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CONCEPTUAL REPORT OF MANDAMARRI SHAFT BLOCK
  1. LOCATION

Mandamarrishaft block is situated on dip side of KK-2 Incline to KK-5 Incline. The block covers an area of 13.089 sq.km and comes under the revenue jurisdiction of Mandamarri division of Bellampalli region of Adilabad district of Andhra Pradesh and also falls in the northern part of Somagudem- Indaram coal belt. The block lies between the latitude N18°37’ 47” to 19°01’ 56” and longitude E79°28’53” to 79° 31’ 44” and falls in the Survey of India Toposheet no. 56 N/5.

  1. COMMUNICATION

The nearest railhead is the Mandamarri railway station which is on Kazipet-Ballarshah section of the south central railway and is located about 4 km in South West direction of the block. A railway siding extends up to the KK-5 coal handling plant, which is about 1 km from the block. A coal road joining Bellampalli with Godavarikhani is passing close by connecting all SCCL Mines.The block is also well connected with state capital Hyderabad (270 Km) and the district head quarters Adilabad (180 Km.) by road.

  1. FEATURES WITHIN THE BLOCK AREA

PHYSIOGRAPHY

The area is mostly occupied by gently sloping(2.7m/km) plains with local undulations. The local relief varies from 180m above MSL in the southern part of the block in the hilly area it is as high as 368m above MSL in the Northwestern part of the area.

  1. LAND USE PATTERN

The total area of the block is 13.089 sq.km. Out of which 2.85 sq.km is covered by Indaram reserve forest, Mango gardens and agriculture area is covering about 0.347 sq.km. The existing villages/Hamlets are occupying about 0.07 sq.km. A tank exists in the center of the block in an area of 0.085 sq.km. Palavagu and other streams/nallas are flowing towards west in the block.Palavagu flows over an area of 0.173 sq.km in the block. The rest of the area is barren land. NTPC HT line is passing through the block in the southeast side.

Hyderabad – Nagpur state highway and SC Railway line are passing through North west part of the block

  1. BLOCK BOUNDARIES

North :Proved limit / 200m distance from last set of boreholes.

South:Fault F9-F9

East :Proved limit / 200m distance from last set of boreholes

West :Dip side boundary of KK-2,KK-3 and KK-5 Inclines

  1. GEOLOGY OF THE BLOCK

GEOLOGY

Mandamarri shaft block area forms a part of Godavari Valley Coal field and is situated in the Northern part of Somagudem- Indaram Coal belt. It is located in the north western part of the GodavariValley coal field.This coal belt of 40kms strike length, has been intermittently affected by major faults, givingrise to Somagudem, Mandamari, Ramarkrishnapur Srirampur/Indaram group of mines due to shifting of the in crops of the seams.

STRUCTURE:

Almost entire area of Mandamari dip side block is covered by Barren measures. The Barren measures exposures are mainly confined to central and eastern part of the block, while the northwestern part of the block has scanty exposures. No other formation has been exposed on the surface with in the block limits.The coal seams in general trend N 45°-50°W to S 45°-50°E with a swing of N 25°-30°E to S25°-30°U in the North western part of the block beyond boreholes MEM-44 & 45. The gradient of bedding varies from 1 in 3.7 to 6.3.The area of the block is traversed by a total of nine faults with varying amount of throw ranging between 0m to 1000 + m.

  1. DESCRIPTION OF COAL SEAMS

Six coal seams (IB, IA, I, II, III, IV (top) & IV (bottom)) have been established in Mandamarri Shaft block area.

There are five persistent and minable Coal seams present( IA, I, II, III, IV (top) & IV (bot).

The seams are deep seated and have been intersected in this block from about 92 m to 636 m. The workable seams assessed in the sector-B are IA,I&III seams having usual thickness of 4.50m,1.70m & 2.50 m respectively.Out of 98 nos. of boreholes, 83 nos. of boreholes intersected coal seams fall within the block area, 7 nos. of boreholes are abandoned and thus the borehole density in MandamarriShaft block comes out to 7.49 nos. of boreholes per sq.km.

  1. IA SEAM:It is the top most seam of significant workability and considered for assessment of quality and potentiality. This seam has beenintersected in almostall the boreholes with more than 3.00m thickness. Only in one borehole MEM-14 the thickness is less than3.00m. It occurs below to seam IB with a partingranging in thickness from19.03m to 24.30m.The parting is predominantly constituted of sandstone and occasional clay and shale. The thickness of the seam varies from 2.51m to 5.62m.
  2. I SEAM : It occurs below IA seam with a parting ranging in thickness from 16.08 m to 25.70m predominantly-constituted of sandstone with occasional shale,carbonaceous shale and Carb Clay. The thickness of seam varies from 0.78m to 2.60m.
  3. III SEAM:It occurs below II Seam with a parting ranging in thickness from 11.79m to 28.41m, predominantly sandstone with occasional SH and CSH.The seam intersected in 44 boreholes out of 48 boreholes and the thickness varies from 0.69m to 3.15m. The thickness of majority of the boreholes falls in the range from 1.51m to 3.00m.
  4. IV (top) & IV(bottom)seams are not considered for extraction as the thickness is less.

7.1Thickness and Quality of Coal seams

SEAM / THICKNESS IN M / UHV (K.Cal/Kg) / Average grade
Min / Max / Min / Max
I A / 3.10 / 5.91 / 2428 / 4318 / F
I / 0.54 / 3.41 / 2404 / 5160 / E
III / 0.69 / 3.15 / 3697 / 6043 / C
IV (top) / 0.18 / 1.76 / 29.66 / 6388 / C
IV(bottom) / 0.12 / 2.13 / 2614 / 5727 / D

7.2GEO-ENGINEERING DATA:

Nature of Immediate Roof & Floor

Seams / Immediate roof / COMP.
STRENGTH
(KG/CM²) / Immediate floor / COMP. STRENGTH
(KG/CM²)
IA / SST,Clay,SH
weak to moderately strong / 40 to 490 / SST,SH,CSH
weak to moderately strong / 43 to 325 Kg/cm2
I / SST,SH,CSH,Carb.Clay weak to strong. / 43-775 / SST,CSH
Moderately weak to moderately strong. / 83-458
Moderately weak to moderately strong.
III / SST,CSH
Moderately weak to moderately strong / 51 to 421 / SST,CSH
Moderately weak to moderately strong / 73 to 459

7.3MINE DETAILS:

For the convenience of reserves calculation in Mandamarri shaft block, the block is divided in to five sectors. In which sector-B is considered as separate mine for developing by Longwall method of extraction. The reserves estimated in this Sector are 55.10 MT in 4.94 Sq.Km area. 28 Bore holes were drilled in the Sector- B with a borehole density of 5.67 No.s / Sq.km area and the seams are assumed as Degree- I gassiness.

Mine take area : 4.94 Sq Km

Strike length : 4.00 Km.

Dip length : 1.68 Km.

ForestLand: NIL

Non ForestLand : 494Ha

No of Bore holes drilled: 28

Bore hole density: 5.67 Nos /Sq.Km

Gassiness : Degree I (Assumed)

7.4MINE BOUNDARIES

North: Proved limit / 200m distance from last set of boreholes.

South: Fault F4-F4

East : Proved limit / 200m distance from last set of boreholes

West: Fault F2-F2

8.EXTRACTABLE RESERVES OF WORKABLE SEAMS

The extractable reserves in this Project worked out to be around 32.64 Mt.

Reserves Of Coal Seams Considered For Extraction In Sector-B

SEAM / USUAL THICKNESS(M) / GEOLOGICAL RESERVES
(MT) / EXTRACTABLE RESERVES
(MT)
I A SEAM / 4.50 / 28.56 / 16.93
I SEAM / 1.70 / 10.34 / 6.06
III SEAM / 2.50 / 16.20 / 9.65
TOTAL / 8.70 / 55.10 / 32.64

9.METHOD OF WORK

Longwall method is considered suitablefor extraction of IA, I and III seam in this project due to large extent of property without faults except at the boundaries of the block. However presence of undisturbed property planned for Longwall shall further be confirmed by drilling additional number of exploratory boreholes.

Three Road headersand 3 SDL are required for development of trunk roads andgate roads.

9.1MODE OF ENTRY:

Two tunnels are proposed from surface to No. III seam through IA & I Seam for coal transport, conveyance for men, haulage and ventilation. Chair car is proposed in Manway incline of III seam.

9.2Coal Transport:

Trunk belts are plannedfromsurface to III seam. Coal from all the three seams will be transported through main trunk belt.On surface, Bunkers of 2000T capacity are provided.

9.3Ventilation:

There will be three entries in all for ventilation i.e. two inclines from surface as intake and one return air shaft.Main mechanical ventilator will be provided at air shaft.

9.4 Pumping:

Water from all the seams would be collected at III seam main sump where 3No.s of 265 KW x 750 GPM capacity pumps will be located to deal an inflow of around 1500 GPM to surface and an intermediate sump is planned at 15 L with2No.s of 265 KW x 750 GPM capacity to deal 1500 GPM directly to surface.

10.RODUCTION CAPACITY AND TECHNOLOGY

As presented above the production capacity of the project will be about 1.50MT per year. To achieve this One Longwall unit along with three Roadheaders and 3 Nos of SDLare envisaged.

11. LIFE OF THE PROJECT

The life of the project will be around 24 years including construction period at a production capacity of 1.50MTPA.

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MandamarriShaft block