Quality of Coal

QUALITY OF COAL AND INDUSTRIAL USES:

Lakhra coal is classified as lignite with medium ash, high sulphur and averaging 6057 Btu/lb, 3365 Kcal/kg calorific value. Coal is used as fuel for Lakhra Power Station. Fluidized bed combustion has (FBC) technology has been used in the boiler of the power plant.FBC suitable technique for burning coal with high sulphur content.

ITEM PARAMETERS REQUIRED Applied Basis (%) LAKHRA COAL QUALITY For reference (Applied Basis %)
CARBON

33.04

34.74

HYDROGEN

2.45

2.70

OXYGEN

7.04

9.15

NITROGEN

0.75

0.62

SULPHUR

5.20

4.98

ASH

19.52(maximum 30%)

15.69

MOISTURE

30%

25 to 30%

VOL: MATTER

26.00

28.38

FIXED CARBON

22.48

24.47

CALORIFIC VALUE

3195 kcal / kg

6057 Btu/lb

= 3365 kcal/kg

 COAL ANALYSES DATA

Analysis as received Parameters Required Applied Basis (%) Coal Quality for references (Applied basis) %
Moisture 30%  Fresh coal 25 to 30%
Ashes 19.52 Maxi: 30% 20.44
Volatile matter 30.19 30.13
Carbon 23.19 22.98
Total Sulfur 5.20 4.98
Hydrogen 2045 2070
Oxygen 7.04 9.15
Nitrogen 0.75 0.62
Fixed Carbon 22.48 24.47
Basis as received Content % Average %
H2O 7.04 9.15
Ashes 8.69- 46.35 21.72
C 63.00 -70.40 67.40
H2O 7.04 9.15
S 4.40 – 14.80 9.00
N 1.0-            1.40 1.20
O 14.40 – 19.20 17.20
CI 89 106
Total
PCS indicated as received 3195 kcal/kg 6105Btu/lb/3365 kcal/kg
PCI Net. calculated as received 2871 Kcl/kg 5501 Btu/lb3056 kcal/kg
Hardgrove index 2.45 2.70
Ashes Analysis Content % Average %
SiO2 19.44– 39.36 30.17
Fe203 18.40 – 42.59 29.78
A1203 13.81- 28.27 20.89
Ti02 1.36
CaO 1.92 – 8.42 4.83
Mg0 0.96-2.94 2.24
K20 0.38- 1.99 0.66
S03 1.93 – 12.18 6.44
Na20 0.42 – 2.06 1.08
P205 9.84 — –

COAL RESERVES
Lakhra Coal filed has total 1328 million tones coal reserves, while compact block reserves worked out by Chinese have been estimated as 82.4 million tones as mineable reserves. About half area of LCDC has been granted to a Private Sector Company and about 42 million tones reserves area has been left with LCDC. These reserves are sufficient to meet the coal requirement of the present operating thermal plant for 30 years.

HYDROGEOLOGY
The depth of ground water table is 110.20 meters while elevation of the water table is 20.80 meters. Coal seams are generally above the ground water. Climate is semiarid. Average annual rainfall is 20 to 30 cm. Rainfall recharge to the aquifers is very limited. The ground water is sulphate-chloride water with excessive mineral intensity.

COAL SEAM:
Significant coal beds are three i.e. Dhanwari, Lalian and Kath. Lalian seam is thickest and persistent in comparison to two other coal seams. Its thickness varies from 0.75 to 2.5 meters and average thickness is 1.5 meter.

Leave a Reply

Your email address will not be published. Required fields are marked *