简介:Ricehuskwasusedtopreparethesilicaofamorphousnaturebeingseveraltimesmorereactivethanthatobtainedfromthemineralkingdom.Numberofricehuskbatcheswerepyroprocessedundervaryingtime-temperatureparametersforthispurpose.Theashresultingfromabatchpyroprocessedat500℃for8hcontained92.01%silica.Itwasupgradedto98.50%byapplyingphysicochemicalpurificationprocedures.Themineral,wollastonite(CaSiO3),wassynthesizedfromthuspreparedsilicaandlimestonecontaining55.91%CaO.Solidstatereaction,betweenCaOandSiO2wasattemptedatdifferenttemperaturesinthepresenceofamineralizer.Thesinteringtemperature,foraffectingthesaidsynthesis,wasrangedbetween900℃to1300℃withthestepsof100℃.SpecificchemicalanalysistechniqueswereappliedtodeterminetheeffectivenessofcarriedoutreactionandpromisingbatchesweresubsequentlysubjectedtoXRDinvestigations.Theproducedmineralwasalsocharacterizedregardingitsphysicalpropertieslike:colour,hardness,meltingpointandspecificgravity.Percentyieldoftheproducedwollastonitewasalsoestimatedandcomparedwiththatofobtainedbyotherresearcherswhosynthesizeditbyusingsilicafrommineralkingdom.Batchessinteredat1200℃and1300℃for1hshowedtheoverallbestresults.
简介:FordeterminingtheoptimalpercentageofRAPmaterialincentralplanthotrecycling,binderwasrecoveredfromRAPbymeansofAbsonrecoverymethod,andpropertiestestsofmixedbindersconsistingofrecoveredasphaltandfreshasphaltatdifferentratioswereperformed.Inaddition,theperformancesofmixturewithdifferentpercentagesofRAPsuchasruttingresistance,anti-cracking,moisturesusceptibilityandfatigueresistanceweretested.ThebindertestresultsshowedthatthehightemperatureperformancewasimprovedwiththeincreaseofthepercentageoftheRAP,whilethelowtemperatureperformancewasdeclined.Whenthepercentageoftherecoveredbinderwaslessthan30%,themixedbindercouldmatchthetechnicalstandardsforfreshasphalt.TestsonthemixturesshowedthatruttingresistanceincreasedgraduallyasRAPpercentageincreased,whilethermalanti-crackingatlowtemperatureandfatiguepropertiesdeclined.TheeffectofthepercentageofRAPonmoisturesusceptibilitywaslimited.ItisindicatedthatlowtemperatureperformanceandfatiguepropertiesareimportantforselectingtheoptimalpercentageofRAP.Basedondataobtainedfrombindersandmixtures,itisconcludedthatthemaximumpercentageofRAPisapproximately30%withouttheadditionofrejuvenatingagent.
简介:Reducingthechloridecontentinregeneratedironoxides(RIO)fromsteel-picklingacidwasteeconomicallytreatedbyRuthnerprocessisthemostcriticalissueforthedevelopmentofRIOasausefulrawmaterialresource.Inthispaper,theresultsofanewmethodforcharacterizationandmodificationofRIOproducedinMobarakehSteelComplexwerereported.