High Capacity Underground Coal Mining (L15)

1
High Capacity Underground Coal Mining (L15)

• A joint project (Scoping Study) between CSIRO
  Exploration Mining and University of
  Queenslands Sustainable Minerals Institute (SMI)

2
Scoping Study Objectives

• Benchmark current practices and determine what is
  needed to achieve a high capacity underground
  coal mine (15Mtpa) and optimisation of existing
  operations
• Report on strategic research directions needed to
  support future high capacity mining.
• Identify specific, high impact research and
  development projects to facilitate high capacity
  mining.
• Identify opportunities for operational, technical
  and postgraduate training in areas relevant to
  high capacity coal mining

3
Process

• Develop a predictive model (15Mtpa coal mine) on
  which comprehensive research proposals would be
  dependent. Incorporates LW productivity,
  utilisation, seam characteristics, development
  requirements, sensitivities and cost model.
• Considerations included 1.8 4.5m seam
  thickness LTCC and multi-seam operation
• Segregate the overall strategy into 7
  sub-categories for further study, under the
  respective objectives
• Provide separate reports addressing the
  requirements of the scoping study

4
15Mtpa model identified key issues

• Criticality of system uptime
• High shearer speed/power to deliver tonnages
• Support hydraulics for rapid support cycle times
• Optimise cutting cycle uni-di bi-di half web
• Development rate increase
• Improved coal clearance for minimal bottlenecks

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Coal Resources and Deposit Delineation
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Coal Resources and Deposit Delineation
Update of UNSW thick seam database from public
sources (113 mines-330 point source data)
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Research Direction

• To create confidence that a deposit will be able
  to host a 15Mtpa operation requires integrated
  analysis of geologic data across company
  boundaries at the district scale, similar to that
  in the ACARP Supermodel 2000 project
• High tonnage longwall operation will require
  enhanced interpretation of structure and
  interburden characteristics
• Multi-scale modeling of fault geometries and
  simulation of behaviour under variable rock mass,
  stress and mining methods

8
Geological and Geotechnical Assessment and
Support
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Current Status

• Greater propensity for stability problems in
  thick seams operations
• Geotechnical downtime generally occurs
  comparatively more frequently on the face (a
  shift from gateroads)
• Geophysical methods of rock mass characterisation
  are preferred but there is a lack of experienced
  people to interpret the information
• Typically 1-2 normal faults per panel

10
Research Direction

• Implementation of real-time face and gate road
  Smart monitoring which includes interpretation
  and control measures
• Determination of interaction between cutting
  height and operational characteristics
• Interaction of seams in multi-seam operations
• Enhanced fault detection and definition for
  mining through in-panel faults possibly
  utilising microseismic technology

11
Roadway Development Systems
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Current Status

• Later generation, best practice mines with good
  conditions could attain 15Mtpa mines without
  major developments in mining equipment and
  systems
• Infrastructure limitations will constrain older
  mines from making major improvements in mine
  capacity, while adverse conditions generally
  associated with depth pose additional
  productivity challenges to these mines (and to
  later generation mines as they mature)
• Technology developments are currently underway
  that are likely to address a number of key
  process constraints in the short to medium term,
  thus providing the potential to improve system
  capability across all mines

13
Specific Research Projects

• Extensible (monorail mounted) face services (e.g.
  ventilation, power, water, compressed air, pump
  out)
• Integrated development mining system
• Extensible, self advancing coal clearance system
• Alternative skin reinforcement and confinement
  measures
• Complementary technology developments including
  automation and robotics, machine guidance
  systems, light weight materials, face pumping
  systems, roadway construction and consolidation

14
Projected Gains
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Gas and Ventilation
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Longwall Gas Emissions Related to FaceProduction
17
Research Direction

• Gas Drainage
• Extensive pre-drainage of gas including
  optimisation of MRD gas holes for
  pre-drainage/deep gas drainage technology and
  stimulation
• Coordination and cooperation with petroleum and
  gas developers to utilise/reduce gas reservoir
• Optimise goaf inertisation strategies for
  operational use including exclusion foams

18
Research Direction

• Spontaneous Combustion
• Development of low impact inertisation systems
• Heat
• Development of heat extraction techniques for
  fixed and possibly mobile plant
• Dust
• Optimise coal seam water injection techniques
  prior to mining

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Water Management
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Current Status

• Water Consumption
• Highest users have the highest losses lowest
  users have the lowest losses
• Water Inflow
• Typical inflows range from 3-5 Ml/day some up to
  15Ml/day

Water use ML/Mtpa Water loss ML/Mtpa
Range 55 192 29 180
Average 130 90
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Strategic Research Directions

• Reduction in water consumption and variability
  through integration of research into water usage,
  management and technology
• Integrated approach to hydro-geology and
  geotechnical aspects
• Underground water recycling and reuse technology

22
Longwall Face Equipment and CoalTransport
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Current Status

• Current equipment is capable of delivering at or
  about the 15Mt target
• Average production from the top 5 mines based on
  the last 3 years was 4,647,660 tonne
• The average cutting hours per year calculated
  from the 8 mines studied over the last 3 years
  was 2745 hours
• The average output per hour from the longwall
  faces was 1693 tonne

24
Current Status

• Longwall faces cut for only 31 of the total time
  in a year
• Breakdown maintenance outweighs planned
  maintenance by 4 to 1
• The shearer, panel belt and AFC, respectively,
  are the largest contributors to down time
  totalling over 50
• Planned maintenance effort does not reflect the
  downtime statistics and is ad-hoc

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Downtime Breakdown
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Research Directions

• Further development and implementation of face
  automation
• Effective analysis of monitoring data on a real
  time basis for maintenance purposes
• Real-time maintenance prioritisation system
• New sensors and systems for condition monitoring

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Licence to Operate
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Specific Research Projects

• Assessment, prediction and validation of the
  impact of increased mining height and width on
  local and regional water resources and catchments
• Development of realistic and achievable
  engineering controls for dust, noise and heat
  management
• Assess and validate current subsidence prediction
  methodologies for high capacity contexts