第23卷第2期2023年2月过程工程学报TheChineseJournalofProcessEngineeringVol.23No.2Feb.2023SynthesisofzeoliteSODfrompotassicrocksactivatedbyNaOH-NaClsub-moltensaltmethodWenzhuoLIU1,2,YangLIU1,2,YunLI1,2*,HongfeiGUO1,2*,JilinCAO1,21.SchoolofChemicalEngineeringandTechnology,HebeiUniversityofTechnology,Tianjin300130,China2.EngineeringResearchCenterofSeawaterUtilizationTechnologyofMinistryofEducation,Tianjin300130,ChinaAbstract:Potassicrocksarealuminosilicatecrystalscontainingabundantpotassiumelements,whichcouldbeusedtoproduceK-fertilizersbyextractingK+,synthesizingzeolites,andpreparingvaluableindustrialproducts.Torealizetheefficientutilizationofpotassicrocks,thesub-moltensaltmethodwasusedtoactivatepotassicrocksusingNaOH-NaClastheactivatingagent.TheeffectsoftheadditionofNaOH,NaCl,andH2OontheleachingrateofK+wereinvestigated,respectively.Therawmaterials,activatedproductsandfiltrationweredeterminedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),andtitrationmethod.Theexperimentalresultsshowedthattheoptimalactivationconditionsarem(NaOH)/m(potassiumrocks)of0.7,m(NaCl)/m(potassiumrocks)of0.7,m(H2O)/m(potassiumrocks)of1.0,activationtemperatureof160℃,andactivationtimeof120min.TheleachingrateofK+couldreachabout92%,andthealkaliconcentrationwasdecreasedto41wt%.ComparativeinvestigationsweremadewiththeeffectofactivationofpotassicrocksusingtheNaOHsub-moltenmethodconcerningtheleachingrateofionsofK+,SiO32−andAl3+andactivatedproductsintheidenticalreactionconditions.TheconcentrationsofK+,SiO32−andAl3+inthemotherliquorobtainedfromNaOH-NaClsub-moltensystemweresignificantlyincreasedincontrastwiththatfromthesystemintheabsenceofNaCl,demonstratingthepromotioneffectofNaClfortheactivationofpotassicrocksandthepeaksassignedtoSODzeoliteweregreatlyintensifiedwiththeintroductionofNaCl.Comparedwiththeactivationeffectandconditionsofotheradditivesinthesub-moltensaltmethodreportedintheliterature,NaOH-NaClsub-moltensystemexhibitedasatisfactoryleachingrateofK+undertheconditionofsignificantlydecrea...
