Crandall Canyon Shaft Project PLATEAU MINING CORPORATION
Dec 18, 2015
Crandall Canyon Shaft Project
PLATEAU
MINING
CORPORATION
Crandall Shaft Depths
Crandall Canyon Shafts 1470 & 1456 feet Deep
Crandall Canyon Shaft Vs L.D.S. Church Office Bldg.
About 3 ¼ LDS Church Office Buildings
Crandall Shaft Volumes Both Shaft approx. 46,000 yds 158 - Cat 797 haul Trucks (290 yd Capacity)
Liability for Caps Source: USDA, Natural Resource Conservation Service, Mine Shaft and Adit Closing, July 2000
Enclosures, gates, and caps shall be used only where periodic inspection and maintenance is ensured through a maintenance agreement with a responsible government entity, landowner, or organization.”
“Shafts shall be closed with plugs only if another practical solution is not available.”
Permanent Closure of Mines Source: Openings Hazards and Remediation Handbook - Nova Scotia Department of Natural Resources P. 11 & P.22
Long Term Closure- Concrete caps & Bulkheads Effective 30 to 50 years The installation should be monitored, however, as over time , the
concrete will deteriorate, steel reinforcing will corrode and/ or the mine openings may cave or subside.
Permanent Closure Backfilling Closure through blasting
Innovative use of existing Technology for Western Coal
ISSUE: Very little experience with filling
large, deep shafts
Innovative use of existing Technology for Western Coal
Many issues to deal with Size of Shaft Depth of Shaft Methane Water in the shaft Underground issues unknown
Pipes Landings Elevator guide rails Seals
Size of Shaft
Large Track Hoes Used
Multiple Machines Required
Spotters
Depth of Shaft
Material Handling Move Material with scrapers Use Hoes, and dozers for filling
Ventilation
Dump material versus convey
Provides ventilation
Methane Issue 1.8% in Exhaust Shaft
Up to 7.5% in Intake Shaft
Mechanical Ventilation of Shaft
Would Ventilation circuit remain in-tact
Methane Resolution Monitor prior to removal of caps
<3% remove exhaust (20’) cap
Allow to ventilate
<3 % remove intake winze next to (26’) cap
Dump material to provide mechanical Ventilation
Monitor at top of shaft
Collar - 6822'
Fan Drifts (2)
5775'
Collar - 6780'
20' Diameter Exhaust Shaft~1457' Deep
Water Level 12/2002 5785'
5861'D Seam #5 Mine
5324'5402'5352'
5623'5542'
A Seam
Sub 3 Seam #3 Mine
26' Diameter Intake Shaft~1470' Deep
1044'
Water in Shaft Determine depth of water
FOUND Could cause closure of
ventilation circuit
Could cause more material to be used
Provided for safety in lower part of shaft
Structural Issues Summary The bottom 50’ of
shaft stabilized w/ broken concrete
Broken Concrete through mined Seams
Clay plug to seal water and methane
Other Issues Could not cut guide
rails at top of shaft.
Landings/ pipes may provide for bridging.
Steel in shaft could cause for ignition of >5% Methane concentrations
Intake Headframe from Exhaust Shaft Prior to Reclamation
Intake Shaft Headframe & Hoist
Removing Exhaust Cap
Moving Fill Material
Filling Exhaust Shaft
Exhaust Shaft filled/Collar Exposed
Intake Shaft Filled & Collar Demo
Rough Grade at Intake Shaft
Checking Streambed Gradenear exhaust shaft
Stream Grade CompleteTop Soil Placement
Intake Shaft, Final Reclamation
Crandall Canyon Shaft ProjectPermanent Reclamation
PLATEAU
MINING
CORPORATION