June 3, 2014 Beneficiation of LVC Coal in India A Challenge Dr Kalyan Sen, Director Central Fuel Research Institute Dhanbad
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 mt Non- coking Coking Others
June 3, 2014 COKING COAL FOR METALLURGICAL USES REQUIREMENT : 25mt /yr. IMPORT ( ) : 10.6mt SHORTFALL : < Depletion of good upper seam coal < high cost of underground mining ( )
June 3, 2014 LVC Coal Scenario in India Low Volatile Coking 50% of Total Coking Coal 15,680 mt Available Resource Alternative Proposition
June 3, 2014 LVC Coal Scenario in India Annual Production ( 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)
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
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
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
June 3, 2014 LVC Coals Presently NLW grade Unwashable ! Formidable to wash !
June 3, 2014 Liberation Potential of GOCP Coal Raw coal X 75mm & deshaled Deshaled coal X 13mm
June 3, 2014 Liberation of coal/ mineral particles by progressive size reduction is insignificant
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
June 3, 2014 Theo. Yield of products from GOCP coal Ash,% Yield,% 2- product separation Cleans ~30% of ash 18% Rest ash 45% ( sale value ? )
June 3, 2014 Theo. Yield of products from GOCP coal Ash,% Yield,% Cleans ~30% Ash 18% 3- product separation Rejects ~20% Ash 60% Middling 50% Ash ~41% ( fate? )
June 3, 2014 CFRIs Concept 4 Sp.Gravity based Washability Model 4 Limiting Characteristics Ash 4 Multi-stage washing
June 3, 2014 Density-wise mass distribution of GOCP Coal ClaensRejects Foundry Coal Power Coal 4- product separation
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%)
June 3, 2014 Technological Solution
Issuies for Attention c Economics of Clean coal c Washing Circuit c Quality of Product c Effect of Raw coal ash on yield
June 3, 2014 Price of Clean coal at % ash ?
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
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
June 3, 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
June 3, 2014
Circuit for 1 mt washery
June 3, 2014
Purpose of HM Drum & HM Cyclone in the Second Stage
June 3, 2014 Cut Densities for HMB & HMC
June 3, 2014 Quality of Clean coal
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
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
June 3, 2014 Washed Coal Coke Property Porosity %48.5 CRI12.6 CSR72.9 M M
June 3, 2014 Effect of Change in Raw Coal Ash on Clean Coal Yield
June 3, 2014 Predicted cleans from Raw coals of varying ash values
June 3, 2014 Predicted Cleans Vs. Raw coal ash Raw coal ash,% Yield at 17.5% ash o o o o Y = ash
June 3, 2014 Thank You