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Triaxial compression behavior of large-scale jointed coal: a numerical study

International Journal of coal Science & Technology 2022年第5期9卷 81-95页

作者： Xiaoqing Wang Fuqiang Gao CCTEG coal Mining Research institute BeijingChina Mining&Designing Branch China Coal Research InstituteBeijingChina State Key Laboratory of coal Mining and Clean Utilization(China coal Research institute) BeijingChina

Accurate estimation of the triaxial compression behavior of jointed coal is essential for coal *** studies addressed the triaxial compression behavior of large-scale rock mass,especially with real joint *** employed a numerical synthetic rock mass(SRM)method to study the triaxial compression behavior of jointed ***-coal specimens were constructed based on in-situ joint measurements and microparameter calibration against laboratory experiments.A series of triaxial compression tests under different loading orientations and confining pressures were numerically performed to obtain joint and confining-pressure effects on the triaxial compression behavior and reveal the failure mechanism of jointed *** suggest that the triaxial compression behavior of the jointed coal has strong joint and confining-pressure *** weaken the strength and elastic modulus,reduce the lateral deformation,and affect the geometries of the shear-rupture *** increase in the confining pressure causes the peak and residual strength increase *** an increase in the confining pressure,the elastic modulus increases sharply at low confining pressure,the mechanical behavior transitions from brittleness to ductility,the failure mode transitions from shear-rupture surface to plastic flow,and the joint effect diminishes and even *** jointed coal fails by means of a shear-rupture surface under triaxial compression loading with a confining pressure(which is not too high),and the geometries of the shear-rupture surface vary with the distribution of joints.

关键词： Jointed coal Triaxial compression Synthetic rock mass Failure mode

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Grouting theories and technologies for the reinforcement of fractured rocks surrounding deep roadways

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Deep Underground Science and Engineering 2023年第1期2卷 2-19页

作者： Hongpu Kang Wenzhou Li Fuqiang Gao Jianwei Yang CCTEG coal Mining Research institute BeijingChina coal Mining Branch China Coal Research InstituteBeijingChina State Key Laboratory of coal Mining and Clean Utilization(China coal Research institute) BeijingChina

Grouting is an effective method to improve the integrity and stability of fractured rocks that surround deep *** years of research and practice,various theories and a complete set of grouting technologies for deep roadways with fractured rocks have been developed and are widely applied in Chinese coal mining *** paper systematically summarizes and analyzes the research results concerning the theory,design,materials,processes,and equipment for the grouting and reinforcement of fractured rocks surrounding deep ***,in terms of grouting methods,pregrouting,groutingwhile-excavation,and postgrouting methods are explored;in terms of grouting theory,backfill grouting,compaction grouting,infiltration grouting,and fracture grouting theories are *** addition,this paper also studies grouting borehole arrangement,water-cement ratio,grouting pressure,grouting volume,grout diffusion radius,and other grouting parameters and their determination *** this basis,this paper explores the physical and mechanical properties of organic and organic-inorganic composite grouting materials,and assess grouting reinforcement quality testing methods and *** as the field cases,the application of pregrouting in front of heading faces,groutingwhile-excavation,and postgrouting in the Kouzidong coal mine are then introduced,and the effects of the grouting reinforcements are *** paper proposes a development direction for grouting technology based on problems existing in the grouting reinforcement of fractured rocks surrounding deep roadways.

关键词： deep roadways development direction field study fractured rocks grouting materials grouting methods high-pressure grouting

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Numerical analysis on the factors affecting post-peak characteristics of coal under uniaxial compression

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International Journal of coal Science & Technology 2024年第1期11卷 42-60页

作者： Zhiguo Lu Wenjun Ju Fuqiang Gao Taotao Du CCTEG coal Mining Research institute BeijingChina State Key Laboratory of coal Intelligent Mining and Strata Control(China coal Research institute) BeijingChina

The post-peak characteristics of coal serve as a direct reflection of its failure process and are essential parameters for evaluating brittleness and bursting *** the significant factors that influence post-peak characteristics can offer valuable insights for the prevention of coal *** this study,the Synthetic Rock Mass method is employed to establish a numerical model,and the factors affecting coal post-peak characteristics are analyzed from four perspectives:coal matrix mechanical parameters,structural weak surface properties,height-to-width ratio,and loading *** research identifies four significant influencing factors:deformation modulus,density of discrete fracture networks,height-to-width ratio,and loading *** response and sensitivity of post-peak characteristics to single-factor and multi-factor interactions are *** result suggested that feasible prevention and control measures for coal bursts can be formulated through four approaches:weakening the mechanical properties of coal pillars,increasing the number of structural weak surfaces in coal pillars,reducing the width of coal pillars,and optimizing mining and excavation *** efficacy of measures aimed at weakening the mechanical properties of coal is successfully demonstrated through a case study on coal burst prevention using large-diameter borehole drilling.

关键词： Post-peak behavior Synthetic rock mass coal bursts coal burst prevention

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Synthesis and characterization of BZSM-5 and its catalytic performance in the methanol to hydrocarbons reaction

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Chinese Journal of Chemical Engineering 2021年第7期34卷 196-203页

作者： Junhua Gao Keming Ji Hao Zhou Jiayao Xun Zenghou Liu Kan Zhang Ping Liu State Key Laboratory of coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China

Five kinds of BZSM-5 molecular sieve with different Si/B ratio and a SiZSM-5 molecular sieve were prepared by hydrothermal synthesis method followed by acid exchange and *** samples were characterized by XRD,SEM,FT-IR,ICP,low temperature N_(2) physical adsorption and desorption,NH3-TPD and *** catalytic performance in the reaction of methanol to hydrocarbons was evaluated in the fixed bed *** with SiZSM-5,the amount and strength of Bronsted(B)acid were enhanced by introducing skeleton boron and the activity of the catalyst was greatly *** characterization and evaluation results indicated that the BZSM-5 catalyst synthesized from the gel of SiO_(2)/B2 O320 with Si/B ratio 74.48 had modest acidity strength,acid amount of 0.18 mmol NH3·g^(-1) and large mesopore volume of 0.23 cm3·g^(-1).The B acid ratio was higher and the acid strength of BZSM-5 was weaker than that of AIZSM-5,which could inhibit the deep coke formation and increase the activity stability.B-2 had the best lifetime which could reach 672 h under the same evaluation reaction conditions,due to the best matching of moderate acidity and good diffusion properties.

关键词： ZSM-5 Catalysis Methanol Hydrocarbons

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Efficient photodegradation of phenol assisted by persulfate under visible light irradiation via a nitrogen-doped titanium-carbon composite

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Frontiers of Chemical Science and Engineering 2021年第5期15卷 1125-1133页

作者： Yan Cui Zequan Zeng Jianfeng Zheng Zhanggen Huang Jieyang Yang State Key Laboratory of coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan030001China

To realize the utilization of visible light and improve the photocatalytic efficiency of organic pollutant degradation in wastewater,a nitrogen-doped titanium-carbon composite(N-TiO_(2)/AC)prepared by sol-gel methods was applied in the photodegradation of phenol assisted by persulfate under visible light irradiation(named N-TiO_(2)/AC/PS/VIS).The results show that a synergistic effect exists between visible-light photocatalysis and persulfate *** with TiO_(2)/PS/VIS,the phenol degradation rate was found to be observably improved by 65%in the N-TiO_(2)/AC/PS/VIS *** significant increase in degradation rate was mainly attributed to the following two factors:1)The N and C doping can change the crystal structure of TiO_(2),which extends the TiO_(2)absorption wavelength range to the visible light region.2)As an electron acceptor,PS can not only prevent electrons and holes from recombining with each other but can also generate strong oxidizing radicals such as·SO_(4)^(−) and·OH to accelerate the reaction *** process of phenol degradation was found to be consistent with the Langmuir pseudo-first-order kinetic model with an apparent rate constant k of 1.73 min^(−1).The N-TiO_(2)/AC/PS/VIS process was proven to be a facile method for pollutant degradation with high pH adaptability,excellent visible-light utilization and good application prospects.

关键词： N-TiO_(2)/AC visible light photocatalysis persulfate activation phenol

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STUDY ON THE GASEOUS PRODUCTS OF HIGH TEMPERATURE PYROLYSIS OF ACRYLONITRILE POLYMERS BY ON-LINE FTIR METHOD

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Chinese Journal of Polymer Science 1987年第2期5卷 87-94页

作者：赵根祥陈邦杰 institute of coal Chemistry Academia Sinica Taiyuan institute of coal Chemistry Academia Sinica Taiyuan

The gaseous products of high temperature pyrolysis （300℃ to 960℃） of aerylonitrile polymers were measured continuously under nitrogen atmosphere by on-line Fourier Transform Infrared Spectroscopic method （FTIR）. From the variations of characteristic peaks it was found that the nitrogen of macromolecules evolved were mainly in the form of hydrogen cyanide and ammonia. During the pyrolysis amorphous carbonaceous element was formed, and crosslinked to form network structure. Three kinds of samples were used for comparison. The experimental results show that the gaseous products of volatile small molecules were HCN, NH;, CH;, C;H;and cyanide. CO and CO;were also formed when copolymers of PAN were thermally pyrolyzed.

关键词： Pyrolysis Acrylonitrile Polymer FTIR

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Composition of phenolic compounds in wastewater from the fixed-bed gasification of Baishihu coal

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International Journal of coal Science & Technology 2021年第6期8卷 1461-1467页

作者： Yuan Zhao Beijing Research institute of coal Chemistry China Coal Research InstituteBeijing 100013China State Key Laboratory of coal Mining and Clean Utilization Beijing 100013China

Crude phenols extracted using organic solvent from the wastewater of a typical fixed-bed gasification process was used as a raw material,and the distillation range was *** wide and narrow fractions of the raw material derived from distillation range analysis were cut using a real boiling point distillation *** phenolic compounds in the different fractions were then qualitatively and quantitatively analyzed by gas chromatography after derivatization *** yield of thecoal tar,making them difficult to ***,due to their strong polarity and good water solubility,catechol and 5-indenol are enriched in gasification wastewater by water selection,allowing their further extraction.

关键词： Gasification wastewater Phenolic compounds Derivatization pretreatment Gas chromatography

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Chemical Degradation of Amine-cured DGEBA Epoxy Resin in Supercritical 1-Propanol for Recycling Carbon Fiber from Composites

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Chinese Journal of Polymer Science 2014年第11期32卷 1550-1563页

作者： Hua Yan 吕春祥 De-qi Jing Xiang-lin Hou National Engineering Laboratory for Carbon Fiber Technology Institute of Coal ChemistryChinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of coal Conversion Institute of Coal ChemistryChinese Academy of Sciences

Chemical degradation of diglycidyl ether of bisphenol A（DGEBA） epoxy resin cured with an aliphatic amine in supercritical 1-propanol was investigated under different reaction temperature and time. The combination of GC-MS and LC-MS proved that the epoxy resin was decomposed to five main products including phenol, 4-isopropylphenol, 4-isopropenylphenol, bisphenol A, and 4,4’-（cyclopropane-1,1-diyl）diphenol. The 13C-NMR results verified the chemical structures of the degradation products. The change of the products′ yield with time was evaluated by an effective means of HPLC. In addition, the GPC analysis confirmed the formation of soluble low molecular weight clusters during the degradation reaction. A possible free-radical reaction mechanism was proposed for chemical depolymerization of the epoxy resin in supercritical 1-propanol. After the homolytic cleavage of the aromatic ether linkages, the resulting bisphenol A biradical either produced 4,4’-（cyclopropane-1,1-diyl）diphenol after intramolecular rearrangement or generated bisphenol A after capturing hydrogen from 1-propanol.

关键词： Epoxy Thermosets Degradation Recycling.

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STUDY ON THE PROPERTIES OF DIFFERENT ACTIVATED CARBON FIBERS AND THEIR ADSORPTION CHARACTERISTICS FOR FORMALDEHYDE

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Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 467-472页

作者： H.Q. Rong, Z.Y. Ryu and J.T. Zheng (institute of coal Chemistry, The Chinese Academy of Sciences, P.O.Box 165, Taiyuan 030001, China) institute of coal Chemistry The Chinese Academy of Sciences

Porous structure and surface chemistry of activated carbon fibers obtained by differ-ent precursors and activation methods were investigated. Adsorption isotherms werecharacterized by nitrogen adsorption at 77K over a relative pressure range from 10 6to 1. The regularization method according to Density Functional Theory (DFT) wasemployed to calculate the pore size distribution in the samples. Their specific surfaceareas were calculated by BET method, micropore volume and microporous specificsurface area calculated by t-plot method and MPD by Horvath-Kawazoe equation. Mi-cropore volume of rayon-based ACF was higher than that of other samples. The staticand dynamic adsorption capacity for formaldehyde on different ACFs was *** results show that steam activated Rayon-based A CFs had higher adsorption capac-ity than that of steam and KOH activated PAN-A CFs. Breakthrough curves illustratedthat Rayon-ACFs had longer breakthrough time, thus they possessed higher adsorp-tion capacity for formaldehyde than that of PAN-ACFs. The entire sample had smalladsorption capacity and short breakthrough time for water. Rayon-A CFs had exccl-lent adsorption selectivity for formaldehyde than PAN-ACFs. And the samples withhigh surface areas had relatively high adsorption capacity for formaldehyde. Elementaicontent of different A CFs were performed. Rayon-based A CFs contained more oxygenthan PAN-ACFs, which may be attributed to their excellent adsorption capacity forformaldehyde.

关键词： activated carbon fiber porous structure surface chemistry formaldehyde adsorption characteristic

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Theory,technology and application of grouted bolting in soft rock roadways of deep coal mines

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1463-1479页

作者： Hongpu Kang Jianwei Yang Pengfei Jiang Fuqiang Gao Wenzhou Li Jiafeng Li Huiyuan Chen coal Mining Research institute China Coal Technology and Engineering Group Co.Ltd.Beijing 100013China coal Mining Branch China Coal Research InstituteBeijing 100013China State Key Laboratory of Intelligent Mining and Strata Control Beijing 100013China

The grouted bolt,combining rock bolting with grouting techniques,provides an effective solution for controlling the surrounding rock in deep soft rock and fractured *** has been extensively applied in numerous deep mining areas characterized by soft rock roadways,where it has demonstrated remarkable control *** article systematically explores the evolution of grouted bolting,covering its theoretical foundations,design methods,materials,construction processes,monitoring measures,and methods for assessing its *** overview encompassed several key elements,delving into anchoring theory and grouting reinforcement *** new principle of high pretensioned high-pressure splitting grouted bolting collaborative active control is introduced.A fresh method for dynamic information design is also *** discussion touches on both conventional grouting rock bolts and cable bolts,as well as innovative grouted rock bolts and cables characterized by their high pretension,strength,and sealing hole *** examination of the merits and demerits of standard inorganic and organic grouting materials versus the new inorganic–organic composite materials,including their specific application conditions,was ***,the article presents various methods and instruments to assess the support effect of grouting rock bolts,cable bolts,and grouting ***,it provides a foundation for understanding the factors influencing decisions on grouted bolting timing,the sequence of grouting,the pressure applied,the volume of grout used,and the strategic arrangement of grouted rock bolts and cable *** application of the high pretensioned high-pressure splitting grouted bolting collaborative control technology in a typical kilometer-deep soft rock mine in China—the soft coal seam and soft rock roadway in the Kouzidong coal mine,Huainan coal mining area,was ***,the existing problems in grouted bolting control

关键词： deep coal mine soft rock roadway grouted bolting rock bolt and cable grouting material high-pressure splitting grouting collaborative control technology

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