用FGD激活废弃粗粉煤灰固化稳定重金属废物的研究

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1、武汉理工大学博士学位论文用FGD激活废弃粗粉煤灰固化/稳定重金属废物的研究姓名：乔秀臣申请学位级别：博士专业：材料学指导教师：林宗寿;潘智生20040301AbstractStabilization／solidification(s／s)hasbeenroutinelyusedforthefinaltreatmentofhazardouswaslespriortolanddisposal．Theseprocessesinvolveaddingoneormoresolidifyingreagentsintothewastetotransformitintoamonol

2、ithicsolidwithimprovedstructuralintegrity．Cementbasedsystemswithpartialreplacementbypulverizedfuelash(PFA)havebeenwidelyusedtominimizeleachingofcontaininantsfromhazardouswastes．Thefiner行acfionofPFA(“5一岫，fineflyash,伍A)，producedbypassingtherawashthroughaclassilyingprocessiscommonlyusedin

3、buildingandSISprocesses．Low—gradeflyashisrejected(rFA)fromtheashclassifyingprocessandislargelyunusedduetohighcarboncontentandlargeparticlesizebutrepresentsasignificantproportionofPFA．FlueGasDesulphurisation(FGD)sludgeisaby-productoftheairpollutioncontrolprocessincoal—firedpowerplants．I

4、tschemicalcompositionismainlygypsum．AsthereactivityofflyashcanbeactivatedbygypsulD_，itwasofinteresttoconductresearchonthepossibleactivationofrFAusingFGDandusingthesematerialsinS／Sprocess．Thisthesisincludestworesearchparts，onefocusesontheresearchonthepozzolanicpropertyofrF氏theotherfocus

5、esontheresearchonthefeasibilityofusingrFAandFGDinthecement—basedSISofasyntheticheavymetalwaste．TheresultsonthepozzolauicpropertyofrFAshowthatr-FAgenerallyhasalowerrateofhydrationthanf-FAparticularlyattheearlystageofhydration．AddingCa(OH)2alonealmosthadnoeffectonacceleratingthehydration

6、ofr·FA．ButaddingNa2S04togetherwithCa(OH)2cansignificantlyacceleratethestrengthdevelopmentbothat28and90days．AddingK2S04onlyshowseffectiveat28claysandtheFGDtakesobviouseffectat90days．TheeffectofaddingCaCl2onthereactionofrFAislessthanNa2S04orK2S04．Pre仕eatmentofsteamcuringcanslightlyincrea

7、sethestrengthat28daysbutdecreasethes仃engthofsamplesat90days．Thegrindingofr-FAcansignificantlyincreasethestrengthat90days．Addingchemicalactivatoringroundr-FA—Ca(OH)2systemshowsthemosteffectivebothat28and90days．IITheresultsontheSISeffectusingrFAandFGDinthecement-basedSISprocessshowthat