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Temperature variation and smoke composition of flame-retardant conveyor belt in the early stage of friction accident
DUAN Jialei, LIANG Yuntao, JIA Baoshan, SUN Yong, WANG Ruide, LUO Yihang, CUI Xinfeng
2024, 9(2): 135-143.   doi: 10.19606/j.cnki.jmst.2024.02.001
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This study improves the roller friction experiment platform for monitoring the temperature of flame-retardant conveyor belt in order to realize the early warning of belt conveyor fire.Mass spectrometry is used to analyze the patterns of temperature rise and smoke composition of steel cord flame-retardant conveyor belt in the early stage of friction accident.Results show that as friction progresses, the flame-retardant conveyor belt exhibits symmetrical distribution of surface temperature, where the highest temperature gradually approaches to the center of the conveyor belt and the composition of smoke changes with temperature.The steel cord flame retardant conveyor belt warming process could be divided into three stages according to their warming rate and smoke composition output: stage of oxidation reaction(ambient temperature to 100 ℃), stage of substitution reaction(100~160.2 ℃), and pyrolysis reaction(after 160.2 ℃).The initial stage features low heat capacity of the conveyor belt with quickly-rising temperature, where the products are mostly alkyl and ester compounds.The second stage exhibits gradual increase of heat capacity, slowly-rising temperature, where the products are mostly nitro, ether, and carboxylic acid compounds.The last stage features stable heat capacity of the conveyor belt, the lowest heating rate, where the chlorine-containing compound is detected for the first time in the smoke composition.
High-temperature and high-pressure simulation of coal graphitization with SiO2 additive
CHEN Gaojian, CAO Daiyong, WANG Anmin, WEI Yingchun, LIU Zhifei, ZHAO Meng
2024, 9(2): 144-155.   doi: 10.19606/j.cnki.jmst.2024.02.002
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This study investigates the effect of SiO2 minerals on coal graphitization under natural conditions through high-temperature and high-pressure simulation experiment to invert the coal-based graphite formation environment.We thoroughly mixed the SiO2 additive with the sorted vitrinite in coal (from the Gemudi mining area in Guizhou province[SW China]) and then carried out high-temperature and high-pressure simulation experiment with ranging from 600 ℃ to 1 200 ℃, 1.5 GPa to 2.0 GPa.The graphitization products of the samples were analyzed by X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM) to investigate the influence of the SiO2 additive on the process of coal graphitization.Results show that in contrast to the graphitization-promoting ability exhibited in high-temperature environments, SiO2 demonstrates a hindering effect on graphitization in high-temperature and high-pressure environments, inhibiting the growth of coal graphitization.This finding provides an hypothesis for the lower graphitization of coal in areas with strong tectonics under natural conditions.
Study on site selection of underground gasification in deep coal seam: a case study of J148 area in Dongsheng Gas Field
WANG Jinchang, LIU Gang, ZHANG Hui, WENG Xinlong, MA Chao, ZHANG Ru
2024, 9(2): 156-166.   doi: 10.19606/j.cnki.jmst.2024.02.003
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The feasibility of underground gasification of Yan 9 coal seam of the middle-lower Jurassic Yan ′an Formation in J148 area of Dongsheng gas field is systematically studied from the perspectives of geological structure, hydrogeology and coal gasification characteristics, and the prospects of carbon sequestration by using the pore layer, aquifer layer and tight gas layer in the deep coal gasification cavity are discussed.The results show that the coal seam of Yan 9 in this area is stable when the buried depth is 1 264~1 285 m and the dip angle is less than 1°.In the interior of the gasification target constituency, the structural faults are not developed, the joint cracks are not developed, there are occasional cracks but the section is fresh and closed, and the cavity of the coal seam after gasification has a good tightness, which has little influence on the construction and expansion of coal gasification furnace, and can meet the implementation of large-scale coal gasification projects.There is a continuous water barrier layer on the top and bottom of Yan 9 coal seam, which can prevent the influence of groundwater on the direct water filling of coal seam, and is conducive to the layout of underground gasifier.The thickness of the roof water-barrier layer is less than the height of the water-conducting fissure zone, there is a risk of indirect water filling through the roof aquifer, but the roof aquifer is a weak water-rich aquifer, and the risk of small water inflow is controllable.The thickness of the floor water barrier layer is greater than the safe thickness of the floor water barrier layer, which can effectively prevent the risk of direct water filling to the coal seam.In general, Yan 9 coal seam has moderate thickness, little waste, low ash, low sulfur, high calorific value non-stick coal, high coke reactivity, and has a good development prospect.In view of the large amount of CO2 emission from large-scale gasification mining of deep coal seam, the feasibility of CO2 safe geological storage by using coal seam burning and caving area, top and bottom aquifer and lower tight natural gas layer was discussed.The analysis shows that 60.8 % ~88.2 % of CO2 produced by coal seam gasification can be stored in the pore layer and the top and bottom aquifer in the gas-burning and air-burning zone of Yan 9 coal seam.Combined with the development of tight natural gas in the Upper Paleozoic of Dongsheng gas field, it is expected to achieve near-zero carbon emissions in the process of deep coal seam gasification mining by using CO2 generated by coal gasification for natural gas displacement and storage.
Adsorption and seepage properties of permeable reaction barrier construction materials for underground coal gasification
WANG Fan, XV Bing, CHEN Lunjian, XING Baolin, SU Faqiang
2024, 9(2): 167-177.   doi: 10.19606/j.cnki.jmst.2024.02.004
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Groundwater pollution induced by Underground Coal Gasification(UCG)seriously hinders its development.Permeable Reactive Barrier(PRB)remediation therefore stands out as a major research focus for in-situ groundwater remediation, where the characteristics of PRB material is crucial to their effective operation.This study thus examines the adsorption properties of sand, organic bentonite, and activated carbon on phenol, a characteristic organic pollutant associated with UCG.A self-constructed permeation experimental system is employed to study the adsorption and permeation characteristics of sand, organic bentonite, activated carbon, mixtures of sand and organic bentonite, as well as sand and activated carbon to investigate their comprehensive impact in purifying contaminated water.The results indicate that: ①Organic bentonite exhibits a rapid adsorption rate for phenol in solution, reaching adsorption equilibrium within 10 minutes, despite a relatively low adsorption capacity(1.98 mg/g). Activated carbon, on the other hand, demonstrates a slower adsorption rate yet a higher adsorption capacity(2.22 mg/g).②The adsorption of phenol by organic bentonite conforms to the Freundlich isotherm model, with parameters kF = 0.040 and n = 1.207.Activated carbon follows the Langmuir isotherm model, with parameters Smax = 2.44 mg/g and kL= 0.125 L/mg.③The permeability coefficients of sand and activated carbon are 1.006×10-3 m/s and 4.761×10-2 m/s, respectively.The mixture of sand with activated carbon or organic bentonite could effectively moderate the permeability of the mixed material.When the mass ratio of sand to organic bentonite increases from 1∶1 to 3∶1, the permeability coefficient of the mixed material increases from 2.624×10-6 to 3.468×10-5 m/s.Conversely, when the ratio of sand to activated carbon increases from 1∶1 to 3∶1, the permeability coefficient of the mixed material decreases from 1.379×10-3 to 1.301×10-4 m/s.
Experimental study on the influence of seawater corrosion on the physical and mechanical properties and microstructural failure behavior of sandstone
ZHOU Tao, CHEN Changpeng, ZHANG Yangyang, YIN Xuehan, CHEN Jiarong
2024, 9(2): 178-189.   doi: 10.19606/j.cnki.jmst.2024.02.005
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In this study, experimental tests were conducted on sandstone specimens to study the influence of seawater corrosion on their physical and mechanical properties as well as failure behavior.Different concentrations of simulated seawater solutions were prepared based on seawater sampling data from the vicinity of the Shenzhen cross-harbor tunnel.Sandstone specimens were first treated with corrosion immersion in these solutions for different times before they were subjected to uniaxial compression tests.The acoustic emission and scanning electron microscope(SEM)techniques were employed to investigate damage and microstructural evolutions of the corroded sandstone.The results show that as the concentration of corrosive solution increases, the surface of sandstone specimens peel off earlier, the area is larger, and there is a slight increase in specimen density.The peak stress and elastic modulus both decrease with increasing corrosion time, but the magnitude and rate of decrease are different.With the increase of corrosion time and concentration, the active period of acoustic emission events increased in all sandstone specimens, except for the ones in the high concentration group, where the active period of acoustic emission events was shortened after 45 d of corrosion.SEM results show that with increase of corrosion time and concentration, the internal microdefects in the sandstone specimens progressively developed, and the microstructures gradually loosened.Furthermore, the area of honeycomb corrosion area increased in size and the area of white crystallization of salt ions gradually expanded.
The impact of temperature and pre-wetting of aggregates on rheological properties of coal gangue mortars
WANG Zhenbo, FAN Yurun, ZUO Jianping
2024, 9(2): 190-198.   doi: 10.19606/j.cnki.jmst.2024.02.006
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Mine filling and tunnel spraying projects pose high requirements on the rheological properties of cement-based materials.The types, conditions of fine sands and the exposed environment have significant effects on the rheological properties.In this light, this paper uses coal gangue sand instead of quartz sand as the fine aggregate of cement-based material and investigates the effect of temperature and aggregate prewetting on the rheological properties of mortar and its mechanism.Results show that the shear stress-shear rate relationship of coal gangue mortar conforms to the characteristics of Herschel-Bulkley(H-B)model, with higher rheological index(higher than 1)and higher consistency than that of quartz sand mortar.The apparent viscosity of coal gangue mortar decreases with increasing temperature, but the effect of aggregate prewetting is not significant.The yield stress of coal gangue mortar at 30 ℃ is 2.99 Pa, 1.45 times higher than that at 10 ℃, and 2.13 times higher after prewetting.The thixotropic ring area of coal gangue mortar is higher than that of quartz sand mortar, and the thixotropic ring area of pre-wetting coal gangue mortar is 398.4 Pa/s, while that of dry coal gangue mortar is 283.3 Pa/s.The obtained results are expected to provide evidence for the rational utilization of coal gangue sand and the design and preparation of rheological materials served in complex environment.
Study on dynamic splitting and evolution mechanism of sandstone under freeze-thaw cycle
YANG Guoliang, SHANG Zhuo, ZOU Zehua, BI Jingjiu, DONG Zhiwen
2024, 9(2): 199-208.   doi: 10.19606/j.cnki.jmst.2024.02.007
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This study attempts to investigate the dynamic tensile mechanical properties of sandstone under freeze-thaw cycle by using the split Hopkinson pressure bar (SHPB)test system to perform dynamic splitting tests on sandstone samples with freeze-thaw cycle 0, 10, 20 and 40 times at different impact speeds.Also adopting the high-speed digital image correlation (DIC), we observed the dynamic tensile failure process of the specimen, where we analyzed the strength characteristics, deformation process and failure form of frozen sandstone under dynamic tensile stress in different freeze-thaw cycles.Results show that 1)the dynamic tensile σ-t curves of frozen sandstone and ordinary sandstone exhibit similar patterns of stress variation under different freeze-thaw cycles, which can be divided into four stages: low speed growth section, high speed growth section, peak plateau section and decreasing section; 2)the peak tensile stress increases linearly with the increase of stress loading rate; 3)the peak tensile stress of frozen rock has a certain freeze-thaw cycle effect, and there is a strong correlation between the peak tensile stress and the number of freeze-thaw cycles.The dynamic tensile strength of frozen rock increases first and then decreases as the number of freeze-thaw cycles increases.Under the same impact pressure, the frozen rock specimen shows certain freeze-thaw cycle effect as the tensile strain at the center shows N=40>20>0>10 under 4 kinds of freeze-thaw cycles.
Experimental study on the evolution patterns of bursting liability of hard and brittle sandstone under microwave thermal shock
TENG Teng, JIA Wenjian, YI Peng, ZHAO Yixin, ZHU Xiaoyan, XU Duo
2024, 9(2): 209-216.   doi: 10.19606/j.cnki.jmst.2024.02.008
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Rock burst is a major disaster in deep mining, where bursting liability is an important indicator of rock burst risk. This study therefore intends to explore the impact of microwave thermal shock on rocks with strong bursting liability by testing the microwave thermal shock and uniaxial compression of typical hard brittle sandstone and analyzing their physical and mechanical properties and the response of bursting liability indicators after microwave thermal shock. The research results show that: (1) After microwaving, the surface temperature of the sandstone continues to rise with the increase of thermal shock time, until it breaks at 150 s; (2) Microwave thermal shock has a significant effect on the structural damage of sandstone. After 120 s of microwaving, the longitudinal wave velocity and elastic modulus decrease by 15.12 % and 8 % respectively. The AE signal density increases at each stage of uniaxial compression, and the maximum absolute energy at the final destruction of sandstone decreases by 42.3 %; The dynamic failure time of rock increases by 259 %, the impact energy index decreases by 95 %, and the elastic energy index decreases by 92 %. This research offer references for efficient rock breaking in deep earth engineering and prevention and control of rock burst in resource mining.
Research on the application status and material properties of aeolian sand filling mining
WANG Shushuai, YUE Zhongwen, KANG Yiqiang, LUO Lei
2024, 9(2): 217-232.   doi: 10.19606/j.cnki.jmst.2024.02.009
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Using aeolian sand(AS)for backfilling can realize local material extraction and turn waste into treasurethe, and realize coordination of green mining and AS control.The AS filling mining is mainly applied to the backfilling of goaf under Highway, backfilling mining of coal mine and metal mine.Grouting and sand injection in the goaf, solid backfilling mining, high water backfilling mining and cemented backfilling mining are developed.Long wall backfilling mining, strip backfilling mining and roadway backfilling mining are adopted.The research on the properties of cemented AS backfilling materials focused on slurry fluidity and backfill strength.In this paper, the rheological properties of cemented AS slurry with different proportions and curing times are analyzed, and cemented AS backfills are toughened by using polypropylene fiber.The results showed that the rheological parameters of cemented AS slurry increased with the curing time, and the addition of fiber significantly improved the brittleness characteristics of cemented AS backfills.
Research on microseismic source localization based on optimized leading wolfpack algorithm
LI Xiaoyan, ZHANG Mingwei, SONG Lei, PANG Yingchun, ZHANG Jieru
2024, 9(2): 233-242.   doi: 10.19606/j.cnki.jmst.2024.02.010
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In order to analyze the impact of different heuristic methods on the precision of microseismic source localization, an optimized Dominant Wolf Pack Algorithm(DWPA)is proposed.This algorithm builds upon the Dominant Wolf Pack Algorithm and introduces adjustments to two parameters, namely the search step size and the siege step size, enhancing its ability to escape local optima during the search process.The effectiveness of the optimized DWPA is validated through theoretical model inversion and engineering numerical analysis.A comparative study with commonly used heuristic algorithms, Particle Swarm Optimization(PSO)and Simulated Annealing(SA), reveals that the optimized DWPA exhibits faster convergence, higher accuracy, and reduced sensitivity to P-wave velocity errors.This research provides new insights for the application of intelligent heuristic algorithms in microseismic source localization.
Quantitative analysis of dust pollution characteristics and influencing factors in mining areas based on statistical modelling
ZHAO Hongbao, ZHAI Rupeng, GE Haibin, CHEN Chaonan, LIU Shaoqiang, JING Shijie
2024, 9(2): 243-257.   doi: 10.19606/j.cnki.jmst.2024.02.011
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As disorderly dust emission of open-pit mines often leads to ecological degradation, this study therefore conducts a quantitative analysis on the evolution patterns of particle changes and the influence of environmental indicators on the weights of microdust. Taking the main regions of dust occurrence in Hequ open-pit coal mine as the subject for research, this study uses the dust monitoring system to obtain data on TSP, PM10, PM2.5 and environmental indicators in different target regions. We conducted comparative analysis on the differences in the distribution of particles with different sizes based on dust concentration and introduced the Institute for Administrative Quality Improvement method, Pearson correlation matrix analysis and Grey Relation Analysis to explore the core pollutants, the intrinsic correlation of dust with different particle sizes, and the correlation between environmental indicators and dust concentration in the target regions. Based on the univariate regression analysis, MLR and PCA-MLR, we verified the predictions of the MLR and the PCA-MLR model by MRE. The results show that: The concentration of dust with different particle sizes in Region No.1 (excavation site) and Region No.3 (coal yard) exceeded the secondary limit in the current standard, while the concentration in Region No.2 (traffic artery) only exceeded the primary limit. ②The dust pollution capacity of different regions was consistent with results from IAQI assessment: Region 1>Region 3>Region 2, where the core pollutants were all PM2.5. When the concentration of TSP was consistent in different regions, we found Region 2>Region 3>Region 1 in terms of their dust pollution capacity. ③Dust concentrations in different areas were found to be linearly significant. ④The patterns of fitting in multivariate linear equations based on MLR models of different regions tended to be consistent with the Pearson correlation of dust concentration, with the multivariate fit outperforming the univariate fit. We also found Region No.3 (3.02 %)> Region 2 (9.46 %)>Region 1 (10.75 %) in terms of the prediction accuracy of MLR model.⑤TSP and PM10 were strongly positively correlated with barometric pressure while PM2.5 was strongly negatively correlated with relative humidity in Region No.1;dust with different particle sizes was strongly negatively correlated with temperature and wind speed in Region No.2 yet only negatively correlated with temperature in Region No.3.⑥The PCA-MLR model outperformed the direct MLR model with a 56.63 % and 13.41 % increase in microdust weights and environmental indicators.
Bidirectional reinforcement of narrow pillar with inflatable lock-type anchor experimental investigation and its application
WANG Jun, LV Shunzhang, YANG Guang, WANG Bo, GU Changwan, WANG Gang
2024, 9(2): 258-269.   doi: 10.19606/j.cnki.jmst.2024.02.012
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This study targets at asymmetric deformation of narrow coal pillar in gob-side entry driving.We put forward the bidirectional reinforcement of narrow pillar with opposite-crossing anchor cable.Specifically, we designed two types of anchor cable structure: the byelongation type and the expansion lock type, and carried out the pull-out test of opposite-crossing anchor cable, the test shows that both anchor cable structures could meet the tensile requirements.We conducted comparative analysis on the morphology of anchor cable failure, construction convenience and the economic aspect of material selection, where the expansion lock type crossed anchor was selected for narrow coal pillar bidirectional reinforcement.Furthermore, we investigated the bearing deformation patterns of coal pillars and the stress characteristics of anchor cables under different reinforcement methods through similar model tests and numerical simulation.Results show a 96.04% increase of peak load in the specimen reinforced by the double-row tight opposite-crossing anchor cable compared with that of the not reinforced specimen, and higher stability of the narrow pillar reinforced by the double-row tight opposite-crossing anchor cable as the rows of the anchor cable increases in number.The expansion lock anchor type crossed cable improved the energy storage and the critical failure point before the coal pillar was destroyed.Finally, the engineering test of expansive lock type crossed anchor cable to reinforcing narrow coal pillar was carried out in the transportation roadway of 123 lower 04 working face of Jining No.3 Coal Mine.The monitoring show that the anchoring force of the anchor cable exceeded 220kN, with 70& reduction of the coal pillar in the reinforcement area and good overall stability of the narrow coal pillar.It proves the feasibility of the bidirectional reinforcement technology of narrow pillar and provides new technical way for gob-side entry driving.
Study on influencing factors of stope thermal environment in Maoping Lead Zinc Mine
KANG Jianhong, TIAN Jiakuo, WU Yuntao, CUI Shuwen, LI Qing, SONG Xiaolin
2024, 9(2): 270-277.   doi: 10.19606/j.cnki.jmst.2024.02.013
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Mine thermal hazards are increasingly becoming a major problem for the deep mining.Taking Maoping Lead Zinc Mine as an engineering case, this article adopts the methods of field test and numerical simulation to study the influences of different heat sources on the thermal environment of deep mine quarry.A physical model of Maoping Lead Zinc Mine stope was constructed according to the measured temperature gradient and thermal environment parameters, and COMSOL software was used to analyze the effects of four heat sources, including airflow temperature, human body, electromechanical equipment and backfill, on the temperature of the stope and the surrounding rock under the condition of lower ground temperature.The numerical calculations were validated by field temperature measurements.The results show that the current mining level has a low ground temperature of 21.60 ℃, and the ground temperature gradient is 1.66 ℃/hm.Ash-sand ratio is an important factor affecting the heat release of backfill.The heat generated by backfill will not only be transferred directly to the stope by airflow, but also be conducted to the roadway wall through the surrounding rock, resulting in the temperature rise of the stope.Ground temperature has a great influence on stope temperature, and the stope temperature increases linearly with the increase of ground temperature.Each heat source shows different influence degree on the stope environment in Maoping Lead Zinc Mine, with airflow significantly increasing the stope temperature, followed by backfill and electromechanical equipment, and the human body exerting the smallest impact.
Parameter optimization of coagulation and sedimentation for fine suspended solids removal from mine water
HOU Pin, QIN Haoming, LIU Hao, XV Dongying, JIA Shuhan, ZHANG Zhouai, WANG Jianbing
2024, 9(2): 278-285.   doi: 10.19606/j.cnki.jmst.2024.02.014
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In response to the issue of small particle size and difficult removal of suspended particles in the mine water of Baorixile open-pit coal mine, this study probed into the optimal parameters of the coagulation and precipitation process through single-factor and orthogonal experiments, and explored the mechanism behind the coagulation of fine particles in mine water.The optimal process parameters for coagulation and precipitation include: 50 mg/L of polyaluminum chloride (PAC), 5.0 mg/L of non-ionic polyacrylamide (NPAM) under 1 minute of rapid stirring (300 r/min), 8 minutes of slow stirring (50 r/min), and 5 minutes of settling.Under these optimum process conditions, the concentration of suspended solids (SS) is 5.0 mg/L with a removal efficiency of 99.1 %.Compared to the sole addition of PAC, the removal efficiency of fine particles below 10 μm increased by 25.9 %.Additionally, theζpotential of the mine water decreased from -40.9 mV to -16.3 mV, indicating that the coagulation mechanism of fine particles is mainly attributed to the adsorption and charge neutralization of PAC and the bridging effect of PAM.
Modification of lead dioxide electrode and electrocatalytic degradation of anthracene in coking wastewater
ZHANG Liping, YUAN Hexia, AN Yiyun, WANG Jing, DUAN Mengnan, LEI Wenbo, WANG Lifang
2024, 9(2): 286-294.   doi: 10.19606/j.cnki.jmst.2024.02.015
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To investigate the electrocatalytic degradation effect of anthracene in coking wastewater, Ti/PbO2, Ti/PANI/PbO2 and Ti/PANI/PbO2-Ce electrodes were prepared by electrodeposition, and the electrodes were subjected to scanning electron microscopy and X-ray diffraction characterization, electrochemical performance test, hydroxyl radical (·OH) production capacity test and accelerated lifetime test.The results showed that the Ti/PANI/PbO2-Ce electrode modified with polyaniline (PANI) and cerium (Ce) had better surface morphology and higher catalytic activity, and could produce more ·OH with an oxygen precipitation potential of 1.83 V and an accelerated lifetime of 720 min.The Ti/PANI/PbO2-Ce electrode was used for the degradation of anthracene in coking wastewater, and the effects of the main factors on the degradation effect were investigated, and the optimal degradation conditions for anthracene were obtained as voltage 14 V, plate spacing of 1.0 cm, electrolyte concentration of 0.35 mol/L, reaction time of 120 min, pH value of 10.The Ti/PANI/PbO2-Ce electrode showed good electrocatalytic performance.
Research on knowledge graph representation method of mine pressure hazard events in stope whole life cycle
HOU Yunbing, CHEN Youlong, WANG Yaxian, SUN Zhenming, REN Jie, WANG Legeng, MA Jing, DU Jianbiao
2024, 9(2): 295-303.   doi: 10.19606/j.cnki.jmst.2024.02.016
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Knowledge graph is an indispensable part of cognitive intelligence research.Aiming at the problem that the traditional analysis method of stope mine pressure hazard events has insufficient expression of the stress time and space evolution process and the relationship between hazard evolution and risk prevention and control in the coal mining process, this paper proposes a knowledge graph representation method that based on the entire life cycle of stope for mining pressure hazard events.Firstly, from the perspective of geological disasters, the dynamic characteristics of stress and distribution in stope were analyzed.The dynamic correlation of various nodes in mine pressure geological disasters was established, and a knowledge graph representation method for mine pressure geological disasters considering spatiotemporal processes was proposed.Secondly, from the perspective of accidents, the evolution of hazard and the process of risk prevention and control in mine pressure accidents were analyzed.The evolution of hazard and preventive measures were integrated into the knowledge graph representation model.Finally, Neo4j was used to build the knowledge graph of mine pressure hazard events.The results indicate that the knowledge graph constructed based on this representation method not only depicts the spatiotemporal evolution processes of different objects in disaster events but also describes the coupling evolution process of hazards and corresponding risk prevention and control measures.This provides an intelligent research pathway for the prevention and control of mining pressure hazards in intelligent mining.
Research on data trust model and technical architecture of intelligent mines based on blockchain technology
FAN Zhongqi, DAI Lin
2024, 9(2): 304-314.   doi: 10.19606/j.cnki.jmst.2024.02.017
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China's intelligent mine construction is still in the early stage of development, which is seriously constrained by data trust problems such as low credibility of mine data, lack of trust mechanism in the data sharing process and the risk of data security and privacy leakage.To this end, this paper proposes an intelligent mine data trust model by drawing on the holistic approach to national security.Specifically, this study 1) offered a working definition of this model and proposed its underlying conceptions; 2) designed its technical architecture and analyzed the core technologies involved; 3) proposed the implementation strategies of the intelligent mine data trust model based on blockchain technology.This may lay the foundation for blockchain technology to empower intelligent mines and comprehensively enhance its efficiency and productivity, thus promoting the high-quality development of the coal industry.
Experimental study on the extraction of niobium from crude niobium ore by KOH hydrothermal
Wang Weidong, Li Zhao, Wang Xiaohui, Zheng Shili
2017, 2(1): 75-81.  
[Abstract](1063) [PDF 6699KB](103)
Because the crude niobium ore is difficult to be used,according to the composition analysis and phase analysis of crude niobium ore,the KOH hydrothermal method was used to research the dissolution of crude niobium ore and the dissolution of crude niobium under hydrothermal system was researched by changing the temperature and the KOH concentration.The results show that the dissolution of niobium from crude niobium ore could reach 90%,at 30% of KOH concentration,and 200℃;the dissolution of niobium increased first and then decreased with the increasings of KOH concentration and temperature;in the whole process of the dissolution,the alkaline components Fe,Mn,Mg kept a low dissolution yields.XRD and SEM’s results show that the increasings of KOH concentration and temperature accelerated the decomposition of (Fe,Mn)(Nb,Ta)2O6.When the KOH concentration was 30%,and the temperature was 200℃,continuing to strengthen the reaction conditions,the dissolution of Nb decreased significantly owing to the transformation from soluble K8Nb6O19 to insoluble KNbO3.
Mineral resources evaluation model research based on BP neural network and TSVM algorithm
Zhao Xuejun, Li Yuzhen, Wu Wenbin
2016, 1(2): 188-195.  
[Abstract](801) [PDF 4159KB](62)
In the study of mineral resources evaluation model, the problem that the number of positive samples must be specified in the TSVM in the unlabeled samples. Then this article applied the improved algorithm to the evaluation of mineral resources, and the algorithm is TSVM based on BP neural network and BP-TSVM for short. The SVM is applied to studying the discernment and classification of labeling samples. We will annotate the plus or minus of unlabeled data within the boundary of already classified by utilizing BP neural network. The labeling samples as learned by SVM in the next iteration. The new algorithm will avoid decreased classified ability. TSVM can have more accurate estimates of number of plus of labeled data. Also, the number of training samples can reduce training times. The experimental result proves that compared with conventional SVM,TSVM and BP neural network the BP-TSVM is more accurate in evaluation of mineral resources.