PPT - Mining Metallurgy and Exploration - SME

1,721 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,721
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
36
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide
  • Worldwide metal mines are going deeper. For example in Canada, there are 6 such mechanized mines planning production at 3,000m (10,000 feet) depth. This paper explores the overall challenges for supplying airflow in Canada’s deepest mines cost effectively and how the impact of depth could be mitigated by implementing new technologies such as Telemining TM , alternatives to diesels such as fuelcell powered equipment and the use of mine process simulators.
  • Depth can effect the economics of the ventilation system in 3 ways: Increasing distance that airflow must be supplied will increase the mine mine resistance and as a result the ventilation system’s operating cost. Depth can also affect the ventilation economics due to increased leakages in the ventilation system. There is a cubic relationship between the power consumption and supplied airflow: Power = RQ 3 . Fore example, if a mine has to supply 10% additional airflow due to leakages, the power consumption underground can increase by 33%. With increasing depth air temperatures in mines will increase as result of auto-compression of the air and heat transfer from strata. To overcome this heat gain, plus heat generated by the mining equipment, the intake air volumes would have to increase with depth. For example, in a Canadian mine already operating at 2,000m depth, an additional 300m depth can increase airflow requirements by 20%. According to the cubic relationship (between power and airflow), these deeper areas would be 50-70% more costly to ventilate. It can be seen that when heat management starts to become a concern the ventilation costs start to increase dramatically.
  • PPT - Mining Metallurgy and Exploration - SME

    1. 1. Heat Study and Modelling of Future Climatic Conditions at Coleman/McCreedy East Mine – Vale Inco <ul><li>Charles Kocsis & Stephen Hardcastle </li></ul><ul><li>CANMET-MMSL, Sudbury, Canada </li></ul><ul><li>Brian Keen </li></ul><ul><li>Vale Inco, Coleman/McCreedy East Mine, Levack, Canada </li></ul>
    2. 2. Objectives <ul><li>Perform climatic survey  quantify changes in T DB , T WB , 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 </li></ul><ul><li>Evaluate the heat load added to the intake air by auto-compression, strata, fans and mining equipment </li></ul><ul><li>Predict the climatic conditions for the deepest operating level (5700L) within the future 170 Orebody </li></ul><ul><li>Predict the climatic conditions along this future orebody’s main haulage ramp – an exhaust airway ascending from 5700L to 5100L </li></ul>
    3. 3. Methodology <ul><li>Perform a climatic survey  collect data  determine the heat load added to the mine environment </li></ul><ul><li>Perform mine activity monitoring to differentiate between constant (i.e. strata) and transient (i.e. mining equipment) heat sources </li></ul><ul><li>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 </li></ul><ul><li>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 </li></ul><ul><li>Extend climatic model to include the ramp system between 5700L and 5100L  predict climatic conditions </li></ul>
    4. 4. Coleman/McCreedy East Mine <ul><li>Two Alphair 11200-AMF-6600 (880 RPM) in parallel </li></ul><ul><li>Power: 1,118 kW (1500hp) each </li></ul><ul><li>Two Joy 72-26-880RPM (Series 2000 )-100hp each </li></ul>
    5. 5. No.1 Intake Shaft Two 1120 kW (1500 hp) Alphair 1120-AMF-6600 (880RPM) in Parallel Arrangement Two Exhaust Fans in Parallel Arrangement
    6. 6. Environmental Data Collection <ul><li>Eleven ACR data loggers were installed along the intake system (surface-4810L) & across the C&F production area </li></ul><ul><li>These pocket units continuously recorded T DB , RH and BP, 24 hrs/day at 1-minute intervals  T WB were calculated using standard equations </li></ul><ul><li>An infrared (Raytek MX) was used to measure wall surface temperatures along the access drifts and stope area </li></ul><ul><li>Kerstel 4000 Pocket Weather Tracker was used for spot measurements within the C&F production stopes </li></ul><ul><li>Environmental data was downloaded to a mobile computer at the end of every production shift </li></ul>
    7. 7. Installation of ACR Units On 4810L (#4 Mining Block)
    8. 8. Mine Activity Tracking on 4810L (#4 Mining Block) <ul><li>During 14-day survey on day-shifts, drilling, bolting/screening, explosive loading, blasting and mucking were monitored and recorded </li></ul><ul><li>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 </li></ul><ul><li>The operational status (On/Off) of the auxiliary fan was also recorded </li></ul><ul><li>The air volumes at the flexible duct discharge to each individual C&F stope was measured for every production arrangement </li></ul>Utility – 37 kW diesel Small truck – 32 kW diesel Fork lifts: 33 & 37 kW diesel Personnel – 100 kW diesel Miscellaneous Vehicles 8 yd 3 – 250 kW diesel 6 yd 3 – 200 kW diesel Mucking-Large LHD: moving ore from the remuck bay to the 4810 level ore pass 2.5 yd 3 – 86 kW diesel Mucking-Small LHD: moving blasted ore from the face of the 3W, 2W, 2WB stopes to the remuck bay Compressed air system Bolting/Screening: Jacklegs 34 kW (45 hp) diesel, 37 kW electrical motor, 2.2 kW compressor motor Drilling: Mini-Jumbo Equipment Information Activity/Equipment
    9. 9. 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
    10. 10. Environmental and Activity Data Analysis <ul><li>The T DB ( 0 C), RH (%) and BP (kPa) data were compiled into daily electronic spreadsheets </li></ul><ul><li>The psychrometric T WB ( 0 C) was calculated for each individual set of measurements </li></ul><ul><li>Within the spreadsheets the collected activity information, the status of the auxiliary fans and air volumes were also compiled </li></ul><ul><li>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 </li></ul>
    11. 11. Wet-Bulb, Dry-Bulb and RH in the C&F Production Stopes <ul><li>During activities not requiring diesel/el. Equipment, stope background temp. were 28.5 0 C & 23.5 0 C </li></ul><ul><li>During two scheduled production delays with aux. fan Off , T DB decreased from 28.5 to 26.9 0 C & from 30 to 28.4 0 C </li></ul><ul><li>During bolting/screening (9:00-10:00) T DB , RH & WB remained fairly constant at 28.0 0 C, 58% & 22.0 0 C </li></ul><ul><li>Elevated temp. occurred during concurrent mining activities (15:40–16:20). Most airflow directed to adjacent stope </li></ul> T DB = 2.9 0 C  T DB = 3.5 0 C  T DB = 4.5 0 C
    12. 12. Average DB and WB Temperatures at the Monitoring Locations (Surface – 4810L) <ul><li>Greatest temp. increase occurred between surface – intake to 4810L (  T DB =+10.6 0 C,  T WB =+6.9 0 C ) mainly due to auto-compression </li></ul><ul><li>Booster fan delivering air to the 4810L produced  T DB =+1.3 0 C in the intake air </li></ul><ul><li>The 150hp aux. fan delivering air to the mining block produced  T DB =+2.5 0 C </li></ul><ul><li>T DB decreased along the aux. duct (  T DB =-0.5 0 C)  some of the fan heat was transferred to the 48” steel duct </li></ul><ul><li>Within the stope area, on average T DB decreased by -2.5 0 C. However T WB increased by 0.4 0 C  evaporative cooling in the production area </li></ul>VRT 4810L = 26.5 0 C +0.5 24.0 -0.3 29.1 Footwall Drift to RAR - Loc.9 -0.4 23.5 0 29.4 Ventilation Drift Return - Loc.2 0 23.9 0 29.4 Access Drift Return - Loc.4 +0.1 23.9 0 29.4 Stope Return - Loc.6 +0.4 23.8 -2.5 29.4 Stope Face (3W/2W/2WB) - Loc.8 +0.5 23.4 -0.4 31.9 Aux. Pipe Discharge - Loc.7 -0.2 22.9 -0.5 32.3 36” Auxiliary Duct - Loc.5 +0.2 23.1 +2.5 32.8 48” Aux. Duct after Fan - Loc.3 +0.3 22.9 +1.3 30.3 48” Aux. Duct Intake - Loc.1 +6.9 22.6 +10.6 29.0 4810 Level Intake - Loc.10 - 15.7 - 18.4 Surface Intake ΔT WB (  C) T WB (  C) ΔT DB (  C) T DB (  C) LOCATION
    13. 13. The Monitored Environmental Conditions in the Production Area <ul><li>Environmental monitoring data showed that T DB , T WB , RH changed quickly according to the mining activities </li></ul><ul><li>Any elevated T DB and T WB returned to stope background conditions with the completion of the activity </li></ul><ul><li>These changes were local as T DB and T WB remained fairly constant at the exhaust of the mining block (  T DB =0.4 0 C,  T WB =0.9 0 C) </li></ul><ul><li>The highest T DB and T WB occurred during concurrent mining activities in adjacent C&F stopes (drilling & mucking) </li></ul><ul><li>Working conditions in the production stopes were a function of the air volume delivered to each individual stope </li></ul>
    14. 14. Climatic Modelling - #4 Mining Block (4810L) <ul><li>The climatic model of the #4 mining block (153 Orebody) developed using Climsim TM </li></ul><ul><li>Model based upon mine layouts and the following rock properties: </li></ul><ul><ul><li>VRT @ 1,466.5m (4810L) = 26.5 0 C </li></ul></ul><ul><ul><li>Geothermal Step: 63 m/ 0 C </li></ul></ul><ul><ul><li>Rock Conductivity 5.6 W/m 0 C </li></ul></ul><ul><ul><li>Diffusivity: 2.5 x 10 -6 m 2 /s </li></ul></ul><ul><li>Model developed by combining all airway segments from surface to 4810L and the C&F stopes </li></ul><ul><li>Simulations showed some difficulties in replicating T DB /T WB in individual stopes with air volume being continually adjusted </li></ul><ul><li>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 </li></ul>VRT was provided by Vale Inco obtained from measurements in boreholes
    15. 15. Example of Ventilation Parameters & Heat Sources used in the 4810L Model <ul><li>Air volume delivered by the auxiliary fan through the 1.2 m steel duct: V d = 27.5 m 3 /s </li></ul><ul><li>Combined air volume directed to the production stopes through flexible fabric ducts: V s = 11.5 m 3 /s </li></ul><ul><li>Depth = 1,466 m; Barometric Pressure: BP = 118 kPa </li></ul><ul><li>Mini-Jumbo power characteristics: P Electrical = 37 kW; P Diesel = 34 kW; P Compressor = 2.2 kW </li></ul><ul><li>Diesel LHD power characteristics: 2.5 yd 3 (86 kW); 6.0 yd 3 (200 kW); 8.0 yd 3 (250 kW) </li></ul>
    16. 16. Model Simulated T DB and T WB for the Active #4 Mining Block (4810L) <ul><li>Comparing simulation vs. average measured data  only major difference is T DB /T WB at the face </li></ul><ul><li>Simulations were set to represent concurrent activities in two adjacent stopes </li></ul>-0.1 +0.5 24.0 24.0 -0.4 -0.3 29.1 29.1 Footwall Drift to RAR – Location 9 -0.2 -0.4 24.1 23.5 -0.4 0 29.5 29.4 Ventilation Drift Return – Location 2 0 0 24.3 23.9 -0.1 0 29.9 29.4 Access Drift Return – Location 4 +0.1 +01 24.3 23.9 -3.0 0 30.0 29.4 Stope Return – Location 6 +0.7 +0.4 24.2 23.8 +1.1 -2.5 33.0 29.4 Stope Face (3W/2W/2WB) – Location 8 -0.4 +0.5 23.5 23.4 -1.0 -0.4 31.9 31.9 Auxiliary Pipe Discharge – Location 7 +1.0 +0.2 23.9 23.1 +2.6 +2.5 32.9 32.8 48” Aux. Duct after Fan – Location 3 _ 22.9 22.9 _ 30.3 30.3 48” Aux. Duct Intake – Location 1 ΔT WB (  C) Simulated Measured T WB (  C) Simulated Measured ΔT DB (  C) Simulated Measured T DB (  C) Simulated Measured LOCATION
    17. 17. Climatic Modelling – Future 170 Orebody (5700L) <ul><li>The 4810L (Depth = 1,467m) climatic model was transposed to the 5700L (Depth = 1,738m) of the 170 Orebody </li></ul><ul><li>Air volumes through the auxiliary ducting system, equipment & auxiliary fan heat sources were similar as within 4810L </li></ul><ul><li>VRT entered according to the deeper 5700L (VRT 5700L =30.8 0 C) </li></ul><ul><li>However, to determine the starting T DB and T WB and barometric pressure of the intake air to the 5700L additional modelling work was required </li></ul>
    18. 18. Determining T DB , T WB and BP Through Climatic Modelling Simulations  T DB = 35.3 0 C; T WB = 24.4 0 C; BP = 123 kPa
    19. 19. Simulated T DB and T WB for the Future Mining Block on the 5700L <ul><li>Intake T DB /T WB at the 5700L increased by  T Db = 5.0 0 C &  T WB = 1.5 0 C due to additional booster fans (4215L) and auto-compression  T DB now exceeds VRT = 30.8 0 C </li></ul><ul><li>The highest T DB & T WB in the production area would occur at the combined return from the stopes, namely 33.6 0 C and 25.7 0 C (for concurrent mucking & drilling in adjacent stopes) </li></ul>0 -01 25.6 24.0 -0.3 -0.4 32.8 29.1 Footwall Drift to RAR – Location 9 -0.1 -0.2 25.6 24.1 -0.3 -0.4 33.1 29.5 Ventilation Drift Return – Location 2 0 0 25.7 24.3 -0.2 -0.1 33.4 29.9 Access Drift Return – Location 4 0 +0.1 25.7 24.3 -3.9 -3.0 33.6 30.0 Stope Return – Location 6 T DB & T WB was much dependant to the air volume delivered to the individual C&F stopes Stope Face (3W/2W/2WB) – Location 8 -0.4 -0.4 25.0 23.5 -1.4 -1.0 36.2 31.9 Auxiliary Pipe Discharge – Location 7 +1.0 +1.0 25.4 23.9 +2.5 +2.6 37.8 32.9 48” Aux. Duct after Fan – Location 3 _ 24.4 22.9 _ 35.3 30.3 48” Aux. Duct Intake – Location 1 ΔT WB (  C) 5700L 4810L T WB (  C) 5700L 4810L ΔT DB (  C) 5700L 4810L T DB (  C) 5700L 4810L LOCATION
    20. 20. <ul><li>The 5700L model was extended to include two sections of the main haulage ramp (5700L - 5475L) and (5475L - 5100L) </li></ul><ul><li>These two sections were considered worst-case-operational conditions </li></ul><ul><li>Example of data used for the 5700L – 5475L ramp section: </li></ul><ul><ul><li>Volume of air through this section: 71 m 3 /s </li></ul></ul><ul><ul><li>Intake airflow conditions from previous segment: </li></ul></ul><ul><ul><li>T DB =32.8 0 C; T WB =25.6 0 C </li></ul></ul><ul><ul><li>Equipment: Two 2.5 yd 3 LHD (2 x 86.5 kW); One 6yd 3 LHD (231 kW); Two diesel trucks (2 x 223.5 kW) </li></ul></ul><ul><li>Total diesel power: 851 kW </li></ul>Climatic Modelling – Main Haulage Ramp
    21. 21. Climatic Modelling – Main Haulage Ramp <ul><li>Climatic simulations along the (5700L - 5475L) section of the ramp predicted: T DB = 36.8 0 C & T WB = 27.2 0 C </li></ul><ul><li>T WB would only exceed the mine’s design criteria (T WB = 25.5 0 C) if all mining equipment would operate at the same time for prolonged period of time </li></ul><ul><li>Predicted T DB & T WB in the upper section (5475L - 5100L) had lower temperatures due to a higher air volume throughout this section </li></ul>
    22. 22. Climatic Simulation Summary – 170 Orebody and Haulage Ramp <ul><li>Temperature conditions predicted for the intake air to the 5700L would be: T DB =35.3 0 C and T WB =24.4 0 C </li></ul><ul><li>Changes between surface conditions (18.4 0 C/15.7 0 C) and 5700L   T DB =+16.9 0 C &  T WB =+8.7 0 C are mainly due to heat generated by auto-compression and main/booster fans </li></ul><ul><li>During concurrent activities (11.5 m 3 /s), the highest temperature conditions would occur at the common return location from the C&F stopes: T DB =33.6 0 C & T WB =25.7 0 C </li></ul><ul><li>Along the return airways the predicted temperatures decrease to T DB =32.8 0 C/T WB =25.6 0 C </li></ul><ul><li>Across the 5700L, heat generated by auto-compression, fans and machinery is rejected into the cooler surrounding rock (VRT=30.8 0 C) </li></ul><ul><li>For the 5700L - 5475L section of the main haulage ramp under worst-case-scenario conditions T DB /T WB was predicted to reach 36.8 0 C and 27.2 0 C – if all potential equipment operate </li></ul>
    23. 23. CONCLUSIONS <ul><li>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 </li></ul><ul><li>Output data generated through simulations were compared and validated vs. measured data (environmental & activity monitoring) </li></ul><ul><li>Environmental and activity monitoring showed concurrent mucking and drilling activities generating some of the highest temperatures </li></ul><ul><li>Elevated temperatures also occurred when auxiliary ventilation was not immediately adjusted to meet changes in production activity (  T DB =+9.4 0 C/  T WB =+3.5 0 C) </li></ul><ul><li>The climatic condition within the future 170 Orebody were predicted using the 4810L model transposed to the 5700L  airflow intake T DB /T WB , BP, VRT entered for that deeper level (5700L) </li></ul>
    24. 24. CONCLUSIONS – Continued <ul><li>Climatic simulations of the future 170 Orebody showed that with the simplified working area T WB = 25.5 0 C would not be exceeded </li></ul><ul><li>However, T WB could be exceeded in the individual C&F stopes depending on the mining activities and air volume delivered to the individual stopes </li></ul><ul><li>The only area where T WB would be exceeded is along the 5700L – 5475L section of the haulage ramp – if all potential equipment would operate simultaneously </li></ul><ul><li>Study showed that providing appropriate auxiliary ventilation distribution able to meet various operating requirements has the greatest role in maintaining adequate environmental conditions </li></ul>
    25. 25. Acknowledgement <ul><li>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 </li></ul>
    26. 26. Thank You <ul><li>Questions ? </li></ul>

    ×