322-paper-practice of perfecting burden preparation in b (1)

1、PracticeofPerfectingBurdenPreparationinBaosteelBlastFurnaceZhuRenliangZhuJingmingHuZhongjie(IronMakingDepartmentBaosteelBranchBaoshanIron&SteelCo.LTD.)ABSTRACTWiththewldwideshtageofhighqualityresourcesfironmakingthereare

2、someconstraintstofurtherimprovethegradeofburdeninblastfurnace.ThetechniqueofperfectingburdeninBaosteelisasystematicalapproachallmaterialssuchaspelletsinterlumpscokecoalfluxarerestructuredoptimizedtogetidealresultsinrespe

3、ctofenvironmentprotectioncosteffectivehighquality.ConsideringthedifferentwkingconditionsofblastfurnacestheiginsofironethestructuresofburdenwereoptimizedinBaosteel.Meanwhileaseriesofmeasuresthatincludecontrollingthetherma

4、lpropertyofcokeimprovingtheprocessofblendingsinteringoptimalingcoalsfinjectionreusingresourceswereadoptedtokeepblastfurnacerunningsmoothlywithhighproductivityhighpulverizedcoalinjectionratio.KEYWDS:Blastfurnaceburdenprep

5、arationstructurepulverizedcoalinjection1.INTRODUCTIONTherearefourblastfurnaceswithvolumeinexcessof4000m3inbaosteelnowtheproductionindexesoftheseblastfurnaceswereimprovedcontinuously.Itisestimatedthatthecapacitywillreach1

6、3milliontonsin2005.Since2000theaverageproductivityofblastfurnacehasbeenkeptat2.25~2.30t(d.m3).InparticulartheaverageproductivityftheNo.3blastfurnacewas2.424t(d.m3)in20042.636t(d.m3)inMarch2005fromJanuarytoOctoberofthisye

7、artheaveragewas2.509t(d.m3)aftersuccessfulresearchactivitiesonhighcoalratiohighproductivityftheNo.3blastfurnace.ThePCR(pulverizedcoalinjectionratio)inthewholefactyhavebeenkeptat200kgtsincethesecondhalfyearof1998.ThePCRof

8、theNo.1blastfurnacewaskeptstablyatabove230kgtafter1999thehighestreached260kgt.SincetheNo.4blastfurnacewasputintoproductionsuccessfullyinApril2005thecapacitiesofpulverizedcoalproducingsupplyingareincreasedtheinjectionrati

9、osoffourblastfurnacesareenhancedfurtherthentheaveragecoalratiosarekeptstableat210kgtnow.Withthewldwideshtageofhighqualityresourcesfironmakingsomeconstraintstofurtherimprovethegradeoftheburdeninblastfurnaceexist.Inthelong

10、productionpracticecostreductionsustainabledevelopmenthavebeenachievedbyoptimizingtheburdenstructurecontrollingthequalityofcokeimprovingthetechniquesofblendingsinteringingthekindsofcoalproperlyfinjectionsoonindertosatisfy

11、therequirementofhighcoalinjectionratiohighutilizationfact.[1].2.OPTIMIZINGTHEBURDENSTRUCTURE2.1ChoosingTheProperBurdenStructureAtpresentsinterasthemainburdensomeamountofpelletslumpsastheauxiliaryistheburdenstructuresoffo

12、urblastfurnacesinBaosteel.Seefigure1.Thetotalironeconsumptionbrokethroughtwentymilliontonsin2005.Theselfmadehighbasicsinterwiththebasicitybetween1.751.85wasusedinBaosteel.Whenthepelletsinterratioinburdendecreasestheprope

13、rtyofslagwouldbemodifiedi.e.thebasicityofslag(CS)willrise.Sotheacidicnonselffluxingpelletswithlittle(no)auxiliarymaterialtocontrolthebasicityofslagreducethequantityofslagarefurnace.Indertoenlargingthekindsofcoaloptimizin

14、gtheresourcestheexpertsystemofcoalmatchingwithartificialintelligenttechnologycameintouseinBaosteeltoensurethehighqualitylowcostofcoke.Byoptimizingthecoalmatchingprocessqualitypredictionsystemgrindingscientificallyprolong

15、ingtheringtimeusingthetechnologyofcokedryquenchingthekeyindexesweremaintainedatgoodsituationeventheproptionofweaklycakingcoalnoncokingcoalrosegradually.Whenthecoalinjectionratiogotover200kgttheindexesfDICRICSRsoonshouldb

16、epaidmuchattentionamongwhichtheCRImustbelessthan26%CSRgreaterthan66%.Theimprovementofcokequalityisessentialbeneficialftheincreaseofcoalinjectionratio.Thetable1showstheindexesofcokeinBaosteel.Tab.1TheindexesofcokeinBaoste

17、elIndex1998199920002001200220032004Ash%11.5811.3011.0611.1511.2911.3211.45S%0.490.470.480.520.510.550.56M40%89.8189.8789.5889.5289.0688.8988.91M10%4.945.155.465.505.485.545.55CRI23.8724.0623.6924.1023.9723.5823.65CSR68.9

18、770.3970.8470.4370.8370.6070.16MSmm51.2351.1854.4454.8754.8754.4654.023.2ResearchOnSinteringWithHighGradeLowSiliconContentIntheprimarystageofstartupinBaosteelthecontentofsilicondioxidewaskeptatabout6%toensuretheDIofsinte

19、rmaketheblastfurnaceatgoodstatus.Therequirementfslaggingcomponentswasraisedyearbyyearwiththedevelopmentofcoalinjectiontechnologysoitisimptanttoproducethesinterwithhighironlowsiliconcontenthighstrength.Since1998byadjustin

20、gtheecoalcokematchingadoptionofthickbedsinteringrelatedtechnologythecontentofSiO2decreasedfrom5.38%to4.5%thegradeofsinterwentupto58.7%from56.5%.ThechangeofthegradeofsintercontentofSiO2canbeseenintable2.Tab.2Thegradeofsin

21、terpastyearsinBaosteelIndex20002001200220032004TFe%59.0359.1558.8558.7358.70FeO%7.467.537.627.787.80SiO2%4.514.434.564.584.59CaOSiO21.811.811.821.821.80TI%76.1276.1175.2875.5075.605mm%4.564.403.603.313.25MSmm20.1020.2021

22、.0020.4020.503.3TechnologyOfMixedCoalInjectionWhenthetechnologyofmixedcoalsinjectionwasadoptedinBaosteelthepropertiesofpulverizedcoalfinjectingwasimprovedcostresourceswereintegratedlyoptimized.Intherespectofthecoalfinjec

23、tinganthracitecoalwithhighcontentofcarbonhasbadcombustibilityhighreplacementratiobutthebituminouscoalisonthecontrary.Theinjectionofthecoalmixcantakeadvantagesoffeaturesofthetwokindsofcoals.Theinjectionofmixturecoalsoverc