Introduction to Mining

By:
Course Code L T P Credits
Prof. Ankush Galav
Department of Mining Engineering MNE201 3 0 0 3
Indian Institute of Technology (Indian School of Mines) Dhanbad
Dhanbad-826004, Jharkhand, India
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Course Objective
To introduce the basic elements of mining engineering with a view to recognize the
key aspects of opening of mineral deposits and different mining methods.

2
Learning Outcomes
Basic understanding of different types of mine openings, mining methods and
equipment, unit operations and ancillary services. Ability to prepare some basic
layouts of different mining methods.

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Textbooks
❖ Introductory Mining by H L Hartman
❖ Elements of Mining Technology (Volume 1, 2 and 3) by D J Deshmukh

Reference Books
❖ Principles and Practices of Coal Mining by R D Singh
❖ SME Mining Engineering Handbook, 3rd Edition by Peter Darling

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 Weightage of different components of evaluation

Sl. No. Component(S) Marks

1. Quiz/Case Study/Assignment etc. 10

2. Mid Semester Examination 30

3. Quiz/Case Study/Assignment etc. 10

4. End Semester Examination 50

Total Marks 100

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 Definitions
● Mining:
▪ the activity, occupation, and industry concerned with the extraction of minerals.
▪ the act, process, or industry of extracting ores, coal, etc., from mines.
▪ the industry and activities connected with getting valuable or useful minerals from
the ground, e.g. coal, diamond, or gold.
▪ the extraction of valuable geological materials and minerals from the surface of the
earth.

• Thus, Mining consists of the processes, the occupation, and the industry concerned with
the extraction of minerals from the earth or any terrestrial body. It is required to obtain
most materials that cannot be grown or feasibly created artificially.
• Mining materials are often obtained from ore bodies, lodes, veins, seams, reefs, or
placer deposits.
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Definitions

● Mine: 3 meanings –
1.“an excavation made in the earth to extract minerals”,
2.“an explosive placed underground or underwater that explodes when
disturbed, or when remotely triggered”,
3.“that which belongs to me.”

For Mining Engineering perspective, “Mine” means an opening or excavation in

the ground for the purpose of extracting minerals.

DGMS: “Mine” means all excavations within the mine boundary and all
premises, plants, machinery and works and the same shall collectively
constitute a mine.

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Definitions

● Mining engineering:

● Mining Engineering is the art and the science applied to the processes of mining and

for the operation of mines.

● It is the practice of applying engineering principles to the exploration, development,

planning, operation, management, closure, and reclamation of mines.

● Modern mining processes involve prospecting for ore bodies, analysis of the profit

potential of a proposed mine, extraction of the desired materials, and final reclamation
or restoration of the land after the mine is closed.

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 History of Mining (1#3)
• The earliest miners date back perhaps to 300,000 BC; their quest was for non- metallic minerals
suitable for utensils and eventually for weapons. Other rocks and minerals (ceramics, clay, salt,
meteoric iron) attracted the miners for jewelry, cosmetics, construction materials, food seasoning,
and coinage.
• At first, their excavations were confined to the surface, either pits or placers. But by about 40,000
BC, mine workings had been extended underground as short adits or shafts, and by 8,000 BC as
elaborate interconnected openings – 300 ft (90 m) in depth.
• Metallurgical separation of metals from their ores and their subsequent fabrication evolved
gradually over the centuries, copper being the first liberated (c. 7000 BC) followed by lead, silver,
gold, and iron. Man enhanced both the sophistication of his utensils and the lethalness of his
weapons by an order of magnitude when his mineral frontiers first extended beyond the non-
metallic to the metallic. And the discovery and utilization of the first of the mineral fuels (coal)
in the late 13th century AD carried civilization another quantum leap forward.
• Much is learned both of mining development and human civilization when plotting a chronology of
historical events. It is astonishing how well they correlate. In fact, one can track the major
migrations of civilization westward and the discovery of the New World with the insatiable lust for
mineral wealth.
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History of Mining (2#3)
• With few exceptions, no nation can achieve a high level of prosperity without a reliable source
of minerals to supply its manufacturing industry. Through mining, emergent (Third-World)
countries can finance growth progressively by the export of raw mineral resources, then by
processing these raw materials prior to export, and finally by achieving progressive industrial
development.
• Mineral reserves, upon which the future of the human race depends, occupy less than 0.1% of the
continental areas. Unfortunately, we are not at present sufficiently skilled to determine exactly where
they occur or how large they may be. They remain elusive targets. Similarly, we do not possess
sufficient knowledge and skill how to exploit all the minerals under what conditions they occur and
what dimension they take with depth.
• As such, Research in mining and metallurgical technology is essential. A new discovery may locate a
mine, but a technological break-through can open up mines all around the world irrespective of their
dimension and depth.
• The economic evolution of society that began in Neolithic prehistory was based then, as it is now,
on minerals, and has led man into modern times. All the elements of the periodic table, all but a few
of which are recovered from widely spaced, often remote, mineral deposits using a variety of
complex mining and metallurgical techniques, form the foundation of modern society.
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History of Mining (3#3)
● There are many evidence that exploitation of minerals like coal, iron-ore, copper, lead- zinc has been
going on in the country from time immemorial.
● India has a long history of commercial coal mining covering nearly 250 years. First recorded history of
mining in India dates back to 1774 when an English Company (M/s Mr. John Summer, Mr. S.G. Heatly and
Mr. Redfarne) was granted permission by Sir Warren Hastings, the-then Governor General of Bengal (of
the East India Company) for mining coal in Raniganj Coalfield along the Western bank of river Damodar.
● Growth of Indian coal mining remained sluggish until it got a boost by introduction of steam locomotives
in 1853. Annual coal production rose to 1 million tonne (MT) and India could produce 6.12 MT per year
by 1900 and 18 MT per year by 1920. The production got a sudden boost from the First World War but
went through a slump in the early thirties - 29 MT by 1942 and 30 MT by 1946.
● M/s John Taylor & Sons Ltd. started gold mining in Kolar Gold Fields in 1880.
● First oil well was drilled in Digboi (Assam) in 1866 - just seven years after the first ever oil well was
drilled anywhere in the world viz. in Pennsylvania State, USA in 1859.
● Till the beginning of 20th century, mining activities in the country remained primitive in nature and modest
in scale up. With progressive industrialization, the demand for and hence the production of various
minerals gradually went up.
● After India became independent, the growth of mining under the impact of successive Five Year Plans has
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been very fast.
 Types of Minerals
● Metallic ores: those ores of the ferrous metals (iron, manganese, molybdenum, and tungsten),

the base metals (copper, lead, zinc, and tin), the precious metals (gold, silver, the platinum group
metals), and the radioactive minerals (uranium, thorium, and radium).

● Non-metallic minerals (also known as industrial minerals): the non-fuel mineral ores that

are not associated with the production of metals. These include phosphate, potash, halite,
trona, sand, gravel, limestone, sulphur, and many others.

● Fossil fuels (also known as mineral fuels): the organic mineral substances that can be utilized

as fuels, such as coal, petroleum, natural gas, coal bed methane, gilsonite, and tar sands
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 Types of Mining (1#3)
● Mining method: It covers specific details of the procedure, layout, equipment, and system
used for mining. This is unique as determined by the physical, geological, environmental,
economic, and legal circumstances that prevail at the site. Two (2) types:
(a) Surface or Opencast (OC) Mining
(b) Underground (UG) Mining
● Access for extracting minerals from the earth is to ‘drive’ (construct) an excavation or an
‘opening’ to serve as a means of ‘entry’ from the existing surface to the mineral deposit.
Whether the openings lie near the surface or are placed underground this fixes the locale of
the mine.
● Surface Mining: If the excavation used for mining is entirely open or operated from the
surface, it is termed a surface mine.
In surface mining an open excavation is made to normally extract thick deposits or near
surface deposits.
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In surface mining or open cast mining extraction of mineral is carried out
strip by strip or in benches. It often necessitates a large capital investment but generally
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results in high productivity, low operating cost, and good safety conditions.
Types of Mining (2#3)
● Variants of Surface Mining:
▪ Open Pit Mining: Massive stock-work deposits–gold, copper etc.
▪ Strip Mining: Bedded deposits–coal, phosphates etc.
▪ Quarry Mining: aggregates, marble, granite etc.
▪ Placer Mining: minerals in alluvium–Gold, Titanium etc.
▪ Solution Mining: For any mineral that is in or may be transported in a liquid state oil,
copper, sulpher, uranium, salt etc.

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Types of Mining(3#3)
● Underground Mining: is started with drivage of either vertical or horizontal or inclined
entries into the deposit which may extend up to few hundred meters or kilometers
depending upon depth of deposits. Underground mining methods differ depending upon
the characteristics of the rock strata housing the deposit and techniques of managing rock
strata to mine the deposit with due consideration to conservation & safety.
● If the excavation consists of openings for human entry below the earth’s surface, it is
called an underground mine.
● The trained professional who relates mining and mining engineering is the mining
engineer;
● A Mining Engineer is responsible for:
● Helping to locate and assess mineral deposits in the mine,
● Planning, designing and developing of a mine,
● Exploiting and managing a mine safely & successfully, and
● Post-mining, systematic closure of a mine to make it sustainable.
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 Mining Terminology (1#6)

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Mining Terminology (2#6)

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Mining Terminology (3#6)

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Mining Terminology (4#6)
● Mineral: a naturally occurring inorganic element or compound having an orderly
internal structure and a characteristic chemical composition, crystal form, and physical
properties. Examples:
● Quartz - SiO2 (an oxide)
● Hematite - Fe2O3 (an oxide)
● Covelite - CuS (a sulphide)
● Rock: any naturally formed aggregate of one or more types of mineral particles
● Economic differences in the nature of mineral deposits:
● Ore: a mineral deposit that has sufficient utility and value to be mined at a profit. The ore
must be a rock or mineral that contains valuable constituent, can be extracted or mined
economically.
● Gangue: the value-less mineral particles within an ore deposit that must be discarded.
● Waste: the material associated with an ore deposit that must be mined to get at the ore and
must then be discarded. Gangue is a particular type of waste.
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Mining Terminology (5#6)
● Shaft is a vertical opening/access to a mine driven from the surface to the ore body which is
used for transport of ore/manpower & ventilation. It is normally circular in cross-section with
6-7m dia.
● Downcast Shaft: Shaft through which intake/fresh air enters the mine
● Upcast Shaft: Shaft through which return/foul air comes out of the mine
● Adit is a horizontal or a nearly horizontal entrance to an underground mine especially in a
hilly deposit. It has normally rectangular cross-section.
● Slope/Incline: Primary inclined opening, usually a inclined shaft, connecting surface with
underground workings with normally rectangular cross-section.
● Decline: Secondary inclined opening or may be spiral, driven downward to connect levels on
the dip of a deposit with normally rectangular cross-section.
● Drifts/Cross Cuts: are Horizontal or nearly horizontal underground drivages to intersect ore-
body/ coal seams. It is primary or secondary horizontal or near horizontal opening oriented
parallel to the strike of the deposit.
● Tunnel: A horizontal, or near-horizontal, underground passage that is open to the surface at
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both ends.
Mining Terminology (6#6)
• Dip: Angle at which the ore-body/ coal seam is inclined with horizontal. It is normally
expressed in degrees, percentage or 1 in ‘n’ (n may be any number; higher is the number
flatter is the deposit)
• Strike: Main horizontal course or direction of a mineral deposit in any horizontal plane
across the dip at any point.

Dip angle (θ) is expressed in degrees (⁰), or in 1 in n.

Dip angle (θ) = tan-1(1/n) (in deg.)

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 Why do you mine minerals?

Every person born will need (on a broad estimate) following minerals in his/her lifetime in
Indian Context:

✓Salt : 5 tonne ✓Gold: 50.0 gm

✓Coal: 100 tonne ✓Bauxite: 1.0 tonne
✓Petroleum: 50 kl ✓Copper: 0.3 tonne
✓Natural Gas: 50 kl ✓Zinc: 0.2 tonne
✓Lead: 0.2 tonne
✓Cement: 15 tonne ✓Phosphate rock: 4.5 tonne
✓Iron ore: 5 tonne
✓Clays: 10 tonne ✓Other minerals & metals: 10 tonne
✓Stone, sand & gravels: 50 tonne

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 Classification of Mineral Deposits
● Hydrothermal Ore Deposits
● As magma cools, more abundant metals (silicon, aluminium) deposit first.
● Solidification of magma releases water – a hydrothermal solution.
● Minerals precipitate from hydrothermal solution and deposit in cracks or veins in rock
● Sedimentary Ore Deposits
● Accumulation, burial and petrification of vegetation, e.g. Coal, Lime stone Deposits etc.
● Deposition of dense, resistant minerals in streams, lakes etc. (Alluvial Deposits), e.g. Placer gold
● Precipitation of minerals from ancient oceans (Evaporite Deposits), e.g. Potash and salt deposits
● Metamorphic Ore Deposits
● Concentration of minerals caused by high temperature and pressure near intrusions

Examples:
● Lead-zinc deposits
● Diamonds
● Garnets
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Categorization of Minerals
● Metallic ores: those ores of ferrous metals (Iron, manganese, molybdenum and tungsten),
the base metals (copper, lead, zinc, and tin), the precious metals (gold, silver, and the
platinum group metals), and the radio-active minerals (uranium, thorium and radium)
● Non-metallic Minerals (also know as industrial minerals): the non fuel mineral ores that are
not associated with the production of metals. These include phosphate, potash, halite, trona,
sand, gravel, limestone, sulphur etc.
● Fossil fuels also known as mineral fuels – the organic mineral substances that can be
utilized as fuels such as coal, petroleum, natural gas, coal bed methane etc.

● Economically important metal concentration in earth’s crust: Aluminium 8.0

Iron 5.8
Metal Concentration (% by weight) in Ore: Copper 0.0058
Nickel 0.0072
Zinc 0.0082
Uranium 0.00016
Lead 0.001
Silver 0.000008
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Gold 0.0000002
 What is ore grade?
● Ore grade is the concentration of economic mineral or metal in an ore deposit and is
expressed in:
● Weight percentage (base metals)
● Grams/tonne or oz./ton (precious metals)
● Cutoff Grade: It is the grade at which the gross value of the ore mined is exactly equal to
the cost of mining. Therefore mining becomes uneconomical for ore body with grade
below cutoff grade.

Cut-off grade = Cost /(Price x recovery)

● If Price of copper in India is Rs.600/kg and Production cost of copper ore (cost of mining
together with milling cost) is Rs.5000/Tonne, Cutoff grade of ore will be 8.33 kg of
copper per tonne of ore and if recovery is 90% the cut off grade will be slightly higher
i.e. 9.26 kg/tonne of ore or can also be expressed as 0.926% by weight.
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 Metal Ore

● Economically Important Metals: Typical Grades of Ore Deposits which is

economically extractable:

Metal Typical Grade (% by weight)

Aluminium 30
Iron 53
Copper 0.5 – 4.0
Nickel 1
Zinc 4
Uranium 0.3
Lead 5
Silver 0.01
Gold 0.0001-0.001
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 COALasCOAL
a as a MINERAL

❖ What is Coal?
❖ Origin of Coal
❖ Types of Coal
❖ Coal Rank & other Coal Characteristics
❖ Coal Geology

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How coal was formed?
• Coal is a combustible black or brownish-black sedimentary rock with
a high amount of carbon and hydrocarbons. Coal is classified as a non-
renewable energy source because it takes millions of years to form. Coal
contains the energy stored by plants that lived hundreds of millions of
years ago in swampy forests.
• Layers of dirt and rock covered the plants over millions of years. The
resulting pressure and heat turned the plants into the substance we call
coal.

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Origin of coal
• Coal is a fossil fuel and is the altered
remains of prehistoric vegetation that had
originally accumulated in swamps and
peat bogs and has been compacted,
hardened, chemically altered &
metamorphosed by heat & pressure over
geologic time.
• Seam is a stratum or bed or layer of coal
(or other mineral); generally applied to
large deposits of coal. A bed of coal
usually thick enough to be profitably
mined is called seam.

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Formation of Coal of different types

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 Coal Formation Theory
● The formation of coal occurs over millions of years via a process known as carbonation. In
this process, dead vegetation is converted into carbon-rich coal under very high temperature
and pressure.
● There are two theories proposed for the mode of accumulation of the plant debris to transform
into coal, which are:
● In - situ (Autochthonous) Theory, and
● Drift (Allochthonous) Theory.
● In-Situ or Autochthonous Theory: According to this theory, the coal seams are observed
most where the forest grew. The forest land was sinking slowly and the plant matters went
underwater gradually. Again, with the passage of time, the land of the forest came out of the
water and this cycle remained repeating. This eventually resulted in the formation of coal
strata and seams.
● Drift or Allochthonous Theory: According to this theory, the plant debris is transported with
the flowing water from one place to another and finally gets deposited in the place like
swamps, lakes, and basins. These places have suitable conditions for the supply of sediments,
e.g. Indian Coal Seams are of drift origin.

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 Mode of Deposition of Coal (1#3)
● Coal is formed mainly from the terrestrial plant material that grows on dry land.
The plant debris gets transported by water and then gets deposited under the water
in the water bodies.
● The sediments - organic and inorganic, get settled down gradually. This
sedimentation process continues till the deposit is covered completely with minerals
and sand which results in coal seams.
● Coal has a wide variety because of the varied types of vegetation deposition.
● The plant debris that accumulates in wet and fluviatile conditions is deposited and
is buried by sand, mud, and silt. After the deposition, the metamorphosis of the
wood occurs because of temperature and pressure effects. It produces various types
of coal.

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 Mode of Deposition of Coal (2#3)
• The initial transformation of debris material includes various kinds of decay
and degradation because of bacterial and fungal action. Slow atmospheric
oxidation also takes place.
● The organic material which is water-saturated, spongy, and plant-derived,
known as peat, is known as the precursor of coal. This is called peatification-
the primary transformation.
● The secondary transformation is a slow process. It includes the aging of Peat
deposits under substantially anaerobic conditions, elevated temperatures, and
higher pressures. This process is known as Coalification.

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 Mode of Deposition of Coal (3#3)

● The Coalification process is the progressive transformation of peat to higher

coals.
● Day to day increasing deep burial has a requirement of younger sediment to
advance coalification to the bituminous and anthracite stages.
● The pressure that is exerted by the weight of overlying sediments and the
heat that is increased by the depth and length of exposure, determines the
degree of coalification and the rank of coal.

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 Types of coal
• Based on Rank:
● Peat - with high moisture content (Carbon <25%)
● Lignite – low rank coal also known as Brown coal (Carbon >25% to
<35%)
● Sub-bituminous coal (Carbon >35% to <45%)
● Bituminous coal – dense and usually black (Carbon >45% to <86%)
● Anthracite – Highest rank, glossy black coal (Carbon >86% to <97%)

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 Types of coal

• Based on Caking Properties:

• Coking coal: Coal which when heated in absence of air form coherent bead,
free from volatiles, with strong and porous mass, called coke. It is used in:
● Coke making
● Steel making
● Metallurgical industries
● Non-coking coal: This coal does not have caking properties, mainly used for:
● Power generation
● Cement, fertilizer, glass, ceramic, paper, bricks manufacturing and
● Other heating purposes

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Coal: Type vs. Rank

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Coal Type-wise Characteristics

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 Types of coal & their uses
CARBON/ ENERGY CONTENT OF COAL HIGH
MOISTURE CONTENT OF COAL
% OF WORLD RESERVES

LOW RANK COALS HARD COAL

47% 53%

LIGNITE SUB-BITUMINOUS BITUMINOUS ANTHRACITE

17% 30% 52% 1%

THERMAL
METALLURGICAL
STEAM COAL
COKING COAL

Largely Power Power Generation Power Generation Manufacture Of Iron Domestic/Industrial

Generation Cement Manufacture Cement Manufacture & Steel Using Smokeless Fuel
USES

Industrial Uses Industrial Uses

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 Coal Terminology (1#4)

• Coal: A solid, combustible fossil sedimentary rock. Coal comes from

buried vegetation transformed by the action of strong pressure and high
temperatures over millions of years.
• Coal rank: The degree of transformation from the original plant
source. It is loosely related to the age of the coal and is mainly
determined from random reflectance of the vitrinite, one of coal’s
organic components. The ranks of coal, in decreasing order of
transformation from high to low, are: anthracite, bituminous coal, sub-
bituminous coal, lignite and peat.
• Coal classification: Refers to a range of coal age, composition and
other properties. Many classifications are used around the world with
the main parameter being the coal rank, supplemented by its intended
use, i.e. thermal or metallurgical applications.

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 Coal Terminology (2#4)
• Coal quality: Represents a variety of properties exhibited by coal when it is
used. Calorific value and impurity content are the main parameters defining
the quality of thermal coal, whereas caking properties, resistance and
impurity content are the distinguishing characteristics for coking coal.
• Thermal (or steam) coal: Refers to hard coal used for purposes other
than metallurgy in this report.
• Coking coal: High-quality coal to produce coke used in blast furnaces to make
pig iron. Coking coal and metallurgical coal are terms sometimes used
interchangeably.
• Semi-soft coal: High-quality steam coal mixed with coking coal to produce
coke for blast furnaces.
• Pulverized coal injection (PCI) coal: A high-quality steam coal injected into a
blast furnace to reduce coke consumption.

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Entry into a Coal Seam

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45
 Coal Terminology (3#4)
• Metallurgical coal: Refers to coking coal, semi-soft coal and pulverised coal injected in
Blast Furnace. Although anthracite is often used for metallurgical purposes, it is classified
as thermal coal.
• Run-of-mine (RoM) coal: Raw coal as it is mined before any processing.
• Tonne of coal equivalent (tce): A unit of energy widely used in the international coal industry.
It is defined as 7 million kilocalories (kcal). Therefore, the relationship between tce and
physical tonnes depends on the net calorific value the coal.
• 1 tonne of coal (with a net calorific value of 7000 kcal/kg) = 1 tce.
• Coal mining: A technique used to remove coal from a natural deposit. Coal deposits in the
Earth’s crust occur at various depths and seam configurations, which determine the mining
method used. Generally, deep deposits are mined underground and shallow deposits are
exploited through opencast mines. The stripping ratio largely determines whether an opencast
mine is profitable or not.
• Stripping ratio: The overburden or waste material removed, usually expressed as cubic meters
per tonne of coal extracted. High stripping ratios make opencast mining unprofitable.

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 Coal Terminology (4#4)
• Opencast mining: A method in which the overburden is first drilled, then blasted, and
when the deposit is accessible, coal is removed in a similar way to the overburden. To
remove the coal, power shovels, conveyor belts and trucks may be used, as well as some
extremely large machinery such as draglines and bucket wheels. Opencast mining is usually
less labour-intensive than underground mining, but has higher consumable costs,e.g. for
tyres, diesel and explosives. Generally, opencast methods imply greater environmental
impact than underground mining.

• Underground mining: A method in which access to coal seams is gained through

underground shafts, galleries and tunnels. Although there are many ways to mine an
underground deposit, coal is usually stripped by automatic shearers or continuous
mechanical miners using either short/long walls or room-and-pillar exploitations.
Underground mining is generally more labour-intensive and requires higher capital
investments than opencast mining.

• Coal washing/upgrading: A process in which impurities (i.e. ash, moisture) are

partially removed from raw coal to produce a higher-quality coal.

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Coal Map of India (Ref. 01.04.2023)

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 Major Coalfields in India
• Jharkhand: Jharia; Raniganj; Rajmahal; Bokaro (E & W); Karanpura (N & S)
● Odisha: Ib-River; Talcher
● West Bengal: Raniganj; Birbhum
● Madhya Pradesh: Singrauli; Sohagpur; Pench-Kanhan
● Chhattisgarh: Mand-Raigarh; Korba; Hasdeo-Arand; Bishrampur
● Maharashtra: Wardha-Valley; Kamptee; Umrer-Makardhokra; Nand-Bander
● Telangana: Godavari Valley
● Bihar: Rajmahal
● Uttar Pradesh: Singrauli
● Andhra Pradesh: Godavari Valley
● North-East States (Assam, Arunachal Pradesh, Meghalaya, Nagaland & Sikkim):
Makum; Dilli-Jeypore; Namchik; West Daranggiri; Siju; Borjan, Rangit Valley.

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Schematic
Diagram
showing Seam
Succession

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