This document discusses high wall mining, which is a remotely operated mining method used to extract coal from thin seams in exposed faces of overburden and coal in surface mines. It involves driving parallel entries into the coal seam from the high wall face without roof support using a continuous miner machine equipped with a cutter head and push beams. The miner can penetrate nearly 300 meters into the coal seam. High wall mining provides an economical way to extract coal reserves locked up in the high wall and can be used when open pit mining limits have been reached or for thin seams where conventional mining is not viable. It has advantages of high coal recovery rates, safety due to lack of manned entry, and low establishment costs.

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