Company Presentation - · PDF filewashed coal of around 82 to 83% yield having ash < 34% to...
Transcript of Company Presentation - · PDF filewashed coal of around 82 to 83% yield having ash < 34% to...
Company Presentation
Kolkata Unitcompleted its 40 years of
operation
& is proud to be part
of KHD Humboldt Wedag on completion of its 150 years of
operation
HUMBOLDT WEDAG INDIA
Company Presentation
BENEFICIATION OF INDIAN NON COKING COAL - ISSUES, PROBLEMS & REMEDIES
Gurudas Mustafi, Vice President, Humboldt Wedag India Pvt. Ltd.Kolkata, India
Beneficiation of Lump Sized CoalIssues
A great percentage of the power station coal mined throughout India has been burned so far without preparation or refuse separation, because the preparation costs are too high or combustible substance is lost in the preparation process. Considering, however, the lower wear in the boiler houses and the increased volume of transportation in the case of prior separation of refuse from the power station coal, then a preparation, at least of the lump sized portion should be profitable. Test regarding the abrasive properties of different types of coal shows that the abrasion and thus the wear are considerably limited due to a separation of refuse from lumpy run-of-mine coal.
HUMBOLDT WEDAG INDIA
Company Presentation
Benefits
The removal of a certain portion of the refuse from the uncrushed raw coal offers great advantages for the preparation process, such as for example
- Decrease of power requirements for size reduction.
- Increased yield of graded coal in the case of domestic coal production,
- decreased yield of slurry,
- decrease of ash content in the raw slurry,
- more favourable homogenising properties of the raw coal,
- decreased wear in the concentration machines,
- more favourable utilisation of the preparation capacity, i.e. increased efficiency of the preparation plant.
HUMBOLDT WEDAG INDIA
Company Presentation
Remedies
The development of the ROMJIG (Fig 1) opened the possibility, to use a very simple process for
the beneficiation of the lump size coal - the top size is 400 mm and the bottom feed size is 30
mm - by using only one technologically improved machine and some standard auxiliary
equipment.
In fact the idea was to solve the problem of preparing non coking coal, as far as possible dry.
After many years of development, such plants have been installed at Bina and
Kargali and are in operation to separate refuse and clean coal. (Ref : Flow Sheet 1)
HUMBOLDT WEDAG INDIA
Company Presentation
Bina / India:Deshaling in front of a Powerplant ROMJIGHUMBOLDT WEDAG INDIA
Flow Sheet 1: ROMJIG Process for Run of Mine Coal
Company Presentation
Separation
ROMJIGfor separation of coal 30 - 400 mm
HUMBOLDT WEDAG INDIA
Fig 1: ROMJIG
Company Presentation
ResultsBINAPresently from this plant of NCL washed coal is produced with ash < 34% and is linked to Delhi Vidyut Board. In general the results are:
Raw Coal Screen analysis: Products of that plant:Grain size Wt. % Ash % Product Wt. % Ash %
250 - 30 mm 68.78 42.13 deshaled coal 49.76 31.3430 - 0 mm 31.22 38.08 unwashed coal 31.22 38.08
250 - 0 mm 100.0 40.87 saleable product 80.98 33.94Refuse 19.02 70.37
KARGALIDuring the performance tests conducted over a span of 15 days a series of tests were conducted and following results were computed on an average basis:
Raw Coal Screen analysis: Products of that plant:Grain size Wt. % Ash % Product Wt. % Ash %
350 - 50 mm 45.3 40.75 deshaled coal 34.26 30.750 - 0 mm 54.7 32.56 unwashed coal 54.7 32.56
350 - 0 mm 100.0 36.27 saleable product 88.96 31.84Refuse 11.04 71.96
At a cut density of 1.9, the average imperfection determined was 0.089
HUMBOLDT WEDAG INDIA
Company Presentation
Prospects
The successful employment of a ROMJIG for large refuse separation of
run-of-mine coal opens a wide field of future applications. In view of the
favourable secondary conditions, such as low water and power
consumption, low expenditure for necessary auxiliary equipment this
process stands any time economical compared with other proven
technologies of large refuse separation and is the ideal process, in case
people think of a pit head instalment.
HUMBOLDT WEDAG INDIA
Company Presentation
Beneficiation of coarse grain coal
Issues
Whenever the characteristics of the raw coal does not allow, to achieve the
required product quality with the ROMJIG by only washing the lump size coal,
the grain size of beneficiation has to be reduced. Reasons can be the grain size
distribution, when the amount of material < 30 mm is more and the ash content
of this fraction too high.
HUMBOLDT WEDAG INDIA
Company Presentation
Remedies
This leads immediately to the beneficiation of coarse coal by means of Batac® Jig (Fig 2)
or Heavy Media Teska® Separator / Heavy Media Bath (Fig 3).
A typical process for such a jig plant requires only very few equipment while some
additional equipment and the magnetite circuit essentially comprising of magnetizer,
primary & secondary magnetic separators and de-magnetizer are involved in such a HM
Separator / Bath plant. The raw coal with a top size of 75 (100) mm is at first screened
at 13 / 6 mm. The coarse product 75 (100) – 13 / 6 mm is fed either to the Batac jig or
Heavy Media Teska Separator / H.M.Bath, where it is separated into refuse and clean
coal and un-washed fraction (-) 13 / 6 mm mixed with Clean Coal. (Ref : Flow Sheets 2
& 3)
The process is closed by means of a combination of cyclones, filters & thickener (Ref :
Flow Sheets 5 or 8)
The top size can be reduced to 50 mm depending on the grain size distribution.
HUMBOLDT WEDAG INDIA
Company Presentation
raw coal
+ 75 mm
- 75 mm
refuseclean coal
circulating water
Humboldt Wedag75 - 0 mm
13/6 - 0 mm
Flow Sheet 2: Jigging Process for Coarse Coal
to refuse
Standard-FlowsheetJigging process for Power Station Coal
HUMBOLDT WEDAG INDIA
Company Presentation
- 13 mm
Humboldt Wedag
mixed fine coal
clean coal
+ 13 mm
13 -1 mm
1 - 0 mm
13-1 mm
+ 13 mm
13-0 mm
(-)25 mm
Flow Sheet 3: Heavy Medium Process for Coarse Coal
raw coal
+ 13 mm
circulating water
refuse
cleancoal
+25 mm
Standard-FlowsheetHeavy Medium for Power Station Coal
Slurry sump
HUMBOLDT WEDAG INDIA
Company Presentation
Separation
Coarse Coal BATAC - JIGfor separation of coal 10 - 150 mm
HUMBOLDT WEDAG INDIA
Fig 2: Batac Jig
Company Presentation
SeparationTESKA - Separator
Heavy Medium separation 10 - 150 mm
HUMBOLDT WEDAG INDIA
Fig 3: Teska Bath
Company Presentation
Prospects
The Batac jig is so flexible that the bottom washing size can be reduced
from 13 mm to 6 mm or even to 3 mm, without a modification of the flow
sheet. The only problem is the dry screening at the lower sizes, which can
be solved by using the right screening system.
Equally good operating results are achieved with the Heavy Media Teska
Separator / H.M.Bath without reducing the lower size and for which it needs
to be ensured that the media recovery circuit is properly designed and
media of the correct quality & quantity is made available.
HUMBOLDT WEDAG INDIA
Company Presentation
ResultsPIPARWARPiparwar washery under Central Coalfields Limited having a capacity of 6.5 mtpa is equipped with two such Batac Jigs, which forms the heart of the plant supplying washed coal of around 82 to 83% yield having ash < 34% to NTPC for their Delhi based power plants. Raw coal presently fed has an ash in the range of 39 to 40%
PRIVATE WASHERIESPlants with Jig and HM Bath for similar application have been set up for private entreprenuers to wash power grade coal in different locations adjacent to MCL, SECL & WCL mines. Some of these are already in operation. (Results attached)Additionally the depth of beneficiation can be increased by adopting further processes, like the combination of coarse and fine coal jigging or combination of coarse coal HM Bath and fine coal HM Cyclone or combination of jigging with heavy media process and at the end the addition of the flotation system, which is relatively seldom in the beneficiation of non coking coal.
HUMBOLDT WEDAG INDIA
Company Presentation
ResultsThe ash in raw coal received varies between 34 to 38%. Results shown in both cases are with 38% ash in raw coal but from different mines of WCL. HEAVY MEDIA BATHThe results from a plant installed at Wani supplying washed coal to MSEB are:
Raw Coal Screen analysis: Products of that plant:Grain size Wt. % Ash % Product Wt. % Ash %50 - 13 mm 68.00 37.80 washed coal 41.00 24.1013 - 0 mm 32.00 40.00 unwashed coal 32.00 40.0050 - 0 mm 100.00 38.50 saleable product 73.00 31.07
Refuse 27.00 58.60Operating Cut Density : 1.45 BATAC JIGThe results from a plant installed at Ghugus supplying washed coal to MSEB are:
Raw Coal Screen analysis: Products of that plant:Grain size Wt. % Ash % Product Wt. % Ash %
50 - 6 mm 85.0 37.90 washed coal 49.80 24.606 - 0 mm 15.0 38.13 unwashed coal 15.00 38.13
50 - 0 mm 100.0 37.93 saleable product 64.80 27.73Refuse 35.20 56.71
Operating Cut Density : 1.5
HUMBOLDT WEDAG INDIA
Company Presentation
Beneficiation of medium and fine grain coal
Issues
In good coal reserves - preferably in open cast mining - a relatively big amount of
good quality raw coal is dumped, i.e. wasted, due to the selective mining method.
This is the material close to the border between coal seam and shale band, which
contains up to 50% of saleable coal.
Further whenever the characteristics of the raw coal does not allow, to achieve the
required product quality with only washing the coarse coal, the grain size of
beneficiation has to be reduced. Reasons can be the liberation in course of crushing,
grain size distribution, presence of amount of material < 13 / 6 mm is more and the
ash content of the fine material is too high.
HUMBOLDT WEDAG INDIA
Company Presentation
Remedies
This leads immediately to the beneficiation of small coal by means of Heavy
Media Cyclones (Fig – 4) or fine coal Batac® Jig (Fig – 5).
World over plants are being installed to process especially such type of
interface material. The process flow sheet of such a plant appears very
simple. The heart of this plant is the HM Cyclone or Batac jig and depth of
beneficiation is again defined by the raw coal characteristics and the product
requirements. Due to this the flow sheets of such plants vary widely. Here we
present a sample of both systems, which can be considered as a standard
for this duty (Ref: Flow Sheets 4,5,6,7 & 8).
HUMBOLDT WEDAG INDIA
Company Presentation Feed ( -) 25 mm Water addition
0.5 - 25 mm E.P
to Thickener E.P
to hydrocyclone stage P to Thickener C.V.
Middlings (-) 25 mm
Over Dense Media Sump
SlurrySump
Clean Coal 0.5 - 25 mm
C.VWater
D..B. addition
Density Guage H.M.Sump Dilute Media Sump
Coal Processing PlantHeavy-Media Cyclone Single Stage ProcessKHD Proj.-Nr.: B40.3610Date: 15.07.2007
Flow Sheet 4: Heavy Medium Single Stage Cyclone Process for Small Coal
Company Presentation
Middling (-) 0.5 mm
Coal Processing Plant - Slurry CircuitHeavy-Media Cyclone ProcessKHD Proj.-Nr.: B40.3610Date: 15.07.2007
Process-water Tank
Flow Sheet 5: Slurry Circuit
HUMBOLDT WEDAG INDIA
Company Presentation
Feed 0 - 0,5 mm
to finest coal section
(-)25mm25 - 0 mm
0 - 0.5 mm
25 – 0.5 mm
(-)0.5 mm
25 – 0.mmto outgoing middlings conveyor
25 –0.5 mmto outgoing
clean coal conveyor
GEBComp
Coal processing plantBatac Jig Single Stage ProcessKHD Proj.-Nr.: B40.3654Date: 19.07.2007
25 – 0.5 mm
Flow Sheet 6: Batac Jig Single Stage Process for Small Coal
HUMBOLDT WEDAG INDIA
Company Presentation
FIG-5
Flow Sheet 7: Batac Jig Single Stage Process for Small Coal with Crushed Refuse for Power Generation
Company Presentation
(-) 0.5 mm
Coal beneficiation plantSlurry CircuitKHD Proj.-Nr.: B40.3654Date: 19.07.2007
To common outgoing middlings conveyor
Flow Sheet 8: Slurry Circuit
HUMBOLDT WEDAG INDIA
Company Presentation
Separation
HMS - Cyclonesfor separation of coal 0 - 50 mm
HUMBOLDT WEDAG INDIA
Fig 4: HM Cyclone
Company Presentation
Separation
Fine Coal BATAC - JIGfor separation of coal 0 - 20 mm
HUMBOLDT WEDAG INDIA
Fig 5: Small Coal Batac Jig
Company Presentation
Prospects
Such plants having a simple designed process can be very useful
for producing washed coal required for consumers besides power
viz. sponge iron plants, cement plants to name a few.
HUMBOLDT WEDAG INDIA
Company Presentation
Results
Coal washeries with both Jig and HM Cyclone process are in operation in JSPL,
BPSL, BSL,Grasim Cement & Gujarat NRE to name a few while ACC, UltraTech
are in the process of setting up their captive coal washeries at different locations
which includes 3 product washery with either two stage H.M.Cyclone process
(Ref: Flow Sheet 9,10 & 11) or combination of jigging with heavy media process
(Ref: Flow Sheet 12 & 13) having provision to operate as and when required one
circuit to produce two products.
More are being set up to wash non coking coal in different locations adjacent to
WCL, MCL & SECL mines by private entrepreneurs to meet the rising demand of
washed coal.
HUMBOLDT WEDAG INDIA
Company Presentation
To SlurryPum p & C om pressor
From ExistingSource ofIndustria l W ater
W ashery feed Conv.
(-) 0 .5m m .
(50-
0.5m
m.) (50-0.5m m .)Reject
(50-25m m .)
(-) 0
.5m
m.
To Reject Bunker
(25-0.5m m .)
To Thickener O verflow
From Thickener O verflow Pum p
O .H. Process W ater Tank
Jig O .H .Tank
Coal Hopper
R .P . G ate
V.Feeder
S ieve BendW et Coal Hopper
D eslim ing Screen
Jig S lurry Tank
Sealing & CoolingW ater Pum p
Process W ater Tank
Process M ake-UpW ater Pum p
S INGLE / DO UBLE STAGE JIG CUM CYCLO NE W ASHERY
Subm ersib lePum p
Slurry Feed Pum p To
Hyd
. Cyc
.
J ig B lower
Com p.For Jig
Batac
Buc
ket E
leva
tor
F ixed Screen
Dewatering Screen
S izing Screen
To H .M . Tank For
To Centrifuge at H .M . Section
D ouble Stage W ashing
(For S ingle Stage W ashing)
To Centrifuge at H.M .
W ashing Section (for single
stage washing)
Jig
To C lean coal conv.
Flow Sheet 9: Two Stage Batac Jig & HM Cyclone Process
Company Presentation
W ater
W ater
De-
mag
netiz
er
T o S lu rry T ank T o S lurry Tank
(50 -0 .5m m .)
from B a tac J ig
H .M . C yc lone
S ieve B end S ieve B end
D e-pu lp ing &R ins ing S creen
F or M idd lingR ins ing S creen
C en trifuge
T o M idd ling C onv.
D ilu te M ed ia S um p
D ilu te M ed ia P um p
D e-pu lp ing &R insing S creenFor C lean C oa lF or M idd ling C oa l
F or C leanR insing S creen
C en trifugeC lean C oa l
C lean C oa l C onv.
H .M . C yc loneF eed P um p
H .M . S um p
(50-0 .5m m .)
D ense M ed iaT ank
O ver D ense M ed ia P um p
C la rify ing C one
M agnetic S ep .
F rom B atac J ig W ash ing
S ection (25-0 .5 ) (M idd ling)
W ash ing (25-0 .5 m m .)
50-2
5 m
m.
25-0
.5 m
m.
5 0 -25 m m .
D ensity A d jus tingT ank
D ens ity G auge
F rom B a tac J ig
S IN G LE / D O U B LE S TA G E JIG C U M C Y C LO N E W A S H E R Y
T o S lu rry T ank
S pray
Mag
netiz
er
M ed ia
Flow Sheet 10: Two Stage Batac Jig & HM Cyclone Process
Company Presentation
+ 0.5mm.
Filtrate
Filtrate
(-)0.5mm.
Slurry Pond
Thicking Hydro Cyclone
Sieve Bend
Check SlurryScreen
From Slurry Feed Pump
Slurry Distributor
Vacuum Filter
Blower
Receiver
MoistureTrap
Vacuum Pump
Filtrate TransferPump
SINGLE / DOUBLE STAGE JIG CUM CYCLONE WASHERY
Tank Thickener O.F.Pump
To J
igO
.H. T
ank
From
Ove
rflow
O
f Jig
O.H
. Tan
k
Slurry Thickener
Middling Coal(Product)
Flocculent Dosing Unit
Thickener U.F.Pump
To Air
To ProcessWater Tank
Flow Sheet 11: Slurry Circuit
Company Presentation
W a te r
T o S lu rryP u m p & C o m p re s s o r
W A S H E R Y F E E D C O N V E Y O R
F ro m E x is t in gS o u rc e o fIn d u s tr ia l W a te r
R e je c tsC o n ve yo r
(50 -0 m m .)
W a te r
S L U R R Y S U M P
F R E S HW A T E RT A N K C IR C U L A T IN G
W A T E RT A N K
S U R G EH O P P E R
R A C K & P IN IO NG A T E
V IB R A T IN GF E E D E R
W E T T IN G B O X
S IE V E B E N D D E S L IM IN G H E A V Y M E D IAD IS T R IB U T IO NB O XS T A G E -I
H E A V Y M E D IAD IS T R IB U T IO NB O XS T A G E - II
H E A V Y M E D IAS U M PS T A G E - I
H E A V Y M E D IAS U M PS T A G E - II
(U S E D D U R IN G T W O S T A G E O P E R A T IO N )
F L A P G A T E
H E A V Y M E D IAC Y C L O N E S T A G E - I
S IE V E B E N D
D & R S C R E E NS T A G E - I (C L E A N S )
D & R S C R E E NS T A G E - I (R E J E C T S )
S T A G E - I C L E A N C O A LT R A N S F E R R E D T O S T A G E - I I H . M . S U M PD U R IN G T W O S T A G EO P E R A T IO N
D E S L IM E D C O A L T R A N S F E R C O N V E Y O R
S C R E E N
T O H E A V Y M E D IAC Y C L O N E S T A G E - II
T 0 T H IC K E N IN GC Y C L O N E
F R O M D IL U T E M E D IA S U M P S T A G E -II
F R O M T H IC K E N E R O V E R F L O W P U M P
T O D IL U T E M E D IA S U M P S T A G E -II F R O M D . & R . S C R E E N
S T A G E -II
Flow Sheet 12: Two Stage HM Cyclone Process
Company Presentation
To S lu rry Tank
S pray
Mag
netiz
er
T o A ir
To P rocessW ate r T ank
W ater
De-
mag
netiz
er
M ed ia
S LU R R Y P O N D S
T H IC K E N E R
M IDD LING S CO NVEYO R
To S lu rry TankTo S lu rry Tank
S IE V E B E N D S IE V E B E N D
H E A V Y M E D IAC Y C LO N E S TA G E - II
D & R S C R E E NS T A G E - II (C LE A N S )
D & R S C R E E NS TA G E - II (M ID D LIN G S )
R IN S IN G S C R E E N(C LE A N C O A L)
R IN S IN G S C R E E N(M ID D LIN G S )
C E N TR IFU G E(C LE A N S )
C E N T R IFU G E(M ID D LIN G S )
D ILU TE M E D IAS U M PS TA G E - II
C LA R IFY IN GC O N E
M A G N E TICS E P A R A TO R
O V E R D E N S E M E D IA S U M P
C LE A N C O A L C O N V E Y O R
M ID D LIN G S C O N V E Y O R
C LE A N C O A L
M ID D LIN G S
TH IC K E N IN GC Y C LO N E
S IE V E B E N D
C H E C K S LU R R YS C R E E N
V A C U U MP U M P
D IS CF ILTE R
F ILTE RB LO W E R
FILT R A TES U M P
E Q U IP M E N T F LO W S H E E TT W O S T A G E H E A V Y M E D IA C O A L W A S H E R Y
TO C IR C U LA T IN G W A TE R TA N K
TO H E A V Y M E D IA D IS T R IB U TIO N B O X S TA G E -I & II
FR O M H E A V Y M E D IA S U M P S TA G E -II
FR O M S LU R R Y S U M P
TO H E A V Y M E D IAD IS TR IB U TIO N B O X S TA G E -II
Flow Sheet 13: Two Stage HM Cyclone Process
Company Presentation
Selection of Process
Selection between the HM & jigging process depends on several factors inter-alia the following:
• raw coal characteristics
• washed coal quality required
• use of reject coal
• operating & maintenance cost
• availability of required quality & quantity of magnetite
Both HM & jigging are the proven processes accepted on worldwide basis for such applications.
HUMBOLDT WEDAG INDIA
Company Presentation
Conclusions
According to today’s standard it is no longer required or necessary to work
with open washery circuits and to damage the environment as well as to
spoil energy. The described processes for the various applications have
proven their flexibility as well as their acceptance in the coal beneficiation
industry. In future it will be a must throughout the world, to beneficiate the
raw coal before being used to produce power, cement, sponge iron etc. The
users will appreciate the better and consistent coal quality, being fed to their
plants.
HUMBOLDT WEDAG INDIA
Company Presentation
HUMBOLDT WEDAG INDIA
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