(SR) 3. Mining Method
The mining property is mostly within a 29 km long and 19 km wide block. It belongs to the region of Grande prairie, which has an elevation of 666 m from the mean sea level. From 1961 to 1990, the temperature varied from 34.5°C in Summer to -52.2°C in Winter. The number of days per year with measurable rainfall is 130. The 9G, the 9H and the LB4 Mines have ceased to operate in recent years. The 5B-4 Mine is currently active, with a production of 3500 tonnes per day from 1 continuous miner in the depillaring area and 3 continuous miners at the development faces. From the depillaring face alone, 900 tonne-coal is produced per shift.
Since 1969, much of this property was mined out by opencast method. Susequently, Longwall method was practiced in 2 panels in the #10 seam. Both the early attempts of Longwall mining failed. Consequently, retreat Room and Pillar method has been adopted. The mining in the #5 Mine is the only underground mine currently active in this coalfield (Figure SR4).
Mining in the #4 seam is carried out in both the Smoky River and Sheep Creek valleys. The 5-4 Mine was reportedly closed within a short period due to strata control problem. The current underground operation, i.e. the 5B-4 Mine, is located in the Smoky River Valley slightly to the North of the 5-4 Mine.
Room and Pillar mining is practiced extensively in #4 seam, which is the most significant mineable seam in the Smoky River Coal property. Depillaring follows the christmas tree cut sequence during retreat. In addition, coal is recovered from the floor simultaneously. 3 people are required at a development face whereas 4 people are required at a depillaring face.
Historically, the roof stability has become a common problem in the Smoky River valley. Depth of cover for the #4 South panel is about 275 m (916.7 feet). Previous Mines of Smoky River coal were never mined at a depth more than 300 m (1000 feet). However, much of the 5B-4 Mine reserve is under as much as 550 m (1833.33 feet) of cover.
Ventilation is completed with a blower system. Figure SR5 shows the ventilation network and the mine layout.
The major equipment deployed in the 5B-4 Mine undergound is as follows:
# of pieces
Specification
Equipment type
4
Joy 12 CM
Continuous Miner
5
10SC22
Shuttle Car
2
10SC32
5
-
Stampler Breaker Feeder
3
Fletcher CHDDR-15 2-Boom
Roof Bolter
1
Fletcher CHDDR-17 2-Boom
Roof Bolter
1
Eimco EJC130
Scoop
3
Wagner ST-3.5S
Scoop
1
Tamrock Model 975PC
Manrider
1
DW54
Manrider
There are 90 Shuttle trucks required per shift to transport the coal from the continuous miner at the depillaring face to the conveyor belt, each Shuttle truck with a capacity of 7 ~ 8 tonnes. Coal is then transported to the surface by the conveyor belt.
(SR) 3.3 Development Method & Equipment
At present, a 5-entry main is driven towards East from the portal. From the mains 4-entry panels are driven up-dip towards South. Figure SR6 reveals the overall panel layout of the 5B-4 Mine and the cover depth. Despite changes in the development layout pattern since 1969, "in the seam" developemnt has always been followed.
Equipment used for the development is listed in the section (SR) 3.2.