This document provides an overview of coal preparation and washing in India. It discusses the types and properties of Indian coal, the importance of proper coal sizing and conditioning prior to combustion. It also examines existing coal preparation plants in India, case studies that show improved yields from full-wash plants, and the evolution and growing importance of coal washing to meet industry demands. Future plans include installing more washing capacity to process India's deteriorating coal reserves and research into techniques tailored for India's difficult-to-wash coal characteristics.

1. COAL PREPARATION SCENARIO IN
INDIA
GUIDED BY-
SUSANT KUMAR PRADHAN
DONE BY-
INDRANEELA PRADHAN
1801104104
MINERAL 3RD YEAR

2. INTRODUCTION
Energy is available to man from FUELS
SOLID LIQUID GASEOUS NUCLEAR
Coke,coal,
wood,cha
rcoal
Diesel,pe
trol
Lightning
gas,cokeoven
gas
Uranium
based energy

3. TYPES OF COAL
Non-coking coal Coking coal
(on basis of heating
value of coal)
(on the basis of
ash percentage)
HIGH CALORIFIC VALUE
&
LOW VOLATILE MATTER
3

4. The common coals used in Indian industry are bituminous and sub-bituminous coal. The
gradation of Indian coal based on its calorific value is as follows:
Grade
A
B
C
D
E
F
G
Exceeding 6200
5600 – 6200
4940 – 5600
4200 – 4940
3360 – 4200
2400 – 3360
1300 – 2400
Calorific Value Range ( in kCal/kg)
are available to
Indian Industry
Analysis of Coal
4

5. PROPERTIES RANGE
Density 1.1 -1.5
megagrams/M3
Porosity •macropores (d>50
nm)
•mesopores (d 2 to
50 nm)
•micropores
(diameter <2 nm)
Reflectivity 0.60% to 0.90%
Preparation of Coal
Preparation of coal prior to feeding into the
boiler is an important step for achieving good
combustion.
Large and irregular lumps of coal may cause
the following problems:
1. Poor combustion conditions and inadequate
furnace temperature.
2. 2. Higher excess air resulting in higher stack
loss.
3. Increase of unburnts in the ash.
4. 4. Low thermal efficiency.
Sizing of Coal-Proper coal sizing is one
of the key measures to ensure efficient
combustion. Coal is reduced in size by
crushing and pulverizing.
Conditioning of Coal-The fines in
coal present problems in combustion on
account of segregation effects.
5

6. India has been involved in coal preparation
since the early 1950s.
While the coal preparation plants that were
built earlier were primarily for metallurgical
coal, in the last two decades the Indian
government has realized the importance of
coal cleaning even for thermal coal.
•As surface mining and mechanization
expanded, the ash content and calorific
value of Indian coal deteriorated
Existing Indian Coal Preparation
Indian coal preparation plants typically
receive coal with a head ash ranging from 35.0
% to upwards of 50.0 %.
This has led to the reduction in the overall CPP
product yield, as the Indian coal characteristics
limit the product ash that can be achieved.
6

7. Importance of Proper Coal Testing
The size distribution and washability of the plant feed is the most important information
to be obtained before determining the best flowsheet option.
In India, the general practice is to
Perform the particle size distribution and corresponding washability analysis based on
dry tumbling data.
•The most important thing in the size distribution is to correctly estimate the
amounts of fines generation during mining and processing because underestimation of
fines can affect the loadings as well as the performance of various processing equipment
7

8. Case Studies on Indian Coal
Various studies were performed both in metallurgical coal and in thermal coal to compare
the performance of the coal preparation plant circuits that exist in India with those in
North America.
‡ One such study was performed in 2015
1. While partial-wash plants can produce <34.0 % product ash with the desired moisture
content,
the product yield from a full-wash plant using the Equal Incremental Ash method is
significantly higher than those from the partial-wash plants.
2. Partial-wash plants can be considered as a flowsheet option if the plant feed head ash
is ≤40.0 %.
3. If the plant feed head ash is >40.0 %, which is the majority condition, the
full-wash plants flowsheets with multiple gravity separation circuits (HMC-Spirals) should
also be preferred.
8

9. Evolution of coal washing in India
After setting up Steel Plants in India (in 1907), Tata Iron and Steel Company (TISCO)
started explorations to meet the demand of coking coal for their steel plants; and, first
breakthrough was achieved by Mr. A. Farquhar during his washability studies of Jharia and
Raniganj coal during 1918–1926.
TISCO decided to set up Coal Washeries in West Bokaro (1951) and Jamadoba (1952)
Cone separator (a dense media separator utilizing sand as media) was the first
washing equipment installed in Jamadoba Coal Preparation Plant .
Hindustan Steel Limited (HSL) was set up in 1954, for expansion of Steel Industry in
India. Similarly, National Coal Development Corporation (NCDC) was founded for planned
growth of coal mining industry in India. Durgapur, Dugda, Bhojudih and Patherdih were
envisaged; and Kargali Washery was commissioned in 1958 by NCDC as first public sector
washery in India. Durgapur, Dugda, Bhojudih and Patherdih Coking Coal Washeries were
commissioned during the III and IV Five Year Plans.
9

10. Growing importance of washing
India has proven coal reserves of total 125.91 billion tons, out of which only 18.4 billion
tons is that of coking coal. Over the years, prime-coking coal reserves in the Jharia Coal Field
have been exploited from the upper seams, leaving behind lower seams of inferior grade coal
for further extraction.
Increasing demand of growing steel industry and diminishing production of metallurgical
grade coal has resulted in increasing import burden on Indian Steel Industry to meet its
demand for quality coking coal
•Inferior quality of Indian coking coal
•Insufficient washing capacity
Approx. 79 % of the total national demand is met by imported coal.
Principal reasons behind this huge demand
supply gap-
Washing coal increases its efficiency
and quality, therefore increasing its
price.
Coal washing can also help to reduce
emissions from burning. The washability
characteristics of a coal reserve are
provided by obtaining liberation data on
the raw coal 10

11. Existing scenario of coking coal washing in India
So far,
25 coking coal Washeries have been installed and commissioned in India out of which only 19
are in operation at present with a total washing capacity of 33.17 MTY; out of these Washeries,
15 are operating in Public Sector.
No washing equipment has been designed specifically to treat Indian Coal with difficult
washing characteristics, which is not encountered in case of carboniferous coal.
 Heavy Media Cyclone is the most widely used separator in these washeries.
Presence of high proportion of near-gravity-material (NGM) mandates cyclone washing
11

12. Characteristic of Indian coal
•Indian coals of drift origin (Gondwana Coal) can be characterized by high ash content with
impurities disseminated in the coal bed.
•Very thin bands (5 mm–3 cm) of impurities are often encountered in between coal bands. Such
coal has high near gravity material (NGM > 30 %) content.
However, operating a coal washery with such small coal size is not feasible under present
techno-economics.
This makes Indian Coal difficult to wash, resulting in poor yield and low organic efficiency.
Indian industries find Indian Coal inferior to the imported coal mainly because-
•High ash content
•Low sulfur (0.2 %–0.7 %)
•Low iron
•Low chlorine
•Low toxic/rare earth elements
12

13. Future of coal washing industry
Installation of 20 Coal Washeries in public sector with total installed capacity of 111.10 MT was
envisaged.
At present, CIL has taken up installation of 15 coal washeries on build
6 are coking coal washeries, under
the ownership of Bharat Coking
Coal Limited with total design
capacity of 18.6 MTY
9 Washeries are Non-Coking Coal
Washeries with total designed
capacity of 74.5 MTY under the
ownership of CCL
13

14. The six coking coal washeries of Bharat Coking Coal Limited will be equipped with advanced
automation and control circuits.
Three of these washeries are under construction with the remaining under various stages of
finalization.
Typical cyclone—
Cyclone, Jig—Cyclone combination has been used.
Deshaling cyclone and teeter bed separator (TBS) are being used for the first time in India.
S&T Mining, a joint venture between Steel
Authority of India Limited (SAIL) and Tata
Steel Limited has been formed to look into the
Mining and Coal Preparation activities of the
newly acquired coal blocks to meet the
demand of coking coal for their steel plants.
With installation of upcoming coal washeries in
BCCL, total designed capacity of coking coal
washeries in India will be 55.77 MTY
14

15. Scope for research and development
• With deteriorating quality of coal, the complexity of washing would increase, and operators
would resort to 4–5 stages of washing.
•Outcomes of several experiments carried out on Indian Coal and South African Coal (also of
Gondwana Origin) reveal that separate washing of different size fractions have resulted in
higher yield
BATAC Jigs can be utilized to wash difficult-to-
wash coal
Several experiments on Indian Coal and have
arrived to a conclusion that -
Washing −13 + 1 mm fraction in Heavy
Media Cyclone, −1 + 0.106 mm fraction in
spiral concentrator and −0.106 mm fraction in
flotation cells will yield better results
compared to −13 + 0.5 mm in HM Cyclone and
−0.5 mm by Flotation
15

16. Conclusions
The existing situation of Indian coal washing Industry is a resultant of gross negligence of
the industries to strengthen R&D for development of indigenous technologies.
The Industry has relied from the very beginning on imported technology and machinery,
ignoring the fact that foreign technologies have been developed taking into account the
nature of coal in those countries, which is significantly different from that of Indian Coal,
which possess difficult washability characteristics because of its drift origin.
Neither the industry nor the government agencies have sponsored an exhaustive R&D
project dedicated to coal, despite it being the primary source of energy and
infrastructural element in India.
Thus, attractiveness of Coal Washing Industry in India is high, but also full of challenges.
PESTEL analysis of coal washing industry suggests that India is heading towards
mandatory coal washing before end utilization. The deteriorating quality of raw coking
coal poses challenges before the scientific community and the industry to find out
simple and economically viable coal washing scheme for maximum recovery of coking
coal for usage in metallurgical sector. There also lies scope for analyzing present
condition of existing washeries, especially in public sector, to look for innovative
techniques for revival of these washeries.
16