简介：Manganesewasextractedfromleachinglow-grademanganeseoreinsulfuricacidmedium.Theeffectsofgranulediameter,leachingtime,liquid/solidratio(V/W)andtheconcentrationofsulfuricacidwereinvestigatedthroughorthogonalandsinglefactorexperiments.Theexperimentalresultsshowedthattheoptimalleachingconditionsare,sizeof0.054mm,120minutesofreactiontime,3(V/W)ofliquid/solidratioand30%oftheconcentrationofsulfuricacid(g/g).Underthoseconditions,theleachingefficiencyis96.73%.Thekineticsoftheleachingprocessisinaccordancewiththecharacteristicsoffractalreaction.

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简介：Thepreparationofchemicalmanganesedioxide(CMD)fromlow-graderhodochrositeore(LGRO)inXiushan,Chongqing,wasstudiedandimproved,includingleachingwithsulfuricacid,purifying,crystallizinganddecomposingofMnCO3,andrefiningofprimaryMnO2.TheproductwascharacterizedbyX-raydiffraction.Theresultsshowedthattheextractionratio,themanganeserecoveryratioofpurifying,crystallizationandrefiningreached96.8%,93.9%,97.7%and85.4%,respectively.Theoptimumconditionsofrefiningweredescribedasfollows:liquid(H2SO4)/solid(primaryMnO2)ratiowas3L/g,theconcentrationsofNaClOexceeded20%,andreactiontimewas3hours.Undertheaboveconditions,thecontentsofMnO2andMnintheobtainedmanganesedioxidewererespectively85.1%and53.9%.TherefinedMnO2canbeusedasthesupergrademanganesedioxideminepowderinchemicalindustry.TheXRDindicatedthatthestructureoftheproductwasγ-MnO2.

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简介：Thelow-gradevanadium-containingstonecoalusedinthisexperimentwascollectedfromWuxiCountry,ChongqingCity,China.Theexperimentfocusedonthevanadiumrecoveryfromroastedresiduethroughoptimizingtheprocessconditionsofaneffectiveandenvironmentally-friendlytechnology,namedcalcifiedroasting-sulfuricacidleachingtechnology.Bysingle-factorexperimentsandorthogonalexperiments,theeffectsofroastingtemperature,roastingtime,sulfuricacidconcentrationandleachingtimeontheleachingratioofvanadiumwereanalyzed.Theresultsshowedthattheleachingratioofvanadiumreached85.5%underthepropertechnologicalconditionsofroastingtemperature=950℃,roastingtime=4h,40%concentrationofsulfuricacidandleachingtime=6h.

简介：Relationshipbetweentheδ13CoftreeringcellulosefromPinusKoraiensisandclimateparameterswasinvestigated.Asignificantlynegativecorrelationbetweenδ13Candmeanlow-cloudamountfromMaytoJulywasdiscovered,whichcontributestoreconstructingthemeanlow-cloudamountfromMaytoJulyatAntuinrecent200years.Periodicalsofquasi-8-year,quasi-4-yearandquasi-2-yearweredetectedbothinδ13Cseriesandinthereconstructedlowcloudamountserieswith95%confidencelevel.Quasi-8-yearperiodmayreflecttheintegratedinfluenceofsolaractivity,monsoonactivityandlocalregionalfactors.Quasi-4-yearandquasi-2-yearperiodsindicatetheinfluencesofENSOandQuasiBiennialOscillation(QBO)ofEastAsianmonsoon,respectively.