Analyzing ventilation requirements and the utilization efficiency of the Kidd Creek mine ventilation system 12 th North American/U.S. Mine Ventilation Symposium Reno, Nevada, U.S.A., June 9-11, 2008

Analyzing ventilation requirements and the utilization efficiency of the Kidd Creek mine ventilation system Stephen Hardcastle, Charles Kocsis & Gary Li,Stephen Hardcastle, Charles Kocsis & Gary Li, CANMET – MMSL, Sudbury, Canada Kingsley HortinKingsley Hortin Hatch Associates, Sudbury, Canada (Formerly with Xstrata Copper, Kidd Creek, Timmins, Canada)

Kidd Creek Mine Northern Ontario Started as Open Pit in 1966 Mines #1, #2, #3 & now Mine D (Planned to Level 3,110m) Developed to Level 91 (2,770m) >7,000 tpd copper sulphide from Mines #3 & D 200 diesel units (>38,000hp) 50 Production units (>14,000hp)

Kidd Ventilation Surface New NVS Exhaust Fans 2 x 2,600kW (3,500hp) Open Pit (Cold Stope Intake)  7.5MWR #1 Shaft (7.5MWR Bulk Air Cooler) #2 Shaft SVR Exhaust Fan 1,300kW (1,750hp) Portal Ramp Access

Total Installed Primary System Fan Motor Power 13,600kW (  18,300hp) Operational Capacity 1,220m 3 /s (  2.6Mcfm) New Underground Booster Fans, 2 x 3,000kW (4,000hp) at 60 Level 1,800m below surface Kidd Ventilation Underground/Combined Very Significant Operating Cost Exhaust Air Plug Ø) would wrap around the Earth 25x per year X 25

Ventilation Reviews Objective - to reduce cost/improve efficiency Initial brainstorming review: Need to address routing of air to avoid high resistance fan assisted routes SVR system redundant with respect to Mines #3 & D More detailed review needed to assess efficiency and the need for increased ventilation management 1,500kW (2,000hp) Fan Power removed X

Detailed Reviews Available Data Long-term production plans such as - a month by month, 18-month schedule of activity - a year by year, 10+ year tonnage plan Historical data of daily equipment activity recorded by mines personnel Design Criteria 0.06 m 3 /s per kW diesel engine power (  100cfm/bhp)

Generalized Activities PRODUCTION Toro 1400 LHD (325hp) 14.5m 3 /s Shotcrete Hauler (240hp) 10.7m 3 /s DRILLING Cubex Aries ITH (147hp) 6.6m 3 /s Kubota M6800 Tractor (68hp) 3.0m 3 /s MISCELLANEOUS 14.5m 3 /s sufficient for standard LHD

Future Requirements Iteration #1 Predictive based upon 18-month plan Global 20% allowance for leakage & non-active levels Extrapolated based upon tonnage Minimum flow m 3 /s 1,220m 3 /s capacity should be sufficient Year Activity Total with Leakage

Future Requirements Iteration #1 – Possible Caveats Leakage of auxiliary systems ignored No allowance to prevent recirculation at auxiliary fans 20% allowance to inactive areas/leakage may be insufficient considering number of leaks Failing to provide sufficient air to non-productive areas for support activity Assumes timely redistribution of airflow Experience indicates 2 production LHD’s as a regular occurrence

Iteration #2 Predictive: 18-month plan & extrapolation Production  29m 3 /s, Drilling  14m 3 /s, Miscellaneous  20.7m 3 /s & Non-active  3.5m 3 /s System leakage 20% Minimum flow m 3 /s, Total including leakage Future Requirements Iteration #1 1,220m 3 /s capacity remains sufficient Still based upon working to an idealized plan Year 1,093918Iteration #2

Past Requirements Retrospective based upon production records SIMS end of shift data Work Location Diesel Unit Work Duration Shift Data exportable to Microsoft Excel

Past Requirements Pivot Table conditional analysis 1.Equipment identified and associated airflow requirement allocated to a mining level (or levels) 2.Assume concurrent activity and sum requirements per level per shift 3.Adjust to prevent recirculation at auxiliary fan i.e. where only a single vehicle operated 4.Allot minimum leakage flow – sufficient for small service vehicle (tractor) 5.Determine maximum flow needed for each level per averaging period: month, week, day

Past Requirements Pivot Table month based analysis of 36 Levels On average - each level “active”: 316 days/year & 31 of 36 levels “active”/day Flow requirements, 3.5 to 114m 3 /s, average 27m 3 /s Minimal Flows Maximum Flows Limited Inactivity

Past Requirements Pivot Table week based analysis of 36 Levels On average - each level “active”: 252 days/year & 25 of 36 levels “active”/day Lower average level airflow requirement of 19m 3 /s More Minimal Flow Shorter Duration Maximum Flows Increasing Inactivity

Past Requirements Pivot Table daily based analysis of 36 Levels On average - each level active: 174 days/year & 17.5 of 36 levels active/day Level airflow requirement now averages 11m 3 /s Minimal Flow The Norm Short Duration Maximum Flows Increasing Inactivity

Past Requirements Pivot Table Analysis Differences/Caveats Potential double accounting – same vehicle more than one location – this can happen Multiple vehicles, up to 5, generate high demands Available data provides duration but no time-stamp Consequently it was not possible to determine whether the activity was concurrent or sequential This backward analysis, based upon observed discontinuous activity, highlights maximum demand The previous forward analyses were based upon idealized continuous averaged activity

Efficiency/Redundancy System Efficiency ≠ Utilization Efficiency An efficient “System” is one with minimal leakage regardless of whether the air distribution is appropriate Utilization/redundancy is a function of whether the distribution meets/exceeds production demands All a question of definition: Today’s production air could be tomorrow's leakage Production demand – is that by day, week or month?

Airflow Requirements Lower Mine – Mines #3 & D Airflow requirement based upon monthly distribution with diesel based backfill Mine Delivery Capacity 1,220m 3 /s Monthly average with diesel backfill 1,261m 3 /s Demand greater than available supply hence perceived problems

Capacity 1,220m 3 /s Monthly average with diesel backfill 1,261m 3 /s Airflow requirement based upon monthly distribution with pastefill Monthly average with pastefill 983m 3 /s Airflow Requirements Lower Mine – Mines #3 & D

Monthly average with diesel backfill 1,261m 3 /s Capacity 1,220m 3 /s Monthly average with pastefill 983m 3 /s Airflow requirement based upon weekly distribution with pastefill Airflow Requirements Lower Mine – Mines #3 & D Weekly average with pastefill 681m 3 /s

Monthly average with diesel backfill 1,261m 3 /s Monthly average with pastefill 983m 3 /s Capacity 1,220m 3 /s Weekly average with pastefill 681m 3 /s Airflow requirement based upon daily distribution with pastefill Daily average with pastefill 400m 3 /s Airflow Requirements Lower Mine – Mines #3 & D

Monthly average with diesel backfill 1,261m 3 /s Monthly average with pastefill 983m 3 /s Weekly average with pastefill 681m 3 /s Capacity 1,220m 3 /s Daily average with pastefill 400m 3 /s Production plan based monthly requirement with diesel placed backfill, average 642 m 3 /s Airflow Requirements Lower Mine – Mines #3 & D

Analysis Findings Historical analysis shows the dynamic nature of production in a base metal mine – constant change Hence perceived under performance/inadequacy Future plan based requirements are optimistic Airflow distribution need to be managed to limit total volume of air supplied- significant benefits More frequent redistribution lowers the redundancy - the optimum would be daily Redistribution frequency needs to be more often than future planning period to operate within the design capacity

Ventilation Management Primary system is automated Secondary system control is being considered

Ventilation Management Mine introduced more frequent redistribution of secondary airflow & adjustment of primary system 1.Production Engineering schedule upcoming activities automatically producing airflow demands 2.Ventilation Department reviews requirements and produce an action plan 3.Operations Group implement changes prior to the commencement of the next week’s work activities

Realized Benefits Power Savings from …. Elimination of a surface fan (initial review) Numerous auxiliary fans turned off on inactive levels Reduced demand/lower operating point for the 2 x 3000kW boosters On average the mine now operates on 930 m 3 /s which is 23% less than delivered at the start of the review process The number of ventilation related complaints has decreased

Conclusions Base metal mining is never constant Ventilation needs vary with changing activity Overall demand depends on how often the ventilation is adjusted Significant differences between operational needs if airflows are redistributed daily, weekly or monthly Long range plans are idealized averages - actual operation is different Both Forward and Backward analyses have a place - both can have limitations Ventilation management can save power & money - it can also be simple

Acknowledgements: Xstrata Copper – Kidd Creek Mine