Lime (material) - Wikipedia

Dry slaking is slaking quicklime with just enough water to hydrate the quicklime, but to keep it as a powder; it is referred to as hydrated lime. In wet slaking ... Lime(material) FromWikipedia,thefreeencyclopedia Jumptonavigation Jumptosearch Calciummineral Forotheruses,seeLime. LimestonequarryinBrønnøy,Norway Limeisacalcium-containinginorganicmineralcomposedprimarilyofoxides,andhydroxide,usuallycalciumoxideand/orcalciumhydroxide.Itisalsothenameforcalciumoxidewhichoccursasaproductofcoal-seamfiresandinalteredlimestonexenolithsinvolcanicejecta.[1]Thewordlimeoriginateswithitsearliestuseasbuildingmortarandhasthesenseofstickingoradhering.[2] Thesematerialsarestillusedinlargequantitiesasbuildingandengineeringmaterials(includinglimestoneproducts,cement,concrete,andmortar),aschemicalfeedstocks,andforsugarrefining,amongotheruses.LimeindustriesandtheuseofmanyoftheresultingproductsdatefromprehistorictimesinboththeOldWorldandtheNewWorld.Limeisusedextensivelyforwastewatertreatmentwithferroussulfate. Therocksandmineralsfromwhichthesematerialsarederived,typicallylimestoneorchalk,arecomposedprimarilyofcalciumcarbonate.Theymaybecut,crushed,orpulverizedandchemicallyaltered.Burning(calcination)ofthesemineralsinalimekilnconvertsthemintothehighlycausticmaterialburntlime,unslakedlimeorquicklime(calciumoxide)and,throughsubsequentadditionofwater,intothelesscaustic(butstillstronglyalkaline)slakedlimeorhydratedlime(calciumhydroxide,Ca(OH)2),theprocessofwhichiscalledslakingoflime. Whenthetermisencounteredinanagriculturalcontext,itusuallyreferstoagriculturallime,whichtodayisusuallycrushedlimestone,notaproductofalimekiln.Otherwiseitmostcommonlymeansslakedlime,asthemoredangerousformisusuallydescribedmorespecificallyasquicklimeorburntlime. Contents 1Production 2Cycle 3Buildingmaterials 3.1Romanconcrete 4Seealso 5References 6Furtherreading 7Externallinks Production[edit] Inthelimeindustry,limestoneisageneraltermforrocksthatcontain80%ormoreofcalciumormagnesiumcarbonate,includingmarble,chalk,oolite,andmarl.Furtherclassificationisdonebycompositionashighcalcium,argillaceous(clayey),silicious,conglomerate,magnesian,dolomite,andotherlimestones.[3]Uncommonsourcesoflimeincludecoral,seashells,calciteandankerite. Limestoneisextractedfromquarriesormines.Partoftheextractedstone,selectedaccordingtoitschemicalcompositionandopticalgranulometry,iscalcinatedatabout1,000 °C(1,830 °F)indifferenttypesoflimekilnstoproducequicklimeaccordingtothereaction: CaCO 3 calcium   carbonate → heat CaO calcium   oxide + CO 2 carbon   dioxide {\displaystyle{\ce{{\overset{calcium~carbonate}{CaCO3}}->[][{\text{heat}}]{\overset{calcium~oxide}{CaO}}+{\overset{carbon~dioxide}{CO2}}}}} . Beforeuse,quicklimeishydrated,thatiscombinedwithwater,calledslaking,sohydratedlimeisalsoknownasslakedlime,andisproducedaccordingtothereaction: CaO + H 2 O water ⟶ Ca ( OH ) 2 calcium   hydroxide {\displaystyle{\ce{{CaO}+{\overset{water}{H2O}}->{\overset{calcium~hydroxide}{Ca(OH)2}}}}} . Dryslakingisslakingquicklimewithjustenoughwatertohydratethequicklime,buttokeepitasapowder;itisreferredtoashydratedlime.Inwetslaking,aslightexcessofwaterisaddedtohydratethequicklimetoaformreferredtoaslimeputty. Becauselimehasanadhesivepropertywithbricksandstones,itisoftenusedasbindingmaterialinmasonryworks.Itisalsousedinwhitewashingaswallcoattoadherethewhitewashontothewall. Cycle[edit] Thelimecycleforhigh-calciumlime Theprocessbywhichlimestone(calciumcarbonate)isconvertedtoquicklimebyheating,thentoslakedlimebyhydration,andnaturallyrevertstocalciumcarbonatebycarbonationiscalledthelimecycle.[4]Theconditionsandcompoundspresentduringeachstepofthelimecyclehaveastronginfluenceoftheendproduct,[5]thusthecomplexandvariedphysicalnatureoflimeproducts. Anexampleiswhenslakedlime(calciumhydroxide)ismixedintoathickslurrywithsandandwatertoformmortarforbuildingpurposes.Whenthemasonryhasbeenlaid,theslakedlimeinthemortarslowlybeginstoreactwithcarbondioxidetoformcalciumcarbonate(limestone)accordingtothereaction: Ca(OH)2+CO2→CaCO3+H2O. Thecarbondioxidethattakespartinthisreactionisprincipallyavailableintheairordissolvedinrainwater[6]sopurelimemortarwillnotrecarbonateunderwaterorinsideathickmasonrywall. Thelimecyclefordolomiticandmagnesiumlimeisnotwellunderstood[5]butmorecomplexbecausethemagnesiumcompoundsalsoslaketopericlasewhichslakemoreslowlythancalciumoxideandwhenhydratedproduceseveralothercompoundsthustheselimescontaininclusionsofportlandite,brucite,magnesite,andothermagnesiumhydroxycarbonatecompounds.Thesemagnesiumcompoundshaveverylimited,contradictoryresearchwhichquestionswhetherthey"...maybesignificantlyreactivewithacidrain,whichcouldleadtotheformationofmagnesiumsulfatesalts."[7]Magnesiumsulfatesaltsmaydamagethemortarwhentheydryandrecrystallizeduetoexpansionofthecrystalsastheyformwhichisknownassulfateattack. Buildingmaterials[edit] Limeusedinbuildingmaterialsisbroadlyclassifiedas"pure","hydraulic",and"poor"lime;[8]canbenaturalorartificial;andmaybefurtheridentifiedbyitsmagnesiumcontentsuchasdolomiticormagnesiumlime.Usesincludelimemortar,limeplaster,limerender,lime-ashfloors,tabbyconcrete,whitewash,silicatemineralpaint,andlimestoneblockswhichmaybeofmanytypes.Thequalitiesofthemanytypesofprocessedlimeaffecthowtheyareused.TheRomansusedtwotypesoflimemortartomakeRomanconcrete,whichallowedthemtorevolutionizearchitecture,sometimescalledtheConcreterevolution. Limehasmanycomplexqualitiesasabuildingproductincludingworkabilitywhichincludescohesion,adhesion,aircontent,watercontent,crystalshape,board-life,spreadability,andflowability;bondstrength;comprehensivestrength;settingtime;sand-carryingcapacity;hydraulicity;freelimecontent;vaporpermeability;flexibility;andresistancetosulfates.Thesequalitiesareaffectedbymanyfactorsduringeachstepofmanufacturingandinstallation,includingtheoriginalingredientsofthesourceoflime;addedingredientsbeforeandduringfiringincludinginclusionofcompoundsfromthefuelexhaust;firingtemperatureandduration;methodofslakingincludingahotmix(quicklimeaddedtosandandwatertomakemortar),dryslakingandwetslaking;ratioofthemixturewithaggregatesandwater;thesizesandtypesofaggregate;contaminantsinthemixingwater;workmanship;andrateofdryingduringcuring.[9] Purelimeisalsoknownasrich,common,air,slaked,slack,pickling,hydrated,andhighcalciumlime.Itconsistsprimarilyofcalciumhydroxidewhichisderivedbyslakingquicklime(calciumoxide),andmaycontainupto5%ofotheringredients.Purelimesetsveryslowlythroughcontactwithcarbondioxideintheairandmoisture;itisnotahydrauliclimesoitwillnotsetunderwater.Purelimeispurewhiteandcanbeusedforwhitewash,plaster,andmortar.Purelimeissolubleinwatercontainingcarbonicacid,anatural,weakacidwhichisasolutionofcarbondioxideinwaterandacidrainsoitwillslowlywashaway,butthischaracteristicalsoproducesautogenousorself-healingprocesswherethedissolvedlimecanflowintocracksinthematerialandberedeposited,automaticallyrepairingthecrack. Semi-hydrauliclime,alsocalledpartiallyhydraulicandgreylime,setsinitiallywithwaterandthencontinuestosetwithair.Thislimeissimilartohydrauliclimebuthaslesssolublesilica(usuallyminimum6%)andaluminates,andwillsetunderwaterbutwillneverharden.[10] Hydrauliclimeisalsocalledwaterlime.Hydrauliclimecontainslimewithsilicaoraluminaandsetswithexposuretowaterandcansetunderwater.[11]Naturalhydrauliclime(NHL)ismadefromalimestonewhichnaturallycontainssomeclay.Artificialhydrauliclimeismadebyaddingformsofsilicaoraluminasuchasclaytothelimestoneduringfiring,orbyaddingapozzolanatopurelime.[10]Hydrauliclimesareclassifiedbytheirstrength:feebly,moderatelyandeminentlyhydrauliclime.Feeblyhydrauliclimecontains5-10%clay,slakesinminutes,andsetsinaboutthreeweeks.Itisusedforlessexpensiveworkandinmildclimates.Moderatelyhydrauliclimecontains11-20%clay,slakesinonetotwohours,andsetsinapproximatelyoneweek.Itisusedforbetterqualityworkandexteriorwallsinfreezingclimates.Eminentlyhydrauliclimecontains21-30%clay,slakesveryslowly,andsetsinapproximatelyaday.Itisusedinharshenvironmentssuchasdamplocationsandnearsaltwater.Hydrauliclimeisoff-whiteincolor."Thedegreeofhydraulicityofmortarswillaffectmanycharacteristics.Byselectinganappropriateratioofclaytolimestonemortarsthatcarbonateorsethydraulicallytoavaryingextentscanbedesignedforparticularapplicationrequirementssuchassettingtime,strength,colour,durability,frostresistance,workability,speedofsetinthepresenceofwater,vapourpermeabilityetc."[11] Poorlimeisalsoknownasleanormeagerlime.Poorlimesetsandcuresveryslowlyandhasweakbonding.Poorlimeisgreyincolor. Magnesiumlimecontainsmorethan5%magnesiumoxide(BS6100)or5-35%magnesiumcarbonate(ASTMC59-91).[12]Dolomiticlimehasahighmagnesiumcontentof35-46%magnesiumcarbonate(ASTMC59-91).[12]DolomiticlimeisnamedfortheDolomiteMountainsintheItalianandAustrianAlps.[13] IntheUnitedStatesthemostcommonlyusedmasonrylimeisTypeShydratedlimewhichisintendedtobeaddedtoPortlandcementtoimproveplasticity,waterretentionandotherqualities.TheSintypeSstandsforspecialwhichdistinguishesitfromTypeNhydratedlimewheretheNstandsfornormal.ThespecialattributesofTypeSareits"...abilitytodevelophigh,earlyplasticityandhigherwaterretentivityandbyalimitationonitsunhydratedoxidecontent."[14]ThetermTypeSoriginatedin1946inASTMC207HydratedLimeforMasonryPurposes.TypeSlimeisalmostalwaysdolomiticlime,hydratedunderheatandpressureinanautoclave,andusedinmortar,render,stucco,andplaster.TypeSlimeisnotconsideredreliableasapurebinderinmortarduetohighburningtemperaturesduringproduction. Kankarlime,alimemadefromkankarwhichisaformofcalciumcarbonate. Seleniticlime,alsoknownasScotts'cementafterHenryYoungDarracottScottisacementofgreychalkorsimilarlime,suchasintheLiasGroup,withabout5%addedgypsumplaster(calcinedgypsum).[10]Seleniteisatypeofgypsum,butseleniticcementmaybemadeusinganyformofsulfateorsulfuricacid.[15]Sulfatearrestsslaking,causesthecementtosetquicklyandstronger. Romanconcrete[edit] Mainarticle:Romanconcrete TheRomansmadeconcretebymixinglimeandvolcanicashtocreateapozzolanicreaction.Ifthiswasmixedwithvolcanictuffandplacedunderseawater,theseawaterhydratedthelimeinanexothermicreactionthatsolidifiedthemixture.[16] Seealso[edit] Agriculturallimeandliming(soil) Calcisol(soiltype) Eco-cement Hideglue Limelight Limesoftening(watertreatment) Limewater Liming(leatherprocessing) Plasterwork Sascab:abuildingandpavingmaterial(CentralAmerica) Soda–limeglass References[edit] ^"LimeinHandbookofMineralogy"(PDF).Retrieved24April2017. ^"OnlineEtymologyDictionary".Retrieved24April2017. ^Lazell,EllisWarren.Hydratedlime;history,manufactureandusesinplaster,mortar,concrete;amanualforthearchitect,engineer,contractorandbuilders.Pittsburgh:Jackson-RemlingerPrintingCo.,1915.21.Print. ^"TheLimeCycle".27October2011.Retrieved24April2017. ^abKrzysztofKudłacz,"PhaseTransitionsWithintheLimeCycle:ImplicationsinHeritageConservation"Thesis.April,2013.UniversityofGranada. ^BritishLimeAssociation ^HeatherHartshorn,"DolomiticLimeMortars:CarbonationComplicationsandSusceptibilitytoAcidicSulfates"Thesis.May2012.ColumbiaUniversity ^Rajput,R.K..EngineeringMaterial:(IncludingConstructionMaterials).3rded.NewDelhi:S.Chand&Co.Ltd.2006.74.Print ^"S.PaviaandS.Caro,"PetrographicMicroscopeInvestigationofMortarandCeramicTechnologiesfortheConservationoftheBuiltHeritage"".Retrieved24April2017. ^abcHeath,A.H..Amanualonlimeandcement,theirtreatmentanduseinconstruction..London:E.&F.N.Spon;,1893.6.Print. ^ab"JohnWHarrison,"CarbonatingandHydraulicMortars-thedifferenceisnotonlyinthebinder.Aggregatesarealsoimportant.""(PDF).Retrieved24April2017. ^abHewlett,PeterC..Leaʼschemistryofcementandconcrete.4.ed.Amsterdam:ElsevierButterworth-Heinemann,2004.27.Print. ^HeatherHartshorn,"DolomiticLimeMortars:CarbonationComplicationsandSusceptibilitytoAcidicSulfates"Thesis2012ColumbiaUniversity ^ASTMC207quotedinMargaretL.Thomson,"WhyisTypeSHydratedLimeSpecial?".InternationalBuildingLimeSymposium2005.Orlando,Florida,March9-11,2005 ^Smith,PercyGuillemardLlewellin.Notesonbuildingconstruction:arrangedtomeettherequirementsofthesyllabusoftheScience&ArtDepartmentoftheCommitteeofCouncilonEducation,SouthKensington....2nded.London:Rivingtons,1879.Print. ^"RomanSeawaterConcreteHoldstheSecrettoCuttingCarbonEmissions".BerkeleyLab.Retrieved14June2013. Furtherreading[edit] J.A.H.Oates,Projetde.LimeandLimestone–ChemistryandTechnology,ProductionandUses.Wiley-VCH,ISBN 3-527-29527-5(1998) USGeologicalSurvey Externallinks[edit] LookuplimeinWiktionary,thefreedictionary. TheNationalLimeAssociation(US&Canada) TheBritishLimeAssociation TheBuildingLimesForum(UK) TheEuropeanLimeAssociation(EULA) GlossarybyRobertW.Piwarzyk,SantaCruzPublicLibraries,Ca AuthoritycontrolNationallibraries UnitedStates Japan CzechRepublic Other MicrosoftAcademic Retrievedfrom"https://en.wikipedia.org/w/index.php?title=Lime_(material)&oldid=1056776918" Categories:BuildingmaterialsCalciummineralsLimestoneOxidemineralsPlasteringAlchemicalsubstancesHiddencategories:ArticleswithshortdescriptionShortdescriptionisdifferentfromWikidataArticleswithLCCNidentifiersArticleswithNDLidentifiersArticleswithNKCidentifiersArticleswithMAidentifiers Navigationmenu Personaltools NotloggedinTalkContributionsCreateaccountLogin Namespaces ArticleTalk Variants expanded collapsed Views ReadEditViewhistory More expanded collapsed Search Navigation MainpageContentsCurrenteventsRandomarticleAboutWikipediaContactusDonate Contribute HelpLearntoeditCommunityportalRecentchangesUploadfile Tools WhatlinkshereRelatedchangesUploadfileSpecialpagesPermanentlinkPageinformationCitethispageWikidataitem Print/export DownloadasPDFPrintableversion Inotherprojects WikimediaCommons Languages العربيةAzərbaycancaবাংলাБеларускаяBoarischCatalàDanskDeutschEestiΕλληνικάEsperantoفارسیFrançaisGaeilgeGàidhlig한국어Հայերենहिन्दीHrvatskiIdoBahasaIndonesiaItalianoಕನ್ನಡKiswahiliKreyòlayisyenKurdîLietuviųLimburgsLombardМакедонскиमराठीNederlands日本語NorskbokmålNorsknynorskPolskiRomânăРусскийSakizayaᱥᱟᱱᱛᱟᱲᱤSicilianuSimpleEnglishSlovenčinaСрпски/srpskiSrpskohrvatski/српскохрватскиSvenskaТоҷикӣTürkçeУкраїнська文言粵語Žemaitėška中文 Editlinks