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You can update the information available in this reading material. I will be very happy if someone can improve the content of this stuff and volunteer to give a summary talk of 20 minutes in the class!
Basic Concepts of Surface Mining
Minerals are the basic raw materials for manufacturing the goods required for fulfilling the needs of
the developed society. Fossil fuels like coal and lignite are still the major sources of energy in the
world. The minerals and fossil fuels occur in the earth at different places of the earth under different
situations. Mining is the process by which these earth resources are made available for human
welfare. Earth scientists i.e. the geologists and geophysicists explore the occurrences of mineral
resources and provide the necessary information regarding how particular mineral deposits exist
under the earth surface. Mining engineers use this information to determine the amount of
economically mineable resources considering the grades of the deposits, processing needs, market
demands and the technology available for mining the deposit.
Thus it is essential for the mining engineers to understand the basic terminology the geologists use
for describing the occurrence of mineral deposits. These are covered in the course of Geology that is
compulsory for any undergraduate mining engineering course. The important definitions are
discussed below for quick recapitulations.
Ore
The earth materials from which metals are extracted economically are called ores. Ores occurs in
many different kinds of rocks and in many different geological environments.
Deposit
The metalliferous compound from which metals are extracted is concentrated by geologic
processes to form commercial deposits at specific locations.
Types of deposits vary with metal to metal. Gold deposits are of two principal types: lode
(primary) deposits and placer (secondary) deposits.
Hypothesis of formation of Gold Deposits
One widely accepted hypothesis proposes that many gold deposits, especially those found in
volcanic and sedimentary rocks, formed from circulating ground waters driven by heat from
bodies of magma (molten rock) intruded into the Earth's crust within about 2 to 5 miles of the
surface. Active geothermal systems, which are exploited in parts of the United States for
natural hot water and steam, provide a modern analog for these gold-depositing systems.
Most of the water in geothermal systems originates as rainfall, which moves downward
through fractures and permeable beds in cooler parts of the crust and is drawn laterally into
areas heated by magma, where it is driven upward through fractures. As the water is heated, it
dissolves metals from the surrounding rocks. When the heated waters reach cooler rocks at
shallower depths, metallic minerals precipitate to form veins or blanket-like ore bodies.
Another hypothesis suggests that gold-bearing solutions may be expelled from magma as it
cools, precipitating ore materials as they move into cooler surrounding rocks. This hypothesis
is applied particularly to gold deposits located in or near masses of granitic rock, which
represent solidified magma.
A third hypothesis is applied mainly to gold-bearing veins in metamorphic rocks that occur in
mountain belts at continental margins. In the mountain-building process, sedimentary and
volcanic rocks may be deeply buried or thrust under the edge of the continent, where they are
subjected to high temperatures and pressures resulting in chemical reactions that change the
rocks to new mineral assemblages (metamorphism). This hypothesis suggests that water is
expelled from the rocks and migrates upwards, precipitating ore materials as pressures and
temperatures decrease. The ore metals are thought to originate from the rocks undergoing
active metamorphism.
Placer deposits represent concentrations of gold derived from lode deposits by erosion,
disintegration or decomposition of the enclosing rock, and subsequent concentration by
gravity.
Classification of Deposits
Basis Types Description
1. Shape Isometric Extending in all directions, e.g. massive deposits, bosses,
nests
Bedded, flat Stretched in two directions, layers
Pipe-like and
columnar
Extended in one direction
Intermidiate Lens, vein, folds, bends, tectonically dislocated strata
2. Surface
Relief
Slope
Hill
3. Position
with respect
to surface
Surface type OB thickness of 20-30 m
Deep OB thickness 40-250m
High Type Above the prevailing surface
High-Deep Partially above and partially below the prevailing surface
4. Angle of
inclination
Gently dipping Dip upt 8-100
Dipping or inclined Dip between 8-100 to 25-300
Steeply dipping Dip more than 25-300
Steep Dip within 56-900
5. Complex
bedding
Anticlinal or synclinal folds, faults, variable dip
When mining horizontal and gently dipping deposits, it is possible to locate waste dumps in the
mined out area of a quarry. This is sometimes possible in the mining of dipping and steeply dipping
stretched deposits.
I II III
I IIIII
IIIII
I
Hq
I II III
I IIIII
IIIII
I
Hq
What is surface mining?
Surface mining can loosely be defined as extraction of valuable minerals, coal or lignite by forming
pits. Surface mining basically involves three specific tasks. These are stripping, mining proper and
development.
Figure 1 Broad groups of surface mining operations.
Stripping includes removal, haulage and disposal of over burden. Mining Proper means extraction,
haulage, storage and unloading of valuable minerals. Development tasks are manifold. All other
activities necessary to stripping and mining proper are categorised as development activities.
Trenching, pumping, road construction, etc. are some of the important development tasks.
Schemes of Opencast Mining of Deposits
MINED OUT SPACEINTERNAL WASTE DUMP WORKING BENCH
NON-WORKING BENCH
ULTIMATE PIT CONFIGERATIONMINED OUT SPACEINTERNAL WASTE DUMP WORKING BENCH
NON-WORKING BENCH
ULTIMATE PIT CONFIGERATION
STRIPPING
MINING PROPER
DEVELOPMENT
Road
Pumping Trenching
REMOVAL
TRANSPORTATION
DISPOSALOB
EXTRACTION
HAULAGE
STORAGE
RECLAMATION
MINERAL
MINERAL EXPOSED
Hq
Grade Control
The mining operation is an integration of number of tasks arranged in sequence. These are often
referred to as unit operations. Site preparation, Drilling and blasting, Excavation and Loading,
Transportation, Stock Piling or Spreading and Reclamation are such unit operations required to be
carried out as surface mining unit operations. There are numerous ways of performing these tasks.
These methods depend on the characteristics of deposits, expected rate of extraction and life of the
mine, scheme of completion of the unit operations. Table 1 shows the main unit operations that are
sequentially carried out in a surface mine. Following a system approach the operations mentioned in
INTERNAL WASTE
DUMP
WORKING
BENCH
EXTERNAL
DUMPK
ULTIMATE PIT
CONFIGERATION
Hq
EXTERNAL DUMPKWORKING BENCH
WORKING BENCHMINED OUT SPACE
ULTIMATE PIT CONFIGERATIONULTIMATE PIT CONFIGERATION
BERM
EXTERNAL DUMPKWORKING BENCH
WORKING BENCHMINED OUT SPACE
ULTIMATE PIT CONFIGERATIONULTIMATE PIT CONFIGERATION
BERM
Hq
Table 1 are carried out and thus the whole opencast mining can be considered as comprised of well
defined unit operations or mining subsystems. Each of these subsystems is characterised by the type
of equipment deployed and subsequent methodology followed. The selection of equipment and
design of work organisation are dependent on the characteristics of the deposit, market demand
and available technological know-how.
Table 1 Operations at different phases of surface mining.
Phases Operations
Preparation
Clearance of wood Timber felling and stumping Drainage network construction Top-soil excavation and storage Infra-structure development Construction of erection yard Approach road construction Electricity supply system construction Temporary and permanent building construction
Construction phase
Removal of overburden
Drilling Blasting Excavation Loading Transportation Dumping
Dump yard construction Levelling Environmental Protection Measures
Infrastructure Development
Development phase
Overburden removal Mineral/ore excavation
Drilling Blasting Excavation Loading Transportation Storage Reclamation
(Work is similar to construction phase with additional machinery and more work loads)
Exploitation phase As in Development Phase. However, full set of machinery is deployed for targeted production.
Reconstruction phase Replacement of old machines or technology
Extinction phase Restoration of site for alternative uses
Types of Surface Mines and Quarries
Depending on the geo-technical and economic consideration surface mines and quarries are
operated by various ways. Figure 2 shows various types of surface excavations. Surface type
of mining is suitable for horizontal or gently dipping deposits, placer deposits and stone
quarries. Deep-surface type of mines is more practical in mining ore deposits and steeply
dipping coal deposits. These mines may be as deep as 800 metres. On-slope type surface
mining is applicable for deposits lying at a level higher than the prevailing surface level.
Some deposits lie under the river bed, sea bed or lake bed. The mining type used in these
cases is under-water type of mining. Each of these methods deploys different set of
machinery. Figure 3 shows examples of surface mining using different machinery.
Vast mines are characterised by depth up to 100 metres and occupying a large surface area.
The elongated mines are characterised by larger dimension along the strike length several
times larger than the dimension across the strike length. For columnar type of deposits and
for deep deposits rounded mines are constructed. Rzhevsky (1985) classified opencast mines
as shown in Table 2.
Continuous mining is a system of mining in which there is no time delay between extraction
and loading and loading and transport. The excavation continues without stopping and
loading to the transport system is done simultaneously. For example when a bucket wheel
excavator is continuing to excavate loading to the conveyor is also simultaneously done.
However, in a shovel operation the shovel does not excavate while the bucket is carrying the
excavated material to load on a dumper. That is why the shovel-dumper system is not a
continuous system but a BWE-conveyor is a continuous mining system.
TYPES OF SURFACE EXCAVATION
Surface Excavation
Position Shape and Size Mining Method
Surf
ace T
ype
Deep S
urf
ace T
ypes
On S
lope T
ype
Under
Wate
r T
ype
Vast
Elo
ngate
d
Rounded
Conti
nuous
Cycli
c
Com
bin
ati
on
Figure 2 Types of surface mines
Figure 3 Different types of surface excavation
Table 2 Classification of opencast mines (Rzhevsky, 1985).
Field Size Type of OCM Open pit Area
(Km2)
Open- Pit Depth
(m)
Volume of
Rock(m3)
Quarry Life
(Years)
Very small Surface
On-Slope
up to 0.4
up to 0.3
up to 20
up to 40
up to 10
up to 10
Small Surface
On-Slope and
Deep
0.4 ---- 2.0
0.3 ---1.5
up to 40
40 ---100
10 ------ 100
10 ---- 25
Medium Surface
On-Slope and
Deep
2.5 --- 6.0
1.5 ---5.0
up to 60
100 --- 200
100 --- 500
25 --30
Large Surface
On- Slope and
Deep
4 --- 20
4 --- 12
up to 80
100 --- 250
500 --- 2000
30 --- 60
Very Large Surface
Deep
10 ---40
10 --- 30
up to 120
200 ---800
2000 ---10,000
Common Types of surface mining methods include
1. open pit mining 2. quarrying, glory holing 3. strip mining 4. placer mining.
1. Open pit mining is a surface mining method in which nearly all of the deposit and ore is removed
in terrace-like working areas on the side of a pit. Grade and tonnage of materials available
determine the size and limits of the pit developed as well as the size and configuration of waste rock
dumps. In this type of mining, it is often necessary to blend different ore types to maintain character
and grade of the mill feed, or different types of ore (i.e., oxide verses sulfide and low-grade ore) may
need to be managed and processed differently (Lacy, 1999). Oxide and sulfide ores require different
types of beneficiation and processing, and some low-grade oxide ores may be processed in a leach
pad facility. Open pits are often closed or reclaimed by simply allowing the pit to develop into a pit
lake and waste rock dumps are usually closed and reclaimed in place.
2. Quarrying is similar to open-pit mining, however, it is usually restricted to mining dimension stone
or prismatic blocks of marble, granite, limestone, sandstone, etc.
3. Surface Glory Hole method is generally performed on hillsides and often used to define irregular
deposits of the surface. The method has a mine opening at the surface and ore is removed by gravity
through raises connected to adit haulage ways. Ore is transported to the surface or side-hill using
tramways (Lacy, 1999). This method generally results in smaller volumes of waste rock removed and
deposited in surface dumps.
4. Strip mining is surface mining where reclamation is contemporaneous with extraction. It is
applicable to shallow, flat-lying deposits of coal, oil-shale, clay, sand, gravel, and some uranium,
phosphate and placer deposits. As the overburden is removed from one portion of a mineral
deposit, it is used to fill in the trench left by the previous removal. In this manner, the overburden is
continuously refilled to the adjacent previously mined area and reclaimed.
5. Placer mining is a method for the recovery of heavy minerals using water to excavate, transport,
and or concentrate the mineral being mined (Lacy, 1999). Placer methods vary greatly depending on
the size and characteristics of the deposit being mined. However, placer mining in general, usually
affects large areas because the ore bodies are in large alluvial deposits with low-grade, but a high
volumes of mineral. The method can be highly visible and create large areas of disturbance. Many
historic placer operations created serious impacts to stream channels, hydrologic systems and
aquatic habitats.
Ref: http://www.epa.gov/ORD/NRMRL/Pubs/600R01043/600R01043AppA.pdf
Classification of Surface Mining Systems.
Classification of mining systems may be based on different operational features. Systems with
machines capable of excavating continuously and loading the excavated material simultaneously to a
means of continuous transport are known as continuous mining system. Bucket Wheel Excavator
(BWE) with belt conveyor is such a system. Direct hydraulicking of soft solid without ground
preparation is also in this category. All other mining systems are non-continuous mining system.
Systems with shovel and truck or excavating with dragline follows a definite working cycle. That is
why such systems are also referred as cyclic system.
Based on the mode of movement of excavated material surface mining systems can be transport-
less or direct casting type. Mining with dragline or stripper shovel falls under this category.
In the semi-continuous system the excavation is carried out by conventional non-continuous or cyclic
machine but the transportation is by belt conveyors. Figure 4 shows the classification of surface
mining system.
Figure 4 Classification of surface mining system.
Mining system may also be classified based on method of face advance. There are two principal
methods applicable to stratified deposits, which may be applied separately or in combination. One is
the parallel advancing of faces called as parallel advance system. The other is pivotal advance
system. In the former transport arrangements are to be advanced at regular intervals, while in the
latter, permanent transport arrangements from the pivot is easily arranged.
A surface mine being highly mechanised the performance of any mining venture depends
mainly on the selected equipment for the system. Table 3 shows the equipment complexes in
different unit operations of various opencast mining systems.
Table 3 Equipment complexes in different unit operations of various opencast mining
systems.
Unit Operations
Systems Drilling and
Blasting
Excavation and
Loading
Transport Storage and
Dumping
Auxiliary
Equipment
Cyclic 1. Drill Electric Shovel Dump Truck Dozer Dozer, Crane,
Grader
2. Drill Hydraulic Shovel Dump Truck Dozer Do
3. Drill Dragline --------- ------Do----- Do
Semi-Cyclic 1. Drill Shovel,
Mobile Crusher
Conveyor Belts Tripper,
Spreader,
Dozer
-----Do-----
2. Drill Shovel, Dumper and
Conveyor Belt
-----Do---- -----Do----,
Semi-Mobile or
In-Pit Crusher,
Continuous 1. Drill Bucket Wheel
Excavator, Mobile
Transfer
Conveyor,
Transfer Feeder
Conveyor Belts Tripper,
Spreader,
Dozer,
Reclaimer
Dozer, Track-
Shifter, Crane,
Grader, Mobile
Crusher
SURFACE MINING
TRANSPORT-LESS WITH TRANSPORT
MACHINES• DRAGLINE
• STRIPPER SHOVEL
CONTINUOUS SEMI-CONTINUOUS NON-CONTINUOUS
BUCKET WHEEL EXCAVATOR
BUCKET CHAIN EXCAVATOR
DREDGER
SHOVEL-TRUCK
FRONT END LOADER-TRUCK
SHOVEL-BELT CONVEYOR
2. Drill Bucket Chain
Excavator
------Do---- -----Do---- ----Do----
3. ------- Continuous
Surface Miner
-----Do----- -------Do---- ------Do----
Surface Mining Operations
Surface mining operations involve the following operations:
1. Performing basic earth moving operations: The loose or loosened earth materials or broken
rock mass are separated from the massif and moved for further handling. The basic earth
moving operations are carried out during site preparation as well as during production and
site restoration. These operations include dozing, ripping, levelling, spreading, stacking etc.
a. Operations with dozers
b. Operations with scrapers
2. Haul road construction and maintenance operations
a. Operations with motor graders
b. Operations of compactors
c. Operations of water truck for haulroad dust control
3. Drilling and blasting operations: To produce broken rock mass from the insitu rock blast
holes are drilled for placing explosives to blast the rock. Surface mining involves blasting of
the overburden or waste rock and the minerals or coal separately ensuring that the grade of
the ore is not diluted by mixing of more overburden with the ore or loosing ore with the
overburden.
4. Operations of excavators: The loosened rock mass is excavated by using excavators suitable
for the operations under the site specific geo-mining conditions and production
requirements. Different systems used in surface mining include:
a. Operations with electric rope shovel
b. Operations with hydraulic excavators and back hoe
c. Operations with front end loaders
d. Operations with dragline
e. Operations with bucket wheel excavators
f. Operations with bucket chain excavators
g. Operations with surface miner
h. Operations with auger miner
i. Operations with high wall miner
5. Transporting operations in surface mines
a. Bulk material transport by truck
b. Conveyor operations: shiftable, mobile and slew conveyors
c. Bridge conveyor operations
d. Slurry transport operations
6. Dewatering operations in surface mines
7. Stacking and reclaiming operations
8. Operations for dump formations
Mining Industry in India
India is one of the important mineral producing country in the world. Mining industry in India plays
an important role in Indian economy. Production and use of minerals in India has a very old history.
Coal, iron-ore, copper, lead-zinc were mined in India from the dawn of civilisation and does not
have any systematic records. Records of mining activities in India is found in the Kautilya’s
Arthasastra which indicates taxation on mineral produced in the 4th century. After India was
captured by the British, East India Company permitted a English Company to undertake mining
operation at Raniganj Coal field in 1774. In 1880, M/s John Taylor & Sons Ltd. started gold mining in
Kolar Gold Fields. Oil production started in India in 1866 and coal production in Makum Coal field of
Assam started in 1882. Mining industry in India started developing in the 20th century and was
predominantly to serve the interest of the British Government. After independence, the mining
industry is being continuously shaped to serve the National interest and welfare of Indian People. In
1971 coal mines were nationalised. Subsidy was given to the industry so that basic raw materials for
Nation building could be made affordable. National investment for mining is planned in every Five
Year Plans and the activities inn this industry are governed by National Mineral Policy, which has
been recently modified to encourage more International investment and welfare generation in the
country.
Surface Mining in India
India produces both fossil fuel and ores from surface mines. Number of surface mines are operating
in different parts of India. A brief overview of the occurrence of mineral deposits are presented
below:
Coal Deposits in India
Today’s coal mining in India exploits coal seams up to a depth of about 600m. However, coal seams
are available up to a depth of 1000-1200m. The mineability of these deeper seams is yet to be
properly evaluated. The major coal fields are discussed below:
Raniganj Coalfield
This coalfield spreads in the states of West Bengal and Jharkhand. This is the easternmost field of the
Damodar valley. It is a synclinal basin and its southern side is bounded by faults. It covers an area of
1550 sq km. The coal seams in this coalfield belong to Raniganj & Barakar formations (Table 1).
There are 10 major coal seams in Raniganj formation, thickness ranging from 1-11m and 7 major
seams in Barakar formation, thickness ranging from 1- 24m. The coal seams dip to the south at
angles between 3˚- 11˚. In some places they are invaded by igneous sills and dykes and faults. Total
in situ coal reserve of this coal field has been estimated as 22 Gt. The gas content is about 5 – 7
m3/t. It covers an area of 1550 sq. km.The geothermal gradient varies from 25 ˚C -52 ˚C for 1 km.
Coal of Barakar formation is of coking type with low moisture and low to medium volatile mater
content. Coal of Raniganj formation is non-coking type with high moisture and high volatile matter.
Table 1 Geologic succession of Raniganj Coalfield
Age Formation Thickness ( m)
Recent River alluvium
Sub-recent Laterite
Jurassic or Tertiary Rajmahal traps or Deccan traps
Jurassic Rajmahal traps or Earlier
Upper Triassic Supra-panchet 305
------------------UNCONFORMITY----------------
Lower Triassic Panchet formation 610
Upper Permian Raniganj formation 1035
Middle Permian Ironstone Shale 365
Lower formation Barakar formation 610
Upper Carboniferous Talchir formation 375
------------------UNCONFORMITY----------------
Crystalline archaeans (basement rocks)
Figure 1 shows the geological map of this coalfield.
Figure 1 Geological sketch map of the Raniganj coalfield showing major structural features and
various localities mentioned in the text. Note numbered squares denoting Poradih (1),
Jemua (2), Jaideb (3) and Dishermohan (4) (S.C. Ghosh / Sedimentary Geology 147 (2002)
155–176)
Subsidence is common phenomena in coal mining areas of this coalfield. The coal seams are of
shallow depth. There are two sets of major faults with trends NNE-SSW in the Western part and
NNW-SSE in the eastern part traverse the area. The latter one has better potential for ground water.
The Jharia Coalfield
It is the most important coalfield in India with the sole deposit of the coking coal. It is situated in the
heart of the Damodar valley along the north of Damodar River. It covers an area of 450 sq km in the
state of Jharkhand. The coalfield is bound by major faults towards SSW direction. The stratigraphic
succession at the coalfield is given in Table 2.
Table 2 Stratigraphic succession of Jharia Coalfield
Age Formation Litho-type Maximum thickness
Jurassic or Tertiary Dolerite dyke
Lower Jurassic Mica lamprophyre, dykes & sills
Upper Permian Raniganj Fine grained feldspathic sandstone, Shale with coal seams
800 m
Middle Permian Barakar measures Buff coloured sandstone, Shale & 730 m
carbonaceous shale
Lower Permian Barakar Buff coloured sandstone, Grits, carbonaceous shales & coal seams
1250 m
Upper Carboniferous Talchir Greenish shale & fine- grained sandstone 245 m
-----------------UNCONFORMITY-------------------
Archaean Metamorphics (Basement complex)
The structure is a half graben bounded by major faults towards SSW direction. In this coalfield
(Figure 2) there are a total of 42 coal seams present upto a depth of 1200m, which belong to Barakar
formation (individual seam thickness varies from 0.3 – 33.0 m) and 10 – 20 coal seams are present in
Raniganj formation (thickness varies from 0.1 – 4.7 m). It covers an area of 450 sq. km. The total
reserve estimated as 17 Gt. The gas content of these coal beds is estimated as 7 – 26 m3/t.
Figure 2 Geological map of Jharia Basin, India
The CBM production initiatives in this coalfield have successfully implemented to have the first CBM
well in the country.
These coal field is one of the oldest coalfields in India. The multiple seams occur to a greater depth (
Barakar formation).
Talcher Coalfield
It covers an area of 1815 sq km in Orissa. Structurally it is a broad synclinal basin with a dip varying
from 3˚ - 7˚. No igneous intrusion has taken place. The total reserve estimated is around 36 Gt with
huge quantity of inferior grade non-coking coal in thick seams, lying at comparatively shallow
depths. The degree of faulting varies across the field. The coal seams belong to Karharbari (12
seams) & Barakar (1 seam) formation (Table 3). The thickness of the coal seams varies from 1- 60 m.
Barakar formations are of low quality with high ash, high volatile and high moisture content. The
total reserves were estimated 28 Gt in 1993. Structurally it is a broad syncline. The degree of faulting
varies across the field. No igneous intrusion has taken place.
Table 3 Stratigraphic succession of the Talchir Coalfield
Age Formation Lithology
Recent Alluvium & Laterite
Upper Permian
to Triassic
Kamthi Fine to medium grained sandstone, Carbonaceous shale, coal bands with greenish sandstone and pink clays
Barakar Medium to coarse grained sandstone, Shale, coal Seams with conglomerate (500 m thick)
Lower Permian
Karharbari Medium to coarse sandstone, shale & coal seams (270 m thick)
Talchir Dimictite, fine to medium grained green sandstone, Shale, Rhythmite (170 m thick)
---------------------UNCONFORMITY---------------------
Precambrian Granite Gneisses, Amphibolites, Migmatites
A study conducted by CIMFR, Dhanbad based on their theoretical model and geological information
estimated that there are 1017 Mt of unmineable coal reserve in this coal field and noted that the
average adsorption capacity of CO2 is 20.4 m3/t.
The extension of coal beds below 1200m depth cover in coking and superior grade non coking coal
have not been explored even though the continuity of the coal beds was well indicated within the
lineament. The coal beds of such zones beyond mineable limit have been classed as Grey Area
reserve. For the inferior grade non coking coal, the limit is 600m for Son Mahanadi Valley coal fields.
It has been reported that the grey area coal reserve in Talcher coalfield is 2.41 Bt and the
cumulative coal seam thickness is 120 m.
There are 13 coal seams are occurred in this field with individual seam thickness vary from 1 to 80
meters with a cumulative thickness vary from 80 to 160 meters. A lot of faults are present across the
field with different orientations. Power grade non-coking coal is occurred here. Unmineable
coalbeds are identified in this field below 600m depth. Proximate analysis of Talcher coalfield shows
35-45% of volatile mater and 79-82% of fixed carbon ratio and 0.50-0.55% vitrinite reflectance.
Figure 8.21 and 8.22 shows geological map and coal fields map of the area in Talcher coalfield. This
area has been explored by GSI for the production of CBM.
Figure 8.21 Geological map of Talcher coal field showing explored area by GSI for CBM production
(Web 21)
The Talcher coalfield is now explored by GSI under Indo-US collaboration programme for the
production of coal bed methane (CBM) as and could be used in future for enhanced coal bed
methane production using CO2 injection.
Figure 8.22 Talcher coalfield map (Web 22)
This coal field is of shallow depth without having proper caprock and thus not suitable for CO2
storage.
Ib Valley Coalfield
It covers an area of 1375 sq km in the state of Orissa. Structurally the coalfield is a half-graben
bounded by large fault in the SW direction. Coal seams belong to Karharbari and Barakar
formation. Coal seams belong to Karharbari & Barakar formations (Table 8.15). A total of 6-7
coal horizons (seams) are present. Thickness of coal seams under Barakar formation vary from
20 – 60 m with banded structure and high ash, high moisture and volatile content and therefore
coal is of low rank. Seams under Karharbari formation are 1 – 7 m thick and are of better quality.
Total reserve estimate was 22.23 Gt in 2002 (IPICOL, 2002).
Table 8.15 Stratigraphic succession of the Ib Valley Coalfield
Age Formation Lithology
Recent Thick alluvium, laterite, recent gravel & Conglomerate bed
Upper Permian
to Lower Triassic
Kamthi Conglomerate, Fe-sandstone, Red shale (300 m thick)
Barakar Fine sandstone with conglomerate bands, Carbonaceous shale, Fine clay, coal seams (600 m thick)
Lower Permian
Karharbari Coarse grained sandstone with 1 thin coal seam (90 – 125 m thick)
Talchir Dimictite, greenish sandstone, olive chocolate colored needle shaped rhythmite (130 m)
---------------------UNCONFORMITY---------------------
Precambrian Granite Gneisses, Amphibolites, Migmatites
Figure 8.23 gives the geological map of this coal field.
Figure 8.23 Geological map of Ib-Valley coalfield (Web 23)
This coalfield is overlaid by formation with conglomerate which will not be suitable for limiting any
upward movement of pressurized gas if injected underneath.
Singrauli Coalfield
This coal field is located in the northern Madhya Pradesh near to the Ganga Basin. High capacity
thermal power stations are located in this coal field. The area has number of large point sources of
CO2. However, the sequestering capabilities are not yet fully established. Figure 8.24 shows a
geological map of the area showing large number of fault lines.
Figure 8.24 Geological map of Singrauli coalfield (Web 24)
This coalfield is situated on the border of Uttar Pradesh and Madhya Pradesh and covers an area of
about 2300 km2. Most part of the coalfield lies in M.P. while a small part of it is situated in the
Mirzapur district of U.P. The coals of this field are of non coking type. The total coal reserve of this
field 12.41 Bt. The Barakar and Raniganj formations are the coal bearing measures. Dolerite dykes
and sills are invaded in the west and south of the basin. The faults are very rarely present even these
are along the boundary. The dips of the strata vary from 2˚ to 5˚.
Stratigraphy
The stratigraphic succession of the Singrauli coalfield has written in Table 8.16.
Table 8.16 Stratigraphy of Singrauli Coalfield.
Age Group Formation Lithology
Recent Alluvium
Upper Permian Damuda Raniganj Fine grained sandstone, shales, carbonaceous shales, white to grey clays, with thick coal seams
Middle Permian Barren Measure Very coarse grained to ferruginous sandstones, shales with red green clays
Lower Permian Barakar Medium to coarse grained sandstones, shales, carb, shales, white to pink clays, and coal seams
Upper carboniferous Talchir Tillite, sandstones, needle shales, siltstones, boulder conglomerates
………….Unconformity…………..
Precambrian Bijawar Phyllite, quartzite, schists and gneisses
Pranhita-Godavari Valley Coalfield
The Godavari valley coalfield comprises of 16000 km2 area extends over a length of about 320 km
with an average width of about 55 km. The total coal reserve in this coalfield are estimated as 8.5 Bt
of which 2.129 Bt is under proved category. It is a bituminous coal bearing coalfield in India. The
Gondwana sediments attain a thickness of more than 3000 m. Linear and discontinuous patches of
coal measures are occurred in this Godavari rift basin. The coalfield consists of numerous faults e.g.
strike fault, oblique fault or dip fault etc. The general trend of the coal measures is NW-SE with dips
varying from 10˚ to 25˚ in NE direction except some places. In this coalfield, Barakars and Kampthi
formation are coal bearing formation. The coalfield is devoid of igneous intrusion. The Barakar
formation contains 3 to 10 coal seams out of which 2 to 4 seams are of considerable thickness. The
thickness of the coal seams varies from few centimetres to as much as 30 m. The coals are non-
coking, high moisture, high ash and high volatile type. The lower seams are of better quality than the
upper seams. (R. D. Singh, Principles and Practices of Modern Coal Mining) . The stratigraphy of this
coalfield has shown by Table 8.17 below. Figure 8.25 shows the geological map of this coalfield.
Table 8.17 Stratigraphy of Pranhita-Godavari valley coal field (Modified from Sengupta, 2003 and
Chandra, 2000)
Age Formation Lithology Thickness(m)
Holocene Alluvial sand and clays
…….Unconformity…
25+
Upper Cretaceous Deccan Tap
……..Unconformity…. 65
Upper Jurassic- Lower Cretaceous
Chikiala Sandstone
…….Unconformity………
Conglomerates and ferruginous sandstone
300
Lower-Early Jurassic Kota
………Unconformity…
Sandstone, Siltstone, Clays, Limestone bands
675
Middle-Upper Triassic
Maleri Red or purple clays and sandstone
1000
Upper Permian-Lower Triassic
Kamthi Sandstone, ferruginous, purple siltstone, coal
600
Upper Permian Barren Measures Sandstone, Ironstone and clay bands
500
Upper part of Lower Permian
Barakar Feldspathic sandstone, Carbonaceous shale and coal
300
Lower Permian Talchir
…….Unconformity…… Tillite, Greenish shale 350
Upper Proterozoic Sullavai
……Unconformity……… 545
Lower Proterozoic Pakhal
…….Unconformity………. 3335
Archaean
Granites, Banded gneisses, Biotite gneisses, Hornblende gneisses, Quartz magnetite schist, Biotite schist, Quarz and pegmatite veins
Figure 8.25 Geological map of the Pranhita–Godavari Valley (Source: S. Sengupta, Gondwana
sedimentation in the Pranhita–Godavari Valley: a review, Journal of Asian Earth Sciences 21 (2003)
633–642
Risk associated
As the coals in this field occur in form of discontinuous patches, so it is difficult to identify a suitable
potential site. The presence of numerous different type of faults make the probability of leakage
occurrence is more. Though faults can be proved as suitable traps for sequestration, In that case also
a greater monitoring and verification is needed for leakage.
Korba coalfield
The Korba coalfield situated around Korba town of Madhya Pradesh state. It occupies an area of
about 520 km2. The coal reserves in Korba coalfield is estimated as 10,000 Mt. The coal in this field is
of sub-bituminous non-coking type of coal. The Barakar formation is the coal bearing measureswhich
overlies the Talchir formation. The lithology of Barakar formation consists mainly of sandstone, shale
and coal seams. The thickness of the Barakar formation is more than 800 m. The general strike of
the rocks of Barakar formation is E-W and beds dip to the south below 10˚. There are 21 coal seams
are occurred in this coalfield out of which nine seams are belong to lower barakarwith individual
seam thickness are less than 4 m. But the upper Barakar formation consists of thick seams with a
thickness range from less than one meter to over 30 meter than the lower Barakar formation
(Chandra, 2000).
East Bokaro coalfield
The Bokaro coalfield is situated in Hazaribagh and Giridih districts of Jharkhand state extends over an
area of 237 km2. The total coal reserve in this field is about 5.6 Bt. Out of which 2.8 Bt of coal occur
below 300 m depth.. This coalfield has been divided into two distinct zones namely East Bokaro
coalfield ansd West Bokaro coalfield by the Lugu hill. The East Bokaro coalfield is the eastern zone of
the main Bokaro coalfield. A number of faults are are traversed across the coalfield. Igneous
intrusions are invaded into the coalfield. There are 21 coal seams in Barakar and 8 coal seams in
Raniganj formation are present. Total coal reserve was estimated at 5.6 Gt in 1993. The coal seams
of East Bokaro coalfields are bituminous to sub-bituminous in nature with high gas contents. So
these seams have potential for CBM. The maturity of gas contents increases with increasing depth
due to increase in temperature and pressure conditions. It has experienced igneous intrusions like
dykes, sills & faults. Three coal bearing formations are present. These are
i. Karharbari formation consisting of 4 seams
ii. Barakar formation consisting of 21 seams
iii. Raniganj formation consisting of 8 seams
Stratigraphy
The stratigraphy of the East Bokaro coalfield is shown in the Table 8.18. The deep lying
sedimentary strata may have sequestration potential and should be investigated in detail.
Table 8.18 Generalized stratigraphic succession of the East Bokaro coalfield (Pophare et al.,
2008)
Age Formation Lithology Thickness (m)
Lower Cretaceous Intrusive Lamprophyre and dolerite dykes and sills
Upper Triassic Supra-Panchet Coarse grained ferruginous sandstone, pebbly sandstone and red clay
600
..…Unconformity……
Lower Triassic Panchet Greenish micaceous sandstone, buff fine-grained sandstone, red and green shale
500-600
Upper Permian Raniganj
Medium to coarse grained calcareous sandstone, fine grained greenish sandstone, grey shale, carbonaceous shale and thin coal seams
600
Middle Permian Barren Measure
Flaggy, fine grained ferruginous sandstone, micaceous sandy shale and black shale with siderite band
500
Lower Permian Barakar
Coarse grained arkosic sandstone, fine grained laminated sandstone, grey shale, carbonaceous shale and coal seams
900
Upper Carboniferous to Lower Permian
Talchir Tiliite, greenish sandstones and needle shale
…..Unconformity…...
Pre-Cambrian Granite gneisses, amphibolites and mica schist
Figure 8.26 shows the geological map of this coal field.
Figure 8.26 Geological map of the East Bokaro coalfield (Pophare et al., 2008)
Detailed site evaluation of the coal beds would be necessary to establish their candidature, because
following features make these formations unsuitable for sequestration.
1. The site location is within the moderate seismic zone and is adjacent to the high seismic
zone in the north.
2. Mining activities in the overlying seams may induce cracks and fissures in the cap rock of the
underlying potential CO2 storage coal beds
3. The deeper seams are yet to be designated as Unmineable
Therefore, future initiatives for exploitation of coal bed methane need to be investigated prior to
establishing the storage potential. The permeability, porosity, injectivity, storage capacity as well as
the geochemical properties etc needs to be evaluated.
The resources reported by GSI and other agencies have been classed as mineable and unmineable
on the basis of the following factors (Singh and Sinha, 2007).
Exploration limit of coal has been to 1200m depth cover.
Coking and superior grade non coking coal up to the explored limit has been
classed as mineable.
Inferior grade non-coking coal (Grade E-G) up to 900m depth cover in Damodar
and Mahanadi Valleys have been taken as within mineable limit.
Mineable limit for inferior grade non coking coal of Godavari and Wardha
Valleys have been taken as 800m due to premium pricing structure.
More scientific study and detailed analysis would be necessary to designate these seams as
unmineable. Future development of technology, pricing, alternative exploitation techniques will
have to be considered in such studies.
Neyveli Lignite Field
This is one of the lignite deposit in India with a total reserve 3300 Mt. The lignite field covers an area
of more than 480 km2. Within the lignite field the overburden thickness varies from 45 to 150 m and
the thickness of the lignite bed varies from 2 to 20 m and it is persistent throughout the field.
Stratigraphy
The stratigraphic succession of Neyveli lignite field is summarized in Table 8.19. (Source: Modified
from Geology and tectonics of India: an overview, M. N. Balasubrahmanyam; and D. Chandra et al.,
Text Book of Coal (Indian Context), 2000, Tara Book Agency Publisher, Varanasi) Figure 8.27 and
Figure 8.28 shows the map of the site and the cross section of the area.
Table 8.19 Stratigraphy at Neyveli Lignite field
Age Formation Lithology Thickness (m)
Sub-Recent to Recent Alluvium or soil 37
Mio-Pliocene Cuddalore formation
Mottled sandstone and clay
Lignite
Aquifer sand
20-140
0.2 - 28
376
………………………….. Unconformity…………………..
Eocene to Oligocene Neyveli formation Black clays or shales, grey coloured sandstones, calcareous sandstones, shales and siliceous limestones with fossils
…………………………Unconformity………………………..
Mesozoic Cretaceous Shell limestones, siliceous limestones, marls etc.
………………………Unconformity……………………
Archaean Intrusives Dolerite, pegmatites, quartz veins, granitoid gneisses
Figure 8.27 Geological plan of Neyveli lignite field (Web 25)
Risks Associated
Semi-confined and confined aquifers are occurred above and below the lignite bed and so there will
be contamination. Moreover, the deeper strata must be evaluated for its potential retention
capacity. There is no suitable cap rock above the lignite deposit, thus adsorbing CO2 on lignite seams
will not be feasible.
Figure 8.28 Geological cross-section along one mine in Neyveli lignite field (Web 26)
Wardha Valley coalfields
The coalfield is situated in the Valley of Wardha River lying in the Chandrapur district of Maharastra.
The coalfield extends in NW-SE direction covering an area of 4130 km2.The coals of this coalfield are
non coking type of coal. The coal bearing Barakar formation are 76 m thick and occur in patches. The
estimated reserve of this coalfield 5.7 Bte, out of which 4020 Mt occurred above 300 m from the
ground.
Stratigraphic Succession
The generalized geological succession of the Wardha valley coalfield is given as follows in Table 8.20.
Geological map is shown in Figure 8.29.
Figure 8.29 Geological map of Wardha valley coalfield (Web 27)
Table 8.20 Stratigraphy of Wardha Valley Coal field(reference)
Age Formation Lithology
Recent Black soil
Eocene Deccan trap Basalts
………….Unconformity…………
Upper Triassic Maleri formation (Only in the southeastern extrimity
Fine to medium grained sandstone and red shales
Upper Permian to Lower Triassic
Kamthi formation Red, brown and variegated sandstones, reddish siltstones and variegated shales
……………Unconformity………………
Lower Permian Barakar formation Light grey to white sandstones, shales and coal seams
Lower carboniferous to Lower Permian
Talchir formation Tillites turbidites, varves, needle shales and sandstones
……………Unconformity……………
Precambrian Sullavai sandstones White to light brown quartzitic sandstones, conglomerates
……………..…Overlap…………………
Precambrian Pakhal limestone Grey, bluish or pinkish limestone and cherts
………………Unconformity…………..
Archaean Quartzites, Granites
Rajmahal coalfields
There are five coalfields are occurred in this area extending for a distance of about 160 km in N-S
direction from Suri. The coalfields of this basin are 1. Brahmani, 2. Mahuagarhi, 3. Pachwara, 4.
Chuperbhita and 5. Hura. Brahmani coalfield lies in the southern side containing six seams varying in
thickness from 1.4 to 1.9 m. The coal seams in Mahuagarhi are lens shaped with individual seam
thickness as much as 10 m. There are ten coal seams have been reported in Pachwara
coalfield.Chuperbhita coalfield contains 13 coal seams which are of inferior quality. There are 3 coal
seams are present at Hura. At places the seam thickness attains 37 m. Coals of this region are sub-
bituminous to high volatile bituminous in rank. The coal seams are trending W to E in the western
part of the field, becoming WNW to ESE in the central part, gradually changing to NW to SE and
even N to S in the eastern part.
Stratigraphy
The stratigraphic sequence of Rajmahal basin is given in Table 8.21.
Table 8.21 Stratigraphic succession of Rajmahal basin (Tripathi, 2008)
Age Formation Lithology
Recent to subrecent Alluvium Loose soil, silt and clay
Upper Tertiary Coarse to medium grained sandstone, gravel, pebble beds
………………Unconformity………………
Lower Cretaceous Rajmahal formation ( Traps and intertrappeans)
Flows of basalt, pitchstone, and intertrappean beds
Lower Cretaceous to Lower Triassic
Dubrajpur formation Pebbly and coarse to medium grained sandstone, siltstone, clay, Grey to pink shale
…………….Unconformity……………..
Upper Permian Coal, shale, sandstone
Lower Permian Barakar formation Coarse to medium grained and
pebbly sandstone, grey shale, clay and coal
Talchir formation Tillite, fine to medium grained sandstone, olive green shale
………………Unconformity………………..
Precambrian Basement rock amphibolites, quartzite, gneiss and granite
Vindhyan Basin
The geological map of the Vindhyan basin has shown in the Figure 8.30.
Figure 8.30 Geologic map of the Vindhyan basin, central India (Bengtson et al., 2009)
The depositional sequence of the Vindhyan succession has also given in the Figure 8.31.
Figure 8.31 Inferred depositional sequences of the Vindhyan succession. (Chakraborty, 2006)(Not to
scale )
India’s major workable coal deposits occur in two distinct stratigraphic horizons - Permian, commonly
known as “Gondwana” coals and the Tertiary. About 99% of the country’s coal resources are found
within a great succession of fresh water sediments. The major coalfields are represented by isolated
basins which occur along prominent present day river valleys, viz., Damodar, Koel, Sone-Mahanadi,
Pench-Kanhan, Pranhita-Godavari. Nearly 50 coalfields, varying in size from a few km2 to as much as
1500 km2 are known today, barring the small and lenticular occurrences of coal along the Himalayan
foothills.
Coals of practically all ranks occur in India except peat and anthracite. The share of lignite, however, is
insignificant as compared to sub-bituminous and bituminous coal. Indian bituminous coals are broadly
divided into two categories, coking and non-coking.
Coal exploration in India even today is largely being carried out by conventional methods of
systematic geological mapping followed by drilling, core drilling playing a dominant role. However, in
the recent times modern exploration techniques like photo-geology, remote sensing, non-coring
drilling, geophysical surveys etc. are being increasingly used for detailed and precise exploration.
Coal Reserves
The total coal reserves of the country have been estimated from time to time.
* Proved Reserves: In this case, the reserves are estimated from dimensions revealed in outcrops,
trenches, mine workings and boreholes and the extension of the same for reasonable distance not
exceeding 200m on geological evidence. Where little or no exploratory work has been done, and
where the outcrop exceeds one km in length, another line drawn roughly 200m in from outcrop will
define a block of coal that may be regarded as proved on the basis of geological evidence.
* Indicated Reserves: In the case of indicated reserves, the points of observation are 1,000 m apart,
but may be 2,000 m for beds of known geological continuity . Thus a line drawn 1,000 to 2,000 m from
an outcrop will demarcate the block of coal to be regarded as indicated.
* Inferred reserves : This refers to coal for which quantitative estimates are based largely on broad
knowledge of the geological character of the bed, but for which there are no measurements. The
estimates are based on an assumed continuity for which there is geological evidence, and more than
1,000 to 2,000 m from the outcrop.
Statewise and depthwise Coal reserves are given in the following table,
In Million Tonnes
State 0-300m 300-600m 600-1200m Total
West Bengal 11999 8933 4191 25123
Bihar 40079 17626 6666 64371
Madhya Pradesh 32638 7433 14 40085*
Maharashtra 4590 1686 - 6276
Orissa 35015 11167 37 46219
Andhra Pradesh 5245 3876 1717 10838
North Eastern Region 710 155 - 865
Total 130276 50876 12625 193777
Percentage 67 26 7 100
* includes 1062 Million. Tonnes in UP
The following table gives the Statewise reserves indicating different categories,
State Proved Indicated Inferred Total Percentage
of total
reserve
West Bengal 10590 10867 3666 25123 13
Bihar 28993 28801 6579 64373 33
Madhya Pradesh 9387 20480 9156 39023 20
Uttar Pradesh 662 400 - 1062 1
Maharashtra 3170 1179 1927 6276 3
Orissa 5714 22120 18384 46218 24
Andhra Pradesh 6079 916 3843 10838 5
North Eastern
Region
257 149 458 864 1
Total 64852 84912 44012 193777 100
Percentage 33 44 23 100
Thus, India’s total coal resources now stand at a level of a little over 194 billion tonnes in coal seams
of thickness 0.9m and above and upto a depth of 1200m. This is a little over 1% of the global coal
resources. Of the total coal reserves of 194 billion tonnes, 85% is of non-coking variety and only 15% is
of coking variety. Further, 33% of the reserves fall under ‘Proved’ category 44% in the ‘Indicated’
category and 23% in the ‘Inferred’ category. The coal occurring between 600m and 1200m depths,
which may be economically tapped for development in future, may be grouped as “Resources” and
the rest as “Reserves”.
Lignite Resources
The total lignite deposit of the country is estimated at about 2800 million tonnes, out of which the
major deposit is occurring in Tamilnadu ( 2500 million tonnes). The remaining lignite deposits are
found in Gujrat, Jammu & Kashmir and Rajasthan. Further exploration activities indicate availability of
additional lignite resources in Rajasthan, Gujrat and Tamilnadu.
Indian coal mining and metal mining sector both have large number of opencast mines. There are
205 billion tonne of coal reserve in India of which 15% is coking coal. The reserve of lignite is
estimated to be 27 billion tonne. Out of 571 coal mines in India there are 137 surface mines and 369
underground mines. There are 65 mines with both surface and underground operations.
The trends of coal production in India from underground and surface mines are shown in Table 4 and
Figure 5.
Table 4 Trends of coal production in India from underground and surface mines.
Year Total
(x1000 t)
Opencast
(x1000 t)
Opencast
OMS
U/G
(x1000 t)
U/G
OMS
% by
Opencast
% by U/G Overall
OMS
1951 34983 4784 0.54 30199 0.59 13.67521 86.32479 0.35
1956 39911 4786 0.52 35125 0.64 11.99168 88.00832 0.39
1961 55709 10822 0.64 44887 0.68 19.42595 80.57405 0.45
1966 70387 13387 0.99 57000 0.76 19.01914 80.98086 0.56
1971 75642 17090 1.46 58552 0.86 22.59327 77.40673 0.67
1976 104639 28440 1.48 76199 0.91 27.17916 72.82084 0.69
1981 127325 51120 3.02 76205 0.82 40.14922 59.85078 0.81
1986 170159 95132 4.89 75027 0.77 55.90771 44.09229 1.01
1987 187179 111777 5.69 75402 0.78 59.71663 40.28337 1.11
1988 198349 122104 6.16 76245 0.79 61.56018 38.43982 1.19
1989 206947 133043 6.78 73904 0.77 64.28844 35.71156 1.23
1990 212741 143208 6.95 69533 0.73 67.31566 32.68434 1.26
1991 237757 167026 8.05 70731 0.73 70.25072 29.74928 1.4
1992 249941 178879 8.3 71062 0.75 71.56849 28.43151 1.47
1993 260607 186935 8.75 73672 0.77 71.73061 28.26939 1.57
1994 267522 196878 9.22 70644 0.77 73.5932 26.4068 1.63
1995 284586 216074 10.07 68512 0.78 75.92573 24.07427 1.8
1996 304097 233970 10.69 70127 0.8 76.93927 23.06073 1.91
Figure 5 Trend of coal production in India.
Besides coal about 22.2 Mt of lignite is produced in India from 5 lignite mines. Out of these 2 located
at Neyveli in Tamilnadu provide 17.6 Mt of lignite per year. The rest 4.6 Mt come from 3 mines in
Gujrat. India also produces iron ore and bauxite mostly from opencast mines.
Figure 6 shows the output per manshift achieved in Indian coal mining. This shows that the OMS at
opencast mines have been considerably improved. However, the OMS of underground mining have
been continuously decreasing after 1988.
0
50
100
150
200
250
300
350
1940 1950 1960 1970 1980 1990 2000
Pro
du
cti
on
(M
t) Total (Mt)
Opencast
Underground
Figure 6 Output per manshift (OMS) in Indian coal mining.
In the metal mining sector opencast mining plays an important role in India. All our iron ore mining is
from opencast mines. Bauxite mining is also purely surface mining.
History of Indian Surface Mining
The share of surface mining in total coal production in India has continually increased from the
1960s. At the time of nationalisation it was only 25.4 % of the total coal production. In 1983-84 it
was 45.4% and it is expected to be 65 % by 2000.
First mechanised surface mining in India started during world war II at East Bokaro. In 1958 NCDC
(National Coal Development Corporation) started opencast mining in their new areas such as
Karanpura, East Bokaro, Chirimiri, Bisrampur, Korba and Talcher.
Table 5 List of some important opencast mining projects (Coal Mining)
Sl. No Names Annual
Capacity (Mt)
Average
Stripping Ratio
Total Excavation
(Mm3)
Total Capital
Investment (1983
pricing, MRs)
1 Rajmahal 5.0 1.94 8.81 870
2 Sonepur Bazari 3.0 5.45 1137 1130
3 Jambad 2.25 7.00 472 1130
4 Mukunda 12.0 4.5 - 1300
5 Bina 4.5 2.21 309 1390
6 Dudhichua 10.0 3.29 1356 3410
7 Jayant 10.0 2.6 1132 3130
8 Khadia 10.0 4.28 1457 6550
0
2
4
6
8
10
12
1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000
OM
S
Underground OMS
Opencast OMS
Overall OMS
9 Amlohri 4.0 4.30 1579 4370
10 Nigahi 14.0 3.75 2163 8360
11 Bharatpur 3.5 0.80 243 540
12 Rajarappa 3.0 2.91 456 1060
13 Gevra 10.0 1.0 1039 1730
14 Kusmunda 6.0 1.41 760 770
15 Manuguru 2.75 3.68
16 Ramagundam-I 2.0 3.36
17 Ramagundam-II 2.75 5.61
18 Piparwar
The overburden to coal ratio in the earlier mines using truck and shovel was about 2 m3t-1. In mines
with draglines the ratio was 5 m3t-1. With the increase in the size of equipment mines with larger
stripping ratios were planned. Till mid 50s average over burden thickness was about 50 m in
mechanised surface mines having shovels and dump trucks as predominant machinery. The
thickness of coal seam in such mines was about 20 m with seam dip of 1in 6 to 1 in 12. At present in
India there are opencast coal mines deeper than 100 m. Seam with gradient upto 1 in 3 are also
being operated. There are number of mines in Jharia Coalfield and Singrauli Coalfield where
opencast mining exploits multi-seams. Some opencast mines are opened over developed seams to
excavate the abandoned coal locked in the partially exploited pillars, that is not operable by
underground mines. Table 5 shows example of few of the major opencast projects of India.
Except Piparwar all the mines listed above are cyclic in nature. Dragline and shovel are the primary
mining machinery and dump trucks are used for coal transport. Lignite mining in India is an excellent
example of India,s successful implementation of continuous surface mining. Piparwar is an example
of semi-cyclic opencast mining. In this mine shovels carry out excavation and the transportation of
the excavated material is by conveyor belts. Such system with inpit crushing is also being practiced
at Padmapur (Western Coalfields Limited, WCL) and Ramagundam (Sigarenni Collieries).
COAL RESERVES IN INDIA
(As on 1.1.2007)
(in billion tonnes)
. TOTAL PROVED INDICATED INFERRED
RESERVE RESERVE RESERVE RESERVE
COKING 32 17 13 2
NON-
COKING 255 98 119 36
TOTAL 287 115 132 40
Production
RAW COAL PRODUCTION (in Million Tonnes)
OFFTAKE OF COAL (in Million Tonnes)
DESPATCH TO POWER SECTOR (in Million Tonnes)
OVERBURDEN REMOVAL
MAN PRODUCTIVITY
MAN POWER (As on)
Growth & Production
(In Million Tonnes)
Terminal Year Five Year Plan
Avg. Annual Growth
over previous year.
Production
(India)
1955-56 First 6.95 38.13
1960-61 Second 4.00 55.72
1965-66 Third 0.93 67.74
1973-74 Fourth 7.52 78.17
1978-79 Fifth 6.28 101.97
1984-85 Sixth 6.38 147.43
1989-90 Seventh 5.16 200.91
1996-97 Eighth 7.74 285.66
2001-02 Ninth 4.19 327.79
Companywise Production
Company 74-
75 84-85 94-95 2001-02
2002-
03
2003-
04
2004-
05
2005-
06
2006-
07
ECL
U/G 20.50 16.67 13.61 11.66 10.95 9.91 9.45 9.34 8.27
O/C 2.66 6.44 11.24 16.89 16.23 18.09 17.80 21.78 22.20
Total 23.16 23.11 24.85 28.55 27.18 28.00 27.25 31.11 30.47
BCCL
U/G 15.64 13.34 11.49 7.59 7.29 6.74 6.38 5.47 4.90
O/C 2.10 8.50 17.26 17.66 16.86 15.94 15.94 17.84 19.30
Total 17.74 21.84 28.75 25.25 24.15 22.68 22.32 23.31 24.21
CCL
U/G 5.97 5.48 4.01 2.74 2.76 2.75 2.65 2.31 1.96
O/C 12.34 33.52 27.19 31.07 34.22 34.58 34.74 38.20 39.36
Total 18.31 39.00 31.20 33.81 36.98 37.33 37.39 40.51 41.32
NCL
O/C - - 32.50 42.46 45.10 47.03 49.95 51.52 52.16
WCL
U/G 15.73 24.57 9.60 9.49 9.39 9.51 9.65 10.04 9.92
O/C 3.53 21.48 17.64 27.52 28.43 30.02 31.76 33.17 33.30
Total 19.26 46.05 27.24 37.01 37.82 39.53 41.41 43.20 43.21
SECL
U/G - - 14.55 15.91 16.16 16.36 16.58 16.52 16.20
O/C - - 35.45 48.21 50.44 54.65 61.97 66.50 72.30
Total - - 50.00 64.12 66.60 71.01 78.55 83.02 88.50
MCL
U/G - - 1.94 1.65 1.76 2.05 2.18 2.02 1.97
O/C - - 25.39 46.16 50.47 58.00 63.90 67.59 78.03
Total - - 27.33 47.81 52.23 60.05 66.08 69.61 80.00
NEC
U/G 0.38 0.44 0.40 0.18 0.11 0.12 0.15 0.12 0.11
O/C 0.14 0.37 0.79 0.46 0.52 0.61 0.48 0.98 0.94
Total 0.52 0.81 1.19 0.64 0.63 0.73 0.63 1.10 1.05
COAL INDIA LTD.
U/G 58.22 60.50 55.60 49.22 48.42 47.44 47.04 45.82 43.32
O/C 20.77 70.31 167.46 230.43 242.27 258.92 276.54 297.57 317.59
Total 78.99 130.81 223.06 279.65 290.69 306.36 323.58 343.39 360.91
Overall CIL OBR OMS
(MCum) (Tonnes)
2006-07 537.65 3.54
2005-06 533.95 3.26
2004-05 516.11 3.05
2003-04 496.90 2.82
MINERAL INFORMATION
ALL INDIA DISTRIBUTION OF MINING LEASES
(AS ON 31/3/2005) MINERALWISE | STATEWISE
MINERALWISE Sl.No. Mineral
Code Mineral No. of Leases Lease Area (hect.)
1 01 AGATE 2 45.58
2 65 AMETHYST 5 40.64
3 03 APATITE 1 13.29
4 04 ASBESTOS 39 1846.89
5 05 BALL CLAY 40 1976.19
6 06 BARYTES 128 2542.09
7 07 BAUXITE 289 26531.07
8 08 CALCAREOUS SAND 14 151.75
9 09 CALCITE 63 1627.34
10 10 CHALK 167 677.99
11 67 CHINA CLAY 412 17774.31
12 11 CHROMITE 30 9163.70
13 12 CLAY (OTHERS) 44 945.33
14 14 COPPER ORE 18 10747.16
15 16 CORRUNDUM 12 145.41
16 17 DIAMOND 2 576.51
17 18 DIASPORE 11 80.11
18 19 DOLOMITE 454 17575.85
19 82 DUNITE 1 4.45
20 69 EPIDOTE 1 5.00
21 21 FELSITE 4 80.79
22 22 FELSPAR 184 5196.12
23 23 FIRECLAY 240 16676.52
24 24 FLUORITE 18 1807.41
25 26 GARNET 83 1899.80
26 27 GOLD 10 6702.62
27 28 GRAPHITE 137 4792.00
28 29 GYPSUM 52 17853.27
29 86 IOLITE 8 76.97
30 30 IRON ORE 505 78238.44
31 31 JASPER 5 211.70
32 33 KYANITE 30 3170.50
33 75 LATERITE 131 1463.48
34 34 LEAD & ZINC ORE 13 8225.18
35 36 LIME KANKAR 24 891.14
36 37 LIMESHELL 29 3752.89
37 38 LIMESTONE 1544 113376.15
38 39 MAGNESITE 29 2546.06
39 40 MANGANESE ORE 231 22313.54
40 41 MICA 249 7816.08
41 42 MOULDING SAND 45 898.40
42 44 OCHRE 107 3439.06
43 72 OPAL 1 200.00
44 81 PERLITE 1 144.65
45 46 PHOSPHORITE 15 3490.57
46 47 PYRITES 1 647.50
47 48 PYROPHYLLITE 86 2835.99
48 85 PYROXENITE 8 78.70
49 49 QUARTZ 909 12817.61
50 50 QUARTZITE 59 757.48
51 87 ROCK PHOSPHATE 1 2.20
52 51 ROCK SALT 3 53.86
53 52 SAND (OTHERS) 49 4940.64
54 77 SHALE 30 408.54
55 54 SILICA SAND 483 20205.90
56 55 SILLIMANITE 5 9945.84
57 56 SLATE 17 868.47
58 58 STEATITE 426 20736.83
59 60 TIN 7 128.83
60 62 VERMICULITE 11 212.55
61 63 WOLLASTONITE 4 202.49
Sum 7527 472577.43
STATEWISE
Sl.No. State Code State No. of Leases Lease Area
(hect.) 1 APR ANDHRA PRADESH 1567 54634.12
2 ASM ASSAM 11 981.33
3 BHR BIHAR 10 2030.16
4 CHG CHHATISGARH 294 26406.26
5 GOA GOA 250 18165.99
6 GUJ GUJRAT 1094 23783.54
7 HPR HIMACHAL PRADESH 60 1998.70
8 HRN HARYANA 142 15267.21
9 J&K JAMMU & KASHMIR 19 730.35
10 JHK JHARKHAND 331 36990.92
11 KAR KARNATAKA 425 38627.29
12 KRL KERALA 108 2213.44
13 MAN MANIPUR 2 610.17
14 MEG MEGHALAYA 14 1660.16
15 MPR MADHYA PRADESH 758 19536.80
16 MSH MAHARASHTRA 252 17154.41
17 ORI ORISSA 447 77410.59
18 RAJ RAJASTHAN 1088 103913.78
19 SKM SIKKIM 4 86.00
20 TMN TAMIL NADU 435 6292.91
21 UPR UTTAR PRADESH 93 9424.33
22 UTL UTTARANCHAL 70 3079.72
23 WBL WEST BENGAL 53 11579.25
Sum 7527 472577.43
The trend of productionof Iron Ore in India is shown in Table 6 and Figure 7.
Table 6 Trend of iron ore production in India.
Year 1951 1971 1991 1994 1995 1996
Production (Mt) 3.7 33.0 60.0 65.0 73.0 71.6
Figure 7 Trends of production of iron ore in India.
Figure 8 Trend of production of bauxite in India.
India exports about 32 Mt of iron ore every year mainly to Japan and South Korea. Figure 8 shows
the trend of bauxite production in India.
0
10
20
30
40
50
60
70
80
1940 1950 1960 1970 1980 1990 2000
Year
Pro
du
cti
on
(M
t)
0.05
1.45
3.86
4.7
5.35
0
1
2
3
4
5
6
1940 1950 1960 1970 1980 1990 2000
Year
Pro
du
cti
on
(M
t)
The National Aluminium Co. (NALCO) is the main producer of bauxite in India. The bauxite
production is expected to go up in the country with the capacity enhancement of Panchpatmali
Mines (NALCO) from its existing 2.4 Mt capacity to 4.8 Mt capacity. Figure 9 shows production of
some other minerals in Indian surace mines during 1996. Besides these there was 120 Mt of
limestone produced by surface mining in India during 1996.
Figure 9 Production of minerals from surface mines in 1996 (Mt).
Figure 10 Trend of deployment of shovels in surface coal mines.
Usage of Opencast Machinery
As mentioned earlier Indian surface mining is mainly cyclic in nature. With the increase in demand
from surface mining, the machinery populations have also increased. The installed horsepower has
also increased about 1.5 times during the last ten years. Figures 10-14 show the trend of population
increase of shovel, dumper, dozer and dragline in Indian coal mining.
0.72
2.06
4.75
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Copper Gelena and
Sphelarite
Granite
Pro
du
ctio
n (
Mt)
400
500
600
700
800
900
1000
1989 1990 1991 1992 1993 1994 1995 1996
Nu
mb
er
of
Sh
ovel
s
100
150
200
250
300
350
400
450
500H
P x
1000
Number of Shovel
HP x 1000
Figure 11 Trend of deployment of drills in surface coal mines.
Figure 12 Trend of deployment of dragline in surface coal mines.
Figure 13 Trend of deployment of dozers in surface coalmines.
400
500
600
700
800
900
1000
1989 1990 1991 1992 1993 1994 1995 1996
Nu
mb
er
of
Dri
lls
100
150
200
250
300
350
400
450
500
Insta
lled
HP
x 1
000
Number of DrillHP x 1000
3 6
4 1 4 1
4 74 4 4 3 4 2
5 9
60 .6 6 9
7 0 .7 84
91 .0 13
103 .2 98 104 .1 5 102 .7 18
93 .0 85
112 .5 65
30
40
50
60
70
80
90
100
1989 1990 1991 1992 1993 1994 1995 1996
Nu
mb
er
of
Dra
gli
nes
50
60
70
80
90
100
110
120
Insta
lled
HP
x 1
000
Number of Dragline
HP x 1000
983
1020 1018
1189
11171123
1071
989
318 .139
352 .302355 .221
392 .867396 .887
401 .93
382 .058
353 .741
930
980
1030
1080
1130
1180
1989 1990 1991 1992 1993 1994 1995 1996
Nu
mb
er
of
Do
ze
r
315
325
335
345
355
365
375
385
395
405
Inst
all
ed
HP
x 1
000
Number of Dozer
HP x 1000
Figure 14 Trend of deployment of dumpers in surface coalmines.
Table 7 shows the population of HEMM in Indian Surface coal mining.
Table 7 Population of HEMM in Indian surface coal mining.
Year Shovels Dumpers Draglines Drills Dozers Scrapers Graders Payloader
s
Crane
1989 717 3406 36 635 983 106 140 227 187
1990 787 3663 41 703 1020 100 142 243 227
1991 864 3846 41 703 1018 54 161 208 236
1992 892 4223 47 829 1189 65 169 271 269
1993 910 4385 44 802 1117 16 167 179 283
1994 946 4437 43 822 1123 19 186 195 288
1995 956 4291 42 871 1071 18 189 179 317
1996 961 4038 59 864 989 15 172 171 266
In the non-coal sector, surface mining operations involve in producing bauxite, copper, gelena and
sphalarite, Granite, Iron Ore, Limestone, Mica and stone. There are number of state government
undertakings and private companies working in these areas. Table 8 shows the trend in HEMM used
in the non-coal mines.
3 4 0 6
3 6 6 3
3 8 4 6
4 2 2 3
4 3 8 54 4 3 7
4 2 9 1
4 0 3 8
1486 .1 11
1755 .1 92
1830 .8 98
1 9 02 .2 32
206 3 .6 8 3
2115 .8 5 5
2231 .8 79
2114 .4 5
3200
3400
3600
3800
4000
4200
4400
1989 1990 1991 1992 1993 1994 1995 1996
Nu
mb
er
of
Du
mp
ers
1200
1400
1600
1800
2000
2200
Insta
lled
HP
x 1
000
Number of Dumper
HP x 1000
Table 8 Trend in HEMM used in the non-coal mines.
Year Number of
Mines
Electric
Shovel
Diesel
Shovel
Dumper Dozer Loader Tractor
1980 188 76 331 1160 296 139 119
1981 184 71 333 1259 288 139 124
1982 202 80 328 1291 316 146 119
1983 209 86 326 1309 306 148 117
1984 220 96 349 1355 314 157 104
1985 236 168 329 1434 334 163 118
1986 274 161 358 1590 355 189 138
1987 293 165 418 1784 391 240 141
1988 255 164 364 1748 336 234 116
1989 286 88 455 2391 374 214 108
1990 300 80 474 2263 359 205 108
1991 368 92 553 2744 433 279 134
1992 397 99 566 3067 425 393 144
1993 438 92 697 3221 432 384 145
1994 479 103 720 3416 428 424 166
1995 448 97 753 2814 425 399 146
1996 457 68 841 3409 448 446 150
Manufacture of Surface Mining Machinery in India
In collaboration with foreign companies Heavy Engineering Corporation (HEC), Bharat Earth Movers
Limited (BEML), Hinduastan Motor (HM), TELCO manufacture number of surface mining machinery
in India. Table 9 shows a list of some machinery manufactured in India.
Surface Mining Machinery Manufactured in India.
Machines Size Model Make Collaboration
Walking Dragline 24/96*
32/75
6/45
W-2000 HEC Ramson Rapier, UK
Electric Rope
Shovel
4.6/5 m3
EQC 4.6 HEC USSR
10 m3 195-B HEC Bucyrous Errie,
USA
Hydraulic Shovel
3.2 m3 300CK L&T Poclain, France
6.9 m3 90CK L&T Poclain, France
2.5 m3 H-36 HM Demag, France
3.3 m3 H-51 HM Demag, France
7.5 m3 H-121 HM Demag, France
3.8 m3 PC- 650-1 BEML Komatsu, Japan
Diesel Rope Shovel
1.9 m3 93 M HM
2.3 m3 101 M HM
1.15-1.5 m3 655 B TATA
1.9-2.3 m3 955 A TATA
3-5 m3 0.55 B TATA
Rear Dumper
120 T BEML Wabco, USA
85 T 33-11C HM Texus USA
85 T Haulpack 85 D BEML Wabco, USA
50 T Haulpack 50 BEML Wabco, USA
35 T Haulpack 35 BEML Wabco, USA
35 T R-35 B HM Terex, USA
25 T Haulpack 25 BEML Wabco
25 T R-25 HM Terex
Bottom Dump Coal
hauler
40 T 3040C BEML Wabco
60 T H-60T HM Terex.
* Bucket size is 24 m3 and boom length is 96 m.