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    15 September 2022, Volume 51 Issue 09
    Core Modules and General Development Process of Synergetic Mining Technology
    CHEN Qingfa, HUANG Hao
    2022, 51(09):  1-8. 
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    In order to promote the standardized development of Synergetic Mining technology mode,the core modules and general development process of Synergetic Mining technology are studied.By analyzing the guiding role of the basic principles of Synergy on the Synergetic Mining technology,three core elaborations of the Synergetic Mining technology are summarized,namely:competition and instability are the prerequisites for the development of Synergetic Mining technology,elements and structure of the system are the organizational carriers of Synergetic Mining technology,synergistic effect is the driving force to maintain the orderly operation of the system."Competition and instability","elements and structure of the system","synergistic effect" are regarded as the three core modules that constitute the Synergetic Mining technology,respectively expounding their scientific connotation in Synergetic Mining technology.The general development process of Synergetic Mining technology with determination of project objectives,analysis of competition and instability,determination of system elements and structure,analysis of synergy,and evaluation of synergy degree as the main steps.Finally,combined with the specific mining project case of No.105 fragmentation ore section of Guangxi Gaofeng Mine,the development process of Synergetic Mining technology under the dual hidden dangers of fragmentation environment and goaf is introduced.The research results provide a paradigm reference for the development of Synergetic Mining technology.
    Multi-attribute Decision Optimization and Practice of Mining Method in High Altitude Area Based on Variable Weight Theory
    HAN Chongchong, TAN Yuye, CHEN Diyun, QI Wei, SONG Weidong
    2022, 51(09):  9-17. 
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    In order to meet the special requirements of mining method selection in underground metal mines under high-altitude mining conditions,a multi-attribute decision-making optimization method for mining methods based on variable weight theory was proposed.First of all,using the AHP,based on factors such as technology,economy,labor productivity,resource utilization,safety and environment,a multi-attribute decision-making evaluation index system for mining method optimization was constructed.Taking the steeply inclined thin orebody of Guoluolongwa Gold Deposit as an example,the preferred alternatives for mining methods were initially selected through engineering analogy.Secondly,a multi-attribute decision-making matrix for mining method optimization was constructed,and the matrix was normalized by a reasonable normalization method.Then,the constant weights of the evaluation indicators were obtained by the AHP.On this basis,the special requirements of the high-altitude mining conditions for the evaluation indicators such as stope production capacity,special environmental adaptation degree,labor intensity and working face safety were considered.According to the variable weight theory,the weight of each evaluation index was dynamically adjusted through the state vector function,so that the weight was close to the real state,so as to correctly reflect the actual needs of the project.Finally,the superior degree of each alternative scheme is obtained through TOPSIS approximation of the ideal solution sorting method.The results show that under the condition of considering the equilibrium of indicator state values,the punishment of over-low indicator and the incentive of better indicator,the superiority degree of three mining method schemes A1(middle-deep hole sublevel subsequent filling method ) ,A2 (shallow hole retention method) and A3 (resuing stoping) are 62.1%,57.2% and 37.3%,respectively,and the middle-deep hole sublevel subsequent filling method of A1 is the optimal mining method.The optimization results are more in line with engineering practice,and this method provides a new idea for the optimization of mining methods in underground metal mines.
    Optimization of Room-and-pillar Mining Method Extraction for Section IV of Wawu Phosphate Mine Based on AHP-FUZZY
    ZHANG Weizhong, WANG Weiqing, PENG Yali, KANG Qinrong, ZHANG Dianji
    2022, 51(09):  18-24. 
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    The Ⅳ ore block of Wawu Phosphate Mine is a gently inclined thin medium thick ore body.In the production process,it is difficult to determine the mining method because of the difficulty to draw ore and manage the roof,and the ore body that is not conducive to make full use of the advantages of large self-made equipment.To solve the problem,three mining methods were tested in the mine.It is so difficult to determine the reasonable mining method through simple technical and economic analysis and comparison of advantages and disadvantages.Under this condition,the analytic hierarchy process (AHP) was used to establish the hierarchical structure analysis model with the factors involved in the selection of mining methods as the index system.The weight of each factor was determined according to the basic principle of AHP and the expert scoring system,and then the fuzzy comprehensive evaluation matrix was established according to the determination method of the membership degree of qualitative index and quantitative index to determine the trackless transportation and anchor net roof protection.The room-and-pillar method of wheel drawing was the best mining method in Section Ⅳ of Wawu Phosphate Mine.Practical study showed that the method had good field application effect and applicability in gently inclined thin medium thick ore body,which has certain reference significance for mines with the similar engineering geological conditions.
    Technical Scheme of Low-grade Limestone Recovery in JISCO Xigou Mine
    XU Shouxin, YAN Weishan, BAI Wanming, CHENG Daishan, QIAO Min, KANG Fujun
    2022, 51(09):  25-30. 
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    Full recovery and utilization of low grade ore is an important way to improve the recovery rate of mine resources and comprehensive economic benefits.In order to improve the recovery rate of low-grade ore in Xigou Mine,on the basis of summarizing and analyzing the technical problems in the process of resource recovery and utilization,the technical research was carried out from the aspects of 3D modeling of ore body,grade difference analysis,quality control scheme,remote monitoring of the chute and the reconstruction of the counterattack broken cutting port.The bottleneck problems such as unclear low-grade geological resources,large difference of dilution between divided ore and block ore,prominent fault problem of chaff blockage,easy blockage of crusher feed hole are solved,and the stable production of low-grade ore in the mine was ensured.In recent 4 years (from 2018 to 2021),2.08 million tons of low-grade ore was recovered,and the comprehensive recovery rate of ore was increased from 93.5% to more than 95%.The mine service life was effectively extended,and significant economic and social benefits were obtained,which has a certain reference for similar mines.
    Study on the Simulation Method of Solid-liquid Two-Phase Flow of Filling Pipeline Based on ECT Technology
    QIN Xuebin, LI Mingqiao, SHEN Yutong, YANG Peijiao, HU Jiachen, LIU Lang
    2022, 51(09):  31-36. 
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    In the process of mine filling,the pipe of agglomeration and inclusions of waste rock filling pulp causes blocking pipe or tube and so on serious safety accidents,restricted the application and development of mine filling technology,so in a timely manner to the pipe blockage agglomerate and detect the location and size of waste rock has great significance to the security and stability of mine filling.Based on the technology of Electrical Capacitance Tomography (ECT),the detection method of mine filling pipeline was studied.Aiming at the problems of poor imaging quality and low accuracy of the traditional ECT reconstruction algorithm,a new ECT image reconstruction method based on extreme learning machine and convolutional neural network was proposed,which was suitable for the detection of solid-liquid two-phase flow in filling pipes.The image reconstruction network consists of two parts:a hidden layer feedforward neural network and an image prediction network.The mapping relationship between capacitance data and dielectric constant value was established by using extreme learning machine,and the image was reconstructed by image prediction network.Through the simulation experiment of filling pipe,it is proved that this method can not only effectively reduce the artifact and deformation of reconstructed image,improve the reconstruction accuracy,but also have a good reconstruction effect for the complex situation that may occur in filling pipe.The ECT image reconstruction method proposed in this study has a good effect on the detection of clogging and caking and waste rock existing in the mine filling pipeline,which can improve the application and promotion of ECT technology in the filling pipeline detection.
    Experimental Study on Static Settlement and Semi Industrial Thickening of Two-stage Classification Ultrafine Tailings in A Gold Mine
    YANG Jiguang, WU Zaihai, KOU Yunpeng, WANG Zengjia, SONG Zepu, JING Xiaodong, ZHU Gengjie
    2022, 51(09):  37-42. 
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    In a gold mine,ultra-fine tailings with + 37 μm content below 25% and - 19 μm content above 60% were obtained by cyclone classification of graded fine tailings. Based on the two-stage classified ultra-fine tailings,indoor static flocculation sedimentation test and semi industrial thickening test were carried out. The effects of mortar concentration and flocculant unit consumption on the floc settlement behavior was analyzed by static settlement. It is found that the floc settlement speed decreases with the increase of mortar concentration,while the flocculant unit consumption has an optimal value. If it is higher or lower than this value,the floc settlement speed becomes slower. The influence of the height of the mud layer on the thickening was explored,and the influence of the solid flux on the solid content and underflow concentration of the overflow water was studied by semi industrial thickening test. The experimental results show that the height of the mud layer is nonlinear to the dense underflow concentration,and the underflow concentration increases first and then tends to be stable with the increase of the height of the mud layer. With the increase of solid flux,the solid content of overflow water increases gradually,while the underflow concentration is linearly and negatively correlated with solid flux. The experimental data were successfully applied to 1 000 m3 unpowered high-efficiency thickener to realize industrial application.
    Research and Application of Filling Technology with Glue Powder and Graded Tailing in Jinfeng Gold Mine,Guizhou Province
    JIA Zhuping, ZHENG Lujing, HU Yafei, ZHENG Lulin, RONG Peng
    2022, 51(09):  43-48. 
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    Aiming at the problems of low strength and high filling cost of ultra-fine tailings backfill in Jinfeng Gold Mine, Guizhou Province,the particle composition analysis of graded tailings when the abortion rate of cyclone bottom was 65% and the physical characteristics of backfill with different slurry concentrations and glue powder dosage were carried out. The mixing ratio of glue powder was optimized according to the different filling times. The results showed that the chemical content of glue powder meets the requirements of general solid waste and can be used for underground filling. The mineral composition of tailings is mainly quartz,which is beneficial to improve the strength of backfill. Under the requirements of the same strength and fluidity,the glue powder dosage is half of the cement dosage. When the dosage of glue powder is 5.5%,the strength of backfill with curing period of 7 d reaches 0. 36 MPa,which meets the design requirement. The strength of filling body with glue powder decreases gradually after curing period of more than 28 d,so it is not suitable to use glue powder for render filling. According to the comparison of technical and economic indicators between local cement and glue powder by unit price,the use of glue powder instead of cement filling can save a lot of filling cost,which can provide effective reference for similar mine filling.
    Coupling Technical Scheme of Supporting-Grouting Reinforcement for the Intersection of the -550 m Level Horizontal Large Section in Zhongjiu Iron Mine
    ZHOU Lei, ZHU Wenlong
    2022, 51(09):  49-54. 
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    The phase Ⅰ well lane open-out prolongation is building for -550 m level in Zhongjiu Iron Mine,in order to ensure the safety of roadway excavation and the effectiveness of temporary support,in view of the current situation of large section,broken surrounding rock and developed cracks for 6# intersection at the -550 m level,the technical scheme of roadway surrounding rock stability prevention and control was put forward,which includes the combined support of anchor shotcrete-bolt + anchor cable and the reinforcement of deep and shallow borehole-high and low pressure coupled grouting. During the process of grouting reinforcement,firstly,the shallow pore-low pressure grouting technical was adopted to fill the cracks in the broken surrounding rock and compactness,so that the surrounding rock of the roadway has a certain pressure resistance ability,and the grouting ability of the deep surrounding rock was improved. Then,the deep hole and high pressure grouting technical was used to form the overall structure of the broken surrounding rock and the stable rock strata in the upper part of the roadway roof, which further improves the stability of the support system. Based on the method of theoretical calculation and numerical simulation,the supporting parameters were determined,and the the key technology and construction process of grouting reinforcement were analyzed. The practical effect is remarkable,which provides technical support for the subsequent safe construction of large section bifurcation points.
    Time-frequency Energy Analysis of Electronic Detonator Blast Vibration Signals in Rock Tunneling #br#
    MENG Biao, YIN Haojie, CHEN Hui, TONG Xiaoyong
    2022, 51(09):  55-62. 
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    The underground mining link of the hanging gang mine is accompanied by blasting activities,which can easily lead to final slope instability. In order to investigate the characteristics of the time-frequency energy distribution of vibration signals and assess the vibration hazards,several vibration measurement tests were carried out at the preparation iron ore mine in Hejing County. For the vibration data obtained from monitoring,the Hilbert-Huang transform ( HHT) method,combined with wavelet soft threshold denoising was applied to analyze the vibration signal of this hanging gang mine from the perspective of time,frequency and energy,and the EMD (Empirical Mode Decomposition) postponement identification method and instantaneous energy postponement identification method was applied to the electronic detonator The actual postponement time was identified. The analysis results show that:① The blasting energy is mainly concentrated in the frequency band of 0 ~ 200 Hz, and the main vibration band is 0 ~ 50 Hz;② The blasting energy develops in the direction of low frequency,and contains 51. 22% of energy in the frequency band of 0~ 10 Hz,and the low frequency band contains most of the energy,which is easy to trigger the self-vibration of the building ( structure) and has a great threat to the stability of the slope of the hanging gang mine;③ The blasting energy is in the range of 0. 495 s and 1. 119 s,i. e. ,the blasting of slotted holes and auxiliary holes generate more energy,so it is recommended to set empty holes for slotted holes and appropriately reduce the amount of auxiliary hole charge in section 5;④ Under the conventional extension,the recognition rate of detonator segments of EMD method and instantaneous energy method are 100%,and the recognition accuracy of actual extension time is 95. 2% for EMD method and only 82. 6% for instantaneous energy method. This is a preliminary analysis because the EMD method itself is not completely orthogonal decomposition,the analysis easily causes confusion between the modes,resulting in recognition accuracy not reaching 100%.
    Parametric Modeling of Mine Roadway Based on Dynamo
    LI Wenjing, JIAO Yuhao, QIU Li, ZHANG Xinxin, REN Dajun
    2022, 51(09):  63-70. 
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    In view of the complex spatial structure of mine roadway,this paper puts forward the technical route of threedimensional design modeling using Dynamo visual programming flow,studies the methods of roadway centerline extraction and roadway section parameter family construction,and realizes the rapid modeling when the roadway section changes. The visual program based on Boolean operation realizes the mutual connection of horizontal and inclined intersection roadway,at the same time,the dynamic modification of the model design can be realized by adjusting the parameters through visual programming in the modeling process,so as to improve the reusability of roadway three-dimensional model. Experiments show that:Dynamo visual workflow can accurately control the modeling process,complete the automatic construction of roadway three-dimensional model,and improve the speed of roadway modeling.
    Study on Water Immersion Shear Creep Characteristics and Constitutive Model of Rock Joints
    LIU Honglei, YANG Chen, LIU Xige, ZHU Wancheng
    2022, 51(09):  71-80. 
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    The hierarchical loading shear creep experiment was carried out for the hard joint surface of sandstone under water immersion and natural state. The normal stress and shear stress of the joint surface was loaded proportionally through uniaxial compression. The experimental results show that before the accelerated creep occurs on the rock joint,the instantaneous deformation caused by the graded loading tends to decrease gradually with the loading stress. Based on the Norton-Bailey model and the Kachanov damage model,a new improved Norton-Bailey creep-shear model was proposed,which involved the joint roughness efficient,immersion conditions,and the ratio of shear stress to normal stress. According to the shear creep experiment data of the sandstone joint surface,the parameters of the creep shear model of the sandstone joint surface under water immersion and natural state were fitted respectively. The results show that the improved Norton-Bailey creep shear model has a good fitting effect on the sandstone joint surface,and can reflect the influence of the weakening effect of water immersion on the joint surface.
    Study on Time-dependent Damage Creep Model of Rock Shear Failure under Compression
    GAO Ansen, QI Chengzhi, LUO Yi, LI Changfeng, WANG Biao
    2022, 51(09):  81-86. 
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    The creep sliding instability of rocks is one of the main reasons for inducing fault-slip rockburst. For revealing the mechanical response characteristics of the creep sliding instability process of rocks,the creep growth mode and failure evolution characteristics of rocks shear-slip instability process was analyzed clearly by theoretical analysis and experimental verification. Subsequently,a time-dependent damage creep model was established for the shear-slip failure of rocks and verified by the previous test. The results demonstrated that the time-dependent damage creep model can be used to describe the creep evolution characteristics of rocks shear slip instability under compression, and it can also better characterize the mechanical responses of different creep stages for rocks failure. The shear creep failure process of rocks had obvious stage characteristics, and there existed deceleration creep modes,constant velocity creep modes and accelerated creep modes. The creep growth rate of rocks was affected by its elastic modulus and viscosity coefficient,and it was also affected by its time-dependent damage effect,especially at the accelerated creep stage,which was also one of the main inducements for rocks nonlinear acceleration instability.
    Effect of Reagents Magnetization Treatment on Hematite Flotation and Its Mechanism
    LI Fengjiu, KONG Yaran, ZHAO, Liucheng, JIA Qingmei
    2022, 51(09):  87-93. 
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    In order to indentify the influence law and action mechanism of magnetization treatment on flotation effect,taking hematite and quartz as the main research object,the effects of magnetization treatment process parameters such as magnetic induction intensity,magnetization time,magnetic field position on the flotation indexes were investigated. Meanwhile,the action mechanism of reagent magnetization treatment was revealed from the effect of magnetization treatment on reagents and minerals by using surface tension test,conductivity test,Zeta potential test and other test methods. Under the conditions of magnetic induction strength of 150 mT,magnetization time of 6 min,and No. 1 magnetic field position (high magnetic field gradient),the flotation reagent was magnetized. The recovery rate of hematite was increased to 78. 27%,increased by 23. 62 percentage points compared with unmagnetized reagent. While the recovery rate of quartz almost unchanged and maintained lower level. The test results of the artificial mixed ore showed that with the similar TFe grade,the TFe recovery rate increased by 6. 75 percentage points when the flotation reagent was magnetized. The concentration of sodium oleate ions in the solution increases after magnetization treatment,and the adsorption of oleate ions on the surface of hematite is enhanced,which is conducive to the flotation of hematite. The research results have certain significance for the establishment of magnetization flotation theory system,and can provide reference for the application of magnetization treatment in hematite flotation.
    Study on Gravity Separation Test of a Gold Ore with Knelson Concentrator
    ZHANG Mingwei, TAN Lu, HUANG Yehao
    2022, 51(09):  94-99. 
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    The gold grade of a gold mine is 4. 66 g / t,and single flotation was adopted for recycling the gold in the concentrator. The study of ore properties showed that the gold in the ore mainly exists in the form of bare and semi-bare gold,and the natural gold yield of 0. 295~ 0. 074 mm is as high as 59. 82%,which is suitable for gravity separation recovery. Therefore, the Knelson concentrator was chosen as the main equipment,and the beneficiation test was carried out by gravity separation and flotation combined process. The appropriate conditions for gravity separation are determined as follows:the grinding fineness of -0. 074 mm accounting for 45%,gravity multiple of 60 G,backwash waterflow of 5. 5 L / min,feeding speed of 500 g / min and feeding amount of 20 kg. The yield of heavy sand is 0. 048 9%,and the gold grade and recovery rate is 4 018. 14 g / t and 42. 07%,respectively under the conditions. Aiming at the gravity tailings obtained under suitable conditions, the flotation process of " one roughing,two cleaning and three scavenging" was adopted to concentrate the flotation gold concentrate with 7. 60% of yield,32. 43 g / t of gold grade and 52. 78% of gold recovery rate,and the total gold recovery rate was 94. 85%. The results of particle size analysis showed that the Knelson gravity separation mainly recovered products above 0. 097 mm particle size,and the recovery ability of fine particle size products was limited.
    Effects of Grinding Methods on the Flotation Kinetics of Sphalerite and Pyrite
    GAO Enxia, ZHANG Chun, LI Yuepeng, LUO Jianhui, GAO Ruizhuo, RAN Jincheng
    2022, 51(09):  100-106. 
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    In order to study the effects of grinding methods on the flotation performance of sphalerite and pyrite,the particle size composition and flotation kinetic parameters of these two minerals under different grinding methods and grinding time were investigated by six flotation kinetic models. The results showed that all the six models can well fitted the flotation test data. The flotation performances of sphalerite and pyrite were determined by oxidation rate,grinding method and particle size composition. Pyrite presented a higher oxidation rate and lower flotation recovery compared with sphalerite. The products obtained from wet grinding were finer than dry grinding. In all tests,the yield of -0. 015 mm size fraction was the highest,which was conducive to the exposure of more new surface and led to the rapid enrichment of pyrite. However,wet grinding accelerated the dissolution of Fe3+ from the grinding medium,which reduced the flotation rate of sphalerite. The dry grinding samples exhibited coarser particle size composition and higher surface roughness,inducing higher ε∞ values of sphalerite and pyrite compared with wet grinding.
    Effect of Polyaspartic Acid on Flotation Separation of Scheelite and Calcite and Its Action Mechanism
    XIE Jiawen, FU Junhao, HAN Haisheng, CHEN Zhanfa, LONG Bing, LI Wenheng, XU Tao, WU Jiangyueen
    2022, 51(09):  107-114. 
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    Due to the existence of calcite and other calcium gangue minerals in scheelite ore,scheelite flotation technology was hindered,in which the key is to develop highly selective and efficient inhibitors. The inhibition effect of polyaspartic acid (PASP) was studied by flotation test,Zeta potential test and XPS analysis,and the mechanism was further analyzed by flotation solution chemistry and crystal chemistry calculation with lead ion-benzohydroxamic acid (PB-BHA) complex as collector. The results of pure mineral test showed that the difference of recovery rate between scheelite and calcite could reach more than 70% in the condition of c BHA = cPb = 2. 0×10-4 mol / L、cPASP = 2 mg / L and pH of 10,indicating that the selective inhibition effect of PASP on calcite. Then,the artificial ore mixing test was carried out based on the pure mineral test. The results showed that PASP can greatly improve the CaWO4 grade of concentrate without affecting the recovery rate. When the mass ratio of scheelite to calcite is 1 ∶1,the recovery rate and grade of CaWO4 in concentrate with 2 mg / L PASP are 95. 2% and 85. 0%, respectively. The results of Zeta potential test and XPS analysis confirmed that PASP had strong adsorption on the calcite surface,which changed the electrical and chemical environment of the calcite surface. Crystal chemical analysis showed that the matching degree of polyaspartic acid functional groups with calcite surface calcareous points was obviously better than that of scheelite,which resulted in the selective inhibition effect of polyaspartic acid on calcite.
    Research on Galena Ore Comminution Test Based on High-voltage Electrical Pulses Technology
    GAO Peng, ZHANG Honghao, YUAN Shuai, ZHANG Ningyu, HAN Liren, QIN Yonghong
    2022, 51(09):  115-120. 
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    High-voltage electrical pusles technology is a novel grain boundary fracture technology,which has the advantages of selective crushing,less pollution and no dust. In order to further improve the technical system of high-voltage electric pulses pretreatment technology system,high-voltage electric pulse pretreatment test was carried out for a galena in Liaoning Province. The influence of parameters such as ball gap spacing,output voltage and pulse times on ore crushing effect was systematically investigated. The results showed that the suitable high-voltage electric pulse pretreatment conditions for 7 ~ 5 mm, 10~ 7 mm,12. 5~ 10 mm grain size raw materials were as follows:ball gap spacing of 25 mm,output voltage of 25 kV,pulse times of 150 times,in which the grain size yield of -2 mm crushing product was the highest,and the average crushing ratio and particle size distribution uniformity coefficient were the best. In addition,the particle size distribution coefficient is better with the finer feed particle size,indicating the wider the particle size distribution range and the worse the product particle size uniformity. The particle size of ore is reduced mainly through the impact shear force to achieve the dissociation of mineral in mechanical crushing. However,for the high-voltage electrical pusles crushing technology,the internal structure of the ore is destroyed by the difference of dielectric constant,and a large number of cracks and micro-cracks are generated at the phase interface,which contribute to the further dissociation and fragmentation of the ore.
    Expermental Research on Sulphated Roasting and Leaching Process for Vanadium Extraction from a Low-grade Vanadium Ore
    ZOU Kai, XIAO Junhui, ZHONG Nanlan, GAO Deqiang
    2022, 51(09):  121-125. 
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    In order to achieve the effective extraction for the vanadium from a low-grade vanadium ore,low-temperature sulphated roasting pretreatment technology was adopted for strengthening crystal structure destroying and phase transformation of vanadium-bearing mineral illite during roasting process,which created favorable conditions for the extraction of vanadium from calcine during water leaching. The influence of roasting temperature,roasting time,particle size of raw ore and sulfuric acid dosage on vanadium leaching rate and phase evolution during roasting were investigated. The results showed that the vanadium leaching rate could reach 83. 64% under the optimal roasting conditions of the roasting temperature of 250 ℃ for 2 h, -0. 096 mm of raw ore and 40% sulfuric acid dosage. XRD analysis of the raw ore,roasted products and leached slag showed that under the synergistic effect of sulfuric acid and temperature rising,the aluminosilicate mineral lattice in the raw ore is effectively destroyed,the illite reacts with sulfuric acid to form misenite and easily leached munirite,and the gangue mineral calcite is transformed into gypsum in the roasting process,which creates favorable conditions for the extraction of vanadium by water leaching. The thermodynamic calculation of roasting process further verified the feasibility of low temperature sulfated roasting and water leaching process for vanadium extraction.
    Experimental Study on Beneficiation of a Refractory Manganese Oxide Ore in Yunnan
    ZHOU Yongxing, SUN Xiaoyan, SONG Baoxu, YUAN Jingzhong, MA Nianyu, WANG Yue, ZHU Ya, HUANG Enming
    2022, 51(09):  126-131. 
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    Manganese ore resources in China are rich,but there are some problems such as low grade of manganese in raw ore,extremely fine disseminated grain size of useful minerals and easy slime of gangue components. Therefore,it is of great practical significance to improve the technical level of manganese ore dressing. Taking a manganese oxide ore from Gejiu,Yunnan Province as the research object,the beneficiation tests were carried out by the process of washing,desliming and magnetic separation combined with the ore properties. The results showed that:① the manganese grade of the raw ore is 6. 40%,and manganese mainly exists in the form of manganese oxide minerals such as psilomelane and pyrolusite,among which the extremely fine manganese oxide minerals with the disseminated particle size of -0. 01 mm have a higher yield. ② Under the condition of stirring intensity of 2 000 r / min,the ore slime with a yield of about 69% can be removed by the hydrocyclone in the laboratory,which creates favorable conditions for obtaining high grade manganese concentrate by subsequent sand settling. ③ For manganese oxide minerals in settled sand deposition,magnetic materials with manganese grade of 29. 13% and 7. 86% were obtained by using the high intensity magnetic separation process of one roughing and one scavenging,which realized the efficient recovery of manganese minerals with coarse grain size. For the manganese oxide minerals in the slime,the magnetic materials with manganese grade of 18. 07% were obtained by the process of high intensity magnetic separation with one rough separation,and the comprehensive utilization of fine manganese minerals was realized. Through the whole process test,a manganese concentrate with a cumulative yield of 16. 08%,an average manganese grade of 23. 78% and a cumulative recovery rate of 60. 21% was obtained,which realized the efficient and comprehensive utilization of the refractory extremely low grade and high mud-containing manganese ore.
    Research on Process Mineralogy of a Arsenic-containing Gold Ore in Hunan Province
    LIANG Binjun, HU Haixiang, ZOU Shang, TANG Liqun
    2022, 51(09):  132-139. 
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    A gold ore in Hunan Province contains high arsenic and carbon,and the gold concentrate obtained by flotation process is with low grade and recovery rate,which is a typical representative of refractory gold ore. The process mineralogy of gold ore was systematically studied by means of chemical multi-elements analysis,X-ray diffractometer,optical microscope, scanning electron microscope ( SEM),elemental chemical phase analysis and mineral liberation analysis ( MLA) in order to fully grasp the ore properties for optimizing the flotation indexes. The results showed that the average grade of valuable element gold in the ore was 3. 40 g / t,and the contents of harmful elements arsenic and carbon were 0. 36% and 1. 42%,respectively. The metallic minerals in the ore are mainly freibergite,scheelite,pyrite,arsenopyrite and siderite,while the non-metallic minerals are mainly quartz and sericite,followed by kaolinite,chlorite,serpentine and so on. The gold minerals in the ore are all natural gold with an average fineness of 999. 5‰. The morphology of the gold is mainly angular-grain and angulargrained,followed by long horned granular. The gold particle size of less than 19 μm accounted for 98. 95%,which belongs to the category of micro-fine particle. The distribution rates of monomer,exposed gold and sulfide wrapped gold in the ore are 5. 90% and 88. 79% under the condition of grinding fineness of -0. 074 mm accounting for 65%,respectively. And the total distribution rate of the two is 94. 69%,which is the maximum theoretical recovery rate of the gold at this grinding fineness. The recommended principle process flowsheet is gravity separation and flotation.
    Influence of Grinding Medium on Leaching Effect of Cyanide Tailings for Gold Extraction
    WANG Jiaqi, LI Yanjun, YU Jianwen, XU Hailong, ZHANG Xiaolong
    2022, 51(09):  140-145. 
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    In order to compare the influence of ceramic medium and cast iron medium stirring grinding on the leaching effect of gold in cyanide tailings,the gold leaching tailings of China Gold Group Sanhe Gold Industry Co. ,Ltd. were taken as the research object,and the gold leaching experiment was carried out. The research results show that the optimal process parameters in this experiment are grinding fineness of -6 μm accounting for 90%,dosage of JC leaching agent of 40 kg / t and leaching time of 12 h. Under the optimal process parameters,the technical indicators of leaching slag Au grade of 1. 29 g / t and leaching rate of 54. 45% can be obtained by using ceramic media grinding,and the technical indicators of leaching slag Au grade of 2. 15 g / t and leaching rate of 39. 45% can be obtained by using cast iron medium grinding. The leaching rate of gold under the condition of ceramic media grinding is significantly higher than that of traditional cast iron media grinding. After adding Fe3+ in the ceramic media grinding process,the leaching effect of gold was significantly decreased,indicating that the addition of Fe3+ was not conducive to the leaching of gold. Mechanism analysis shows that Fe3+ will be generated during the grinding process of cast iron medium,and Fe3+ will form iron oxyhydroxide (FeOOH) on the mineral surface,which hinders the diffusion process of CN- and deteriorates the leaching environment,thereby reducing the leaching rate of gold.
    Background and Genesis of Alkali Bearing Formation in Biyang Sag,Nanxiang Basin
    YAN Changhai, MA Zhenbo, LI Xiaolong, PEI Zhongchao, HAN Jiangwei, GUO Bo
    2022, 51(09):  146-154. 
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    Biyang Sag in Nanxiang Basin is rich in oil and gas resources,and contains the largest natural alkali deposit in Asia,which is also the third largest in the world. In this paper,the problems in the huge material source required for the formation of alkali deposit and the symbiosis of salt(alkali) ore and oil and gas resources are studied through comprehensive geological and geophysical analysis,and the background and genesis of alkali bearing formation,the possible genetic relationship between natural alkali,oil and gas and metal deposits in the adjacent Tongbai ore concentration area are discussed. The result shows that the Nanxiang Basin is a tectonic faulted basin formed on a special geological background with abnormal uplift of deep asthenosphere mantle and development of deep faults in the basin. A large number of hydrothermal minerals and mantlederived materials are found in the alkali bearing formation of Biyang Sag,and their component characteristics show strong deep thermal fluid activity. The main ore-forming materials of the whole alkali bearing formation,including dolomite,salt ( alkali), oil and gas (or oil shale),are mainly derived from mantle-derived hydrocarbon alkali fluids,and the upward migration of these fluids into the basin through regional deep faults results in mineralization. There should be bedrock oil and gas reservoirs in the deep part of the basin. The oil and gas,salt and alkali in the alkali bearing formation of Biyang Sag and the metal minerals of Tongbai ore concentration area may be formed in the same complete mantle-derived fluid metallogenic system.
    Study on Step Line Extraction Method of Open-pit Mine Based on Dense Matching Point Cloud #br#
    WANG Jiye
    2022, 51(09):  155-160. 
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    Step line is one of the main objects of open-pit mine survey. The traditional point measurement method of total station and GPS is time-consuming,labor-intensive and inefficient,while the modern measurement method based on UAV point cloud provides the possibility for efficient extraction of step lines. Based on the dense matching point cloud data constructed from UAV images,a step line extraction method with adaptive elevation threshold was proposed. Firstly,the terrain condition was judged by the covariance matrix of the neighborhood point cloud,and different elevation difference thresholds were adaptively selected according to different terrain to extract the step line feature points,which greatly reduced the number of false extraction. Then,based on the number of points in each point cloud cluster and elevation characteristics after point cloud clustering segmentation,the misextracted point clouds were removed,and the cubic B-spline curve was used to fit the feature points. Finally,the step line extraction of open-pit mine was completed. The test results showed that the method can efficiently extract the feature points of the step line in open-pit mine,and effectively distinguish the step line and the road edge line feature points. At the same time,the curve fitted according to the feature points has a good effect and truly reflects the actual position of the step line. The above analysis provides a new solution for the efficient measurement of step lines in open-pit mines.
    Analysis of Muckpile Shape in Open-pit Mine Based on UAV Aerial Survey Technique
    ZHANG Bingbing, LI Pingfeng, XIE Shoudong, CHEN Guangmu, CHEN Jingjing, HUANG Dongxing
    2022, 51(09):  161-166. 
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    Muckpile shape of open-pit mine is an important part of blasting effect evaluation. In order to accurately and efficiently evaluate,the corresponding evaluation index is defined,and the low altitude multi rotor small UAV aerial survey technology with good flexibility is adopted. Taking the blasting area of Tiemen 661 m platform in Dabaoshan Open-pit Polymetallic Mine as an example,according to the spatial layout and accuracy requirements of the stope,the relative heading height is set as 100 m,the side and heading overlap rate is 80% under the five direction aerial photography mode,and four image control points are set around,generate the three-dimensional visual real scene model of two stages before and after the bench blasting by Smart3D software. The error of 3D model and image control point elevation is small and 2. 79 cm respectively,which meets the requirements of aerial survey accuracy. Through the extraction of point cloud and elevation information by IData software,the spacial distribution shape and size parameters of muckpile are obtained. The cracking range of blasting area is large and the partition phenomenon of surface fragmentation is obvious. It is considered that the phenomenon is related to the design of hole network parameters and geological conditions. The engineering practice shows that the UAV aerial survey has certain feasibility in the analysis of muckpile shape,which provides a new idea for the analysis of bench blasting effect.
    Construction and Application of Intelligent System in Open-pit Mine under Dual 5G Network
    GE Husheng, GONG Fuhui, SUN Yanyan, KUANG Guoming, PENG Nanzhu, LIANG Chao, HU Jianhua
    2022, 51(09):  167-173. 
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    The new infrastructure for the new engine of economic development is the direction for the high-quality development of the future digital economy. And the digital twin technology based on 5G and F5G dual networks is the key to the construction of information infrastructure. The communication system of open-pit mine based on dual 5G network is proposed,three platforms of intelligent mining control,comprehensive production execution and three-dimensional visual control are constructed,and the mine safety monitoring and monitoring system is further integrated,so as to construct the construction architecture and system of intelligent open-pit mine. Taking Nannihu Molybdenum Mine as an example,the remote control and operation of intelligent equipment for open-pit mining are realized,which provides a new technical path for the construction of open-pit intelligent mine. The study results show that:① High-speed communication system is the guarantee of intelligent mine construction. The application of 5G and F5G dual communication network can realize real-time and efficient data transmission in the mine,which provides high-speed communication and data transmission channel for intelligent open-pit mine construction. ② With the construction of intelligent control and integrated production platform,a system characterized by digitization of mining environment and automation of mining equipment has been constructed,which realizes the intelligent process of mining design,planning,production and ore distribution,scheduling and decision-making. ③ Based on the three platforms,the intelligent mine architecture integrates the safety monitoring system,which forms the intelligent mode of open-pit mine safety production,and promotes the safe,efficient and intelligent construction of mine production.
    Study on Automatic Steer-by-wire System of Mine Explosion-proof Auxiliary Vehicles
    CHEN Yongfeng, WEI Jianlong
    2022, 51(09):  174-179. 
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    According to the Guiding Opinions on Accelerating the Intelligent Development of Coal Mines,it is proposed that large coal mines should be basically intelligent by 2025,with robots operating in key underground positions,and intelligent unmanned auxiliary transportation,combined with intelligent control technology and road sensing information formation and feedback technology,multi-sensor information fusion technology,an automatic steer-by-wire system for mine explosion-proof auxiliary vehicles was developed. The composition and implementation method of the steer-by-wire system based on the steering angle deviation PI control technique were introduced in detail. The deviation between the target steering angle and the actual steering angle was used as a signal,and the steering wheel deflection direction and angle could precisely controlled through PI closedloop control,so that the system output could be stable and accurate,quickly follow the command and target turning angle,and then realize the precise steering control of the vehicle′s automatic driving. A simulation test was carried out by building an automatic steer-by-wire platform for auxiliary vehicles. The test results showed that the steer-by-wire system based on the steering angle deviation PI closed-loop control technology responded quickly,the automatic steering error was about 2°,and the overshoot was small. It has realized the automatic steering precision control and automatic correction of auxiliary vehicles,and provided a technical path for the realization of the future of Internet + scientific mining with few people (unmanned) mining.
    Design and Development of 3D Virtualization Tectonic Occurrence Based on Unity3D
    PENG Siyuan, LI Xiaohui, YUAN Feng, PENG Hui, MENG Fanrong, CHEN Shouwen, FENG Xiaokun
    2022, 51(09):  180-187. 
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    The occurrence measurement of structural plane is one of the important work of geological survey and research. In the face of inaccessible areas such as high and steep slope and unstable lithology,there are some problems in traditional measurement methods,such as poor safety and low measurement efficiency,which need to be solved by UAV and threedimensional virtualization. Unity3D platform is widely used during this years. It has been gradually applied to geological related work,but the previous research work focuses on 3D visualization,as well as the research on further applying it to 3D geological survey is relatively weak. According to the above requirements,this paper studies the 3D virtual structural attitude measurement method,and designs and develops the 3D virtual structural attitude measurement software system based on Unity3D platform. The system realizes the practical functions of 3D structural attitude measurement based on 3D real scene model,geological recording and automatic drawing of structural interpretation maps. The case study results show that the 3D virtual structure occurrence measurement system based on Unity3D is easy to develop and use. Combined with the nine point measurement method and the adjustment method of finding the mean after removing the quartile,the measurement effect is better,and the error of measurement can be effectively reduced. The measurement results are in good agreement with the traditional field attitude measurement results,and the errors are controlled within 5°,which can meet the basic requirements of engineering application. The related methods and software systems can significantly reduce the difficulty of field measurement and improve the measurement efficiency while ensuring the measurement accuracy.
    Study on Inspection System of Underground Mine Equipment Based on Mixed Reality
    MA Xinbo, JING Hongdi, LIU Xiaobo, YU Jianyang, SUN Xiaoyu
    2022, 51(09):  188-193. 
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    Aiming at the problems of low efficiency,long cycle and complex inspection process caused by insufficient technical ability and complex inspection process of underground mine. This paper designs an inspection system of underground mining equipment based on mixed reality technique. The system uses HoloLens Mixed Reality equipment,builds a virtual simulation development environment of mixed reality through Unity3D platform. The real equipment 3D model and standard maintenance opinion guidance database are established,and the patrol path navigation and equipment information management,equipment model display,maintenance opinion guidance and parts to be inspected are realized. This paper describes the framework design and function of the inspection system,summarizes the process of model establishment and key technologies. Taking the crusher of Yanqianshan Iron Mine as the study object,the comprehensive test of the system is carried out from the perspective of the coordination of user experience and system performance. The application results show that the system simplifies the tedious workflow of the traditional inspection,reduces the complexity of the inspection personnel′s work,effectively improves the inspection efficiency and has good man-machine interaction.
    Study on Optimization of Mine Ventilation System under Surface Air Leakage in Goaf
    NIE Xingxin, GAO Jian, UO Jinping, FU Xiaoyan, ZHAO Haorui
    2022, 51(09):  194-200. 
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    The sublevel caving method with bottom pillar is adopted in Chengde Copper Mine. With the development of underground mining and the increase of mined-out area,air leakage occurs in mined-out area. Due to the limitation of mining method,the air leakage channel cannot be filled,blocked and communicated with the surface,which has a serious impact on the stability of mine ventilation system. By analyzing the characteristics of air leakage in the goaf of the mine,a three-dimensional physical model of the surface of the goaf is established. based on Fluent software,the flow field law of air leakage velocity in the goaf is numerically simulated. The research shows that under the condition of surface air leakage in goaf,the distribution of flow field in working face and goaf has obvious zoning law in all directions. When the air leakage goaf channel is closer to the working face,the greater the impact on the airflow of the working face is,the airflow in the goaf tends to move to a certain rule to the return airway. When the air leakage velocity is small,the air flow in the goaf of the air leakage channel and the working face is roughly U-shaped,and the closer to the working face,the greater the air flow. According to the above analysis,it is proposed that the air leakage channel is added to the ventilation network by using the air return through the surface goaf,and the air return through the surface goaf is induced at the point where the wind direction is most likely to change. The induced ventilation system is formed,and the dynamic model of the ventilation system is reconstructed. The induced ventilation research is carried out for the ventilation network the air leakage in the goaf,and the air leakage problem in the goaf is better solved. The above studies reflect that taking the goaf as the induced ventilation network of the ventilation circuit and re-optimizing the ventilation network are effective means to solve the problem of air leakage control in goaf.
    Grouting Transformation Technology of Ordovician Strong Karst Aquifer Floor in Yanlong Mining Area
    REN Jinwu, GAO Jiaping, JI Hongying, ZHANG Pan
    2022, 51(09):  201-208. 
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    Yanlong mining area is located in the west of Henan Province. In deep mining,No. 2 coal seam is threatened by karst fissure water of Ordovician strong aquifer,its mining safety is affected by increasing water pressure in the Ordovician limestone,the structure development of coal seam floor,the instability of water-barrier,etc. Based on the analysis of hydrogeological data and detection of water-rich floor by transient electromagnetic technology,the accurate calculation model of correction floor grouting depth was established,and the water disaster prevention technology of floor grouting reconstruction of No. 2 coal seam in Yanlong mining area was put forward,besides that,the industrial test was carried out. The results showed that three types of abnormal water-rich areas were in 12061 working face floor,where rock joints and fractures were more developed. The abnormal water-rich areas covered most of the working face floor,where water inrush could occur. The rhomboid borehole arrangement was beneficial to reduce the hole-spacing. The final floor grouting transformation depth was 65 m,the grouting pressure 9 MPa,the grouting diffusion radius 25 m. The aquifers of Ordovician limestone and the lower section of Taiyuan Formation could become a relative water barrier by grouting,which cut off the hydraulic connection between the floor Ordovician limestone aquifer and No. 2 coal seam. After floor was grouted,the water yield of the test hole was no more than 10 m 3 / h,the borehole wall was smooth,the original five abnormal water-rich areas disappeared,and the grouting transformation effect was remarkable.
    Ecological Restoration Model and Existing Problems Analysis of Legacy Abandoned Mine in the Trunk Stream and Tributaries of the Yangtze River:a Case Study of Sichuan Province
    WEI Peng, WANG Daguo, LIU Yun, YU Chen, LI Tian
    2022, 51(09):  209-215. 
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    In order to promote the construction of national ecological civilization,Ministry of Natural Resources of the People′s Republic of China and provincial natural resources departments have issued relevant policy documents in succession, making it clear that ecological restoration will be carried out on legacy abandoned mine in key areas such as the Yangtze River Basin. In order to analyze the problems existing in the ecological restoration of legacy abandoned mine and summarize its ecological restoration model,based on the field investigation of ecological restoration of nearly 1 000 legacy abandoned mine in Sichuan Province,combined with relevant national and local policy documents,the connotation of ecological restoration of legacy abandoned mine in the trunk stream and tributaries of the Yangtze River is elaborated,the main ecological restoration modes of stope slope,stope bottom platform and industrial square,and waste dump are induced,the classic cases of ecological restoration are summarized,and the existing problems in the process of ecological restoration,such as incorrect geological patch range and geological direction,unclear concept of cultivated land,focous on geological hazard engineering but less to ecological restoration engineering,and unreasonable arrangement of engineering measures are analyzed. It provides reference for the ecological restoration of legacy abandoned mine in the future.
    Study on Physical Properties and Heavy Metal Stability of a Tailings Filling Material from Sichuan
    HOU Puyao, FU Kaibin, ZHA Wei, LIAO Fei, DENG Quanlin
    2022, 51(09):  216-222. 
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    In order to reveal the physicochemical properties and heavy metal toxicity of a tailings filling material in Sichuan,tailings and common cement were used as raw materials to prepare the underground filling materials. Full-factor test was used to explore the influence of tailing particle size and cement-sand ratio on the physicochemical properties and heavy metal stability of samples. Regression approach with SPSS software was conducted to study the fluidity and compressive strength of filling materials. XRD,FTIR and SEM were carried out to reveal the hydration reaction process and the stabilization mechanism of heavy metal in filling materials. The test results showed that the compressive strength of the tailings filling material increased with increasement of the tailings particle size and the cement-sand ratio. The filling material with the coarse tailings met easily the strength requirements. However,the large flake and angular particles led to the decreasement of the flow performance of the filling material. The heavy metal was immobilized in the coarse tailings filling materials through precipitation,electrostatic adsorption and ion replacement during the hydration reaction process of cement. The leaching toxicity analysis showed that heavy metals concetration met the Ⅲ groundwater water quality standard. The tailings underground filling material consisted of the tailings and the cement was reliable and safe,which meet the requirement of physicochemical properties and heavy metal stability.
    Study on Hydrogen Sulfide Removal with Calcined Product from Medium and Low-grade Magnesite
    LI Dongliang, WANG Kangjun, LI Yunjia, ZHENG Yuhua, XU Guangwen, CUI Yanbin
    2022, 51(09):  223-229. 
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    Medium and low grade magnesite is piled up because of the difficult in direct ultilization,while the preparation of high temperature desulfurizer is one of the effective ways for its resource utilization. The desulfurization performance of the calcined products under different calcination temperatures and calcination time were studied. The grain size,specific surface area and pore size of the products were characterized by XRD,SEM and BET,and the removal mechanism of H2S was analyzed from the microscopic perspective. Under the conditions of calcination temperature of 750 ℃ and calcination time of 30 min,the specific surface area of calcination products can reach 168. 42 m2 / g,the average pore size is 4. 44 nm,and the grain size is small (9. 10 nm). The calcination products obtained under these conditions were used for desulfurization. Under the adsorption temperature of 500 ℃ and the space speed of 7 200 h-1,the H2S penetration time was 162 min and the sulfur penetration capacity could reach 14. 75 mg / g. The results provide a new way for the resource utilization of medium and low grade magnesite.
    Study on the Strength and Hydration Characteristics of Phosphogypsum-phosphorus Slag Composite Cementitious Material
    LIU Dongmei, WANG Weiqi, PENG Yanzhou, SHI Hongyu, LI Dongsheng, WANG Bin
    2022, 51(09):  230-237. 
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    In order to realize the recycling of phosphogypsum and phosphorus slag solid waste materials,and improve the utilization rate of industrial solid waste,the experiment uses phosphogypsum and phosphorus slag as the main raw materials,along with using water glass,cement clinker and phosphogypsum to jointly stimulate the activity of phosphorus slag for preparing phosphogypsum-phosphorus slag-based composite cementitious materials. The paper discuss the effects of phosphogypsum content,sodium silicate content,and phosphorus slag grinding system on the strength of phosphogypsum-phosphorus slag-based composite cementitious materials,while using SEM and XRD to analyze the microscopic structure and composition morphology of phosphogypsum-phosphorus slag-based cementitious materials hardened. The results showed that when the content of phosphogypsum is less than 50%,the strength of the composite cementing material at each age is inversely proportional to the content of phosphogypsum;when m(phosphogypsum) ∶ m( phosphorus slag) ∶ m( clinker) is 20 ∶ 72 ∶ 8,the sodium silicate content is 1. 5%,the 28 d compressive and flexural strengths of the cementitious material reach the maximum value of 43 and 6. 3 MPa. The grinding system will produce " micro-medium effect" ,which is beneficial to improve the strength of composite cementitious materials. The main hydration products of composite cementitious materials are C—S—H gel and ettringite. The ettringite and undissolved phosphogypsum are formed as the skeleton and was wrapped,filled and interwoven together by C—S—H gel to form a compact structure. When composite cementing materials are used to replace cement as filling materials in mining areas, the recommended phosphogypsum content is 20% ~ 40%.
    Study on Preparation and Properties of Controlled Low Strength Materials with Alkali Activated Red Mud
    SONG Di, PANG Laixue, YANG Da, LU Mingyang, ZHAO Yongqiang, CHEN Renshan
    2022, 51(09):  238-243. 
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    Controlled low-strength materials(CLSM) were prepared with red mud,fly ash and mineral powder as raw materials,NaOH as activator and polycarboxylate superplasticizer as dispersant. The working and mechanical properties of the materials under different mixture ratios of red mud and fly ash were studied. When the dosage of red mud and fly ash is 2 ∶1,the dosage of mineral powder is 10% and the dosage of NaOH is 1. 5%,the maximum fluidity of mixing flow is 236 mm,and the maximum unconfined compressive strength of the specimen at 28 days is 6. 5 MPa,which meets the specification requirements of controlled low-strength materials. XRD,FTIR and SEM were used to explore the mineral composition and microstructure of controlled low-strength materials. It was found that red mud,fly ash and mineral powder were hydrated to form C—S—H,AFt, a small amount of hydrated calcium pyrite and C4AF. The strength development of materials depends on the microstructure of flocculent,honeycomb and sheet. The research results provide a new technical way for the large-scale application of industrial solid waste in the field of controlled low-strength materials.
    Influence of Low Grade Spodumene on Preparation of Mulite-based Compound Ceramics with Bauxite Tailings
    YANG Fan, WANG Qi, MIN Xin, FANG Minghao, HUANG Zhaohui, LIU Yangai, WU Xiaowen, MI Ruiyu, LIU Changmiao, LIU Yulin, HUANG Feihui
    2022, 51(09):  244-250. 
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    On the basis of ceramic preparation with reusing of bauxite tailings,explore the influence of melting effect of low grade spodumene on the preparation of mulite-based compound ceramics. The effects of admixture content (0%,2%,5%, 10%) and sintering temperature (850,900,950 ℃ ) on the phase behavior,microstructure and mechanical properties of mullite multiphase ceramics,which are prepared by batching-mixing-drying-forming-sintering were studied. The results show that the main phases of mullite multiphase ceramics prepared by low temperature sintering is quartz,mullite and corundum,increasing sintering temperature is beneficial to mullite formation in both thermodynamic and kinetic aspects. The melting effect of low garde spodumene can increase the high temperature resistant phases of mullite and corundum in the samples,and play a supporting role in the microstructure,which is beneficial to improve the mechanical properties of the samples. The test sample,with the admixture content of 10% and preparation at 950 ℃ for 2 h,was appeared the compressive strength of 47. 0 MPa and the volume density of 1. 77 g / cm3.