[PPT] 自然崩落法（全英文）_ppt

1、FRAGMENTATION & BLOCK CAVE DRAWFragmentationEquipment selectionRock handling strategiesDraw point production (mm/day/ draw/ cave height)BCF Primary (Back rock blocks- inputs joint dist, stress, RMR)Secondary (back rock blocks crush by cave muck pile )Hang-up programme (draw point blockage freq or dr

2、awn tons)Equipment/ strategies realties to draw point block sizesDraw production = draw point area x draw point tonnage/ratesFragmentationOther usesDrawpoint sizes/spacingDilution entryExperience levels of staffFragmentationPrimary fragmentationSecondary fragmentation/ broken by muck pile weightPrim

3、ary fragmentationPanel cave (Massmin 92)Muck pile model (Bartlett 1997)Fragmentation DeterminationEmpirical tables (Laubscher 2000)- Primary- Secondary- effectsBCF (Esterhuizen 1994)- Primary secondary- Secondary- Draw rates and hang-up frequencyCHASM (Butcher 2000)- Primary fragmentation- Visualiza

4、tion toolJKFrag ( Harries 2001)-Primary -Rigorous toolMethod usesDesktop Experience, EmpiricalBCF, Scoping with general dataCHaSM, JKFRAG , more BCF above scopingMethod limitationsChaSM, - LABOURIOUS, PRIMARY FRAG ONLYBCF, Joint stats may cause errors in block formationEmpirical. limited to authors

5、experienceJKFRAG, Research toolAll are modelsFragmentation input dataPrimary- Mean dip/ dip direction- Spacing statistics- Rock mass strength- Dip/ direction of the cave face- General stress regime SecondaryAspect ratioRate of drawCushing/ finesCave height and muck pile pressureJoint input data (Sta

6、cey & Swart 2000) ChaSMFragmentation (BCF)Fragmentation (BCF)Equipment selectionM3 % passing fragmentation criterion% 2 or 3m3:2m3 (4.6m3 LHD bucket- 1400E)3m3 (6.4m3 LHD bucket-0010)Primary Frag 2m3 =40%Secondary Frag 2m3=15%Rock handling strategiesDrawpoint hang-up freqType of hang-up/ type freqDr

7、awpoint blocker 1024m3High hang-up 128m3Low hang-up16m3100% LHD bucket 2 m3DrawratesDrawrates/production 3 TypesGeotechical Acceptable ActualGeotechnical =Frag (BCF) + hang-up modelsAcceptable= limited geotechnical (burst protection)Actual = Acceptable - mining system readinessDraw rate reductionMin

8、ing system readinessExtraction level damageConstruction behindEquipment not availableDraw point secondary blasting crews not availableCrushers and infrastructure not operationalDraw rate reductionMining system readinessExtraction level damageConstruction behindEquipment not availableDraw point secon

9、dary blasting crews not availableCrushers and infrastructure not operationalDraw rate rulesDo not exceed 200mm/day (maturity)Soft cave start draw rate 75-100mm/dayHard cave start draw rate 40-75mm/dayMining system readiness reduction 25-40%Block caving draw controlReasonPrevent dilutionUniform draw

10、down of orePrevent point loading on driftsCommutation of ore fragmentsPrevention of :-Air blasts- Rock burstsTrue block caveOre/waste interfaceUniform draw down (mass Flow)Draw points drawn evenlyPANEL CAVEDraw planeCave planeMAINTAIN SHAPEBlock cave draw principlesWhat is the overall draw strategy-

11、Block cave-Panel caveAll draw points drawn evenlyAll drawpoints to drawn to form cave/ draw planeThe open area should be big enough to achieve production tonnage (have enough drawpoints )The above must have 30- 15% extra drawpointsSimple draw strategies-fewer drawpoints, flat draw planes are betterD

12、ifferent geotechnical areas for draw rateDraw is about disciplineRequired draw dataA draw reserveWhat is going to be extracted by the cave drawpointsDraw reserve :- Ore reserve covered by extraction level draw bells- Types of draw reserve- Extraction dilution tons/factors - Drawpoint number and tonn

13、age, tonnage types- shut-off level- drift repair dataDraw controlDraw reserve adjusted to footprintDraw points have tons allocated to themDraw reservesVertical draw reserveWedge draw reserveWASTEDWPTDefined by break back angleDaily draw dataBogger tons taken from drawpointsDilutionDrift repair/ draw points outDraw beacons damagedDaily adjustment of extraction dataComputer programmesReconciliation underground 5%Secondary blastingBock caves are like red wine older betterCoarse rock start at caveA f