overview of high wall mining

1. HIGH WALL MINING
PRATEEK SHARMA
B.TECH MINING II YEAR
UNIVERSITY OF PETROLEUM AND ENERGY STUDIES (UPES)

2. INTRODUCTION
 High wall is the unexcavated face of exposed overburden
and coal in a a surface mine.
 High wall mining is a remotely operated mining method to
extract coal from thin seams or underlying seams in the high
wall.
 In this method extraction of coal is done from a series of
parallel entries driven in the seam from the face of the high
wall without roof support.
 This technology provides an economical way to extract coal
reserves locked up in the high wall.

3. APPLICABILITY OF THE
TECHNOLOGY
 When the open pit mining has reached beyond the stripping
ratio or the limit of mining operations.
 When coal is present in thin seams for which no conventional
mining method is available or economically viable.
 Can be applied where coal is present in the boundaries.
 The seam should be flat ( -5 to 8 degree).
 Coal seam thickness should be thicker than 80cm.

4. EQUIPMENTS USED
 Continuous miner machine
 Push beams
 Cutter unit
 Conveyor
 Generator
 Anchoring system

7. Recovery Rate SHM vs Auger
300 m = 100% 150 m= 50%
60% 30%
SHM 60%
Auger 15% 4x
SHM Auger

8. AUGER DISADVANTAGES OVER
HIGH WALL MINING
 Diminishing power with increased depth.
 Fixed cutting height that diminishes the coal size degradation
and depth.
 Rigid structure of the auger drill due to which no ability to
negotiate dip in the seam.
 Low production rate.

9. METHODOLOGY
• In high wall mining the coal seam is penetrated by a
continuous miner propelled by a hydraulic push
beam transfer mechanism.
• Cycle includes sumping (launch pushing forward)
and shearing (raising and lower the cutter head
boom to cut the entire height of the coal seam).
• The push beam transfer mechanism (PTM)
automatically inserts a 6.01m long rectangular push
beam (screw conveyor segment) into the center
section of the machine between the power head and
the cutter head.

10. • The push beam system can penetrate nearly 300m
into the coal seam.
• High wall mining system use auger enclosed inside
the push beam that prevent the mined coal from
being contaminated by rock debris during the
conveyance process.
• Using a video imaging and/or a gamma ray sensor
and/or other geo radar system like a coal-rock
interface detection sensor the operator can see ahead
projection of the seam rock interface and guide the
continuous miner’s progress.

12. CONTINUOS MINER USED FOR
HWM
 Length base = 16-17 m
 Width base = 8-9 m
 Weight = 225 ton
 Length of push beam = 6m
 50 push beams per miner
 Weight of push beam =
5150 kg

13. THE MACHINE
CUTTERHEAD MODULE

14. PUSHBEAM(FRONT)
PUSHBEAM (BACK)

15. PUSHBEAM
Push beam plays an important role for parallel
drivage of entries.
It contains two contra-rotating augurs for
transportation of coal from the coal face.
It allows the cutter head to negotiate the undulating
contour of the coal seam.
Normal length of push beam is about 6.0 m.

16. ADVANTAGES OF HIGH WALL
MINING
 Coal which is blocked in high wall can be recovered at
reasonable cost.
 Maximum conservation of coal
 No man power is required to enter into the entries made by high
wall miner, hence this method is good from safety aspect.
 Operation is unmanned and remote.
 Operates with 4-5 worker per shift.
 Upto 65% coal recovery is achieved.
 Low establish cost.

17. LIMITATIONS
 The roof and floor should be strong.
 Length of push beam is generally 300m.
 Their should not be geological disturbances such as faults.

18. REFERENCES
 Masabatulla.V. venkoos/highwall-mining-technology-
4768813?qid=6bc513c7-a0ff-4a3a-975f-
4f6fbf38d34c&v=&b=&from_search=3.
 Prasad.K.D. High wall Mining an overview.

19. THANK YOU