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June 3, 2014 Beneficiation of LVC Coal in India A Challenge Dr Kalyan Sen, Director Central Fuel Research Institute Dhanbad 828 108
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June 3, 2014 Coal Scenario in India 83.0% 14.0% 3.0% Prime coking LVC MVC HVC Semi-coking 19% 50% 15% 11% 6% Total Coal Reserves 206239.5 mt Non- coking Coking Others
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June 3, 2014 COKING COAL FOR METALLURGICAL USES REQUIREMENT : 25mt /yr. IMPORT (1997-98) : 10.6mt SHORTFALL : < Depletion of good upper seam coal < high cost of underground mining (1998-99)
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June 3, 2014 LVC Coal Scenario in India Low Volatile Coking 50% of Total Coking Coal 15,680 mt Available Resource Alternative Proposition
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June 3, 2014 LVC Coal Scenario in India Annual Production (16 -18 mt) n 8 to 10 mt from Jharia n 6 to 8 mt from East Bokaro Present Use l Power Stations (major consumption) l Beehive ovens (minor consumption)
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June 3, 2014 Mining Condition f LVC coals outcrop near the fringe areas of coalfields f Easy for Opencast production f Low overburden : coal ratio f Low slope f Possibility of high scale mechanization
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June 3, 2014 WASHABILITY STUDIES WITH LVC COAL Lab. and Pilot plant study at CFRI Sample : V/VI/VII/VIII Seam coal of Jharia Coalfield D
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June 3, 2014 Characteristics of LVCC p High raw coal ash 35-45% p High Maturity Ro = 1.3 p Low volatile matter content 15-16% p High Inertinite content (60-70%) p Poor washability potential
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June 3, 2014 LVC Coals Presently NLW grade Unwashable ! Formidable to wash !
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June 3, 2014 Liberation Potential of GOCP Coal Raw coal X 75mm & deshaled Deshaled coal X 13mm
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June 3, 2014 Liberation of coal/ mineral particles by progressive size reduction is insignificant
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June 3, 2014 Difficult - to - wash Due to Z Typical Geological formation Z Intergrown Mineral matter Z High NGM at desired d 50 Z Poor plant performance
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June 3, 2014 Theo. Yield of products from GOCP coal 0 10 20 30 40 50 60 70 80 90 100 010203040506070 Ash,% Yield,% 2- product separation Cleans ~30% of ash 18% Rest ash 45% ( sale value ? )
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June 3, 2014 Theo. Yield of products from GOCP coal 0 10 20 30 40 50 60 70 80 90 100 010203040506070 Ash,% Yield,% Cleans ~30% Ash 18% 3- product separation Rejects ~20% Ash 60% Middling 50% Ash ~41% ( fate? )
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June 3, 2014 CFRIs Concept 4 Sp.Gravity based Washability Model 4 Limiting Characteristics Ash 4 Multi-stage washing
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June 3, 2014 Density-wise mass distribution of GOCP Coal ClaensRejects Foundry Coal Power Coal 4- product separation
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June 3, 2014 A Typical Flowsheet A Typical Flowsheet Cleans SinksCleans Sinks Conc..Tailings Screened 13/6 mm & 0.5mm R..O.M Coal X75mm Cleans ARejectsEffluents Precleans 75-13/6mm13/6-0.5<0.5mm Rewash in HM Bath/Cyclone Flotation Total CleansFoundry Fuel Power Coal 20-28%(a 60-65%) 50% (a21-23%) 20-28%(a34-37%) 25-28%(a17-18%) 20-23%(a27-29%)
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June 3, 2014 Technological Solution
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Issuies for Attention c Economics of Clean coal c Washing Circuit c Quality of Product c Effect of Raw coal ash on yield
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June 3, 2014 Price of Clean coal at 17 - 18 % ash ?
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June 3, 2014 Beneficiation in existing washeries k 2-product circuit About 70-75% with 40-45% ash with no market outlet Cost of clean coal is approximately 5 times that of raw coal
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June 3, 2014 Beneficiation in existing washeries k 3-product circuit LVCC requires disposal of 20% as reject 50% middling with 41% ash (outlet ?) Cost of clean coal is 4 times that of raw coal
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June 3, 2014 4-Product Circuit k Cleans (25-30%), 17-18% ash k Foundry cleans (20-25%), 28% ash k Middlings (20-22%), 34% ash k Rejects (28-30%), 60-65% ash Cost of clean coal is about 3 times that of Raw coal price
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June 3, 2014
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Circuit for 1 mt washery
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June 3, 2014
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Purpose of HM Drum & HM Cyclone in the Second Stage
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June 3, 2014 Cut Densities for HMB & HMC
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June 3, 2014 Quality of Clean coal
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June 3, 2014 Washed Coal Analysis Petrographic Analysis Mean Ro % 1.27 Vitrinite %53.2 Semi Vitrinite % 4.8 Exinite % 0.3 Inertinite %31.5 Mineral Matter %10.2
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June 3, 2014 Washed Coal Analysis Chemical Analysis Moisture % 0.9 Ash %18.3 V. M. (%dmf)21.0 S.I. 5.0 Max Fl. (ddpm) 150.0
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June 3, 2014 Washed Coal Coke Property Porosity %48.5 CRI12.6 CSR72.9 M 40 82.6 M 10 9.8
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June 3, 2014 Effect of Change in Raw Coal Ash on Clean Coal Yield
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June 3, 2014 Predicted cleans from Raw coals of varying ash values
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June 3, 2014 Predicted Cleans Vs. Raw coal ash 3234363840 Raw coal ash,% 20 25 30 35 40 Yield at 17.5% ash o o o o Y = 60.3 - 0.9 ash
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June 3, 2014 Thank You
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