steven chandler, yancoal technology development
TRANSCRIPT
12th Annual Longwall Conference
Design and Concept of Longwall Top Coal Caving from
Austar Coalmine to North Goonyella Coalmine
Introduction
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Speaker
Steven Chandler
• Initial Longwall Top Coal Caving kit at Austar Coalmine
• Phase 2 Longwall Top Coal Caving kit at Austar Coalmine
• Phase 3 Longwall Top Coal Caving Kit North Goonyella Coalmine
• Phase 4 ( Proposed ) at Austar Coalmine
• Future Developments of LTCC in Australia
Initial LTCC at Austar Coalmine
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Design for the Austar 2 leg shield was developed in China by the Yanzhou
Mining Company ( Part of the Yankuang Group )
Yankuang Group owned the patent for the 2 leg LTCC Shield
Yankuang Group and DBT developed the 2 leg caving shield and manufactured to DBT Standard
Yankuang purchased Austar Coalmine to Introduce LTCC System of mining to the western world
Austar face first full face of 2 leg caving shields in the world
Initial LTCC at Austar Coalmine
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• Greta Seam Coal Measures
– 5.5m – 7m thick
– low strength (5 - 8MPa)
– Immediate 15m of roof laminated (20-60MPa)
• Immediate floor soft mudstone (20MPa)
• Geotechnical Issues
– seam highly cleated and jointed
– inseam shear zones
– High horizontal stresses (40-50MPa)
• Operational Issues
– 1m of coal in the floor on development
– LTCC requires 8.5m to 9.5m wide installation roadway
Initial LTCC at Austar Coalmine
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• LTCC Kit had to be down rated
The Drift is the largest constraint on the capacity of the mine
• The same drift infrastructure is still operating today
• Drift belt capacity 1000t/hr
• Maximum load for drift winder 54 tonnes
• Envelope for drift transport 3250mm x 2400mm
• Caterpillar ( DBT then Bucyrus ) & Yancoal worked closely with the design of the equipment to allow it to be stripped into manageable size units
• Selecting and educating the Longwall crews to extract the above horizon .
Initial LTCC at Austar Coalmine
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MG ROADWAY
SUPPORT
REAR AFC
DISCHARGE
FACE SHIELD
FRONT AFC
CRUSHER
BSL
Initial LTCC at Austar Coalmine
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Initial LTCC at Austar Coalmine
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• EL 2000 Shearer
• 540 kW AFC Motors with KP 45 class CSTs Chain speed 1.1m/s
• 400kW Crusher and BSL motors Chain 1.5m/s
• 2 x leg 1900/3500 mm 971 ton shield
• Canopy Ration of 2.3 :1 Leg angle of 12 degrees and caving angle of 29 degrees
• 6 leg Gate end shield
• AFC centres of 6.9m with bent rear AFC
• Open Bottom Rear AFC pans 1142 mm PF 5 42mm chain
• 1342mm BSL
• 150m face for A1 Panel the 220m A2 Panel
• PMCR electro Hydraulic shield control
• BSL Current control
Phase 2 LTCC at Austar Coalmine
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The opportunity for this was the re-handing of the Kit for Area 2
Improvements implemented
• Move the Rear Tail gate drive from the end of the face to 4 shields into the block
• Rear TG drive on a base plate with tunnels
• Introduce 4 larger capacity 4 leg shields operating 1 web back at the Tail gate end of the face
• Introduce the Cross frame and P drive onto a 1542mm base for the Rear AFC MG Drive but the BSL is only 1342mm, extra room for coal flow past front drive
• Introduce 2 x 4 Leg Buttress shields into the Maingate inbye of the cross frame
• Shorten the Roadway shield and position at highest abutment area of the Main gate roadway
• Straighten the Rear AFC and decrease the AFC centres to 6.150m
• Lower the TG drive and apply 3.5 degree attack angle to the bed plate
• Flatten out the Rack bar at the MG so the shearer does not lift
• Introduce Big Foot ( a hydraulic stab jack) to Lift the Goaf side of the Front MG drive
Phase 2 LTCC at Austar Coalmine
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Phase 2 LTCC at Austar Coalmine
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Phase 2 LTCC at Austar Coalmine
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Phase 2 LTCC at Austar Coalmine
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Phase 3 of the LTCC North Goonyella Coalmine
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• The Yancoal / Peabody LTCC project provided to opportunity to develop and
implement phase 3 of the LTCC equipment .
• A detailed review of the Austar kit identified many areas of improvement, with
these implemented into the design with Caterpillar for the North Goonyella
equipment to improve reliability, efficiency and maintainability.
• 1000mm web was selected due to following reasons
1. Lower extraction height improved roof strength ( thicker beam, Austar Mine )
2. Increased support density of the new shield
3. Shield Lower . Advance . Set. operating one shield behind leading drum
4. Variable cutting cycle designed to assist with face conditions and production
Phase 3 of the LTCC North Goonyella Coalmine
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New equipment design to improve the efficiency of the LTCC performance.
• In-line rear AFC drive unit ( AFC centers 7.150m with both AFC parallel )
• 3 leg special gate end shields with increased advance force on the DA ram
design ( to improve support density at gatends )
• Cross – frame rear M/G drive arrangement
• Side shift cylinder from rear of No 3 shield to base plate of rear AFC cross frame
• Mono rail mounted pump station
• Double ended Pump motors with pumps mounted on both ends
• Fully automated cutting and caving cycle with automated Dust control
• Closed bottom rear AFC with Coal saver attached to improve recovery of Top
coal
Phase 3 of the LTCC North Goonyella Coalmine
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Due to the difficult Middle Goonyella seam the Run of face shield design was
improved to provide a higher support density
These are
• Shield centres 2050mm
• Increased Cylinder leg size to 450mm
• Improved shield hydraulic circuitry to reduce return pressure
• Leg angle increased slightly
• Caving Canopy angle increased slightly
• Canopy ratio 2.29 :1
• Caving door position constant thru height range
Phase 3 of the LTCC North Goonyella Coalmine
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North Goonyella Mine
Run of face shield Austar Mine
Run of Face Shield
Phase 3 of the LTCC North Goonyella Coalmine
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Phase 3 of the LTCC North Goonyella Coalmine
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Phase 3 of the LTCC North Goonyella Coalmine
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Phase 3 of the LTCC North Goonyella Coalmine
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• Tons per metre /Shear = 2512 tons
• Sheared Coal = 1542 Tons Caved Coal = 970 Tons
• 305m face , 3000t/hrs system
• 1200Kw drives on the AFC with 600Kw drives on Crusher and BSL
Phase 4 ( proposed) LTCC at Austar Coalmine
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• Replacement of the 6 leg shield with the 4 leg shield
Phase 4 ( proposed) LTCC at Austar Coalmine
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Future Development of LTCC Equipment
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• Reduce the Length of the Rear Tail gate Drive unit
• Design Walking Tailgate roadway shields
• Onboard shearer dust scrubber
• Determine the most efficient cut to cave ratio
• Determine the most efficient face length
• Mobile fleet that can efficiently relocate the size of the current LTCC kit
• Reduce the amount of coal left in the Goaf
• Improve Maintenance Strategies to achieve higher engineering availabilities
• Therefore higher % utilization and higher productivity at lower cost .
Conclusion
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• Australian coal companies need to embrace this concept
• Maximize Resource Recovery
• New Technology concepts developed from the Operators
• The Operators work closely with the Designers from Caterpillar to improve the
design of the equipment
• Keep the Process Simple
• Maintain High Operational and Engineering Standards
• Automation