2019 Vol. 4, No. 1

Display Method:
Fine detection of overburden strata based on time lapse high density resistivity method
LiFei1, , ChengJiulong1, ChenShaojie2, KangQingtao2, LiGaige2
2019, 4(1): 1-7.
Abstract(695) PDF(295)
Abstract:
Finedetectionforthedeformationfailureofoverburdenstratacausedbyundergroundmining mayprovidereliableguidanceforsafety,highefficientandgreencoalmining*Firstly,theprincipleofo⁃ verburdendetectionbasedontimelapsehighdensityresistivitymethodwasinvestigated*Then3Dgeo⁃ logic⁃geophysicalmodelsofoverburdenstratabeforeandafterminingwereconstructed,andthecorre⁃ sponding numerical simulation was carried out by using these models*It is demonstrated that deformationfailureofoverburdenstrataishourglass⁃likeintheresistivitychangerateprofileandorifice istheseparatrixbetweenthefracturedzoneandthebendingzone*Furthermore,fieldtestswerecarried out,resultsshowthatthesurfacesubsidencecausedpositiveanomalyandprecipitationcausednegative anomalyintheresistivitychangerateprofile*Basedonthehourglass⁃likeanomalymorphologyandkeystratumlayer,theheightoffracturedzonewasdeterminedtobe98m*Finally,theresultsfromtime lapsedetectionwereverifiedbydrillingresults*
Molecular dynamics simulation of deformation and failure mechanism of kaolinite at different temperatures
HeManchao1, HanZongfang1,
2019, 4(1): 8-16.
Abstract(510) PDF(154)
Abstract:
UniaxialtensilesimulationswerecarriedoutinOA,OBandOCdirectionsofkaoliniteatdifferent temperaturesbyusingmoleculardynamicssimulations*Thedeformationandfailureprocessesofkaolinite werestudiedattheatomisticscale*Thechangeofmicrostructure,deformationmechanismandtemperature effectoftensilemechanicalpropertiesofkaoliniteatdifferenttemperatureswerealsoanalyzed*Thiswork wouldbehelpfultounderstandthemechanismsoflargedeformationandfailureofsoftrock*Theresultsindi⁃ catedthattheincreasingoftemperatureresultsinthethermalexpansionofkaoliniteafterrelaxation*Once thecracknucleationappears,itpropagatesveryquicklyandleadstoasharpdecreaseinstressalongOAand OBloadingdirections*ThelayerseparationoccursduringloadingalongOCdirection,whilethestructure couldfailsincethehydrogenbondsarebroken*Themechanicalpropertiesofkaolinitehaveastrongdepend⁃ enceontemperature*Thereisanegativecorrelationbetweentensilestrength,Young*smodulusandtempera⁃
ture*Withtheincreaseoftemperature,thetensileultimatestrainandresidualstrengthtendtodecrease,and thestrengthattenuationcoefficienttendtoincrease*Inaddition,OCdirectionisthemostaffectedbythetem⁃ perature,followedbyOBdirection,andOAdirectionistheleastaffected*
Research on unsaturated seepage problems based on fractional order derivative
WangRui, ZhouHongwei, ZhuoZhuang
2019, 4(1): 17-22.
Abstract(586) PDF(161)
Abstract:
Unsaturatedseepagephenomenonwidelyexistsincoalengineering*Theexperimentalshows thatthereisa nonlinear relationship between mean square displacement and time,while the classic Richardsequationfailstocharacterize*Tosolvethis,weintroducedtime⁃fractionalorderintoclassice⁃ quationbyinvolvingtwoformsofhydraulicconductivitysoastogettime⁃fractionalRichardsequation andnumerical results were obtained*Furthermore,the effect of the parameters in the time⁃fractional Richardsequationonthewatercontenthasbeendiscussedinthispaperandthefittingresultshave beenappliedtotheexperimentalresultsfromformerpaper*Thefittingresultsshowthatthenewmodel canfitbettertotheseepageprocessinunsaturatedporousmedia*
Discrete element numerical simulation of triaxial fluid solid coupling based on seepage experiment
ZhangCun1, , , TuShihao4, ZhaoYixin1
2019, 4(1): 23-33.
Abstract(436) PDF(107)
Abstract:
Thecouplingcharacteristicsofcoalseamstress,fractureandseepagedirectlyaffectthemi⁃ grationcharacteristicsofpressurereliefgasduringtheprotectiveseammining*Inthispaper,combined withcubiclaw,themethodfortheselectionofthefluidsolidcouplingparametersofelasticjointsand persistentfracturewasproposedbasedontheexperimentaldataoftheelasticandpersistentfracture coalsamples*Meanwhile,thesimulationmodelingoffluidsolidcouplingfortriaxialflow testofcoal sampleswasbuilt*Onthebasisofthissimulationmethod,thecouplingcharacteristicsofthecoalsample stress,fractureandflowweresimulatedandanalyzedduringuniaxialandtriaxialloading*Thesimulation
resultsshow that the permeability of coal samples changes as S type with the increase of axial strain*Thepermeabilityofcoalsampledecreasesgraduallywiththeincreaseofaxialpressurebeforethe fractureofcoalsampledevelopment*Thepermeabilityofthecoalsamplesincreaseswiththedevelop⁃ mentofthefractures,andthefasterthefractureexpansionrateis,thehigherthepermeabilityincrea⁃ ses*Theincreaseofconfiningpressureresultedinthedecreaseofinternalfracturegenerationandprop⁃ agation,andthepermeabilityreductionstagewasextended*Theinitialpermeabilityandyieldingperme⁃ abilityofthecoalsamplesdecreasedgradually*
Research on lift pressure system with combined pipeline and intensive drill⁃hole gas drainage along the layer in low permeability coal seam
XieShengrong, YangBo, ZhangQing, SongHaizheng, SuoHaixiang, ZhangTao
2019, 4(1): 34-40.
Abstract(398) PDF(175)
Abstract:
Aimingattheproblemofgaspre⁃drainageinhighgasandlowpermeabilitycoalseam,the strengthentechnologyofcoalseamgasextractionwasputforwardwhichisthesystemofcombinedpipe⁃ linetoliftthenegativepressureandintensivelargediameterdrill⁃holealongseam*Theextractionprin⁃ cipleofrealizingthepermeableincreasinginallzonebyintensivelargediameterdrill⁃holealongseam wasexplained*Accordingtothecontinuityliquidflowequationandenergyequation,theexpressionof liquidenergychangeswasestablishedtogetliquidenergygradientlinesinsectioncompetent pipe⁃ line*Combinedwiththe“negativepressure⁃flow”characteristiccurveofpre⁃drainagegasdrill⁃hole,the mechanismofincreasethenegativepressureandextractionscalarthroughcombinedpipelinewasclari⁃ fiedandtheparametersofstrengthenextractiontechnologyincoalseamwasconfirmedbypracticalex⁃ perience*Thepracticeshowedthatthistechnicaleffectongovernancegaswasremarkable,thegasex⁃ tractionrateinworkingfacewasabove55% andtheproductioncapacityincreasedfrom1*2Mt/ato 1*8Mt/a*Theuppercornergasconcentrationwasunderthesafetystandard,andthusthesafetyandef⁃
ficientlyminingincomplicatedgeologicalconditionswasrealized*
Evaluation of the effect of water infusion of coal seams based on drifting degree and uncertainty measurement model
XueLiming1, ZhuLinlong1, WangHaojie1, WangEn1, ZhengZhixue2, GeYinghui1
2019, 4(1): 41-49.
Abstract(379) PDF(130)
Abstract:
Theeffectofwaterinfusionofcoalseamshasadirectinfluenceonthedisasterprevention andmitigationandefficientproductioninmines*Uncertaintymeasurementtheoryintegratedwithcom⁃ binedweightingofdriftingdegreeisappliedtoestablishthedriftingdegree⁃uncertaintymeasurement modelinordertoevaluatetheeffectofwaterinfusionofcoalseamsaccurately*Theuncertaintymeas⁃ urementfunctionofeachindexisestablishedbyusingtheuncertaintymeasurementtheorywhichcan getthematrixofsingleindexmeasurementevaluation*Thentheweightcoefficientsareallocatedbyu⁃ singthedriftingdegreetoobtainamoreaccuratecombinedweight*Finally,onthebasisofcrediblerec⁃ ognitioncriterion,thegradingsoftheeffectoftheprojectswerejudgedwiththeevaluationvectorof multi⁃indexescomprehensivemeasurementevaluation,andtheevaluationresultswererefinedbytheex⁃ pectedvalueandmeasurementofthesample’sgrade*Takingtheengineeringprojectofwaterinfusionofthecoalseamoftheworkingfaceasanexample,theeffectiscomparedwithotherevaluationmethods andtheresultsshowthatthemethodinthispaperismoreconsistentwithpracticalsituation*Thismodel surmountstheinfluenceofsomeuncertaintyinformationsuchastheindexgrade’sintervaldividingand the allocation of weight coefficient on the evaluation*This method provides a new reference for evaluatingtheeffectofwaterinfusionofcoalseams*
Determine the reasonable haulage roadway position of successive panel based on the split⁃level mining method
WangZhiqiang1, , SunZhongwen1, XuChunhu1, SuYue1
2019, 4(1): 50-57.
Abstract(425) PDF(111)
Abstract:
Thispaperstudymainlyonthereasonablehaulageroadwaypositionofsuccessivepanelbe⁃ tweentwoadjointpanels*Relyingonaminefortheprojectbackground,bythetheoreticalanalysis, threezonesintheverticaldirectionofthesolidcoalsideweregiven:Solidcoalstresszonealongone sideofthegoaf,transitionalzoneandelasticzonealongthefloor*Accordingtotheprincipleofroadway layout,theroadwayshouldbearrangedverticallyintheelasticzonealongthefloorandhorizontallyin thelow⁃stressregionofthelimitequilibriumzone*Thereasonablestaggeredhorizontaldistancebetween adjacentroadwaysforthisprojectbackgroundwasfoundtobe2mbytheoreticalanalysisandFLAC3D numericalsimulation*Intheengineeringapplication,combinedsupportwasappliedonthehaulageroad⁃ way,andthedeformationofthesurroundingrockintheroof,floorandsidesofthehaulageroadwaywas effectivelycontrolledaccordingtotheactualfieldtest*
Study on stochastic constraint environment modeling method for optimal deviation rectification path of boom⁃type roadheader
YangJianjian, TangZhiwei, WangXiaolin, WangZirui, WuMiao
2019, 4(1): 58-65.
Abstract(427) PDF(102)
Abstract:
Aimingatpathplanningproblemoftheunstructuredenvironmentattributionsforroadheader roadwaythispaperanalyzestheattributesandbehaviorconstraintsofunstructuredenvironments,anda dynamicrandomgridnetworkmodelwithconstraintinformationwasdefined(C⁃GNet)*Theminimum costmodeling method was proposed by optimization of best path target point set through improved VSAPSOalgorithm*Resultsshowsthatthemodelandalgorithmproposedinthispapercouldeffectively solvetheproblemofnetworkpathplanningunderdynamicrandomwithminimumcostroadheaderexca⁃ vation*Itsconvergence rate and advance rate meet the requirements of roadheader rectification path planning,andtheeffectivenessandpracticabilityofthismethodwereverified*
Preparation and characterization of fly ash⁃metakaolin based geopolymeric foaming materials
LiuRuiping, WangHui, GuoFei, DongYue
2019, 4(1): 66-71.
Abstract(663) PDF(444)
Abstract:
Thealkaliactivatedflyash⁃metakaolinbasedgeopolymericfoamingmaterialswereprepared atlowtemperaturebyuseofflyash,metakaolin,sodiumhydroxide,sodiumsilicateasthemainrawma⁃ terial*Theeffectofthetypesandcontentsoffoamingagentontheporestructureandpropertiesofthe porous geopolymer were studied,and the thermal stability and structure were also investigated. Comparedtothealuminumandsodiumborate,thefoamingeffectofhydrogenperoxidewasbetter*The properties of geopolymeric foaming materials prepared in ths paper were with bulk density of 0*985g/cm3,compressivestrengthof8*9MPa,lowestthermalconductivityof0*10W/ (m·K)and goodthermalinsulationeffect,whenthecontentofhydrogenperoxidewas0*5%,theconservationtem⁃ peraturewas40℃,conservationhumiditywas70% andconservationtimewas7d*
FengLaihong, WangShuai, ZhangRuijie, ChaiZhifang, ZengMing
2019, 4(1): 72-78.
Abstract(472) PDF(556)
Abstract:
Inordertosolvetheproblemofcoarsecoalseparationincoalcleaningplant,improvethe effectofcoarsecoalseparation,aninflatableliquid⁃solidfluidizedbedseparatorisdevelopedontheba⁃ sisoftheprincipleofgravityfloatingcouplingforthecoarsecoal,andtheseparationtestsareconducted forcoarsecoalwithsizeof1*000~0*125mminthelab*Withtheincreaseofthesuperficialwaterve⁃ locity,aerationquantityandfrotherdosage,thefinecoalash,thefinecoalyieldandtherecoveryrateof thecombustiblebodyareallincreased*Whenthesuperficialwatervelocityis30mm/s,aerationquantity is0*36m3/h,andthefrotherdosageis0*06285mmol/L,theseparationeffectisthebest*Compared withtraditionalliquid⁃solidfluidizedbedseparationtest,itcanbeseenthattheproductionrateofeach gradeinthecleancoalissignificantlyincreased,andtheyieldofeachgradeinthetailcoalissignifi⁃ cantlyreduced,andtherecoveryrateofcoarseparticlesisincreasedby29*12%,andthe Ep(Ecart probable)is0*08,andtheseparationeffectissignificantlybetterthanthatoftraditionalliquid⁃solid fluidizedbedseparator*
Mechanism study on ozonization degradation of salicylhydroxamic acid in flotation wastewater
ZhangLiping1, XiangJun1, YanZhenyu1, ZhaoSiqin2, WeiHanyu1, ZhangNan1
2019, 4(1): 79-85.
Abstract(497) PDF(544)
Abstract:
Salicylhydroxamicacidisanovelflotationreagent,thispaperstudiedO3oxidationtreatment ofsalicylhydroxamicacidinsimulatedflotationwastewater*Meanwhile,thepossibledegradationpathway ofsalicylichydroxamicacidwasdeducedthroughultravioletspectrophotometry,infraredspectrumand highperformanceliquidchromatography*Theexperimentalresultsshowedthattheremovalefficiencyof salicylichydroxamicacidtreatedbyO3 oxidationwasobviously*Wheninitialconcentrationofsalicyl⁃ hydroxamicwas50mg/L,pHvaluewas8,ozoneconcentrationwas1*3mg/Landreactiontimewas 15min,theremovalratewasgreaterthan90%,butthemineralizationratewasjust19*99%*Through theanalysisofintermediates,thedegradationpathwayofsalicylhydroxamicacidwaspreliminarilycon⁃ cludedas:salicylhydroxamicacid→salicylicacid+hydroxylamine→catechol→maleic→smallmole⁃ culeorganicacid+carbondioxide+water*
Effect of polymeric aluminum on hydration hardening characteristics of lithium slag⁃cement composite cementitious materials
WangYiren, WangDongmin, ZhaiMengyi, LiXiaolong
2019, 4(1): 86-94.
Abstract(592) PDF(494)
Abstract:
Lithiumslagisusedasasupplementarycementitiousmaterialincement⁃basedmaterialsdue toitspozzolanicactivity,butitslowerhydrationactivityleadstoadeclineinthemechanicalproperties anddurabilityofthecement⁃basedmaterial*Inthispaper,forthelowdegreeofhydrationoflithiumslag incompositecementitiousmaterials,aninorganicpolymeraluminumwasusedasanactivatortoimprove thehydrationactivityoflithiumslag*Theeffectsandmechanismofpolymericaluminumonhydration hardeningof lithium slag⁃cement composite cementitious materials were investigated through macro propertiesofcompressivestrengthandnon⁃evaporablewatercontent,andmicrocharacteristicsofhydra⁃ tionheat,mineralcompositionofhydrationproductsandBSEmicroscopicmorphology*Theresultsindi⁃ catethattheadditionofpolymericaluminumsignificantlyimprovesthecompressivestrengthandnon⁃e⁃
vaporablewater content in the lithium slag⁃cement composite cementitious material,which increases 26*8% and5% respectivelyinthe28dperiod*Intheearlyhydration,polymericaluminumaccelerates themineralphasedissolutionandcrystalgrowthinthelithiumslag⁃cementcompositecementitiousma⁃ terial,andincreasesthetotalnucleationofhydrationproducts*Alargenumberofettringite,hydration calciumaluminates,calciumhydroxideandamorphoushydrationgelsappeareinthehydrationproducts, whichpromotehydrationoflithiumslag⁃cementcompositecementitioussystem,thedissolutionandero⁃ sionoflithiumslagparticles*