08級(jí)設(shè)計(jì)-采礦-英文原文

英文原UseofMineralCoalforSorptionSewageTreatmentofmining,industrial,householdandothersewageisanactualproblemformanyminingandprocessingenterprises.Coal-miningindustryisnotanexception.Usually,atcoalenterprises,treatmentofminesewagebeforeitisdumpedconsistsinsettlingandsubsequentfiltering.Manypollutantsarenotremovedfromthesewagebythismethod.Hence,dumpedwaterfrequentlydoesnotsatisfysanitaryrequirementsregardingthepermissiblecontentofoilproducts,dissolvedsubstancesandotherparameters.Foradditionalcleaningofsewageitispossibletousesorptionmethods.Bythesemethodswateriscleanedofoilproducts,heavymetals,anumberofanicsubstancesandotherpollutingsubstances,dependingontheusedsorbentproperties.Bothnaturalandartificialmaterialscanbeusedassorbents.Constraintforwideuseofsorptionmethodsofsewagetreatmentinthecoalindustryishighcostofthemajorityofsorbents.Anumberoftechnologiesforobtaininginexpensiveandgoodqualitysorbentsfromcoalmineralshavebeendeveloped.Thesesorbentscanbemanufactureddirectlyincoalmineswhichhasadditionaladvantageofreducingtransportcosts.Theprocessessorbentsmayberecycledorburnt.Apartfromthatproductionandsaleofsorbentscanservethecoal-miningenterprisesasanadditionalsourceof Oneofthemostwidespreadsorbentsisactivatedcoal.Qualityactivatedcoalsarecarbonsorbents,havinganinternalspecificsurfaceofmorethan500㎡/g,andcharacterizedbyiodineadsorption(iodinevalue)ofmorethan500mg/g.mineralcoal,peatandwoodcanserveasrawmaterialsforactivatedcoalproduction.Traditionalproductiontechniquesofactivatedcoalincludetwobasicstagesofthermalprocessingoftheinitialcarbon-containingrawmaterial-carbonizationandactivation,doneindifferentdevices.Bothstagesareenergy-consumingandecologicallydangerous,whichexplainsthehighcostofactivatedcoal,receivedthroughthistechnology(1200-4000dollars/MT).Carbonizationistheeliminationofvolatilesubstancesbyheatinguptothetemperatureof600-900℃,becausewithvolatilecomponentstherearebasicallyformedtheoxygenandhydrogen,andincreasecarboncontentininitialrawmaterial.Carbonizationisdoneinminingorrotatingfurnaceswithutilizationofexternalform-holder,asarule,wastegaseswithtemperaturesof600℃andhigher.Activationmeansincreasingthevolumeandporesurfacesofcarbonizedmaterialheterogeneousreaction.Themostusedreagentiswatervapourwiththetemperatureof900℃andhigher,andtheprocesstakes15-20hours.Bothstagesareenergyconsumingandposethreattoenvironment.Foronetonneofactivatedcoalfrom2upto4tonnesofspecificfuellikecrudeoilandnaturalgasareconsumed.From1000upto1500m3ofprocessedgasseswithhighcontentofSOx(1-2g/m3),H2S(200-250mg/m3),resinoussubstances(10-40mg/m3),phenols(50-70mg/m3),carbonoxides(upto5%)andalsoothersubstanceswhicharecarcinogenicandmutagenicareformedandreleasedintotheatmosphereduringbothstages.High-energyconsumptionandenvironmentaldanger,whichrequireslargeinvestmentsinnatureprotectionactivities,resultinthehighcostofquality-activatedAnothergroupofcarbonsorbents,whichwaswidespreadinthe80’s,consistsofinexpensivecarbonsorbentsusedinnatureprotectiontechnologiesandindustry.Suchsorbentsareproducedbyaone-phasetechnology,withoutadditionalactivation.Theiradsorptionactivityisnothigh(iodinevaluelessthan300mg/g)butthecostislow(250-700USD/MT).becausethepriceofthesesorbentsiscomparabletothecostoftheirregeneration,theyareusedonlyonceandareburntaftersaturation.TheleadersintheproductionofsuchsorbentsareRheinbraunAG(Germany,200thousandMTperyear)andAustralianChar(Australia,150thousandMTperyear),whichproducebrowncoalsemi-cokeusedfortreatmentofwastewaterandsmoke.InRussiaresearchworkinthisdirectionisconducted,butonlytestworkshavebeendonesofar,althoughthequalityofcarbonsorbentsobtainedfromKansk-AchinskcoalsdidnotconcedetoproductionfromRheinbraunAGandAustralianChar.Oneofthedirectionsofutilizationofsemi-cokefromKansk-Achinskcoals,productionofwhichwasplanedatKrasnoyarscthermalpowerstation2(deviceETX-175),wasitsutilizationascarbonsorbent.Thereasonforproductionofinexpensivecarbonsorbentsbyone-phasetechnologiesbeingnotdevelopedinRussiaistheabsenceofdemandforthisproduct.Thisproductionisbasicallyusedforcleaningofsewage,howeverthereisnoeffectiveecologicalserviceinRussia,andthepenalsanctionsoftheenvironmentalprotectionlegislationaresoinsignificantthatindustrialenterprisesdonothaveantmotivationtoinvestinnatureprotection.In1992-1994theemployeesfromJoint-StockCompany“Carbonica-F”(atthattimeOpenCompany“Sibtermo”)havedevelopedanewmethodofproductionofcarbonsorbents,whichconsiderablyfromallknowntechnologies.Duringtheresearchofdynamiceffectsinalayerevaporatortheregimeconditionsweredefinedunderwhichtheeffectof“thermalwave”couldbeobservedinthedevice.Usingthiseffect,theauthorscreatedalayerevaporatorinwhichvolatilecomponentsofcoalwereexposedtogasification(pleteoxidation),andthedegreeofcarbonconversionwasadjustedbythemodeofinjectionfeed.Bychangingtheregimeparametersitwaspossibletoconducttheprocessasfuelgasification(withonlyashesremainingintheend)withoutanyresidue,andalsoasgasificationofvolatilecomponentsofcoal,thusreceivingso-calledsemi-cokecontainingsolidcoal.FromonetonneofKansk-Achinskcoalwithcalorificcontentof3600-3800kcal/kgcanbeproducedabout0.33tonnesofsemi-cokewithcalorificcontentupto7000kcal/kg(asanthracite)andupto1700m3ofcombustiblegaswithcalorificcontentof800-900kcalJm3,suitableforuseasanenergysource.TechnologicalprocessofJoint-StockCompany"Carbonika-F"hasalargenumberofadvantagesincomparisontothealreadyknownmethodsofobtainingactivatedcoalandsemi-cokeSimplicityofhardware.One-phaseprocess.Thestagesofdrying,pyrolysis, positionofvolatilesubstancesandsemi-cokecoolingareincorporatedinonedevice.Thedeviceisauto-metric;itmeansthatexternalheat-carrierforcoalheatingisnotused.Ecologicalsafety.InthetechnologyofJoint-StockCompany"Carbonica-F"allhydrocarbons,includingresinoussubstances,arebrokendownandgasifiedinsidethedeviceduringtheformationofcombustiblegascontainingonlyCO,H2,CO2,N2,H20,H2SandinsignificanttyCH4.Sludge,pyroligneouswaters,phenolsandotherharmfulimpuritiesarenotformedinthisprocess.Becausethespeedofgasfiltrationfromalayerreactorislow(0,02-0,03m/sincomparisonto0,5-2,5m/sforminefurnaces),theprocessislessdependentonfractionalcompositionofcoal,hydraulicofthelayerandallowstoprocessfine-grainedcoals.Asaresultoflowspeedoffiltrationthephenomenonofcarryingoutofflyashesfromthelayerdoesnotoccur,becausethedeviceworksasagranularfilter.Combustiblegasismovedinuser-boilerorcanmovetothegasturbinewithoutpreliminarycleaning.ThevolumeofSOx,NOx,COcontainedinwastegasesislowerthanthatproducedwhenobtainingequivalenttyofheatbyburningcoal.Combustiblegaswithoutpriorcleaningcanbeusedtoproduceelectricand/orthermalpowerorasanenergycarrierforthermalprocesses.Unlikethealreadyexistingtechnologies,inthegivenprocessthereisnodumpofgaseousheat-carrierintotheatmosphereandconsequentlytheconstructionofotheradditionalgaspurificationsystemsandcatalyticburningofcarbonoxide(CO)isnotTestofthesolidresidue(semi-coke)haverevealed,thatthismaterialischaracterizedbylargespecificsurface(morethan500㎡/g)andhighadsorptionactivity(iodinevalue500mg/gandhigher),andbecauseoftheseparameterdoesnotconcedetoquality-activatedcoal.TheproductreceivedwiththetechnologyofJoint-StockCompany"Carbonica-F"isdasactivatedcoalABG(active,browncoalofgasification),foritthereweredevelopedtechnicalconditionsTU6-00209591-443-95.ThecharacteristicsofABGactivatedcoalproducedfromthecoalof62markfrom"Berezovsky-1"opencastcolliery.HighspecificsurfaceandadsorptionactivityofABGcoalisexplainedbythefactthatbothgasificationofcoalvolatilecomponents,andactivationofcarbon-containingsolidresidueofgaseousproductsoccurinthedevicesimultaneously.Becausegasificationproductscontainupto20%nofhydrogenwhosemoleculesaresmallerthantheonesofwatervapour,andhencetheirpermeabilityinporesofsemi-cokeishigher,activation(heterogeneousreaction)isdonenotonlywithvapour,butalsowithhydrogen,whichpracticallyisnotpresentinthetraditionaltechnologies.Thus,carbonizationstagesandactivationarecombinedinonedevice.Otherpositiveeffectofapplicationofthismethodofcoalprocessingisthatin"thermalwave"modetheproductsofthermal positionwhichcontainverytoxicresinoussubstances(coaltarpitchusedinexperimentalmedicinefortheinoculationofcancerinexperimentsonmice,browncoalismoretoxic),passingthroughahotlayerofsemi-coke(500-700℃)arecompleybrokendownintotwoandthree-nucleigasesH2O,CO2,CO,H2.MeasurementsdoneattheworkingproductionplantofJoint-StockCompany"Carbonica-F"haveshownthatthegasdoesnotcontainhydrocarbonsoflinesabovemethane,andalsocarcinogens,includingbenzo(a)Coolingoftheactivatedcoalfrom550upto70℃beforedischargingiscarriedoutbycompulsorycirculationofgaseousheat-carrier(wastegases)throughalayeroftheproductandfurtherthroughs-and-tubeheatexchangerinwhichwaterusedinclosedcircuitisalsoprovided.Totalprocessefficiencyreaches95%duetothehighdegreeofutilization,whichisassociatedwithutilizingthethermalenergy.Departingwastegasesdonotundergoanycleaning;thereareevennocyclones.Nevertheless,thecontentofharmfulmixtures(NOx150mg/m3,SOx50mg/m3,ashlessthan10mg/m3)isessentiallylowerthantheestablishednormsandparametersofworkingboilerandthermalpowerstations,eventhoseequippedwithmodernmultistagesystemsofgaspurificationincludingelectrofilters.Thisisexplainedbyainsignificantablationofashfromdevices,sorptionofsulfurcompoundsinactivatedcorner,andalsofocustemperaturefromtheuser-boilerislowerthan1600℃-“threshold”temperatureatwhichbeginstheformationofnitrogenoxidesduetotheoxidationofnitrogenfromtheair.ThetechnologyofJoint-StockCompany"Carbonica-F"canbeusedforanynotconglomeratingcoals.Similarsorbentsorslightlyconcedinginqualitytoactivatedcoalareformedbysemi-cokingofunconglomeratedcoal.Semi-cokereceivedbyusingthetechnologydevelopedandpatentedatJoint-StockCompany"Carbonika-F"ischaracterisedbylargespecificsurface(above500m2/g)andhighadsorptionactivity(iodinevalue500mglgandmore),andwiththeseparametersdoesnotconcedeinqualitytoactivatedcoal.Theproductionofthissorbentisecologicallysafe.ThebustiblegascanbeburntinboilersofthermalpowerSomemineralcoals(calledmesoporous)haveinternalporesaccessibletowater,havingthesize3.5-4manometers(mesopores),formingactivesurface,sized50-120m2/g(unlikeallothernaturalcoalswithsurfaceof0.5-1m2/g).Thesecoalscanbeusedassorbentswithoutadditionalactivation.Theyclearwaterofundissolvedanddissolvedmineraloil,deepdispersingmixtures,iron,phenol,ionsofheavymetals,ammonia,nitrates,benzo(a)pireneandsoforth.SorbentMIU-Sreceivedfrompoorlymetamorphosedmesoporecoalcanbeusedfor3-7yearswithperiodicregeneration.Alkaliregenerationsolutionisremovedfromthefitterwithoutotheradditionalneutralization,becauseinalkaliandacidmediumMIU-Spresentsbufferproperties,neutralizingthesemedia.Specificporousstructureofmesoporecoalsassuressorptionextractionofdissolvedmineraloilproductswithconcentrationlowerthan1mg/l,andthusisnotalwaysreachableevenwithactivatedcoals.UsingMIU-Sfiltersindrinkingwatersupplysystemsmadethestabilityoftheirworkinconditionsofcontinuousexploitationevident,maintainingthepropertiesofsorbentsatnullandsub-zerotemperaturesandabsenceofbiomassformation.Besidestheabovementionedtechnologies,sorbentscanbeobtainedfrommaterialcoalbyitsbriquettingandactivation.RawmineralforbriquettescanbecoalsofanyThus,sorbentssuitableforadditionalcleaningofsewagearepossibletobeproducedfrommineralcoalsbyspecialprocess