Coal Beneficiation for Clean Coal Coal Beneficiation for Clean Coal

TechnologyTechnology

Dr Kalyan SenDr Kalyan SenDirector Director

Central Fuel Research InstituteCentral Fuel Research Institute

Dhanbad 828108Dhanbad 828108

Figure: Particle Size distribution for Indian coalsPSD of Indian Non Coking CoalsPSD of Indian Non Coking Coals

Figure 6a : Variation of GCV of noncoking coals

0

1000

2000

3000

4000

5000

6000

7000

0 10 20 30 40 50 60 70

Ash (60% RH)

GC

V (

Kc

al/k

g)

WCL

SECL

SCCL

MCL

NCL

CCL

Figure : Variation of VM of noncoking coal

15

17

19

21

23

25

27

29

31

33

35

0 10 20 30 40 50 60 70

Ash (60% RH)

VM

WCL

SECL

SCCL

MCL

NCL

CCL

Indian Coal as feed to TPSIndian Coal as feed to TPS

Favourable qualities: Huge reserve

Low S content ( <0.6%)

High AFT (>1100oC) Low Iron content Low Chlorine content Low toxic trace elements Reactive inertinites backback

Characteristic Ash vs RD

0.0

20.0

40.0

60.0

80.0

1.2 1.4 1.6 1.8 2 2.2RD

AS

Hnclcclmclw clLinear (w cl)Linear (ccl)Linear (ncl)Linear (mcl)

VM vs. RD

0.0

10.0

20.0

30.0

40.0

1.2 1.4 1.6 1.8 2 2.2

RD

VM

NCLCCLMCLWCLLinear (CCL)

FC vs. RD

0.010.020.030.0

40.050.060.0

1.2 1.4 1.6 1.8 2 2.2RD

FCNCLCCLMCLWCLLinear (CCL)Linear (NCL)Linear (MCL)Linear (WCL)

GCV vs. RD

0

2000

4000

6000

8000

1.2 1.4 1.6 1.8 2 2.2

RD

kca

l/kg

NCLCCLMCLWCLLinear (MCL)Linear (NCL)Linear (WCL)Linear (CCL)

DSC/TG of Density Fractions

0

510

15

10 20 30 40 50 60

ash%

Rmax

., %

/min

Maximum Rate Vs Ch. Ash

385

390

395

400

405

410

415

420

10 20 30 40 50 60

ash%

DT

G p

eak

, o

C

DTG Peak Temperature Vs Ch. Ash

Figure: Liberation characteristics of LVC & non-coking coal

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25 30 35 40

Cum. Ash%

Cu

m. W

t%

X 100mm

X 38mm

X10mm

WB3 X75mm

WB3 X13mm

LVC coal of Western JhariaJig Cleans

Non-coking coal of SECL

Figure 4b:Range of cut density (d50) for power grade cleans from Indian noncoking coals

0

10

20

30

40

50

60

70

80

90

1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00

Relative Density

Fra

c. A

sh

%

50-55%

R & MR & M

National Programme

STRATEGY FOR ACHIEVING STRATEGY FOR ACHIEVING COAL BASED POWER TARGETCOAL BASED POWER TARGET

Improved Improved Coal QualityCoal Quality

• Mine planning • Assessment• Cleaning• Blending

Advance Advance TechnologyTechnology Larger Units CCT

Technology Routes for beneficiationTechnology Routes for beneficiation

Level Scheme Methodology Ash%reducn

Cleans (%)

M % over ROM coal

I Dry benefin. Separation of stone/shale based on differential breakage potentiality

3-4 >90 Nil

II Crushing, screening & coarse coal cleaning

Coarse coal (13/30mm) washed & mixed with untreated fines; dewatering screens.

<10 70-90 2-3%

III Crushing, screening and total cleaning

Coarser fraction washed at optimum efficiency levels: fine coal by Spiral: dewatering

>10 <60 3-4%

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Achievable yield of washed coal by different level of beneficiation

24 25 26 27 28 29 30 31 32 33 34 35 36 37

Ash, %

60

65

70

75

80

85

90

95

100Yield of Cleans,%

Level III (H

M)

Level

III (

JIG) Lev

el I

I (JI

G)Level I

I (HM)

Rotary

Bre

aker

Raw coal ash 37.0%

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