Transcript Document

Heat Study and Modelling of Future Climatic
Conditions at Coleman/McCreedy East Mine –
Vale Inco
• Charles Kocsis & Stephen Hardcastle
CANMET-MMSL, Sudbury, Canada
• Brian Keen
Vale Inco, Coleman/McCreedy East Mine, Levack, Canada
Objectives
• Perform climatic survey  quantify changes in TDB, TWB,
RH and Barometric Pressure of the intake air from
surface to the 4810L, through a Cut &Fill stoping area
and to the exhaust system of the 153 Orebody
• Evaluate the heat load added to the intake air by autocompression, strata, fans and mining equipment
• Predict the climatic conditions for the deepest operating
level (5700L) within the future 170 Orebody
• Predict the climatic conditions along this future orebody’s
main haulage ramp – an exhaust airway ascending from
5700L to 5100L
Methodology
• Perform a climatic survey  collect data  determine the
heat load added to the mine environment
• Perform mine activity monitoring to differentiate between
constant (i.e. strata) and transient (i.e. mining equipment)
heat sources
• Develop a climatic model of the mine’s intake system and
the C&F stopes on the 4810L (153 Orebody)
 validate simulation data against field data
• Transpose climatic model to the 5700L (future 170 Orebody)
with intake airflow, BP and VRT entered for this deeper level
 predict climatic conditions on 5700L
• Extend climatic model to include the ramp system between
5700L and 5100L  predict climatic conditions
Coleman/McCreedy East Mine
• Two Alphair 11200-AMF6600 (880 RPM) in parallel
• Power: 1,118 kW (1500hp)
each
• Two Joy 72-26880RPM (Series
2000 )-100hp each
No.1 Intake Shaft
Two 1120 kW (1500 hp)
Alphair 1120-AMF-6600
(880RPM) in Parallel
Arrangement
Two Exhaust Fans in
Parallel Arrangement
Environmental Data Collection
• Eleven ACR data loggers were installed along the intake
system (surface-4810L) & across the C&F production area
• These pocket units continuously recorded TDB, RH and BP,
24 hrs/day at 1-minute intervals  TWB were calculated
using standard equations
• An infrared (Raytek MX) was used to measure wall surface
temperatures along the access drifts and stope area
• Kerstel 4000 Pocket Weather Tracker was used for spot
measurements within the C&F production stopes
• Environmental data was downloaded to a mobile computer
at the end of every production shift
Installation of ACR Units On 4810L (#4 Mining Block)
Mine Activity Tracking on 4810L
(#4 Mining Block)
Activity/Equipment
Equipment Information
Drilling:
Mini-Jumbo
34 kW (45 hp) diesel,
37 kW electrical motor,
2.2 kW compressor motor
Bolting/Screening:
Jacklegs
Compressed air system
Mucking-Small LHD:
2.5 yd3 – 86 kW diesel
moving blasted ore from
the face of the 3W, 2W,
2WB stopes to the
remuck bay
Mucking-Large LHD:
moving ore from the
remuck bay to the 4810
level ore pass
8 yd3 – 250 kW diesel
6 yd3 – 200 kW diesel
Miscellaneous Vehicles
Utility – 37 kW diesel
Small truck – 32 kW diesel
Fork lifts: 33 & 37 kW diesel
Personnel – 100 kW diesel
• During 14-day survey on day-shifts,
drilling, bolting/screening, explosive
loading, blasting and mucking were
monitored and recorded
• Data included type and location of activity,
start & finish times, mining equipment
used, duration of scheduled (i.e. lunch) &
unscheduled (i.e. equipment breakdowns)
production delays
• The operational status (On/Off) of the
auxiliary fan was also recorded
• The air volumes at the flexible duct
discharge to each individual C&F stope
was measured for every production
arrangement
Mine Activity Tracking - Example
Task Codes: D – Drilling; GS – Ground Support; M – Mucking; L – Explosive Loading
Sub-Task Codes: DH – Drill Holes; IRB – Install Rock Bolts; MFB – Mucking from Face to Bay; MOB – Mucking from Bay to Ore pass;
LH – Load Holes; WU – Wire Holes; CG – Clear and Guard; OW – Other Work; PREP – Prepare for Ground Support Activities; EI –
Equipment inspection
Environmental and Activity
Data Analysis
• The TDB (0C), RH (%) and BP (kPa) data were
compiled into daily electronic spreadsheets
• The psychrometric TWB (0C) was calculated for each
individual set of measurements
• Within the spreadsheets the collected activity
information, the status of the auxiliary fans and air
volumes were also compiled
• Once combined it was possible to identify in
temperature and humidity graphs where and when
mining activity had an impact on the U/G environment
Wet-Bulb, Dry-Bulb and RH in the C&F Production Stopes
• During activities not requiring diesel/el. Equipment, stope background temp. were 28.50C & 23.50C
• During two scheduled production delays with aux. fan Off, TDB decreased from 28.5 to 26.90C & from 30 to 28.40C
• During bolting/screening (9:00-10:00) TDB, RH & WB remained fairly constant at 28.00C, 58% & 22.00C
• Elevated temp. occurred during concurrent mining activities (15:40–16:20). Most airflow directed to adjacent stope
TDB = 2.90C
TDB = 3.50C
TDB = 4.50C
Average DB and WB Temperatures at the
Monitoring Locations (Surface – 4810L)
TDB ΔTDB
(C) (C)
TWB ΔTWB
(C) (C)
Surface Intake
18.4
15.7
4810 Level Intake - Loc.10
29.0 +10.6 22.6 +6.9
48” Aux. Duct Intake - Loc.1
30.3
+1.3 22.9 +0.3
48” Aux. Duct after Fan - Loc.3
32.8
+2.5 23.1 +0.2
36” Auxiliary Duct - Loc.5
32.3
-0.5 22.9
Aux. Pipe Discharge - Loc.7
31.9
-0.4 23.4 +0.5
Stope Face (3W/2W/2WB) Loc.8
29.4
-2.5 23.8 +0.4
Stope Return - Loc.6
29.4
0 23.9 +0.1
Access Drift Return - Loc.4
29.4
0 23.9
0
Ventilation Drift Return - Loc.2
29.4
0 23.5
-0.4
Footwall Drift to RAR - Loc.9
29.1
LOCATION
-
-
-0.2
-0.3 24.0 +0.5
• Greatest temp. increase occurred
between surface – intake to 4810L
(TDB=+10.60C, TWB=+6.90C ) mainly
due to auto-compression
• Booster fan delivering air to the 4810L
produced TDB=+1.30C in the intake air
• The 150hp aux. fan delivering air to the
mining block produced TDB=+2.50C
• TDB decreased along the aux. duct
(TDB=-0.50C)  some of the fan heat
was transferred to the 48” steel duct
• Within the stope area, on average TDB
decreased by -2.50C. However TWB
increased by 0.40C  evaporative
cooling in the production area
VRT4810L = 26.5 0C
The Monitored Environmental
Conditions in the Production Area
• Environmental monitoring data showed that TDB, TWB, RH
changed quickly according to the mining activities
• Any elevated TDB and TWB returned to stope background
conditions with the completion of the activity
• These changes were local as TDB and TWB remained fairly
constant at the exhaust of the mining block (TDB=0.40C, TWB=0.90C)
• The highest TDB and TWB occurred during concurrent mining
activities in adjacent C&F stopes (drilling & mucking)
• Working conditions in the production stopes were a function of
the air volume delivered to each individual stope
Climatic Modelling - #4 Mining
Block (4810L)
• The climatic model of the #4 mining block
(153 Orebody) developed using ClimsimTM
• Model based upon mine layouts and the
following rock properties:
– VRT @ 1,466.5m (4810L) = 26.50C
– Geothermal Step: 63 m/0C
– Rock Conductivity 5.6 W/m0C
– Diffusivity: 2.5 x 10-6 m2/s
VRT was provided by
Vale Inco obtained
from measurements
in boreholes
• Model developed by combining all airway
segments from surface to 4810L and the
C&F stopes
• Simulations showed some difficulties in
replicating TDB/TWB in individual stopes
with air volume being continually adjusted
• As a result & to allow simulation of
concurrent activities in adjacent stopes, a
“block” model combining all C&F stopes
(2W, 2WB, 3W) was developed
Example of Ventilation Parameters &
Heat Sources used in the 4810L Model
• Air volume delivered by the auxiliary fan through the
1.2 m steel duct: Vd = 27.5 m3/s
• Combined air volume directed to the production
stopes through flexible fabric ducts: Vs = 11.5 m3/s
• Depth = 1,466 m; Barometric Pressure: BP = 118 kPa
• Mini-Jumbo power characteristics: PElectrical = 37 kW;
PDiesel = 34 kW; PCompressor= 2.2 kW
• Diesel LHD power characteristics: 2.5 yd3 (86 kW);
6.0 yd3 (200 kW); 8.0 yd3 (250 kW)
Model Simulated TDB and TWB for the Active #4
Mining Block (4810L)
LOCATION
48” Aux. Duct Intake –
Location 1
48” Aux. Duct after Fan –
Location 3
Auxiliary Pipe Discharge –
Location 7
Stope Face (3W/2W/2WB) –
Location 8
Stope Return –
Location 6
Access Drift Return –
Location 4
Ventilation Drift Return –
Location 2
Footwall Drift to RAR –
Location 9
TDB (C)
Simulated
Measured
30.3
30.3
32.9
32.8
31.9
31.9
33.0
29.4
30.0
29.4
29.9
29.4
29.5
29.4
29.1
29.1
ΔTDB (C)
Simulated
Measured
_
+2.6
+2.5
-1.0
-0.4
+1.1
-2.5
-3.0
0
-0.1
0
-0.4
0
-0.4
-0.3
TWB (C)
Simulated
Measured
22.9
22.9
23.9
23.1
23.5
23.4
24.2
23.8
24.3
23.9
24.3
23.9
24.1
23.5
24.0
24.0
ΔTWB (C)
Simulated
Measured
_
+1.0
+0.2
-0.4
+0.5
+0.7
+0.4
+0.1
+01
0
0
-0.2
-0.4
-0.1
+0.5
• Comparing simulation vs. average measured data  only major difference is
TDB/TWB at the face
• Simulations were set to represent concurrent activities in two adjacent stopes
Climatic Modelling – Future
170 Orebody (5700L)
• The 4810L (Depth = 1,467m) climatic model was transposed to
the 5700L (Depth = 1,738m) of the 170 Orebody
• Air volumes through the auxiliary ducting system, equipment &
auxiliary fan heat sources were similar as within 4810L
• VRT entered according to the deeper 5700L (VRT5700L=30.8 0C)
• However, to determine the starting TDB and TWB and barometric
pressure of the intake air to the 5700L additional modelling work
was required
Determining TDB, TWB and BP Through Climatic Modelling
Surface
2 Surface Fans in Parallel Arrangement
P = 3,633 Pa (14.6”) Power = 2 x 1,118.5 = 2,237 kW
Intake fresh Air System from Surface
to the bottom of the 5700 Level FAR
# 1 Intake Shaft
Q = 486 m 3/s (1,030 kcfm )
1248 m
(4094’)
3830’
Level
5.8 m diam.
k = 0.0076 kg/m 3 (41 lb * min 2 / ft 4)
2 Booster Fans I Parallel Arrangement
P = 1,244Pa (5.0 in. wg) Power = 2 x 298 kW (400hp)
Q = 349 m 3/s (739.5 kcfm)
43.6 m 18’ x 17’ transfer drift
(143’) k = 0.0129 kg/m 3 (70 lb * min 2 / ft 4)
15.2 m (50’)
3970’ Level
18’ diam. Alimak
k = 0.0129 kg/m 3
(70 lb * min2 / ft 4)
L = 74.7 m (245”)
Q = 217 m 3/s
(460 kcfm )
Q = 217 m 3/s
(460 kcfm)
22.8 m (75’)
Q = 165 m 3/s
(350 kcfm )
4215’ Level
13’ diam. borehole
k = 0.0055 kg/m 3 (30 lb * min2 / ft 4)
288 m (945’)
Q = 165 m 3/s
(350 kcfm)
5160 ’Level
13’ diam. borehole
k = 0.0055 kg/m 3 (30 lb * min2 / ft 4)
18’ x 17’ transfer drift
k = 0.0129 kg/m 3 (70
lb * min 2 / ft 4)
259 m (850’)
Q = 165 m 3/s (350 kcfm)
96 m (315’)
Q = 165 m 3/s (350 kc fm)
5475’ Level
16’ x 17’ transfer drift
k = 0.0129 kg/m 3 (70 lb * min 2 / ft 4)
131 m (430’)
16’ x 16’ transfer drift
k = 0.0129 kg/m 3 (70 lb * min 2 / ft 4)
96 m (315’)
Q = 71 m 3/s (150 kcfm)
13’ diam borehole
k = 0.0055 kg/m 3 (30 lb * min 2 / ft 4)
5700’Level
Simulations  TDB = 35.3 0C; TWB = 24.4 0C; BP = 123 kPa
Simulated TDB and TWB for the Future
Mining Block on the 5700L
LOCATION
48” Aux. Duct Intake –
Location 1
48” Aux. Duct after Fan –
Location 3
Auxiliary Pipe Discharge –
Location 7
Stope Face (3W/2W/2WB) –
Location 8
Stope Return –
Location 6
Access Drift Return –
Location 4
Ventilation Drift Return –
Location 2
Footwall Drift to RAR –
Location 9
TDB (C)
ΔTDB (C)
TWB (C)
ΔTWB (C)
5700L
5700L
5700L
5700L
4810L
4810L
4810L
4810L
35.3
_
24.4
_
30.3
22.9
37.8
+2.5
25.4
+1.0
32.9
+2.6
23.9
+1.0
36.2
-1.4
25.0
-0.4
31.9
-1.0
23.5
-0.4
TDB & TWB was much dependant to the air volume delivered
to the individual C&F stopes
33.6
-3.9
25.7
0
30.0
-3.0
24.3
+0.1
33.4
-0.2
25.7
0
29.9
-0.1
24.3
0
33.1
-0.3
25.6
-0.1
29.5
-0.4
24.1
-0.2
32.8
-0.3
25.6
0
29.1
-0.4
24.0
-01
• Intake TDB/TWB at the 5700L increased by TDb = 5.00C & TWB = 1.50C due to additional
booster fans (4215L) and auto-compression  TDB now exceeds VRT = 30.80C
• The highest TDB & TWB in the production area would occur at the combined return from the
stopes, namely 33.60C and 25.70C (for concurrent mucking & drilling in adjacent stopes)
Climatic Modelling – Main
Haulage Ramp
• The 5700L model was extended to include two sections of
the main haulage ramp (5700L - 5475L) and (5475L - 5100L)
• These two sections were considered worst-case-operational
conditions
• Example of data used for the 5700L – 5475L ramp section:
– Volume of air through this section: 71 m3/s
– Intake airflow conditions from previous segment:
TDB=32.80C; TWB=25.60C
– Equipment: Two 2.5 yd3 LHD (2 x 86.5 kW); One 6yd3 LHD
(231 kW); Two diesel trucks (2 x 223.5 kW)
• Total diesel power: 851 kW
Climatic Modelling – Main
Haulage Ramp
• Climatic simulations along the (5700L - 5475L) section of
the ramp predicted: TDB = 36.8 0C & TWB = 27.2 0C
• TWB would only exceed the mine’s design criteria (TWB =
25.5 0C) if all mining equipment would operate at the same
time for prolonged period of time
• Predicted TDB & TWB in the upper section (5475L - 5100L)
had lower temperatures due to a higher air volume
throughout this section
Climatic Simulation Summary –
170 Orebody and Haulage Ramp
• Temperature conditions predicted for the intake air to the 5700L
would be: TDB=35.3 0C and TWB=24.4 0C
• Changes between surface conditions (18.4 0C/15.7 0C) and 5700L 
TDB=+16.9 0C & TWB=+8.7 0C are mainly due to heat generated by
auto-compression and main/booster fans
• During concurrent activities (11.5 m3/s), the highest temperature
conditions would occur at the common return location from the C&F
stopes: TDB=33.6 0C & TWB=25.7 0C
• Along the return airways the predicted temperatures decrease to
TDB=32.8 0C/TWB=25.6 0C
• Across the 5700L, heat generated by auto-compression, fans and
machinery is rejected into the cooler surrounding rock (VRT=30.80C)
• For the 5700L - 5475L section of the main haulage ramp under
worst-case-scenario conditions TDB/TWB was predicted to reach 36.8
0C and 27.2 0C – if all potential equipment operate
CONCLUSIONS
• A climatic model of a C&F mining area for the active 153 Orebody
(4810L) was successfully developed based on mine layouts and the
auxiliary ventilation setup
• Output data generated through simulations were compared and
validated vs. measured data (environmental & activity monitoring)
• Environmental and activity monitoring showed concurrent mucking
and drilling activities generating some of the highest temperatures
• Elevated temperatures also occurred when auxiliary ventilation was
not immediately adjusted to meet changes in production activity
(TDB=+9.40C/TWB=+3.50C)
• The climatic condition within the future 170 Orebody were predicted
using the 4810L model transposed to the 5700L  airflow intake
TDB/TWB, BP, VRT entered for that deeper level (5700L)
CONCLUSIONS – Continued
• Climatic simulations of the future 170 Orebody showed that with
the simplified working area TWB = 25.50C would not be exceeded
• However, TWB could be exceeded in the individual C&F stopes
depending on the mining activities and air volume delivered to the
individual stopes
• The only area where TWB would be exceeded is along the 5700L
– 5475L section of the haulage ramp – if all potential equipment
would operate simultaneously
• Study showed that providing appropriate auxiliary ventilation
distribution able to meet various operating requirements has the
greatest role in maintaining adequate environmental conditions
Acknowledgement
The authors would like to thank Vale Inco for their
permission to present this work and recognize the
Ventilation and Engineering Staff of Coleman/McCreedy
East Mine for their support and cooperation in collecting
data and technical information
Thank You
Questions ?