spontaneous combustion testing for hazard management planning dr b basil beamish mausimm cp (min)...
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Spontaneous Combustion Testingfor Hazard Management Planning
Dr B Basil Beamish MAusIMM CP (Min) RPEQTechnical Director
CB3 Mine Services Pty Ltd3/20 Archerfield Road, Darra Qld 4076
T: +61 7 33754100M: +61 488 708 949
[email protected] Conference and Exhibition on Occupational Health and Safety in Mines -
Istanbul December 2014
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Presentation outline
• The Sponcom process and requirements for a Principal Hazard Management Plan
• Assessment of self-heating propensity in Australia
• Examples of spontaneous combustion testing results and interpretation for mine planning
• Conclusions
Sponcom process(Moreby and Chalmers, 2006)
International Conference and Exhibition on Occupational Health and Safety in Mines -
Istanbul December 2014
RETAINED LOST
Intrinsic and extrinsic factors determine reaction rate
Coal + O2 CO, CO2, and H2O + HEAT
CONVECTION
CONDUCTION
EVAPORATION
INCREASES REACTION RATE
INCREASES COAL TEMPERATURE
Balance determines
developmentof event
Incubation period is the time taken for coal to reach thermal runaway with given intrinsic and extrinsic factors.
• Oxidation rate doubles for each 10⁰C rise in temperature, once the coal temperature exceeds 70⁰C
• Coal is a good insulator and can retain heat for years• Coal can retain elevated activity for years• Incubation periods can range from weeks to years• Never use incubation period to avoid controls
MDG1006 Spontaneous Combustion Management Guideline
• Updated by the NSW Mine Safety Operations Branch in February, 2011 released in May 2011
• www.resourcesandenergy.nsw.gov.au/__data/assets/pdf_file/0007/419515/MDG-1006.pdf
• The intent of this guideline is to provide assistance to mines in the development and implementation of a Principal Hazard Management Plan (PHMP) for Spontaneous Combustion.
• Spontaneous combustion testing information is required to assess propensity to self-heat and to obtain data on gas evolution associated with coal temperature increase.
International Conference and Exhibition on Occupational Health and Safety in Mines -
Istanbul December 2014
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Common Sponcom tests used bythe Australian Coal Mining Industry
• Common tests measure the intrinsic spontaneous combustion propensity under set conditions with no indication of time to thermal runaway. Assessment is based on a rating scheme compared against previous coal histories.
• Crossing Point Temperature (CPT) and Relative Ignition Temperature (RIT) are high temperature index tests and do not provide any measure of the coal self-heating at low ambient temperature. They are also measured by force heating the coal in an oven.
• Minimum Self-heating Temperature (SHT) and R70 self-heating rate are low temperature index tests and provide a measure of the coal self-heating at low ambient temperature. They are measured in an adiabatic oven that allows the coal to heat itself, although SHT is now calculated from the oxygen content of the coal.
• New SponComSIM™ testing provides additional data on the time taken to reach thermal runaway using site boundary conditions and is benchmarked against coals with known self-heating performance.
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Sampling strategies for Sponcom assessment of a longwall
mine• Site specific and tailored to suit project objectives
• Top, middle and bottom of seam, plus any rider seams likely to fall into the goaf or floor coal left behind
• Minimum 800g required per sample (25cm of HQ core)
• Longwall operations tested every longwall panel
• Fresh face lumps just as good as core
• R70 testing of all samples for assessing intrinsic
spontaneous combustion propensity
• SponComSIM™ testing of specific samples for benchmarking thermal runaway timeframe
• SponComGAS™ testing for evaluating gas evolution trends in support of TARPs
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Example of repeat R70 testing fora Newcastle high volatile bituminous
coal
20
40
60
80
100
120
140
160
0 1 2 3 4 5 6 7 8 9 10
Tem
per
atu
re (
oC
)
Time (hours)LAB A (Oven 1) LAB A (Oven 1)
R70 = 4.73 oC/h
R70 = 4.90 oC/h
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Example of repeat R70 testing foran Australian sub-bituminous coal
20
40
60
80
100
120
140
160
0.0 0.5 1.0 1.5 2.0
Tem
per
atu
re (
oC
)
Time (hours)LAB A (Oven 1) LAB A (Oven 1)
R70 = 33.42 oC/h
R70 = 34.27 oC/h
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Intrinsic Spontaneous Combustion Propensity classification (ISCP) based on Qld and NSW coal conditions
(Beamish and Beamish, 2012)
Queensland New South Wales
ISCPClass
Propensity ratingR70 value
(°C/h)R70 value
(°C/h)
I low (L) R70 < 0.5 R70 < 1
II low-medium (LM) 0.5 R70 < 1 1 R70 < 2
III medium (M) 1 R70 < 2 2 R70 < 4
IV high (H) 2 R70 < 4 4 R70 < 8
V very high (VH) 4 R70 < 8 8 R70 < 16
VI ultra high (UH) 8 R70 < 16 16 R70 < 32
VII extremely high (EH) R70 16 R70 32
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
New South Wales intrinsic spontaneous combustion propensity plot
0
1
2
3
4
5
6
7
8
0 5 10 15 20 25 30 35 40 45 50
R7
0(o
C/h
, db
)
Ash content (%, db)
Illawarra 1 Illawarra 2 Hunter Valley Upper Hunter
Newcastle Western San Juan Spring Creek
Low
Low - Medium
Medium
High
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Examples of SponComSIM™ testing to establish time to thermal runaway
20
40
60
80
100
120
140
160
0 10 20 30 40 50 60 70 80 90 100 110 120
Tem
per
atu
re (
oC
)
Time (hours)
Kideco Spring Creek Illawarra (Bulli)
Newcastle A LW3A LW3B40
-60
day
s
10-1
5 d
ays
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Example of recent Queensland case study
20
40
60
80
100
120
140
160
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
Tem
per
atu
re (
oC
)
Time (hours)
Kideco Spring Creek K4E Low Ash (35C) K4E Low Ash (40C)
40
-60
da
ys
10
-15
da
ys
67
-100
da
ys
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Quantification of reactive pyrite effect
20
40
60
80
100
120
140
160
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Tem
per
atu
re (
oC
)
Time (hours)R70 SponComSIM
R70 = 1.73 oC/h
RIT = 149 oC
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Effect of increasing amounts of reactive pyrite
(Beamish, Lin and Beamish, 2012)
20
40
60
80
100
120
140
160
0 10 20 30 40 50 60 70 80 90
Time (hours)
Tem
per
atu
re (
oC
)
Kideco Spring Creek BBHVB03 BBHVB06 BBHVB13 BBHVB01
40-6
0 d
ays
10-1
5 d
ays
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Trigger Action Response Plan (TARP) setting for underground
mines• Identification of most appropriate
indicator gases and ratios– Initially based on gas evolution testing of the coal– TARP trigger levels set at logically determined
values that are site specific (internal standard)– Refined as part of the review process with mine site
experience– Possibility of differing geological domains
influencing TARP trigger levels
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Small-scale gas evolution testing
• Characterises the gas evolution trend that occurs in response to coal self-heating as the temperature of the coal increases
• Results are evaluated for the specific trends of individual gases and gas ratios
• The information can be used to identify key indicator gases and ratios for use in TARPs and to support the alarm limits set in the TARP
• Coal is step heated up to approximately 180°C and gases analysed by GC include: O2, N2, CH4,
CO2, CO, H2, C2H6, C2H4
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Individual gas evolution results forArea A of a New South Wales mine
0
1
2
3
4
0.000
0.005
0.010
0.015
0.020
40 60 80 100 120 140 160 180 200
Hyd
roge
n, E
thyl
ene,
Eth
ane,
Met
hane
(%)
Temperature (°C) Hydrogen Ethylene Ethane Methane Carbon Monoxide Carbon Dioxide
Carb
on M
onox
ide,
Car
bon
Dio
xide
(%)
Carb
on M
onox
ide,
Car
bon
Dio
xide
(%)
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Individual gas evolution results forArea B of a New South Wales mine
0
1
2
3
4
0.000
0.005
0.010
0.015
0.020
40 60 80 100 120 140 160 180 200
Hyd
roge
n, E
thyl
ene,
Eth
ane,
Met
hane
(%)
Temperature (°C) Hydrogen Ethylene Ethane Methane Carbon Monoxide Carbon Dioxide
Carb
on M
onox
ide,
Car
bon
Dio
xide
(%)
Carb
on M
onox
ide,
Car
bon
Dio
xide
(%)
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Graham’s ratio trend with increasing coal temperature for
Area A
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
20 40 60 80 100 120 140 160 180 200
Gra
ham
's R
atio
(%)
Temperature (°C)
Measured GRExtrapolated GR
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
Conclusions
• Reliable and accurate results with appropriate interpretation are required by industry for Spontaneous Combustion Principal Hazard Management Planning.
• Relevant laboratory spontaneous combustion testing is required to evaluate the risk of developing an event under the site specific conditions of each mine and within different areas of the mine.
• Gas evolution testing provides support for the selection of appropriate indicator gases and ratios used in TARPs.
International Conference and Exhibition on Occupational Health and Safety in Mines - Istanbul December 2014
References
• Beamish, B and Beamish, R, 2012. Testing and sampling requirements for input to spontaneous combustion risk assessment, in Proceedings of the Australian Mine Ventilation Conference, B Beamish and D Chalmers (eds), pp 15-21 (The Australasian Institute of Mining and Metallurgy: Melbourne).
• Beamish, B, Lin, Z and Beamish, R, 2012. Investigating the influence of reactive pyrite on coal self-heating, in Proceedings 12th Coal Operators’ Conference, N Aziz (ed), pp 295-300 (University of Wollongong and The Australasian Institute of Mining and Metallurgy).
• Moreby, R and Chalmers, D, 2006. Mine ventilation course notes, Mining Education Australia.