Mid semester presentation

TITLE OF THE PROJECT: Study and Performance of Surface miners

and Roadheaders and prospect of combining them in terms of cutting soft

and hard rocks

Under the supervisionof

Dr. PANKAJ KUMAR MISHRA

Presented by :ABHINAV SINGH(2014B2A3955G)ANKIT ANAND (2014B5A3672G)ABHIK ADARSH (2014A8PS363G)

SURFACE MINERS• A surface miner is a technology used to extract cut and load soft rock like

coal, limestone, gypsum etc. in a go.• Before surface miners mining techniques were drilling, blasting, loading

which were hazardous.

Advantages of Surface Miner1. It cuts the rock into very small pieces and with great efficiency.2. The capacity of loading trucks increases to a ton.3. Number of loading trucks are reduced as more rock can be

adjusted into the trucks and hence less road traffic is faced and less fuel consumption.

4. Spillage from loading trucks are less and hence no road blocks are formed and less accidents occur.

5. As there is no need of blasting or other hazardous method there is less loss of property and life.

6. Surface miners use water sprinklers during cutting to stop dust from getting generated.

LIMITATIONS OF SURFACE MINER

• Can cut only soft rocks.• Can only work on plains or mildly inclined lands, it

cannot work on rough terrain.• Picks gets damaged regularly and has to be replaced

frequently.• Machine requires very high maintenance and therefore

is costly.• Can work only in open cast mines.

ROADHEADER

What is Roadheader?

Excavating machine consisting of a cutting head, a loading device and a crawler to move the machine

Applicability

For soft to medium strength rocks(can be used for hard rocks by making some structural changes)

Can excavate almost any profile By making structural changes( increased weight, stiffer frame,

more cutterhead power) , it can be used to cut even hard rock Known for its mobility, flexibility & selective mining capability

leading to cost effective operations

Limitations Hard rock cutting ability due to high wear experienced by drag

bits in hard, abrasive rocks. Regular changing of spikes/picks on the cutting head due to

wear and tear. Other maintenance stoppage and cost.

How to overcome these limitations

By upgrading technology. For eg. Using mini-disc cutter(developed by Colorado School of Mines). It cuts hard rocks better and reduces maintenance stoppage. It is currently in its developing stage.

By accurately determining the areas where various types of roadheaders needs to improve by analyzing its performance known as performance prediction.

Performance Prediction It assess the instantaneous cutting rate (ICR), measured in

tons/hr., bit consumption rate, pick consumption rate and machine utilization for different geological units.

Extensive database available related to field performance (released by Colorado School of Mines)

Conclusion of Database Study

ICR=27.511 X e^0.0023 X(RPI)

RPI=(P X W)/UCSRPI=Roadheader Penetration IndexICR = Instantaneous Cutting RateP = Cutterhead PowerW= Roadheader WeightUCS =Uniaxial Compressive Strength

Use of sensors in Roadheaders Intelligent Mining Roadheader (IML) technology. 3-D laser scanner system scans the heading face within

infrared system  Integrated signal processor calculates the coordinates of the

coal seam and transfers them to the control of the machine, which determines the next step of excavation.

Features of Surface Miner and Roadheader

Feature Surface Miner RoadheaderUCS (MPa) 80 – 100 100 – 160Cutting Depth (m) 0 - 0.6 0 - 0.5Cutting Speed (m/min)

0 - 25 0 - 6.5

Max capacity (tonnes/hr)

2500 1000

Cutting Width (m) 1 - 5.2 3.6 - 6.15Installed Power (KW) 450 - 1200 500 – 700Engine (HP) 800 – 1600 400 - 530Travel Speed (Km/min)

0 - 5 0 -2.2

Electronics involved in Surface Miner and Roadheader

Sensors used in The Control system

• Cable Sensors – Scanning the distance to a reference plate sliding on the surface

• Non Contact ultrasonic sensors – Measuring the distance to the side plate or the surface

• Multiplex Sensors –Levelling uneven surfaces in longitudinal and transversal direction

• Laser Sensors – Working with a transmitter and receiver

Applications and Problem faced• Surface Miner – Soft Rocks• Roadheader – Hard Rocks

Problem – Roadheader (Hard Rock Cutter) is costly and we can’t use Surface Miner to Cut Hard Rocks

Picks Diagram of Surface Miner and Roadheader

Future Works• Double Pick Layer – Rock type sensed and related layer

coming out• Hard rocks can be detected by sensors, video imaging or

CID( Coal-rock Interface Detection)• Softening the Hard Rocks

• Special liquid using certain plants • Soapy water with salt – Iodine in salt will soften the Hard

Rock• Water jets can be used to weaken the hard rock.• Laser technique can be used to weaken the hard rock

structure.

References•A study into the influence of intact rock and rock mass properties on the performance of surface miners in Indian Geo mining conditions by Dr. AMAR PRAKASH

•Application of surface miner in Indian Coal Mines by Samrat Dutta

•Roadheader applications in mining and tunneling industries by H.Copur , Ozdemir, Rostami.(Colorado School of Mines)

•Website- http://www.iml.fraunhofer.de

THANK YOU!