自然崩落法SUB LEVEL CAVING培訓

SUBLEVELCAVINGCONTENTSSLCDESIGNCONCEPTSDRAWTHEORYSLCDESIGNLAYOUTDEBATEDesignrulesDrawiskingCriticalissuestobeansweredbeforegeotechnicaldesign:

-Howmuchdevelopmentforhowmuchrecovery? -Howmuchsupportforhowmuchrecovery? -SLC/blockcavetonnagecut-off? -SLCsustainingdevelopmentrateforreqtonnage? -hardorsoftcavingenvironment?1000msoftcavegeotechnicalcut-offInter-activedrawbecomesharderatdepthRecoveryharderatdepthWastegradebecomebetteratdepth(muckpilesalting)Norightorwrong,justprobabilitiesofsucessSLCBALANCECONCEPTSupportDrawBlastingProductionDrawtheoryHowthebrokengroundisdrawn/flowsDrawpointspacing’storeducedilution/increaserecoveryStillnotwellunderstoodPhysicalmodels/bunkers-Kvapli&Jenike1960’sMathematic/numericalplasticflow–Pariseau1960’sFullscalemarkertests–Kvapli,Just&Janelid1960’sPhysicalmodelsLaubscher,Tayloretc-1970-1980’sKvapilcurvesrevisited/Laubscher-Bull&2000ICS2001-presentPhysicalmodelsPFCRingmarkertrialsYENGE1980“theflowofcavedorecannotbedescribedsatisfactorybytheoriesdevelopedfortheflowofothergranularmaterialssuchassandpowderandserialgrains“DrawtheoryBestwehavegottodayWewillneversolvematerialvariabilityWemaygetcloserDesign’smustbetemperwith

-Commonsense -ExperienceTwodesigntheories

-kvapil -LaubscherFlowofmaterialBasicdrawtheoryEllipsoidareasEliposideformationMainpointsTwozones -DRAWOREXTRACTION

ellipsoid(MATERIALREMOVED) -Limitellipsoid(materialmovement/loosens)

Drawzone -Koperzoneincenter -shearzoneatthesidesPoints: -materialmovesfasterincentre -Finermaterialslimmerdrawzone -coarsermaterialwidedrawzone -drawzonewidthrelatedtomaterial/drawpointsizeSLCDesignClassificationMRMRbased2classes:Softcaves<class3Hardcaves>class3SUPPORTDESIGNSLCDESIGNLayoutsbasedondrawandblastingreqAbovereqdrawpointsclosetogetherWiderdrawpointsViolatesthelayoutstressrulesOperationaldepthlimitsoftcavesGreatersupportHardcavesbrowinstabilitySUSTAININGDEVELOPLEMENTDesignLayoutsbasedondrawKvapliLaubscherDrawinteractionSublevelheightDrawpointspacingFlatwidedrawpointsbacksLowerdriftheightsSublevelheigth: -Development -DrillingaccuracyDraw-interactionFLATBACKSLowdriftheight/ringangleKvapilLayoutdesignonbins/observationsprecisedeterminationofspacingCorrectionwithextractionelipsoid/IDZAppliescorrectionsfordriftbackprofile/oreUsesgraphsandformulaDeterminesSublevelheightDriftspacingDiggingdepth/burdencorrectionofsimmingofellipsoidforheigthKvapilDriftwidth,determinedfromgroundconditions

-MRMRclass4max4.5m(better3.8m) -MRMRClass3>max6.0mApplydriftcorrectionDeterminesublevelheigthDeterminewidthofextractionellipsoidDeterminedepthofextractionellipsoidDeterminedriftcenterspacingDriftcorrectionEllipsoidwidthDigwidthCavegradingKvapligradings110%extractionClass1,80%(ore)<30%wasteClass2,75%(ore)<35%wasteClass3,65%(ore(<45%wasteReferas70/30or60/40Dilutionentryabout40%materialdrawnRemarksOldsystemExactnumberCloserspacingHasbeenchallengedICSmaysuggestthatthismaynotbewrongCloserdrawpointspacingGradingoftypesofdrawReductionofdrawpointsizewithdrawheigth18mthecut-offLaubscherBin&observationsShabanieIsolateddrawzonediameterconceptIDZ=LimitellipsoidIncreasedinteraction/spacingduetoaboveDrawpointspacing=IDZxinteractionfactorLaubscherbinsDrawpointwidthsDilutionentrygraphsDilutionentrygraphLaubscherIDZconceptInteractionfactor?NodirectuseMainblockcavingRequiresskillUsefragmentationsizeRangeofdrawpointspacingsMissingdataBullandPage2000,SLCdesignrationaleNewmodelofbehaviorOldbintheorylayoutscausedmethodproblemsEmbracedYenge’sstatementExcessivedilution&lowrecoveryAboveledtoSLCbeingunpopularRecentevidenceshowedbetterrecoveriesDrawbehaviorwassimilartoblockcavingLayoutswerebasedonLaubscherviewAdvancedtheconceptofIsolated/interactivedraw14.5mdrawpointspacingRecoveryimprovements: -moreinteractivelayouts -StrictapplicationofdrawstandardsInteractive/isolateddrawDrawstandardsBullRulesorcommandments

-Alignmentoffaces(3-5faces) -Uniformdrawofblastedmaterial -Goodblastingstandards -Goodroadways/support -Bogacrossfullwidthofface

DrawstandardsBullRulesorcommandments

-Alignmentoffaces(3-5faces) -Uniformdrawofblastedmaterial -Goodblastingstandards -Goodroadways/support -Bogacrossfullwidthofface

DrawstandardsBullRulesorcommandments

-Alignmentoffaces(3-5faces) -Uniformdrawofblastedmaterial -Goodblastingstandards -Goodroadways/support -BogacrossfullwidthoffaceCumulativedilutiion15-24%(40%)Metalrecoveries90-100%Dilutionentrypoint50%(20%)

Bull&pageChallengedDoesnotworkCriticsisunfairDesignphilosophyissuesDowedesignmine’swithhumansystemerrorGreyarearegardingthe14.5mdrawpoint(Massmin200546Fig8):

-8mto10mapartinteractivedraw -10mto18mgrayarea(nocommentdegreasingeffectiveness) -18misolateddrawconditionsInteractionofinteractionfactorsnotclearSLCClassificationMRMRbased2classes:Softcaves<class3Hardcaves>class3SUPPORTDESIGNSLCClassificationMRMRbased2classes:Softcaves<class3Hardcaves>class3SUPPORTDESIGNDRAWPOINTSPACINGDS=IDZxINTERACTIONFACTORInteractionfactorsRangefrom1.2to1.6Blockcavesnomuckpileconfinement=1.5Recentlayouts4caves(25m)Dilution30%extraction76to98%Class4Drawpoints4.5to6mwideSpacingbetween11to14.5m85to98%extraction=IFof1.2to1.376to85%extraction=1.3to1.514.5m=1.613.5=1.5Bull&page>12mdrawpointspacing?Questions: -whatinteractionfactorused? -howsensitivetodrawcontrolstandard? -Probabilityofachievingtheabove?(30%) -Gainscomparedtoisolateddrawlayout -recovery/dilution,sustaindev.CAPEXNotwrongProbabilistic/riskforrecoveryGoodanswersnotopinionrequired13mlayoutspacing=recoveryvsCAPEXfordevINCO/STOBIEIsolateddrawsituation200225mx25mlayoutsHustruid/LKABlargesublevelsbadfordilutionReducecostswidelyspaceddrawpointsandsublevelsIsthisbadNoInsitugradeoftheringCut-offofshut-offgradeDrawinteractionisasecondaryissueMuckpilesaltingovertimeWhattoyoucalldilutionCONFUSED?DifferenceapproachesNotwrongHowdowedesignasublevelcave?WhatapproachshouldbeusedApproacheconomicnotgeotechnicalUselayoutthatgivesbestreturnIssues: -projectcapital/sustainingdevvsrecovery -Canyoudeveloplayoutforinteraction -Greyareapossiblebyrisky -sizeofcavevsSustainsubleveldev11mton/yrcave26kmsdev/yr15mx15mlayout11mton/yrcave16kmdev/yr18mx30mlayoutWillpillarsbestableatdepthWaste/dilutionWhatiswaste?RockLowgradeoreHighgradeorenotrecoveredMaterialoutsidetheringprofileSaltingincreaseswithdepthDrawenvironment

ore+wasteWastecapWastesaltedwithorefromaboveSLC

wasteheavilysaltedwithoresaltingClassicSLCdrawtheoryIsolateddraw&bull/page

isolateddrawButcher