1. Underground mine Surface facilities Development openings Underground production Development for production Exploration Primary access to the deposit Level development
2. Production operations Drilling and blasting LHD mucking Ore pass Bolting Barricade Hydraulic filling Point de chargement Haulage Drilling Blasting Mucking Loading Haulage Reinforcement Backfilling
3. Primary access to the deposit Shaft Decline Ramp Principal Functions : Ventilation Personnel and Equipment traffic Extraction of Ore and Waste Dewatering Supply of : Electricity Compressed air Water Fill material Supplies Principal primary openings :
4. Ore extraction by shaft - non mechanized mine 200 m 3 /sec 130 m 3 /sec 200 m 3 /sec 10 m 3 /sec 110 m 3 /sec levels 1-5 - shafts 6 - winze 7 - concealed orebody 8 - loading hopper 9 - feeder 10 - orepass 11 - wastepass 12 - lift 13 - pump station 14 - sump, water basin
5. Ore extraction by shaft - mechanized mine Ramp Ventilation shaft (2) Main shaft (1) Ore body Main level Crosscuts Ore pass Drifts Waste pass
6. Ore extraction by shaft - mechanized mine at big depth 1 - ore shafts 2 - ventilation shaft 3 - rockfill pass 4 - ramp 5 - orepass 6 - ventilation rise 7 - sublevels 8 - waste pass 9 - crusher 10 - ore pocket 11 - conveyer 12 - loading hopper 305 m level 1 610 m level 2 765 m level 3 915 m level 4 1040 m level 5 1160 m level 6 1220 m level 7 1280 m level 8 1340 m level 9 1400 m level 10 1460 m level 11 1500 m level 12 1 2 3 4 5 6 7 8 9 10 11 12
8. Vertical shaft section Four 23 t rock skips Single, 200 - man single-deck cage measuring 3.9 x 7.9 m allows access for LHDs without dismantling them.
9. Access by shaft Important capital costs Low operating costs Unique or few loading stations Good knowledge of deposit geometry required Unique solution for depth grater than 300-400 m
13. Access by decline Important and difficult to move crashing station is required Deposit must be well known Straight shape is requires Heading is difficult and expensive Used for massive deposits of intermediate depth (up to 300 m) and a high production rate (more than 3 Mt)
14. Ore extraction by ramp 1 - decline; 2 - ramp; 3 - crosscut ; 4 - haulage drift ; 5 - drifting; 6 - caved rock Angle 18° max and 10 to 12° average
19. Access by ramp High flexibility of exploitation with diesel driven tracks but important gaze emission Using of electric tracts reduces the gas emission but also reduces the flexibility Deposit geometry can be not necessary well known Low capital cost High operating costs Used for deposit of feeble depth (up to 200) and low production rate (300 Mt/year)
20. Siting of primary access - orebody dip - angle of draw in overburden - angle of draw in rock l - safety distance 1 - shaft 2 - safety distance 3 - zone of subsidence
21. Shaft locations Two-shaft mine : side location Three shaft mine : centrally located main shaft and peripheral ventilation shafts Minimizes the costs of primary access Increases the costs of production development Increases the transport cost Optimizes the costs of production development Optimizes the transport cost Increases the costs of primary access
24. Production development by blind crosscuts Ore width 10 to 30 m One footwall drift + crosscuts Footwall drift + fringe drift + crosscuts
25. Production development by blind crosscuts Waste passe 70 of 120m About of 65m 10m Ore body Haulage drift To ramp Stopes Ore passe about of 250m Crosscuts
28. Sizing of circular shaft where : 1.7 et 0.15 - coefficients ; P - tonnes hoisted per operating day, t/j ; D sh -shaft diameter, m. The circular shaft diameter for skip hoisting ore and cage hoisting miners and supplies :
29. COSTS OF SHAFT SINKING Fixed costs for circular shaft sinking : Unit costs for circular shaft sinking : Total costs for circular shaft sinking : where : D - diameter of shaft, m H - shaft depth, m 0 500 1000 1500 2000 2500 3000 3500 200 300 400 500 600 700 800 Shaft depth in m Fixed cost per meter in $/m 12000 13000 14000 15000 16000 Unit cost per meter in $/m Coût fixe Coût variable Coût total, $/m Diamètre 7 m
30. DEVELOPMENT COST Cost per meter of length of an excavation of cross-sectional area S where : S - cross-sectional area of the excavation, m² C ref - reference cost, the cost per meter of a standard 2.5 x 2.5 m, C ref = 1100 $/m k exc - factor taking into account the type of excavation : Drift or crosscuts : k exc = 0.34 Inclined ramps : k exc = 0.4 Timbered rise : k exc = 0.11 Bare rise : k exc = 0.09 Rise in backfill : k exc = 0.07 Service excavations : k exc = 0.095
Notas del editor
Mining Engineering December 2001 p.28 - Mining at Deep Post - Newmont ’s newest underground mine pp.25-29. Access to the Deep Post underground mine is currently through a new peranent portal at the 4480 level. The Deep Post deposit is mined by underhand cut-and-fill and long-hole stoping methods. The stopes are accessed by cross cuts from the access ramps at 26 m (64-ft) level intervals. Each level has five horizontal cuts. Each cut will be about 4-m (13-ft) in height. The top cut is driven under weak, virgin rock and will be maintained at a width of about 4-m. The intermediate and bottom cuts are mined under engineered, cemented backfill. This allows mining width to be increased to 4.9 m and drift rounds drilled up to 3.7 m. Single-boom jumbos prepare the mining face for blasting. A fleet of 2.7 and 4.6 m3 LHD load into 23.5-t haul trucks.