The document discusses continuous surface miners (CSM), which are cutting machines used in surface mines to extract thin seams less than 2.5 cm thick. It provides details on the key components of CSMs including the mainframe, conveying unit, drive unit, crawler unit, and cutting unit. It also describes different methods of working with CSMs based on the sequence of strip extraction, travel mode, and loading mode. CSMs can extract material continuously while crushing and directly loading it onto trucks, providing an environmentally-friendly alternative to conventional drilling, blasting, and loading methods.

2. Continuous surface miner (CSM) is basically a cutting machine
used in surface mines. These machines have been developed
during 1970s primarily for extraction of thin seams (not less
than 2.5 cm thick) and selective removal of thin dirt bands
present in seams.
INTRODUCTION

3. ☻The conventional method of mining includes –
Drilling, Blasting, and Face loading.
☻ Even enough technology development took place to
take care of fly rock, still there is a problems. And the
second foremost is cost effective mining and also
quality control.
☻ To overcome the above problems, a series of research
and development led to the development of new
technology known as Blast free mining by SURFACE
MINER.

4. ☻A significant improvement can be achieved in the following
area-
> Produce clean and high quality material.
> Deposit can be exploited fully.
> Reduction in transportation cost and production
process.
> Environmental friendly mining.
☻It also takes care of both safety part and economics in
mining
Some direct benefits are –
1. Mining with out blasting, therefore no need for drilling.
2. Insitu crushing is feasible & further sizing before conveying
on to the truck is possible.

5. 3. Surface miners have a unique conveying system by
which the mined material is directly loaded onto the truck /
dumper.
4. The haul road preparation and maintenance in deposit are
reduced. Even some times its not required.
This system has special advantage of selective mining
Less coal loss and dilution.
Improved coal recovery especially in areas sensitive to
blasting.
Less stress and strain on trucks due to minimum impact of
the excavated material.
Primary crushing and fragmentation of coal reduces the
capacity requirements for coal washing / preparation
plants.

6. The surface miner mainly consists of 5 units:
1. Mainframe: It consists of operators cabin, supporting
frames, Boom counter weight, Slewing ring etc.
2. Conveying Unit: It consists of two stage conveyors,
one carries the material from the cutting drum and
discharges on the boom conveyor. This conveyor in turn
conveys it on to the trucks.
3. Drive Unit: It consists of a diesel operated engine
whose power is transmitted to the cutting drum via
robustic belts drive. And it consists of hydraulic system
to operate other units.
4. Crawler Unit: Based on the design it may be single pair
crawler or two pair crawler.

8. ☻The most important
parameter is the cutting tool.
☻The selection of right cutting
tool is essential for good
cutting performance & high life,
since, it constitute a major
portion of operation cost of the
machine.
☻The cutting depth can be
regulated by automatic leveling
system mounted on the machine, the pre-selected cutting depth is main
-tained either automatically or manually.
☻Based on the cutting principle and position of the drum, the surface
miner is classified in three types.
5. Cutting Unit:

9. 1.Machine with middle drum configuration
☻In these type of machines the cutting drum is positioned below the
machine in between the front and the rear crawlers, cutting picks are
fitted on a drum and having the depth of cut 500 to 600 mm

10. 2. Machine with front boom cutting drum.
☻In these type of machines cutter drum fitted with picks is mounted on a
Boom, like road headers. Due to longer boom the cutting force of the
machine is limited.

11. 3. Machine with front cutting wheel
☻I this types of m/c, several bucket wheels are arranged in tandem &
cutter picks are fitted on lip of each bucket to form the cutting drum,
which is positioned in front of the m/c.
☻The m/c can exert huge force in cutting both hard coal and rock as the
bucket wheel drum is close to the m/c and the reaction of cutting force is
directly transferred to the ground through a hydraulically loaded dozer blade
behind the bucket wheels.

12. Working Principle of Surface miner.
☻The surface miner is crawler-mounted machine having a
cutting drum located b/w two sets of crawlers and position
-ed at the center of the machine.
☻The drum is lowered and raised by hydraulic system with
powerful hydraulic motors thereby varying the depth of cut
☻The material cut is loaded onto the primary and secondary
discharge conveyors for loading the same on to the
loading / transporting equipment.
☻The rear crawler travel at lower level then the front
crawlers to adjust to the required depth.

13. Precise
cutting depth
Clean, level and
stable surface
Continuous
cutting
Crushed
aggregate
Direct
loading

14. In Wirtgen Surface Miner, a type of CSM, a cutting drum, with
specified number of replaceable picks mounted on it arranged in form
of helix, is fitted below the machine body in between the front and rear
crawlers. When the machine works, the hydraulically controlled drum
rotates in up-cutting direction. The cutting drum is generally kept in
horizontal position during cutting, but can be inclined to some degree
by controlling the hydraulic rams to facilitate cutting of inclined
seams. During its working, the cutting drum rotates in an up-cutting
direction and a layer of predetermined thickness (maximum thickness
depends on the machine model) of the deposit is cut and crushed in
between the picks. The “Electronic Depth Controller System” fitted in
the machine controls the thickness of cut slice/slices. The width of the
cut slice is same as the length of the cutting drum. The methods of
workings of surface miner can be classified based on – (i) sequence of
extraction of strips, (ii) mode of travel and (iii) mode of loading.
Methods of work using continuous Surface Miner

15. Method of working
Based on sequence of extraction of strips
• Wide bench method
• Block mining method
• Stepped cut method
Based on mode of travel
• Empty travel method.
• Turn back method.
• Continuous mining method.
Based on loading:
 Direct truck loading
 Indirect loading

16. Methods of working based on the
Sequence of Extraction of Strips
The working methods of Wirtgen Surface Miner,
based on the sequence of extraction of strips may
be classified into three categories – Wide Bench
Method, Block Mining Method and Stepped Cut
Method.

17. The wide bench method is generally used when the width
of the mineral bench is not very high. In this method,
first the uppermost layer of the whole width of the bench
is extracted in number of slices followed by the
extraction of the next layer and so on till the full height
of the mineral bench is extracted.
42 29
28 20 15
14 11 7 3 2 1
O/B
Spoil
Coal
seam
Wide Bench Method
Wide Bench Method

18. The block mining method is adopted when the mineral bench is
so wide that the extraction by wide bench method is not
suitable. In this method the bench width is suitably divided into
number of blocks, and then the block from the edge side of the
bench is extracted first for the full height of the bench in
number of slices following a sequence similar to that of wide
bench method. After completion of one block the next adjacent
block is extracted and the process continues till the whole bench
is extracted.
45
40
35
41
36
31
26
21
30
25
20 16
15 11
10 6
5 3 1
O/B
Spoil
Coal
seam
Block III Block II Block I
Block Mining Method
Block Mining Method

19. The stepped cut method is used when excess moisture/water is
present in the mineral bench that creates problem in extracting
the slices. In this method also the bench is first divided into
suitable number of blocks and then the individual slices are so
extracted that it forms a number of small steps on the mineral
bench. The formation of steps facilitates the drainage from the
mineral bench thereby improving the machine efficiency.
Stepped Cut Method
O/B
Spoil
Coal Seam
Stepped cut Method
15
6
60
16
15 11
10
26
25
20
2136
35 31
30
46
45 41
40
56
55 51
50

20. The working methods of Wirtgen Surface
Miner, based on the travel mode for
extraction of slices of same layer, may
be classified into three categories –
Empty Travel Back Method, Turn Back
Method and Continuous Mining Method.
Methods of working based
on the Travel Mode

21. In the empty travel back method, the surface miner starts
excavating a slice from one end of the bench and moves upto
the other end. After completion of one full cut, the machine
travels back empty to the starting end, and sets for a new cut
in the adjacent parallel slice, and the process continues. The
process is generally adopted under one or more of the
following conditions.
 Available length of the bench is small (not more
than 200m)
 Turning time of the machine is more than the
empty travel time.
 The machine turning is difficult at the cut ends.
Empty Travel Back Method

22. Empty Travel Back Method
Production travel
Empty travel

23. In the turn back method, the surface miner starts cutting a
slice from one end of the bench and moves to the other end.
After the cut is complete the machine turns back there to
start a fresh cut adjacent and parallel to the previous cut. In
this way the required number of slices are extracted. The
method is most widely accepted and used provided the
following conditions exist.
 Available length of the bench is more than 200m.
 Turning time is less than the empty travel time for the
machine.
 Required turning space is available at the cut ends.
Turn Back Method

24. Turn Back Method

25. In continuous mining method, the machine moves
with cutting the material and near the pit ends it
takes turn with a gentle angle while still cutting the
material. Thus there is no discontinuity in cutting
operation. This results in a round shape of the cut
area particularly at the cut ends. The process
continues till the circular/elliptical turnings become
so sharp that the machine cannot take turn while
continuing the cutting operation. Then the machine
follows the turn back method for mining the rest of
the material at the central portion.
Continuous Mining Method

26. Continuous Mining Method

27. Methods of working based
on the Loading Mode
There are basically two modes of operation possible by
Wirtgen Surface Miner on the basis of loading it can adopt
– conveyor loading and windrowing.
In conveyor loading mode, the material that is cut by the
machine is discharged by the discharge conveyor, which
may directly load large capacity dumpers or shiftable
bench conveyor, or side-cast it. On the other hand, in
windrowing mode, the machine cuts the material and the
cut material is allowed to heap behind the machine in form
of windrows. The cut material from the windrow or the
side-casted heap can be loaded later conveniently to
dumper/tipper by some loading equipment like FEL.

28. LOADING OPTIONS
DIRECT TRUCK
LOADING INDIRECT LOADING
WINDROW SIDE CASTFRONT LOADING REAR LOADING

29. DIRECT TRUCK LOADING

30. INDIRECT LOADING
Windrow

31. SIDE CAST

32. COMPARISON OF LOADING METHODS
ADVANTAGES DISADVANTAGES
Direct
loading No re-handling of material required
 Larger working area required for truck
 Production affected by truck exchange
 Belt wear
Side cast
 Blending of materials in the mine
 Stockpile of material in the mine
 No waiting for trucks
 Restricted to 3-5 cuts
 Belt wear
 Material has to be re-handled
 Material prone to absorb water when
lying on ground
Windrow
No waiting for trucks
No belt wear
Higher production rates than
conveyor loading
Coarser material
Better selectivity on steep inclined
seams
 Larger working area required
 Material has to be re-handled
 Material prone to absorb water when
lying on ground