R.F.Thiesen,E.Osrio,I.A.H.Schneider
LTMDEMIN PPGE3M,LASIDDEMET PPGE3M,UniversidadeFederaldoRioGrandedoSul
Av.BentoGonalves,9500 CEP:91501970,PortoAlegre,RS,Brazil
VivianaNedel Reckziegel
Summary
Introduction
Materials and Methods
Results and Discussion
Conclusions
Acknowledgments
Introduction
Forging is a manufacturing process involving the shaping ofmetal using localized compressive forces.
Lubrificant:1) Reduce the metalmetalfriction,2) Aimingatenablingtheremovaloftheforgedpartfrom
insidethematrix,3) Coolandprotect ,4) Extendtheusefullifeofthematrices.
Types of Lubricants
TYPEOFLUBRICANT ADVANTAGES DISADVANTAGES
Graphite OilbasedIncreaseslifetime
Applicableinawiderangeofforgingoperations.Resistance.
Generationofhighlypollutinganddifficulttotreateffluents
Emissionofsmallamountofsmoke
GraphiteWaterbased
IncreasesarraylifeDoesnotgeneratesmoke
LessenvironmentallyaggressiveEasydilutioninwater
Graphiteparticlesmaybeemitted,possiblydamagingelectricalsystemsoraccumulatingontheshopfloor.
SyntheticAppliedinforgesthatworkwithspecificalloysandincutting
edgeindustriesHighcost
Solidbased Replaces 100%of lubricants
Highcost,limitedtoplaceswhereconventionaltypescannotbeused.Lowcomplexityparts.
Generalcharacteristicsoflubricantsusedintheforgingprocess.
Introduction
Forging Press
Change inProcess
Waterbased lubricant
Oilbased graphite lubricant
Purpose of this article is: studying the sludge generated from the treatment ofthe effluent using waterbased lubricant. The sludge characteristics, its handlingand final destination or reuse possibilities were assessed.
Materials andMethodsPhysicalchemicalcharacteristicsofthewaterbasedgraphitelubricants
Parameter Waterbased lubricant
Color Dark gray
Appearance Homogeneous fluid
Graphite content >=10%
pH of the emulsion >=10
Density at 20 C 1.1 g/cm
Viscosity cSt at 40 C. 1500 mPa.s
Average particle size 4 m
Materials andMethods
Schematicrepresentationofthestepsofthetreatmentstation.
Samples collected
SludgeCharacterization
SettledvolumeASTMD3977; SpecificmassaccordingtoASTMD854, MoisturecontentASTMD221610; Ash,volatilematterandfixedcarboncontent(ASTMD317207); Calorificvalue(ASTMD201500); ElementalanalysisUSEPA3051,USEPA3050BandASTMD537302; CharacterizationregardinghazardsaccordingtotheStandardNBR10004.
Xray diffraction inaSiemensdiffractometer model Kristalloflex D500; Electronic scanning microscopy and (EDS) Granulometric analysis with laserbeam diffraction; Thermogravimetric analysis inaThermobalance Netzsch STA.
Results and Discussion
Parameter Effluent OLStandard Efficiency(%)Raw Treated
DBO(mg/L) 6120 610
SludgeCharacterization
SettledsludgeaftertreatmentintheImhoff Cone(a);afterfiltration(b),afterdryingat60oCandclodbreaking(c);aftercompactionat100MPa(d).
Sedimentation(1hour)=450mLofsludgeperliterofeffluent(55%ofthevolume)(24hours)=400mL(60%ofthevolumeofeffluentintheclarifiedform).
SludgeElementalAnalysis
CLASSIIAWASTE NONINERT
Carbon70,7%
Aluminiun1,6%
Iron4,8%
Oxygen21%
Min.Elem*1,9%
SlugdeCompositionPAC
Carbon
Aluminum
Iron
Oxygen
MinorityElements
SludgeCharacterization
Diffractogram referringtotheDRXanalysisofthesludgegenerated.
WaterbasedsludgeCalorificvalue(cal/g) 5850Ashes(%) 21.4Volatilematter(%) 9.0Fixedcarbon(%) 69.6
Immediateanalysis
Thermogravimetric Analysis
Thermogravimetric analysis
Alternatives forsludge recycling
Thechangeinlubricantsfromoilbaseddowaterbasedsimplifiedthewatertreatmentprocess,andgeneratedasludgethatcanbefiltered,driedandcompacted,reducingstorage,transportationanddisposalcosts.Thecharacteristicsofoilfreesludgeallowedsendingtocementkilns,reducingpartiallythecostsofdestination.
Aftersludgecharacterization,otherusescouldbeconsidered,includingascofiredcombustibletocoalthermalpowerplants.
Conclusion
Forging industries generate considerable amount of emissions, effluents and waste,requiring investments to prevent pollution and environmental damage. The treatment ofeffluents is a required operation. The use of waterbased lubricants, replacing oilbasedlubricants, improves the environmental performance. The change of lubricant enabled asludge that can be easily filtered and handled. It presents a carbon content of 70% mainlyin the form of graphite, with certain level of oxidation. In a regional context, it may besurely employed for power generating purposes in thermoelectric plants or cement kilns.However, other application alternatives are being investigated, including its cleansing andreturn to the lubrication process.
Acknowledgments
TheauthorsaregratefulforthefinancialsupportextendedbyGKN,CAPESandCNPq forthisresearch.
Thanks/OBRIGADA
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