模拟顶板岩层施工人员

Research on Technology of Pressure Pretreatment with Oxygen for Refractory Gold Ores

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Journal of Rare Earths 2007年第S2期25卷 270-272页

作者：刘升明孙体昌陈景河王淀佐 Mineral Processing Department of Civil and Environmental Engineering School University of Science and Technology of Beijing zijin mining company limited Chinese Academy of Engineering

An combined technology of pressure pretreatment with oxygen on refractory gold ores is pointed out and discussed on this paper, according to the experiments included the test in 1 kg grade batch pressure pretreatment with oxygen of the concentrate from the refractory gold ores of Dongbeizhai in Sichuan province, which is called the most refractory gold ores in China. It is shown that gold recovery reach 91.73% in the combined process which is described as follows: The flotation of the sulphide gold ores is under controlled conditions, producing the concentrate for pressure pretreatment with oxygen in acidic medium and the middling for the pressure pretreatment with oxygen in alkaline medium. The thickening and washing process substitute the pressure filtration process of the pulp after pressure pretreatment. The thick slimes of the two kinds of pressure pretreatment were mixed and then enter the CIL process for simplifying the flowsheet. The possible superabundance of acid of pressure pretreatment with oxygen in acidic medium was neutralized by the tailings of flotation and the cost of neutralization will be lower. The combined technology of pressure pretreatment with oxygen has the same advantages as the normal technology of pressure pretreatment and both is helpful for environment protection.

关键词： combined technology pressure pretreatment refractory gold ores

Metallogenic model and prognosis of the Shuiyindong super-large strata-bound Carlin-type gold deposit, southwestern Guizhou Province, China

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Chinese Journal Of Geochemistry 2010年第2期29卷 157-166页

作者： ZHANG Yu XIA Yong SU Wenchao TAO Yan ZHANG Xingchun LIU Jianzhong DENG Yiming State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Geological Party 105 Guizhou Provincial Bureau of Geology and Mineral Exploration ＆ Development Guiyang 550018 China zijin mining Stock company limited Guizhou Zhenfeng 562200 China

The Shuiyindong deposit is one of the largest (more than 100 tonnes of Au) and highest grade (more than 7×10-6-10×10-6), strata-bound Carlintype gold deposits in southwestern Guizhou Province, China. The deposit is controlled by both structure and favorable lithology. It is situated near the axis of the striking Huijiabao anticline and is hosted in bioclastic limestone of the Permian Longtan Formation. Gold mineralization occurred under low temperature with Th of 220℃± and is closely associated with decarbonation, silicification, sulfidation and dolomitization. The deposit has a characteristic elemental assemblage of Au-As-Hg-Tl. Studies of geochemistry and isotope compositions indicated that the ore-bearing materials and fluids of the gold deposit mainly originated from a plutonic source, and possess a mixing feature with the strata matter during transportation from mantle to crust. Fluid inclusions in vein quartz from the gold deposit are rich in volatile flux, indicating that metallogenic fluid is an overpres-sured one. The activity and geothermal state of the Earth's crust in the long period of time are favorable for the formation of overpressured fluids in a large area, and extensive structures would drive the fluids into ore-forming sys-tem and make gold deposits formed. The complexity of structural movement in the upper crust of southwestern Guizhou Province resulted in complicated gold mineralization. Through metallogenic prognosis and exploration, the proven reserves of the deposit increased by tens of tonnes of Au and the deposit has become a super-large strata-bound Carlin-type gold deposit.

关键词：矿床预测成矿模型卡林型超大型水银洞西南部贵州省层控

Potassium superoxide oxygen generation rate and carbon dioxide absorption rate in coal mine refuge chambers

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International Journal of mining Science and Technology 2015年第1期25卷 151-155页

作者： Gao Na Jin Longzhe Hu Haohao Huang Xiao Zhou Li Fan Linyu School of Civil and Environmental Engineering University of Science and Technology Beijing Zenith Steel group company limited

The effects of the molding pressure of a KO2 oxygen plate and the initial concentration of CO2 on the oxygen generation rate, the oxygen generation efficiency, and the carbon dioxide absorption rate were studied using a YES-300 hydraulic press to alter the pressure when forming the oxygen plate used in a coal mine refuge chamber. In addition, changes in the initial concentration of CO2 used in the closedbox model were made by adjusting the CO2 supply system, and a CD-7 multi-function parameter instrument was employed to monitor and record the changes of O2 and CO2concentration in the closed-box model. Results indicate that the oxygen generation rate of KO2 oxygen plates, the oxygen generation efficiency, and the carbon dioxide absorption rate decrease when there is an increase in the pressure used to mold the oxygen plates, but those values increase when the initial CO2 concentration increases. When the initial concentration of CO2 in the closed-box model is 3.5% and the forming pressure is 10 k N, the average oxygen generation rate of 15 g KO2 oxygen plate is 11.88 10 3L/min, the oxygen generation efficiency is 80.3%, and the average CO2 absorption rate is 11.0 10 3L/min. Compared with the condition where the initial CO2 concentration is 1.5%, the results show that average oxygen generation rate of oxygen plates increases by 88.9%, the oxygen generation efficiency increases by 88.9%, and the CO2 absorption rate increases by 100%.

关键词：二氧化碳吸收率煤矿 CO2浓度氧化钾氧气发生器生成效率初始浓度

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mining Science and Technology 2010年第2期20卷 188-192页

作者： WANG, Haifeng CHENG, Yuanping YUAN, Liang WANG, Liang national engineering research center for coal & gas control china university of mining & technologyxuzhou 221008china huainan mining industry (group) limited liability company postdoctoral science research workstationhuainan 232046china

For a study of the movement and deformation of coal-rock mass and low protected seams below a stope,as well as for fracture developments and rules of evolution of permeability,we designed a plane strain model test stand to carry out model tests of similar materials in order to improve the effect of gas drainage from low protected seams and to measure the movement and deformation of coal-rock mass using a method of non-contact close-range photogrammetry.Our results show that 1) using paraffin melting to take the place of coal seam mining can satisfy the mining conditions of a protective seam;2) coal-rock mass under goafs has an upward movement after the protective seam has been mined,causing floor heaving;3) low protected seams become swollen and deformed,providing a good pressure-relief effect and causing the coal-rock mass under both sides of coal pillars to become deformed by compression and 4) the evolution of permeability of low protected seams follows the way of initial values→a slight decrease→a great increase→stability→final decrease.Simultaneously,the coefficient of air permeability increased at a decreasing rate with an increase in interlayer spacing.

关键词： coal-rock mass below stope low protected seam plane strain similar model test

Failure mechanism of bolting support and high-strength bolt-grouting technology for deep and soft surrounding rock with high stress

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Journal of Central South University 2016年第2期23卷 440-448页

作者：李术才王洪涛王琦江贝王富奇郭念波刘文江任尧喜 Research Center of Geotechnical and Structural Engineering Shandong University School of Civil Engineering Shandong Jianzhu University Post-Doctoral Scientific Research Station Yankuang Group Company Limited Liangjia Coal Mine Longkou Coal-Electric Company Limited

In deep underground mining, the surrounding rocks are very soft with high stress. Their deformation and destruction are serious, and frequent failures occur on the bolt support. The failure mechanism of bolt support is proposed to solve these problems. A calculation theory is established on the bond strength of the interface between the anchoring agent and surrounding rocks. An analysis is made on the influence law of different mechanical parameters of surrounding rocks on the interfacial bond strength. Based on the research, a new high-strength bolt-grouting technology is developed and applied on site. Besides, some helpful engineering suggestions and measures are proposed. The research shows that the serious deformation and failure, and the lower bond strength are the major factors causing frequent failures of bolt support. So, the bolt could not give full play to its supporting potential. It is also shown that as the integrity, strength, interface dilatancy and stress of surrounding rocks are improved, the bond strength will increase. So, the anchoring force on surrounding rocks can be effectively improved by employing an anchoring agent with high sand content, mechanical anchoring means, or grouting reinforcement. The new technology has advantages in a high strength, imposing pre-tightening force, and giving full play to the bolt supporting potential. Hence, it can improve the control effect on surrounding rocks. All these could be helpful references for the design of bolt support in deep underground mines.

关键词：失效机理注浆技术高强锚杆岩锚支护界面粘结强度高应力锚杆支护设计高强螺栓