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Orthogonal Experiments on Direct Reduction of Carbon-bearing Pellets of Bayer Red Mud

Journal of Iron and Steel Research(International) 2015年第8期22卷 686-693页

作者： Dun-cheng FAN Wen NI Ai-yun YAN Jian-yue WANG Wei-hua CUI key laboratory of the ministry of education of China for High-efficient mining and safety of metal mines University of Science and Technology Beijing Beijing key laboratory on Resource-oriented Treatment of Industrial Pollutants University of Science and Technology Beijing School of Civil and Environmental Engineering University of Science and Technology Beijing School of Water Resources Environment China University of Geosciences

To recycle residual iron efficiently in Bayer red mud, three-factor three-level orthogonal experiments on carbon-bearing pellets of Bayer red mud were conducted on the basis of their characteristics. The influences of CaO dosage, temperature and roast- ing time on total iron content and iron recovery of reduced iron powder were studied. Results showed that these factors slightly influenced iron recovery, but significantly influenced total iron content. The principal factor influencing total iron content was CaO dosage, followed by temperature and roasting time. An increase in CaO dosage could decrease total iron content, whereas an increase in temperature and an extension of roasting time could improve total iron content. The reduced iron powder with total iron content of 88.4 l% and iron recovery rate of 97.97% can be obtained under the optimal conditions of temperature of 1 275 ℃, roasting time of 60 min and CaO dosage of 7.5%. The X-ray diffraction （XRD） and scanning electron microscopy （SEM） analyses of the reduced pellets showed that iron minerals in red mud were almost completely reduced to metallic iron. The principal factor influencing the total iron content of reduced iron powder was the grain size of metallic iron particles. An increase in CaO dosage hindered the growth of metallic iron particles, whereas an increase in temperature and an extension of roasting time could neutralise the effect of CaO dosage. Therefore, CaO dosage should be decreased when iron minerals in red mud can be adequately reduced into metallic iron.

关键词： Bayer red mud direct reduction orthogonal experiment iron particle growth

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Experimental study on methane dissolved in surfactant-alkane system

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International Journal of mining Science and Technology 2020年第6期30卷 865-873页

作者： Zhian Huang Mingli Chen Jingjing Wang Yinghua Zhang Linghua Zhang Hui Wang Yukun Gao Yupeng Zhou State key laboratory of High-efficient mining and safety of metal mines University of Science and Technology-BeijingMinistry of EducationBeijing 100083China Work safety key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal mines Hunan University of Science and TechnologyXiangtan 411201China State key laboratory Cultivation Base for Gas Geology and Gas Control Henan Polytechnic UniversityJiaozuo 454000China Beijing key laboratory of Operation safety of Gas Heating and Underground PipelinesBeijing Research Center of Urban System EngineeringBeijing 100035China

A surfactant-polyalkane system is investigated using chemical reagents to dissolve methane and control coal seam gas from low-energy,high-efficiency,safety,and environmental protection perspectives.At different temperatures and pressures,a high-temperature and high-pressure reactor,gas chromatograph,and other related experimental equipment were used to perform methane dissolution experiments,and a single surfactant sodium oleate(NaOA)and n-hexane demonstrated superior results.The single-factor experiments of temperature,pressure,and NaOA addition were performed and fitted via a response surface analysis.The optimal conditions for methane solubility were as follows:temperature of 34C,pressure of 4.5 MPa,NaOA addition of 85 g/L,and time of 1 h.The optimal effect of the surfactant-polyalkane system in dissolving methane was achieved with 32.31 mL/100 mL.Meanwhile,the change in the surface structure of coal before and after washing with the system was compared using scanning electron microscopy.The results indicated that the gas after washing with the surfactant-polyalkane system dissolved,and the surface pore structure of the coal changed.Moreover,the specific surface area and pore size of the coal surface increased after washing.Hence,the desorption of gas from the coal surface into the system becomes easy,thereby reducing the gas content in the coal sample.

关键词： Surfactant Polyalkane solution Methane

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白鹤滩柱状节理玄武岩几何结构特征分析及其几何模型构建

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Journal of Central South University 2022年第2期29卷 455-469页

作者：张建聪江权丰光亮李邵军裴书锋何本国 State key laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China key laboratory of ministry of education on Safe mining of Deep metal mines Northeastern UniversityShenyang 110819China

柱状节理岩体具有独特的几何和地质构造特征,其源于基岩冷凝收缩而形成的横截面为不规则多边形的柱体结构,是自然界存在的独特几何构造奇观。在白鹤滩水电站左岸坝基开挖过程中,出露了大面积的不规则柱状节理玄武岩,给大坝基础安全建设... 详细信息

柱状节理岩体具有独特的几何和地质构造特征,其源于基岩冷凝收缩而形成的横截面为不规则多边形的柱体结构,是自然界存在的独特几何构造奇观。在白鹤滩水电站左岸坝基开挖过程中,出露了大面积的不规则柱状节理玄武岩,给大坝基础安全建设带来不均匀沉降变形破坏等隐患,为此本文对其几何结构特征进行了大量的现场调查研究并开展相应的力学机理分析。现场调查表明,白鹤滩柱状节理玄武岩主要由5边、6边和7边柱组成,柱状节理截面呈不规则的多边形裂隙形式。在总结柱状节理岩体横截面多边形的尺寸和形状的定量测量方法基础上,提出了柱状节理截面多边形的不规则程度的评定方法,进而针对柱状节理的不规则多边形节理模式并基于随机Voronoi算法,提出了一种改进的Voronoi多边形(MVP)生成方式。用MVP方法得到的多边形模式包含大量不规则多边形,可以实现随着不规则程度的增加,多边形模式从初始理想的正六边形到最终实际存在的不规则多边形模式的快速演化过程,不同规则度下柱状节理岩体的压缩试验表明,几何不规则性对其力学特性产生较大的影响。该数值重构方法可为构造具有特定多边形特征的柱状节理岩体提供了一种可靠的几何建模方法。

关键词：柱状节理玄武岩几何特征不规则程度数值构建 Voronoi多边形法

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Surface microtopography and micromechanics of various rank coals

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International Journal of Minerals,metallurgy and Materials 2019年第11期26卷 1351-1363页

作者： Xiang-hui Tian Da-zhao Song Xue-qiu He Hui-fang Liu Wei-xiang Wang Zhen-lei Li key laboratory of ministry of education for efficient mining and safety of metal Mine University of Science and Technology BeijingBeijing 100083China School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China School of Civil Mining and Environmental EngineeringUniversity of WollongongWollongong NSW 2522Australia

For a long time,coalbed gas has brought about various problems to the safety of coal mine production.In addition,the mining of gas and coalbed methane(CBM)has attracted much attention.The occurrence and migration of CBM are believed to be closely related to the micro-surface properties of coal.To further explore the characteristics of CBM occurrence and migration,in this study,the micro-surface topography,adhesion,and elastic modulus of five metamorphic coals were measured by atomic force microscopy(AFM).The results show that the microtopography of coal fluctuates around 40 nm,reaching a maximum of 66.5 nm and the roughness of the surface decreases with the increase of metamorphism.The elastic modulus of coal micro-surface varies from 95.40 to 9626.41 MPa,while the adhesion varies from 15.08 to 436.22 nN,and they both exhibit a trend of"M"shape with the increase of metamorphism.Furthermore,a high correlation exists between adhesion and microtopography fluctuation.In most cases,the adhesion is larger in the concavity area and smaller in the convexity area.The research results may provide a new method for revealing the occurrence and migration of CBM and ensure efficient and safe CBM exploitation.

关键词： coal atomic force microscopy microtopography adhesion elastic modulus

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Deformation Analysis and Stability Evaluation of the Main Shaft at Jinchuan Mine No.3

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Journal of China University of mining and Technology 2007年第2期17卷 290-294页

作者： ZHAO Qian-li GAO Qian ZHANG Zhou-ping XIAO Wei-guo Department of Civil Engineering University of Science and Technology Beijing 100083 China key laboratory of ministry of education on High efficient and safety mining for metal mines Beijing 100083 China Mine No.3 Jinchuan Group Ltd Jinchuan Gansu 737100 China

Unexpected,serious deformation failures have occurred during construction of a main shaft. A study of con-struction parameters of the main shaft is required. First,the stability of the shaft and wall-rock is investigated by nu-merical methods. The modeling results are as follows: The convergence of shaft liner is greater than 60 mm at a depth of 650 m; the maximum principal stress in the liner approaches 190 MPa,which exceeds the strength of the liner,so it is inevitable that the liner deform locally. Second,stability analysis of shafts with different liner thicknesses has been completed. The results have the following features: If the depth where the liner thickness is increases from 400 mm to 500 mm is 650 meters,the convergence deformation of the liner is reduced by 3.4 mm while the maximum principal stress is reduced by 5 MPa. At a depth of 250 m if the liner thickness is increased from 400 mm to 500 mm the conver-gence of the liner is reduced by 1.5 mm while the maximum principal stress is reduced by 10 MPa. Therefore,increasing the liner thickness has little effect on liner convergence but can reduce the maximum principal stress in the liner. The thickness of the liner can be increased to reduce the maximum principal stress and increase the capacity for shear defor-mation. Finally,construction techniques employing releasing-displacements have been numerically simulated. The con-clusions are that as the releasing displacement is increased the convergence of the surrounding rock increases linearly while the convergence of the lining decreases linearly. The plastic zone in the surrounding rock mass at first increases linearly but then,at a release-displacement of 95 mm,expands rapidly. These conclusions show that use of suitable re-leasing displacement can increase the self-supporting capacity of the surrounding rock. But when the releasing dis-placement exceeds 95 mm the plastic zone rapidly enlarges and stability rapidly decreases. The maximum principal stress of the lining also decreases as the release-disp

关键词：竖井重新设计变形稳定性煤矿

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Modes of multi-mechanistic gas diffusion in shale matrix at varied effective stresses:Observations and analysis

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Petroleum Science 2023年第5期20卷 2908-2920页

作者： Tian-Yu Chen Yan-Yu Hao Derek Elsworth Hong-Ming Zhang Zhi-Ming Hu Guang-Lei Cui key laboratory of ministry of education on Safe mining of Deep metal mines School of Resources and Civil Engineering and Key Laboratory of Liaoning Province on Deep Engineering and Intelligent TechnologyNortheastern UniversityShenyang110819LiaoningChina National Energy Shale Gas R&D(experiment)Center Langfang065007HebeiChina Department of Energy and Mineral Engineering EMS Energy Institute and G3 CenterPennsylvania State UniversityUniversity ParkPA16802USA Research Institute of Petroleum Exploration&Development PetroChina Company LimitedBeijing100084China

Gas diffusion in the shale matrix has a dominant effect on late-stage production from shale gas reservoirs.However,adequate research on the mechanisms and contributions of gas diffusion for varied pore size populations in shale matrix under recreated in situ stress is lacking.We report gas-diffusion measurements under constant in situ stress but variable gas pressures for contrasting non-adsorbent(helium(He))and adsorbed(methane(CH_(4)))gases to investigate the impact of effective stress on the evolution of dominant mechanisms of diffusion.An intact sample replicates true pore-network topology and diffusion paths.An integrated diffusion model is proposed that combines the effects of slip flow,Knudsen flow,and surface diffusion to constrain the evolution of these flow regimes and their respective contributions to the observational data.Finally,a probability density function(PDF)is employed to separate the gas content distributions of macropores and micropores from the total gas content and to investigate gas contributions in various pores.The results reveal that the diffusion coefficients of both He and CH_(4) in macropores and micropores increase with gas pressure but decrease with increasing effective stress.The diffusion coefficients of He and CH_(4) are different in macropores but remain nearly the same in micropores.The diffusion coefficients of slip flow and surface diffusion increase with decreasing effective stress except for CH_(4) diffusion in the micropores,while the evolution of Knudsen diffusion shows the opposite trend.Slip flow plays a dominant role in He and CH_(4) diffusion within macropores(pore size 45 nm).Knudsen diffusion gradually becomes significant for He diffusion in the micropores(pore size 4 nm),conversely,for CH_(4) diffusion in the micropores,surface diffusion becomes significant.Related to gas production from reservoirs,the contributions of the micropores will increase gradually with the duration of gas recovery,indicating the significant role of gas diffusion in micropores to steady

关键词： Diffusion coefficient In situ stress Varied pore types Diffusion mechanisms Gas-content contributions

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International Journal of Minerals,metallurgy and Materials 2009年第2期16卷 135-142页

作者： Zhuo-ying Tan Si-jing Wang Mei-feng Cai State key laboratory of High-efficient mining and safety of metal mines Ministry of Education of China Beijing 100083 China School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China School of Civil Engineering Tsinghua University Beijing 100084 China

An instrumented drilling system can be applied for the acquisition of drilling process parameters. The system can provide continuous and huge data for geotechnical engineering. However, due to the complexity of ground strata, the variation in the drilling parameters with stratigraphical characteristics is great and the correlation between likely comparable parameters is not high, which limits the use of conventional correlation approaches in this field. How to use the data for engineering and how to get a reasonable interpretation for the relationships among the drilling parameters, as well as between a drilling parameter and formational characteristics, become a technical choke point for the development and application of the instrumented drilling system. Based on similarity criteria, the extraction of sample data and characteristics, the pretreatment of data and feature matching algorithms have been analyzed and an approach of slope coefficient searching identification has been established. A case study was carried out for the similarity between the rotational speed of the drill bit, flushing pressure, and effective thrust force graphics in general weathered granite. The result shows that the similarity coefficients between the rotational speed of the drill bit, flushing pressure, and effective thrust force are 0.72 and 0.83, respectively. Although there are differences between the distances of the graphics, the curves of both rotational speed and flushing pressure agree with the effective thrust curve in shape, which provides a possible method for the identification of various formations by use of the similarity between feature drilling parameters.

关键词： rock drilling process parameters similarity identification slope coefficient

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Influential factors and control of water inrush in a coal seam as the main aquifer

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International Journal of mining Science and Technology 2018年第2期28卷 187-193页

作者： Gao Rui Yan Hao Ju Feng Mei Xianchen Wang Xiulin key laboratory of Deep Coal Resource mining Ministry of Education School of Mines China University of Mining and Technology State key laboratory for Geomechanics & Deep Underground Engineering China University of Mining and Technology Huadian Coal Industry Group Co. Ltd.

In this paper, a combination of field measurement, theoretical analysis and numerical simulation were used to study the main control factors of coal mine water inrush in a main aquifer coal seam and its control scheme. On the basis of revealing and analyzing the coal seam as the main aquifer in western coal mine of Xiao Jihan coal mine, the simulation software of PHASE-2D was applied to analyze the water inflow under different influencing factors. The results showed that water inflow increases logarithmically with the coal seam thickness, increases as a power function with the permeability coefficient of the coal seam, and increases linearly with the coal seam burial depth and the head pressure; The evaluation model for the factors of coal seam water inrush was gained by using nonlinear regression analysis with SPSS. The mine water inrush risk evaluation partition within the scope of the mining field was obtained,through the engineering application in Xiao Jihan coal mine. To ensure the safe and efficient production of the mine, we studied the coal mine water disaster prevention and control measures of a main aquifer coal seam in aspects of roadway driving and coal seam mining.

关键词： Coal seam Main aquifer Water inrush Influential factors Control

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Hydraulic support crushed mechanism for the shallow seam mining face under the roadway pillars of room mining goaf

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International Journal of mining Science and Technology 2017年第5期27卷 853-860页

作者： Wang Fangtian Duan Chaohua Tu Shihao Liang Ningning Bai Qingsheng State key laboratory of Coal Resources and Mine safety China University of Mining&TechnologyXuzhou 221116China School of mines Key Laboratory of Deep Coal Resource MiningMinistry of Education of ChinaChina University of Mining&TechnologyXuzhou 221116China School of Economics and Management Longyan UniversityLongyan 364000China

While the fully-mechanized longwall mining technology was employed in a shallow seam under a room mining goaf and overlained by thin bedrock and thick loose sands, the roadway pillars in the abandoned room mining goaf were in a stress-concentrated state, which may cause abnormal roof weighting, violent ground pressure behaviours, even roof fall and hydraulic support crushed(HSC) accidents. In this case,longwall mining safety and efficiency were seriously challenged. Based on the HSC accidents occurred during the longwall mining of 3-1-2 seam, which locates under the intersection zone of roadway pillars in the room mining goaf of 3-1-1 seam, this paper employed ground rock mechanics to analyse the overlying strata structure movement rules and presented the main influence factors and determination methods for the hydraulic support working resistance. The FLAC3 D software was used to simulate the overlying strata stress and plastic zone distribution characteristics. Field observation was implemented to contrastively analyse the hydraulic support working resistance distribution rules under the roadway pillars in strike direction, normal room mining goaf, roadway pillars in dip direction and intersection zone of roadway pillars. The results indicate that the key strata break along with rotations and reactions of the coal pillars deliver a larger concentrated load to the hydraulic support under intersection zone of roadway pillars than other conditions. The ‘‘overburden strata-key strata-roadway pillars-immediate roof" integrated load has exceeded the yield load that leads to HSC accidents. Findings in HSC mechanism provide a reasonable basis for shallow seam mining, and have important significance for the implementation of safe and efficient mining.

关键词： Shallow seam Room mining goaf Longwall mining Hydraulic support crushed mechanism Safe and efficient mining

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Early-age strength property improvement and stability analysis of unclassified tailing paste backfill materials

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International Journal of Minerals,metallurgy and Materials 2020年第9期27卷 1191-1202页

作者： Qian Zhou Juan-hong Liu Ai-xiang Wu Hong-jiang Wang School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Beijing key laboratory of Urban Underground Space Engineering University of Science and Technology BeijingBeijing 100083China key laboratory of High-efficient mining and safety of metal Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China

High-density tailings,small cementitious materials,and additives are used for backfill materials with poor early compressive strength(ECS),which may greatly affect the mining and backfill cycle,to prepare paste backfill materials(PBMs)with a high ECS.The effects and mechanisms of different early strength agents on the property of PBM are investigated.The action mechanism of additives on the properties of PBM is also analyzed through X-ray diffraction,scanning electron microscope,and energy dispersive spectrometry.Results show that the effects of single-component additives 1,3,and 6 are better than those of the other additives,and their optimal dosages are 3wt%,1wt%,and 3wt%,respectively.The optimum multicomponent combinations are 1wt%of additive 1 and 1.5wt%of additive 6.The ECS of the paste with additive 10 increases to a greater extent than that of the other pastes because of the synergistic action of additive 1 with additive 6.The hydration product of Ca(OH)2 is consumed,and more C-S-H gels are generated with the addition of additives to paste.Tailings particles,ettringite crystals,and gels intertwined with one another form a dense net-like structure that fills the pores.This structure can significantly improve the ECS of PBM.

关键词： paste backfill unclassified tailings binder powder early-age strength microstructure

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