The Singareni Collieries Company Ltd.

CONCEPTUAL REPORT OF LAKSHMIDEVIPET LONGWALL

1.0LOCATION

The Lakshmidevipet Longwall Project is carved out of two geological blocks viz., Lakshmidevipet – Palampet Block and Peddapur Block in the north-western part of Mulugu Coal Belt. These blocks fall in the Venkatapur Mandal of Warangal District of Andhra Pradesh in Godavari Valley Coalfield. The Lakshmidevipet Longwall includes Sector B of Peddapur Block and Lakshmidevipet Sector of Lakshmidevipet – Palampet Block.

The Mine Block is bounded by North Latitude18017’ 55’’ to 180 20’ 35’’ East Longitude 790 55’ 19’’ to 79059’ 28’’. It is covered in Survey of India Toposheet No.56N/15.

2.0 COMMUNICATION

Mallayapalli -Laxmidevpet PWD road which connects the Pasra-Ghanpur PWD road at Palampeta is passing through the central part of the Laxmidevpet Sector. Nearest railway station is Jammikunta, 50 Km away from LaxmidevpetVillage as crow flies. Pasra-Ghanpur PWD road is passing at 6 Km away towards south of the block. The district head quarters Warangal, is located about 70 Km South east of Bhopalpalli.

3.0 PHYSIOGRAPHY

The ground level varies from 188.83m above Mean Sea Level (MSL) to 237.33m above Mean sea Level (MSL). In general the area is of gentle undulatory.

4.0. LAND USE PATTERN

Out of the total Mine block area of 9.258Sq. Km (3.018 Sq Km Sector B of Peddapur Block and 6.24 Sq Km Laxmidevipalli Sector) about 1.35 Sq Km is covered by the Lakshmidevipet reserved forest. The remaining area of 7.908 Sq km is Non forest land. Out of which 0.227 sq Km is under habitation i.e. three villages Porkapalli, Anandapur and Patwaripalli.

4.1. SURFACE FEATURES

Most of the area is covered with paddy fields and forest area. The surface features are three villages (Porkapalli, Anandapur & Patwaripalli), seasonal small nallahs, three small tanks, power line and the PWD road connecting Mallayapalli to Palampeta.

5.0MINE BOUNDARIES

The Mine block boundaries are

  1. NNW-ESEBoundary fault
  2. South WestIncrop of IVA seam
  3. South EastFault F3-F3
  4. North westsplit line of III seam in Peddapur Block

6.0GEOLOGY AND STRUTURE

Barakar and Barrren measure formations are exposed in the mine block.

Total about 128 boreholes have been considered for the assessment, out of which 39 are in the sector B of Peddapur block & 89 are in Lakshmidevipet sector. The borehole density is 13.8 BH/ Sq km.

The general attitude of the coal measures is WNW to ESE with corresponding north easterly dips. The gradient of the seams varies from 1 in 2.8 to 3.3. The entire block is virgin.

6.1 GEO-ENGINEERING PROPERTIES

Studies on geo-engineering data indicated that the roof rocks of all seams of Peddapur Block are poor to excellent and roof rocks of all seams of Lakshmidevipet are Fair to Good.

PEDDAPUR BLOCK

Seam / Compressive strength of roof rock in Kg /sq cm / Roof / Floor
IA / 79-312 / Fine to Medium grained Grey white sandstone / Medium to coarse grained Grey white sandstone
I / 95-340 / Medium to coarse grained Grey white sandstone / Fine to Medium grained Grey white sandstone
II / 112-676 / Fine to Medium grained Grey white sandstone / Fine to Medium grained Grey white sandstone

LAKHSMIDEVIPET SECTOR

Seam / Compressive strength of roof rock in Kg /sq cm / Roof / Floor
IA / 259-405 / Medium to Course grained Greywhite sandstone / Sandstone/ shale /carb. shale
I / 170-583 / Medium to Course grained Greywhite sandstone / Sandstone/ shale /carb. shale
II / 172-543 / Sandstone/ shale /carb. shale / Medium grained Grey sandstone
IV / 223-666 / Medium to Course grained Greywhite sandstone / Sandstone/ shale /carb. shale

7.0DESCRIPTION OF COAL SEAMS

7.1 SEAMS PRESENT

Total 10 seams are present in Peddapur Block namely, IB, IA, I, II, IIIB, IIIA, III (split into two sections), IVA & IV and Index below IV. 13 coal seams are present in Lakshmidevipetsector viz. IB, IA, I, Index, II, Index, IIIB, IIIA, III, IVA, Index, IV and Index band.

7.2 SEAMS ASSESSED

IB, IA, I, II, III (Top section) and III (Composite) are assessed in Peddapur Block. Where as 6 seams are assessed in Lakshmidevipet sector namely IA, I, II, III, IVA, and IV seams

7.3 DETAILS OF COAL SEAMS OF LAKSHMIDEVIPET BLOCK

Seam / Depth / Usual Thickness / Parting
IV / 34.55-367.53 / 1.2
11.36-25.90
IVA / 37.60-352.70 / Not considered
26.03-36.50
III / 38.85-320.20 / Not considered
61.50-70.54
II / 35.90-297.35 / 2.0
30.81-41.30
I / 43.40-277.00 / 2.5
23.38-33.10
IA / 39.10-246.20 / 1.5

7.4 DETAILS OF COAL SEAMS OF PEDDAPUR BLOCK

Seam / Depth / Usual Thickness / Parting
III (Top) / 52.33-352.80 / Not considered
52.52-72.50
II / 37.00-340.00 / 2.0
24.10-38.90
I / 49.45-332.69 / 2.5
27.85-33.49
IA / 36.11-296.60 / 1.5
16.45-22.60
IB / 44.55-275.84 / Not considered

8.0GEOLOGICAL & EXTRACTABLE RESERVES OF WORKABLE

SEAMS

In Sector B of Peddapur Block, IB seam& III seam are thinned down to less than 1m. No. IB seam has attained workable thickness only in 6 Boreholes and No. III seam has attained workable thickness only in patches. Hence these two seams are not considered for extraction.

In Lakshmidevipet sector, most of the area of III & IVA seams is also thinned down to less than 1m. Hence these two seams are not considered for extraction.

The details of reserves of workable seams/ sections are presented below.

Seam / Geological Reserves(Mt) / Extractable
reserves (Mt) / Grade
IA / 9.778 / 3.91 / D
I / 18.718 / 9.46 / F
II / 19.815 / 9.31 / F
IV / 12.444 / 6.23 / C
Total / 60.755 / 28.91

The total extractable reserves in Lakshmidevipet mine are around 28.03 Mt.

9.0METHOD OF WORK

Longwall retreating with caving is chosen as the principal method of mining in all the seams for the following reasons.

a)Large extent of property

b)Potential for Bulk production

c)To work in steep gradients with better strata control

d)Higher percentage of extraction & productivity

e)Concentrated workings and higher standards of Safety

10. MODE OF ENTRIES

Four tunnels are proposed from surface, two to No. IV seam & two to No. II seam for coal transport, conveyance for men, haulage and ventilation. Further two additional inter seam tunnels would be driven from II seam to IA seam to work in IA & I seam.

10.1 MINE VENTILATION

Four Inclines will serve as Intake airways and one return air shaft is proposed up to IV seam by connecting all seams.

10.2COAL TRANSPORT

From II seam and IV seam trunk belts are plannedupto surface. On surface, a bunkerage of 2000T is provided. Coal from IA & I seam will be transferred to II seam trunk belt through CCD (central coal drift)

10.2PUMPING AND DRAINAGE

Two main sumps are proposed in II seam and IV seams. Water from IA seam and I seam will be conveyed to main sump of II seam through boreholes.

11.PRODUCTION CAPACITY AND TECHNOLOGY

The production capacity of the project will be about 1.5 MTPA. To achieve this,Two Longwall units suitable to 1.2-1.5m & 2.0-2.5m height of extraction along with 3 Road headers and 3 Nos of SDL are envisaged.

12LIFE OF THE PROJECT

The life of the project will be around 22 years including construction period at a production rate of 1.5 MTPA.

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1 Rampuram shaft project