2020 Vol. 5, No. 1

Display Method:
Analysis on the status que and causes of fluorine and acid pollution around coal-rich areas in China
HongXiuping, LiangHandong
2020, 5(1): 1-11.
Abstract(543) PDF(369)
Abstract:

Fluorine pollution is widespread and fluorine pollution overlaps with coal-bearing areas in China,while sulfur,which is associated with acids,is a coal-based pollutant.This paper summarizes the present situation of coexisting fluorine and acid pollution in typical coal-rich areas in China.Then the  synergistic mechanism that sulfur in coal is oxidized to acid,and acid promotes fluorine activation,migration, and release in the form of hydrogen fluoride is expounded.On the basis of this,different cooperative models of fluorine and acid pollution in different areas are proposed.The surface fluorine and acid  pollution at the boundary of Yunnan,Guizhou and Sichuan province in southwest China are mainly caused by extensive natural weathering in the coal-bearing strata,which is a natural factor,while the coal-burning endemic fluorosis is caused by the superposition of natural factors and human improper uti
lization.The surface fluorine and acid in the sheep fluorine poisoning area in the northern Helan Mountain of Ningxia are mainly caused by the long-history of coal exploitation and domestic coal burning,along with the spontaneous combustion of coal,which is man-made.Analogously,the high-fluorine and high-acid in Wuda,Inner Mongolia,is caused by coal mining or the joint effect of the increased coal fire and industrial parks.

Characteristics and coal facies of high quality anthracite from coal seam No.5 of Xiaofalu coal mine,Yunnan province
TangYuegang1, GuoXin, LiZhengyue, WangShaoqing, QinYunhu, WeiQiang, ZhuShifei, GaoWeicheng
2020, 5(1): 12-21.
Abstract(570) PDF(197)
Abstract:
:ThecharacteristicsandgeologicaloriginofhighqualityanthracitefromcoalseamNo.5ofXiaofalu,Yunnanprovince,Chinawerestudiedbasedonthetheoriesandmethodsofcoalpetrology,coal chemistryetc.TheresultsshowedthatcoalseamNo.5wascharacterizedbyextremelylowashyieldof rawcoal(Ad:thelowestvalue1.49%).ComparedwithothertypicalanthracitesinChina,coalseam No.5hadhigherhydrogencontent(Hdaf:thehighestwere3.22% ~3.37%)andthehighestfreehydrogencontent(2.95% ~3.12%),aswellasthelowestoxygencontent(1.44% ~2.27%).Bright coalswerethemainlithotype(79.8%).Subgroupswithcellstructurewerethemainmaceralcompositioninbothvitriniteandinertinite.TheTPIandGIvaluesofcoalseamNo.5were0.97~1.44and 4.22~5.78(>4.00),respectively.
Development and present situation of support theory and technology in coal mine roadway in China
2020, 5(1): 22-33.
Abstract(1065) PDF(255)
Abstract:
Roadwaysupporttheoryandtechnologyisthecoreresearchfocusofstratacontrolincoal mine.Inthispaper,therepresentativesupportingtheoriesofroadwayaresystematicallysortedout,and thesupportingtechnologiesofroadwayareexpoundedandanalyzedindetailfromthefollowingthreeaspects:surroundingrockinside,roadwaysurfaceandcompositecontrol.Furthermore,the possible researchfocusisdiscussedandanalyzed.Themainconclusionsshowthatthesupportingtheoriessuchas NewAustrianmethod,brokenrockzone,strengthenhancementofsurroundingrockaremoremature, andnewsupportingtheoriessuchascompressionringenhancedsupporttheory,strongsupportforsidewallanduniformstrengthbeamtheoryareemerging.Thetechnologiesinsurroundingrockincludebolt (cable),groutingandpressurerelief,andsurfacesupporttechnologiesmainlyincludemasonryarch, metalsupportandconcrete-filledsteeltubesupport.Whilethecompositecontroltechnologiesmainlyincludegrouting-bolt (cable),shed-cable and grouting-shed-cable composite technology,and the new technology named full space truss and anchor coordinative support is introduced in detail.The synergisticmechanismbetweensurroundingrockandsupportingbody,newsupportingmaterialandsys
tem,pressurereliefmechanismandtechnology,andmaturequantitativesupportdesignmethodstillneed tobedeeplystudiedinfuture.
Research on mechanical property and engineering application of cable with high constant resistance and large deformation
TaoZhigang, LiMengnan, PangShihui, GuMing, HeManchao
2020, 5(1): 34-44.
Abstract(423) PDF(84)
Abstract:
Inrecentyears,theintensityandfrequencyoflandslidegeologicaldisastershavebeenincreasing yearbyyear.Intheprocessoflandslideoccurrence,thetraditionalprestressedanchorcablecannotresist thelargedeformationofrockandcauseproblemssuchasbreakingandfailure.Inresponsetotheabove problems,threedifferenttypesofhigh-resistancelargedeformationanchorcables(NPRanchorcables)have beenindependentlydeveloped.Itscorestructureconsistsofaconstantresistancedeviceconnectedwitha traditionalanchorcable.Then,throughthefieldstatictensiletest,itisconfirmedthatthecablecanprovidea maximumworkingresistanceof850kNandalargedeformationof2000mm.Secondly,usingSTATICand
GENERALquasi-staticanalysismethodinABAQUS,thenumericalsimulationanalysisofthestress-strain characteristicsoftheconstantresistancedeviceunderstatictensioniscarriedout.Theanalysisresultsprove that the NPR anchor cable stretching process is a process of constant resistance and energy absorption.Finally,throughfieldapplication,itisverifiedthattheNPRanchorcablestructurecanbedeformedgreatlywiththeinstabilityoftheslope,whichavoidsthetraditionalanchorcablebeingbrokendueto largedeformation.Itachievesthegoalofintelligentintegrationoflandslidehazardprevention,monitoringand forecastingandprovidesascientificbasisforreasonablyexplainingtherelationshipbetweenthelawoflandslidemigrationandthemonitoringandearlywarningcurve.
Research status and engineering application of competitive adsorption of multicomponent mixed gases in coal
NieYao, ZhaoYuechao
2020, 5(1): 45-57.
Abstract(708) PDF(112)
Abstract:
Adsorptioncharacteristicsofgasesincoalarethebasisofresearchonpreventionandcontrol ofdynamicdisastersofmethaneincoalmineandECBMengineering.Coalbedmethanecontainsnot onlyCH4,butalsoCO,CO2,H2Sandotheralkanes.Furthermore,intheprojectsofenhancedcoalbed methanerecoverybygasinjectionandpressuremeasurementbygasinjectionactivelyofcoalseam, competitiveadsorptionbehavioroccursduetothedifferenceadsorptioncapacityofdifferentgasesin coal.First,themechanismofcompetitiveadsorptionofgasincoalwasanalyzed.Themulti-component gasadsorptionequilibriumpredictionmodelincoalporousmediawascomparedandanalyzed.Theinfluencingfactors,characteristicsofadsorptionswellingandadsorptiondynamicbehaviorofcompetitive adsorptionwerediscussed.Second,thephenomenonofpermeabilitydecaycausedbytheswellingdeformationintheprocessofCO2-ECBM,thederivedoutburstdisasterriskandthesupercriticalCO2adsorptionwerediscussed.Finally,theadsorptionequilibriumpredictionmodelofmulticomponentgasesin coal,theengineeringapplicationofcoal-rockdynamicdisasterprevention,ECBMandPSAtechnology werediscussed.
ZhaoHongze, WangYuxin, LiLin, GuoShuai, WangJinrui, RenZhihui
2020, 5(1): 58-66.
Abstract(272) PDF(89)
Abstract:
Inordertosolvethemeasurementproblemoftheproductioncapacityofthedragline,apredictionmethodbasedongraycorrelationcombinedwithGA-BP neuralnetworkisproposed.Thegray correlationanalysisiscarriedoutonthe12influencingfactorsaffectingtheproductioncapacityofthe dragline,andtheactualworkinghours,the out rate,the effective casting blast amount,and effective throw-outrateareselected.Fourinfluencingfactorsgreaterthan0.7wereusedasinputvariablesand themonthlyproductioncapacityofthedraglinewasusedastheoutputvariabletoestablishGA-BPneu
ralnetworkandBPneuralnetworkpredictionmodel.Theresultsshowthatthemaximumrelativeerror ofGA-BPneuralnetworkis7.525%,theaveragerelativeerroris3.52%,theaverageerrorvarianceis 0.0156,andthenumberofiterationsis18times.TheperformanceisbetterthantheconventionalBP neuralnetwork.TheGA-BPneuralnetworkmodelprovidesbetterandmoreaccurategeneralizationperformancefortheproductioncapacityofthedragline,andprovidesamoreeffectivemethodforpredicting theproductioncapacityofthedragline.
WangZhiqiang, XuChunhu, WangPeng, LuoJianqiao, ShiLei, SunZhongwen
2020, 5(1): 67-75.
Abstract(296) PDF(65)
Abstract:
Aimingattheseriousdamagecausedbythestressconcentrationintheisolatedworkingface foralongtimeintheundergroundtransportationroadway,theminingtreatmentoftheisolatedworking faceiscarriedouttoreduceitsinfluenceonthestressconcentrationofthesurroundingrockoftheroadway.Thispapercomparesandanalyzesthestresstransferlawofroofandfloorofisolatedworkingface beforeandaftermining,andprobesintothelawofroofsupportingpressureofisolatedworkingfaceand theverticaldistancebetweenunderlyingtransportationroadwayandisolatedworkingfacefloorbynumericalsimulation.Itfoundthatwiththeincreaseofthedistancefromthefloortothefloor,thestress concentrationofthesurroundingrockoftheroadwayshowsadecreasingtrend.Whentheisolatedisland faceismined,thestressofthefloorisobviouslyreleased.Thestressconcentrationfactorofsurrounding rockoffloorroadwayisreducedby52% ~ 60%,andtheshearfailureofsurroundingrockoffloor
roadwaypresentsX failure,which providestheoretical basisfor the optimization of surrounding rock supportinsubsequentroadway.
Control and simulation design of a cascaded single-phase VIENNA switching converter based on small signal modeling
WangCong, HuHaoyu, ChengHong
2020, 5(1): 76-85.
Abstract(522) PDF(101)
Abstract:
Inordertoavoidusingtheheavyandexpensivelinefrequencytransformerinthetraditional high-voltageminingACdriver,andconsideringthattheminingfandoesnotneedenergyfeedback,a three-phaserectifierconsistingofthreestarconnectedcascadedsingle-phaseVIENNAswitchingconverter(CSVSC)isproposed,whichcanbeusedasrectifierstageoftheACdriver.TheCSVSChasthe characteristicsofone-wayflowofenergyandfewerswitchingdevices,whichcaneffectivelyreducethe withstandvoltage of the switching device and diode.Therefore,the CSVSC can be applied to highvoltageandhigh-powerapplications,eliminatingthelinefrequencytransformerandreducingthecostof theACdriver.Small-signalmodelingisofgreatsignificanceforstudyingthedynamicprocessofcircuits.Inthispaper,the small-signal model is established by analyzing the working state of the CSVSC.Thetransfer function of the compensation network is designed according to the given parameters.Thecorrectnessoftheproposedsmall-signalmodelisprovedbyBodediagramandsimulation. Key words:miningACdriver;rectifierstage;cascadedsingle-phaseVIENNAswitchingconverter(CSVSC);smallsignalmodeling;closed-loopcontrol
Parametric modeling of particle reinforced metal matrix composites
XinZhenyang, WangYue, MiaoWencheng, ChenHuahui
2020, 5(1): 86-95.
Abstract(403) PDF(90)
Abstract:
Particlereinforcedmetalmatrixcompositeshavecomplexmeso-structure.Theconstructionof itsgeometricmodelisachallengingworkintheresearchofitsmechanicalproperties.ThroughthePythonlanguageinterfaceoftheABAQUSsoftware,theparametricmodelingofthecomplexmesoscopic modelofparticlereinforcedmetalmatrixcompositeswasrealizedandencapsulatedintoaplug-in.The plug-incanconstructtheaxisymmetricunitcellmodel,thethree-dimensionalperiodicunitcellmodel andtherandomlydistributedrepresentativevolumeelementmodel.Theeffectofzirconiatoughenedaluminaparticles(ZTA)onthemechanicalpropertiesofzirconiatoughenedaluminaparticlesreinforcedironmatrixcomposites(ZTAp/Fe45)wasanalyzed.Theresultsshowsthatthestrengtheningeffectofirregularpolyhedralparticlesontheelasticmodulusofthecompositeswasgreaterthanthatofspherical particles.However,theirregularmorphologyofZTAresultedinmorestressconcentrationinthecomposites.WiththeincreaseofZTAparticlevolumefraction,theelasticmodulusofZTAp/Fe45composites
showsanupwardtrend,whichindicatesthattheelasticpropertiesofcompositescanbeeffectivelyimprovedbyaddingreinforcedparticles.Inthecaseoflowinterfacialmodulus,theimprovementofinterfacialbondingpropertiescansignificantlyimprovetheelasticmodulusofcomposites.Aftertheinterfacial modulusreachesthematrixmodulus,theeffectofincreasinginterfacialmodulusontheelasticmodulus ofcompositesgraduallyslowsdown.
LiHao, ZhangXi
2020, 5(1): 96-107.
Abstract(285) PDF(69)
Abstract:
Aimingattheproblemofslowfollow-upspeedofhydraulicsupportintheautomaticproductionprocessoffullymechanizedminingface,thispaperanalysestherelationshipbetweentheactionof hydraulicsupportandtheoutputflowofhydraulicsupplysystem,andthematchingrelationshipbetween themovingspeedofhydraulicsupportandthespeedofshearer,andstudiestherestrictionrelationship betweenthespeed,position,directionofshearerandtheactionofhydraulicsupportandtheoutletpressureof hydraulic supply system.A method of designing controller based on I/O data of controlled systemisproposed.ACARTrandomforestclassificationtreemodelistrainedwithactualproductiondatato control the emulsion pump.The practical application results show that the method not only improvestheflowondemandsupplydegreeofthefluidsupplysystem,butalsohasgooduniversality
andcanbeappliedtodifferentfullymechanizedautomaticminingfaces.Itprovidessupportforimprovingintelligentdegreeandefficientproductionofthefullymechanizedminingface.
Research on the potential of low temperature waste-heat heating resources based on multi-factor constraints
FengChao, XuZhiqiang, JiangXimei, WangJianfu
2020, 5(1): 108-114.
Abstract(403) PDF(88)
Abstract:
Lowtemperaturewaste-heatheatingisanimportanttechnologyforcleanheating.Buttheresourcepotentialoflowtemperaturewaste-heatusedforheatingwillbeaffectedbytime,space,temperature,industrial development and other factors.Therefore,the resource potential of low temperature waste-heatforlong-term,effective&stableheatingshouldbestudied.Inthisstudy,theresourcepotentialoflowtemperaturewaste-heatforheatingwasstudiedbythescenarioanalysismethodandtheresultsshowthat,thelowtemperaturewaste-heatresourcesavailableforheatinginthenorthernregionare about62.262milliontce,andtheheatingareaisabout8.12 billionsquare metersin2017.Among them,thelowtemperaturewaste-heatresourcesabove80℃ accountfor25.2%.Inthefuture,thelow temperaturewaste-heatresourcesavailableforheatingwillbe68.98milliontce,andtheheatingareais about12.14billionsquaremetersin2020.Thelowtemperaturewaste-heatresourcesavailableforheat
ingwillbe66.487milliontce,andtheheatingareaisabout11.7billionsquaremetersin2030.
Catalytic pyrolysis characteristics of simulated seawater in lean coal
SunRui, MaGaofeng, MaGuoshuai, WangXiaoying, LiangJie
2020, 5(1): 115-121.
Abstract(429) PDF(63)
Abstract:
Intheunderground catalytic gasification processof lean coal,the solid catalyst cannot be usedandrecovered,soitisnecessarytodevelopaninexpensiveliquidcatalyst.Inordertoexplorethe feasibilityofseawaterasacheapgasificationagentforundergroundcoalgasification,andtounderstand thecatalyticeffectofNaClcomponentoncoalpyrolysisandgasification,thispaperselectstheblocksize with3%NaClsolution(simulatedseawater)ascatalyst.TheleancoalofWangxieCoalMineofabout 6cmwassubjectedtopyrolysistest.Theheatingrateinsideandoutsideofthecoalblockandthecompositionofthepyrolysisproducttarweremeasured.Theinfluenceofthecatalystonthesemi-cokestructurewasstudied.Theresultsshowthatthetemperaturetransferintheprocessofpyrolysisofmassive leancoalhashysteresis.Theactivationenergyoflarge-scalecoalwithadditionofNaClcatalystinthetemperaturerangeof350℃~650℃isreducedby39%and45%,respectively,comparedwiththeraw coal;catalyticpyrolysisThebenzenecontentintarincreasedby7.8%,thehydrocarboncontentofcoal sampleⅠdecreasedby14.9%,coalsampleⅡdecreasedby32.4%;thespecificsurfaceareaofcatalyticpyrolysiscoalcharwassignificantlylargerthanthatofnon-catalyzedpyrolysis;Thecontentof—OH bondand* *C* *OhealthcoalⅡcoke
Preparation and properties of buckwheat shell-based activated carbon
HouPin, YueYe, ZhangBen, SunXiaomeng, FanYecheng, ZhuShuquan
2020, 5(1): 123-130.
Abstract(671) PDF(94)
Abstract:
Inordertorealizetheutilizationofsolidwasteresource.Anoveladsorbent,buckwheatshellbasedactivatedcarbonhasbeendevelopedbychemicalactivationwhenapplyingwastebuckwheathull asthrawmaterial.Theauthorsoptimizedtheactivationtemperature,activationtime,typeofactivator, massratioofbuckwheathullandactivatorinthepreparationprocessthroughsinglefactormethod.The adsorptionefficiencyoftheoptimizedbuckwheat-shellactivatedcarbonwasinvestigatedbyiodinevalue andmethylenebluevalue.Porestructure,microcrystallinestructureandmicro-surfacemorphologyofactivatedcarbonwerecharacterizedbygasadsorptioninstrument,X-raydiffractionandscanningelectron microscopy.Theresultsshowedthattheoptimizedbuckwheatshell-basedactivatedcarbonexhibitedthe highestadsorption capacity when applying phosphoric acid as the activator,the activation time of 90min,activationtemperatureof500℃,massratioofbuckwheatshellandactivatoris1∶3.Theiodinevalue and methylene blue value of the optimized buckwheat shell-based activated carbon were 765.8mg/gand222.2mg/grespectively,andthemethylenebluevalueoftheoptimizedbuckwheat
shell-basedactivatedcarbonwashigherthanthatofthethreecommercialactivatedcarbons.Moreover, the optimized buckwheat shell-based activated carbon hosted the highest mesopore percentage (96.8%)andhighertotalporevolume(0.666cm3/ g)thanthatofthecoal-basedandcoconutshell activatedcarbons,andtheBETsurfacearea(785.3m2/ g)wassimilartothecommercialactivatedcarbons,indicatingthatanovelbuckwheatshell-basedactivatedcarbonwithstrongmesopore,highadsorptioncapacityhasbeendevelopedwhenapplyingwastebuckwheathullasrawmaterialandphosphateas theactivator.