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Dr. László A. Gömze associated professor UNIVERSITY OF MISKOLC PowerPoint Presentation
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Dr. László A. Gömze associated professor UNIVERSITY OF MISKOLC

Dr. László A. Gömze associated professor UNIVERSITY OF MISKOLC

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Dr. László A. Gömze associated professor UNIVERSITY OF MISKOLC

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  1. Habilitációs tudományos kollokvium Miskolc, 2011. január 20. MECHANOCHEMICAL PHENOMENONS TAKE PLACE DURING COMMINUTIONS OF CONVENTIONAL BRICK CLAYS ON PAN MILL Dr. László A. Gömze associated professor UNIVERSITY OF MISKOLC FACULTY OF MATERIAL SCIENCE AND ENGINEERING Dept. of Ceramics and SilicateEngineering http://keramia.uni-miskolc.hu femgomze@uni-miskolc.hu

  2. MECHANOCHEMICAL PHENOMENONS TAKE PLACE DURING COMMINUTIONS OF CONVENTIONAL BRICK CLAYS ON PAN MILL THEMES • Ourgoals • Properties of clayminerals and conventionalbrickclays • The aims of crushing and finecomminution of brickclays • Mechano-chemicalprocessesduringfinecomminution • Mechano-chemicalphenomenonstakeplaceduringgrindingclaymaterialsonlaboratorypanmill • Conclusions

  3. MECHANOCHEMICAL PHENOMENONS TAKE PLACE DURING COMMINUTIONS OF CONVENTIONAL BRICK CLAYS ON PAN MILL OUR GOALS • Understandtheessenceof mechano-chemicalprocessestakeplaceduringgrinding and finecomminution of clayminerals. • 2. Understandtheeffects of mechano-chemicalactivationonthephysico-chemical and technologicalproperties of the main components of conventionalbrickclays and clayminerals. • 3. Increasetheefficiencyof crushingofconventionalbrickclays and claymineralsthroughunderstandingthemechano-chemicalprocessestakeplaceduringtheirfinecomminutions.

  4. PROPERTIES OF CLAY MINERALS AND CONVENTIONAL BRICK CLAYS • THE CLAY MINERALS • Claymineralsarehydrousaluminiumphylosilicates, sometimescontainFe+2, Mg+2, Na+, K+ and othercations; • Claymineralsareproducts of commonweathering and lowtemperaturehydrothermalalteration; • Generallytheyarebuilt of tetrahedral(t) and octahedral(o) sheets; • Claymineralsareultra finegrained, dmax< 2 µm; • Typicalt-oclay is kaoliniteAS2H2Al2O3*2SiO2*2H2O; • t-o-tclaysareillite, smectite and others. Tetrahedralstructure Octahedralstructure

  5. PROPERTIES OF CLAY MINERALS AND CONVENTIONAL BRICK CLAYS THE CONVENTIONAL BRICK CLAYS • The conventionalbrickclaysare mix of mineralslike: • Quartz: SiO2 and itsmodifications • Feldspars: • Albite: NAS6 Na2O*Al2O3*6SiO2 • Orthoclas: KAS6 K2O*Al2O3*6SiO2 • Anorthite: CAS2 CaO*Al2O3*2SiO2 • Claymineralsof thefollowinggroups: • Kaolin group: AS2H2 Al2O3*2SiO2*2H2O • Kaolinite and theirmodifications (dickite, halloysit, nacrite) • Smectitegroup: • Montmorillonite(Na, Ca)0,33(Al,Mg)2(Si4O10)(OH)*nH2O • Montronite(CaO0,5,Na)0,3Fe3+2(Si,Al)4O10(OH)2*nH2O • SaponiteCaO0,25(Mg, Fe)3((Si,Al)4O10)(OH)2*nH2O • Illitegroup: illite and claymicas • Chloritegroup: widevariety of similarminerals • Otherminerals: carbides, oxides and organicmaterialsandpollutions

  6. THE TYPICAL STRUCTURES OF CONVENTIONAL BRICK CLAYS Magnification: 1000X Magnification: 1000X Magnification: 10 000X Magnification: 1000X Magnification: 2000X Magnification: 3000X 60. évf. 4. szám 2008/4 építőanyag

  7. STRUCTURE AND TOTAL VOLUME OF PORES IN CLAY MINERALS Where: A and B – thetotalnumbers of opened and closedpores C and D – thetotalnumbers of capillares and gapsbetweenthegrains V– Volume Vnpi – thevolume of „i-th” openpore Vzpj – thevolume of „j-th” closedpore Vkpk – thevolume of „k-th” capillary Vhtl– thevolume of „l-th” void (gap)

  8. THE AIMS OF CRUSHING AND FINE COMMINUTION OF CLAYS • Decreasethesizes and volumes of grains, individualpores, gaps (voids) and capillariesthroughgrinding. • 2. Togettherequiredgrainsizes and theirdistributions of theclaymineralsasrawmaterials. • Increasethechemicalreactivity of thegrains and particles of claymineralsthroughtobtainingtherequiredvaluesofsurface and specificsurfaceareas. • Usemechanicalenergytochangephysico-mechanicalproperties of claymineralsasrawmaterials. • 5. Changethechemical and mineralogicalcompositions of claymineralsthroughmechanicalactivationoftheiratoms and ions.

  9. RELATIONSHIPS BETWEEN THE VOLUMES OF INDIVIDIUAL PORES AND WATERS IN THEM The tensilestress (pk)inwater-droppesgeneratedbysurfacestress: α – contactwettingangle; [°] σ - surfacetension (N/m); r – radius of waterdrop (m) Radius of thepore, (theradius of waterdrop) The requiredmechanicalstresstoovertakethesurfacetension of water MPa MPa MPa MPa

  10. MECHANO-CHEMICAL PROCESSES DURING FINE COMMINUTIONS • Atoms and ionsatthesurfacehave less neighbouringatoms and ionsasinside of the body  Theyhaveextra energyand activityatthesurfaces. • Duringgrindingthetotalvolume of grainsurfacesareincreasing, because of whichthesurfacesbecomechemicallyactivated. • Thesechemicallyactivatedstates of claysareappearedin: • increasedadsorptionactivity, • aggregation and agglomerationphenomenons, • mechano-chemicalprocesses and phasetransformations, • increasedvolume of amorphousphases. Theoretical Practical

  11. THE INITIAL MODEL OF MECHANO-CHEMICAL PROCESSES Cavity is notadsorbed Cavitywalladsorbedwithalienatoms (medium) Propagation of brittlecrackwithdeformationatlowtemperature; Formation of dislocationwithdeformationofhightemperature Formation of crack through penetration of alien atoms (medium) into the stressed and deformed system (TakenfromJushchenko, V. S, Grivtsov, A. G., and Shchukin, E. D.) DAN, SSSR 215 148 (1974) (Taken from Jushchenko, V. S, Grivtsov, A. G., and Shchukin, E. D.) DAN, SSSR 219 162 (1974)

  12. SOME IMPORTANT FACTORS INFLUENCE ON MECHANO-CHEMICAL PROCESSES DURING FINE COMMINUTIONS Cch– Chemicalcomposition and structure; Ccm – Mineralogicalcomposition and structure; Ccr – Crystalstructures of mineralogicalcomponents; Dgs – Grainsizes and structures of components; Fcr – Crushingforces and theirloadings; Fib – Interatomicbondingforces; Poc – Porosity, poresizes and structures; Rmc – Mechanicalproperties, strength and hardnesses. Mcp=f(Cch, Ccm, Ccr, Dgs, Fcr, Fib, Poc, Rmc)

  13. USED EQUIPMENT AND TESTING INSTRUMENTS • Usedequipmentforcrushing and comminution Hosokawamechanofusior Pan grinder b. Usedinstrumentsfor testing Bruker D8 AdvanceX-raydiffractometer Tristar 3000 Specificsurfacetester Hitachi TM 1000 Scanning Electronmicroscope Derivatograph

  14. INFLUENCE OF CRUSHING TIMES ON SPECIFIC SURFACES OF CLAY MINERALS USED IN CERAMIC BRICK INDUSTRY

  15. MINERAL CONTENTS OF MINED CLAY RAW MATERIALS USED IN CERAMIC ROOF-TILES INDUSTRY IN LENTI, HUNGARY

  16. INFLUENCE OF CRUSHING TIME ON MINERAL CONTENTS OF „LENTI” MINED CLAY RAW MATERIALS

  17. CHANGES IN MINERAL CONTENTS OF MINED CLAY RAW MATERIALS USED IN CERAMIC ROOF-TILES INDUSTRY IN LENTI, HUNGARY

  18. CHANGES IN MINERAL CONTENTS OF „LENTI” CLAY RAW MATERIALS AS FUNCTION OF MOISTURE AND CRUSHING TIME

  19. INFLUENCE OF CRUSHING TIMES ON MINERAL CONTENTS AND SPECIFIC SURFACE OF MINED CLAYS USED IN CERAMIC BRICK INDUSTRY IN TISZAVASVÁRI, HUNGARY

  20. INFLUENCE OF GRINDING TIME ON THERMO-ANALYTICAL PROPERTIES OF CONVENTIONAL BLUE CLAY FROM TISZAVASVÁRI

  21. MODELING OF CHEMICAL ACTIVITY OF FINE QUARTZ GRAINS IN WET CLAY MINERALS OF CERAMIC BRICKS AND ROOF-TILES (SiO2*4H2O)m a: adsorptionlayerb: diffusionlayer of cationsm: number of moleculesinthecoren: number of moleculesinthecolloidoutsideofthecoreR1: radius of thecoreR2: radius of thecolloidparticleR3: radius of themicell [(SiO2)m*nSiO32-*2(n-x)H+]*2x*H+

  22. CONCLUSIONS • Claymineralsof ceramicbrick and roof-tileindustrieshavinghighvalues of specificsurfaceareaaremechano-chemicallyveryactivesduringcrushingonpangrinder. • Because of thedissipationofminerals, likeMuscovite 2M and significantgrowth of volumesofQuartz, thespecificsurfacesofLenti claydecreaseconsiderably, dependingoncrushingtimes. • Duringthefinecomminution of claymineralsofbrick and roof-tileindustriestheMuscovite 2M and Illitearethe most instablecomponents, meanwhilethequantity of Albite and Quartzcan be formed. • The free moisture– water – inminedclayminerals and dehydrationanddissociation of sum of theircomponentscanmechano-chemicallyactivatethefineQuartzcrystals, generatingcolloids and micells. Thesemicellsarechemicallyveryactive and canparticipateinformingnewminerals of IlliteorMuscovite 2M, aswell. • Duringgrindingconventionalbrickclaysonlaboratorypangrindera considerablyvolume of amorphousphasecan be formed.

  23. ACKNOWLEDGEMENT The authoracknowledgetothecolleagues and PhD studentsat : Dept. of Mineralogy and Petrologyfor XRD examinations, Dept. of Metallurgical and FoundryEngineeringforspecificsurfacemeasurements, andtothecolleagues, PhD students and techniciansat Dept. of Ceramics and SilicateEngineeringforthecollaborationinlaboratorytestsandmeasurements.

  24. Habilitációs tudományos kollokvium Miskolc, 2011. január 20. Thank you very much for your time and kind attention ! Dr. László A. Gömze associated professor University of Miskolc FACULTY OF MATERIAL SCIENCE AND ENGINEERING Dept. of Ceramics and SilicateEngineering