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Open stoping method 2015

ROOM & PILLAR STOPING
Introduction
In room & pillar mining the tabular or bedded thin to moderately thick orebodies dipping from
flat to incline (up to 40° or so) are mined by driving the rectangular or square shaped openings
in the deposit
...
If the deposit is continuous and the openings are driven in a systematic manner, then
appearance in plan would be as if in a city the rectangular blocks are intersecting the streets
...
S
...
10 This term, room and pillar is also being applied when mining noncoal deposits
...
The method has been applied to mine out coal to a large extent and to lesser
extent the non-metallic and metallic deposits such as lead, zinc, copper, potash, fluorspar, pyrite,
limestone, dolomite, salt and many others
...

● Rock strength: moderate to strong
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● Deposit’s dip: low (usually below 15°, but its variants can mine out orebodies up to
40° dip)
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● Ore grade: moderate
...

Main elements of the system/working parameters
● Dividing deposit in panels of the size _ 600–1200m _ 120–240 m
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8 m
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● Height of opening _ deposit’s thickness
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● Minimum width of pillar in between _ 3m but usually its range: 6–12 m
...


The usual pattern to develop a mine to adopt this method of mining is to first develop the main
haulage roadways
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12
...
The main roads are joined to panels by driving the panel haulage roads
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16
...
30(b) The rooms developed can have neck35as
illustrated in figure 16
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It can be single room with neck in the center; or single room with
neck at one side of the room; or double room with two necks
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As shown in figure
16
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This is
interesting to note that during stope preparation about more than 20% of coal/ore is recovered
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16
...
The conventional cyclic operations
are necessary in hard and tough ores that need fragmentation with the aid of explosive
...

Continuous methods are suitable in conditions such as bad roof, limited number of working
places and to produce fine product (coal)
...
4(a),9 gives a pictorial view of a stope and pillar’s classic variant in a flat and thick
deposit
...
The deposit has been
taken in two slices
...
4(b)9 depicts ‘Post-Room and Pillar’ layout, which is a combination of room and pillar
and cut and fill stopings
...
The fill ensures stope’s stability
...
The recovery is claimed to be better
than classic room and pillar mining

Dc Ratkuria

November 19, 2015

with time
...

I
...
Manual
mucking into tubs
...

II
...
This includes use of
scrapers in inclined deposits and track or trackless loaders in flat deposits
...

III
...

Use of Jumbo and blast-hole drills, ANFO explosives, LHD and trucks of higher capacities in noncoal deposits
...
16
...
The conventional cyclic operations
are necessary in hard and tough ores that need fragmentation with the aid of explosive
...

Continuous methods are suitable in conditions such as bad roof, limited number of working
places and to produce fine product (coal)
...
4(a),9 gives a pictorial view of a stope and pillar’s classic variant in a flat and thick
deposit
...
The deposit has been
taken in two slices
...
4(b)9 depicts ‘Post-Room and Pillar’ layout, which is a combination of room and pillar
and cut and fill stopings
...
The fill ensures stope’s stability
...
The recovery is claimed to be better
than classic room and pillar mining

Dc Ratkuria

November 19, 2015

with time
...

I
...
Manual
mucking into tubs
...

II
...
This includes use of
scrapers in inclined deposits and track or trackless loaders in flat deposits
...

III
...

Use of Jumbo and blast-hole drills, ANFO explosives, LHD and trucks of higher capacities in noncoal deposits
...
16
...
The conventional cyclic operations
are necessary in hard and tough ores that need fragmentation with the aid of explosive
...

Continuous methods are suitable in conditions such as bad roof, limited number of working
places and to produce fine product (coal)
...
4(a),9 gives a pictorial view of a stope and pillar’s classic variant in a flat and thick
deposit
...
The deposit has been
taken in two slices
...
4(b)9 depicts ‘Post-Room and Pillar’ layout, which is a combination of room and pillar
and cut and fill stopings
...
The fill ensures stope’s stability
...
The recovery is claimed to be better
than classic room and pillar mining

Dc Ratkuria

November 19, 2015

with time
...

I
...
Manual
mucking into tubs
...

II
...
This includes use of
scrapers in inclined deposits and track or trackless loaders in flat deposits
...

III
...

Use of Jumbo and blast-hole drills, ANFO explosives, LHD and trucks of higher capacities in noncoal deposits
...
16
...
16
...
16
...
16
...
16
...
16
...


Bord and pillar

This system is suitable for working thicker coal seams than those suitable for room and pillar
mining
...

The cost of maintenance of haulage and ventilation roadways, formed by the network of pillars,
is less
...

At great depth the system suffers disadvantages due to poor recovery, problem of strata control
and complicated ventilation network
...
Thus the ore deposits is divided into large number of rectangular or square blocks of
ore, called pillars, and hence the name – Bord and Pillar
...
6 (a) layout of a bord and pillar within a panel has been illustrated
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6(b)
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Procedure shown in figure 16
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A
stook is attacked from two sides
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6(B), the ore is
extracted in the steps shown
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6(C)
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6(D), illustrates another method where roof is weak
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An indicator stump is left at the starting corner that indicates the roof condition
...
In figure 16
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Discussed below, in brief, are some of the variants of room and pillar method

Block system
In this modified method of room & pillar for mining coal deposits, instead of rectangular pillars
nearly square pillars are formed
...
Roof control is little simpler and timber consumption is comparatively less than
room & pillar system
...
In figure 16
...
Figure 16
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‘Open end ‘method of pillar extraction has been shown
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Dc Ratkuria

November 19, 2015

In figure 16
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This layout can be
developed by deploying a continuous miner or even by adopting cyclic unit operations
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7(b), a scheme to mine out pillars, known as ‘pocket and wing’ has been shown
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7(c) also shows how coal pillars are finally extracted by ‘open end’ method, while keeping a
diagonal line of extraction
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7(a) presents a scheme of developing blocks system of
mining
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November 19, 2015

Open stoping method 2015

Dc Ratkuria



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