Highwall Mining

Economic & Environment

Friendly Coal Extraction by a Safe

World Class method

Presenter:Mr. Anurag Dixit

West Bokaro, Tata Steel

SlideTata Steel

West Bokaro - Introduction

▪ Total lease hole area : 1740 hectare

▪ Two Mining Quarries - QAB & QSE (RC 5.1MT), Two washeries (CC 2.4MT) & Thermal Power Plant (2X10 MW) &

Logistics infrastructure

▪ World class Maintenance facilities for HEMM (Caterpillar, Hitachi, Komatsu, ReCP etc.)

▪ Residential colony with facilities like schools, Banks, hospital and modern amenities including recreational facilities.

▪ Surrounding rural areas developed by TSRDS for infrastructure, livelihood, women/youth empowerment, health & hygiene.

Jharkhand

Jamshedpur

West Bokaro

200 km

Kedla Laiyo

West BokaroColliery

Chainpur Railway Station

Danea Railway Station

KBP

Jhumra Hill

To Hazaribagh

To Lalpania

To Ramgarh

Kedla Washery

Ramgarh Bokaro

To Gomoh

To Barkakhana

KOTRE BASANTPUR & PACHMO

Ramgarh Bokaro

Lalgarh

Parej

PundiGose

CCL Lease

Geological Location :Situated under : West Bokaro Coalfields, Dist. Ramgarh.Nearest National Highway : NH 33 (16 kms by road) Nearest Airport: RanchiNearest Railway Station: Chainpur

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SlideTata Steel

West Bokaro Improvement Journey

1947

The year West Bokaro Came into being

1972

Becomes a division of Tata Steel. Modernization Phase I

1982

Modernization Phase II

1994

Modernization Phase III

2006

1.9 mtpa clean

Underground Opening of Interim Quarry Opening of New Quarry with higher capacity Machineries

0.3 mtpa RC

throughput

0.6 mtpa RC

throughput

2.5 mtpa RC

throughput

4.9 mtpa RC

throughput

2016

Introduction of Highwall Miner

5.1 mtpa RC

throughput

3

First Coal washery

in Asia (1951)

State of the art

Washery – III

(1993)

State of the art Mining

& Maint. Facilities

(SEB) - 2004

2018

Low density

of Explosives

SlideTata Steel

West Bokaro at a Glance : 5.1MT (RC), 2.4 MT (CC), 18.8 MCum (OB )

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SlideTata Steel

Need for New Technology

▪ A significant quantity of coal gets lost forever at mine boundaries.

▪ Non availability of encumbrance free land (LA / FC / Utilities) for Mining / Extraction of coal.

▪ Limited Coal reserves to meet the captive requirements

{Increased mine life + Environment friendly method +

Reduced cost + Proven technology (to meet statutes)}

x Safety of Man and Machinery

= Highwall Mining

5

SlideTata Steel

Adopting the world class technology

6

2010

2011

2013

2014

2016

2017

Ideas conceptualize

Team visits US Mining sites

Feasibility Study (Internal)

Design of HWM Panels

(CIMFR + Tech. Partner)

HWM Assembly at Site

HWM Operation Stabilizes

2005 Trigger of the need

FY’18 = 0.5 MT

• Resource estimation for potential extraction

• Sequence of Panels for HWM deployment

• Collaborate with technological partners

• Web pillar’s empirical design by Sheorey

equation ( CIMFR )

• Grant of DGMS permissions

• Integration of HWM and Open cast running

operations (First of its kind simultaneous

operation)

• Developing skills and know how

2015 Integrated Planning (internal)

SlideTata Steel

Highwall Mining at West Bokaro

Highwall Miner :

▪ Remotely operated cutter head goes underground (Near

horizontal) = no underground exposure to personnel

▪ Extraction by parallel drivages (300m length) leaving coal

web pillars = Provides stability to strata

▪ Ventilation / Roof support not required as no exposure to

the people. = Ergonomic ease in operation

▪ No drilling or blasting hence no vibration/ noise to the

people. = Friendly neighbor hood for operation

▪ Ascending operation : facilitates simultaneous in-pit

overburden dumping = Compaction with Added Stability

▪ First of its kind – simultaneous operation alongside open

cast = Robust Integrated Planning : Reduced Cost

▪ Automation and Digitalization = Advanced safety

interventions

▪ Less Manpower = Single digit in number of people working

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SlideTata Steel

➢ Cutter head (1.5m to 4.5m x 3.5m)

➢ Push beams

➢ Push beam transfer mechanism

➢ Screw Conveyor

➢ Chain Conveyor (RAC)

➢ Operator cabin

➢ Loader / Stacker conveyor

➢ Jack Pad & Crawler

Dimensions / Specs :➢ Length base 16.6 m

➢ Width base 8.3 m

➢ Length push beam 6 m

➢ 49 pushbeams per miner

➢ Max. force

✓ Push in: 210 t

✓ Pull out: 410 tPush Beams

Highwall Miner : Components

Operator Cabin

Cutter Head

Push Beam &

Transfer Mechanism

Coal Transfer

Mechanism

Loader

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SlideTata Steel

Highwall Component :

9

Features Specifications / Details

Cutter Head Cutting height 1.5m to 4.5m

Gathering System Two Gathering arms to collect coal

Horizontal Control Up and Down controlled by lower shear return point

Cable reeling drum Armored protection of power cable, hoses, pipes

Navigation & Steering Fibre Optic Gyro Compass in Cutter head, PLC operated steering

arms

Electric Controls Electrical switchgears operated on Electrical Control Module

Continuous Video Monitoring For real time feedback and control

Hydraulic Control Provided with explosion proof solenoids

Water Spray Interlock Cutting stops when water pressure is below required pressure

Failsafe Methane Monitor Interlocking of methane sensor, If exceeds 1.25%, Power to cut off

SlideTata Steel

Highwall Miner – Operating principle

➢Seam is penetrated by a continuous miner propelled by a

hydraulic push beam transfer mechanism.

➢Cycle includes pushing forward, raising and lowering of the cutter

head boom to cut entire length of coal

➢Push beams of 6 m are placed in between cutter head and power

head as depth of penetration increases

➢Using video imaging and gamma detector, the cutter head moves

inside the seam and cut only coal

➢All functioning is controlled from a touchscreen panel located in

operator cabin.

➢Small crew operates the whole system.

West Bokaro HWM :

➢ Penetration up to 300 meters

➢ Seams of 0.8 m to 4.5m, typical 1m to 3m

➢ Gradient of up to -8 degrees and +15

degrees

➢ Highest Monthly production – 75KT

➢ Operates with 6 man crew

➢ Coal Recovery : 30% – 65%

➢ Simultaneous in pit OB dumping

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SlideTata Steel

Safety Management at Highwall

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o Slope stability Radar for real time slope monitoring (Digital)

o Methane detector for real time methane emission

o Bench monitoring using total station

o Subsidence and slope monitoring at the pit edge / surface

o Bore hole extensometer monitoring to know movement if any

o A protective bund to arrest small boulder’s accidental fall

o Regular dressing down of loose boulders to a height of 5-10m

o Placement of Machine 15 m from the high wall

o Access control / Temporary fencing to prevent entry

o Acceptable limit of Hole deviation is within 0.2%

o On board cameras and sensors working during the extraction

o PLC based Steering Arms

o Gyro sensors

o Water spraying interlock

Slope Stability Radar:

▪ Continuously measures mine wall

movements with sub-millimetric

accuracy

▪ Provides reliable early warning for

progressive slope movement

▪ All weather conditions

▪ Map the long term evolution of slow

moving slopes

▪ Eagle vision assists to High

resolution images

▪ Triggers automated SMS alerts to

concerned.

Continuous Strata monitoring using Radar

SlideTata Steel

Highwall Mining Performance at West Bokaro

15 24

40

13 15

43 27

67

45 44 26

15 8

36 51

40 37

73 52

66

-

20

40

60

80

Au

g-1

6

Sep

-16

Oct

-16

No

v-1

6

Dec

-16

Jan

-17

Feb

-17

Mar

-17

Ap

r-1

7

May

-17

Jun

-17

Jul-

17

Au

g-1

7

Sep

-17

Oct

-17

No

v-1

7

Dec

-17

Jan

-18

Feb

-18

Mar

-18

Monthly HW Coal Production Figs in KT

+36%

Jan

450

Dec

243

Nov

272

Oct

344

Sep

273

Aug

106

Jul

144

Jun

220

May

303

Apr

305

FY

18E

3,190

FY

17

2,344

Run Hour

KPI Apr’16 Jan’18

Run Hour Per day 7.5 9.6

OMS 20 56

Productivity TPH 136 163

MTTR 25 10

MTBF 51 28

Sp Power 3.6 2.2

355352400368294

FY

17

3,752

-21%

Jan

157

DecNov

180

Oct

51

SepAugJulJun

131

May

185

AprFY

18E

2,965

B/D Hours

Challenges Actions taken

Frequent

breakdowns

• Timely replacement of Belly chain, Torque shaft,

Hydraulic pipe

• Optimization of Sumping rate

Face preparation • Advanced Face Planning

Marching delays • Advanced Backfilling to avoid to and fro marching

Power issues • Dedicated power supply

Blasting delays • Maintain time & Provision of blasting shelter

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SlideTata Steel

Economic :

➢ Additional coal from ultimate pit

limits and from constraint area

➢ Less operational cost.

➢ Lessen the burden of imports.

➢ No sizing cost for processing

➢ Homogeneous feed to plant

Social :

➢ Reduces impact of vibration, Dust,

noise pollution in nearby areas.

➢ Extraction of coal from sensitive

areas.

➢ Reduces indirect struggles to get

clearances for land.

Environmental :

➢ Silent mining with minimum impact.

➢ Continuous Monitoring of methane.

➢ Dust suppression system

➢ Interlock of methane sensor (PLC)

➢ Utilization of scarce natural resources.

Safety :

➢ Low man machine interface.

➢ Elevated cabins with cameras.

➢ Blast free technology.

➢ No underground exposure.

➢ Digitalized monitoring

Benefits

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SlideTata Steel

Way Forward / Recommendations

▪ New technology in India

▪ Most promising technology as many open cast mines in India will reach to its ultimate pit slope in next 10-15 years

I

➢ Proven technology to extract blocked resources from its boundaries.

➢ Planned to extract 1 MT coal from the highwall of West Bokaro - differential cost benefit.

➢ Recoveries can further increase from 35% to 50% by backfilling.

➢ Technology suppliers of Highwall miner to enhance knowledge & skill of manpower (workers and executives).

➢ Maintenance support on spares availability and troubleshooting etc. from technology suppliers.

➢ Corporate initiatives to study and understand the benefits of this technology for mining practitioners.

➢ Policy makers to incentivize the introduction of Greener and safer technology to increase the available resource.

➢ Technology suppliers, policy makers & corporates to come together to improve sustainability of mining industry.

Its matter of time and we will see usage of better technologies

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SlideTata Steel 15

Hope have added some value !