简介:Experimentswereconductedtoinvestigatetheeffectofaddingfinesonthetribo-chargingofcoarseglassbeads.Fourtypesoffines,i.e.,copper,stainlesssteel,uncoatedandsilver-coatedfineglassbeads,mixedw让h240-830μmglassbeadswereconveyedbyairthroughastainless-steelspiralpipeactingasatribo-charger.Regardlessofthetypeorelectricalconductivityofthefineparticlestested,addingsmallamountsoffines(upto10wt%)tocoarseglassbeadsresultedinasharpincreaseinthemassandsurfacechargedensitiesoftheparticles.Ingeneral,theprofilesofthemassandsurfacechargedensidesofthefine-coarseparticlemixturesasafunctionofthemixturecompositionweredeterminedbytherelativemagnitudeofcontactpotentialdifferencesandthetotalsurfaceareasofallthecomponents.Thedominantparticletribo-electrificationmechanismswitchedfromcoarseparticle-wallcontactstofineparticle-wallcontactswhenthefinesweightpercentageinthemixtureexceeded10%.Amodelwasdevelopedtopredictthemasschargedensityofbinarymixturesasafunctionofthemixturecomposition.