appendix 33-d comminution circuit energy comparison between hpgr circuit and sabc circuit

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APPENDIX 33-D
COMMINUTION CIRCUIT ENERGY COMPARISON
BETWEEN HPGR CIRCUIT AND SABC CIRCUIT
TM
Report to:

SEABRIDGE GOLD INC.
Kerr-Sulphurets-Mitchell (KSM) Comminution Circuit Energy
Comparison Between HPGR Circuit and SABC Circuit
Document No. 1052880100-REP-R0007-01

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The content of this document is not intended for the use of, nor is it intended to be relied upon by any person, firm or
corporation, other than the client and Tetra Tech Wardrop (Tetra Tech). Tetra Tech denies any liability whatsoever to
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R E V I S I O N H I S T O R Y
REV. PREPARED BY REVIEWED BY APPROVED BY
NO ISSUE DATE AND DATE AND DATE AND DATE DESCRIPTION OF REVISION
00 June 25, 2012 T. L. June 25, 2012 J. H. June 25, 2012 J. H. June 25, 2012 Updated report to BC Hydro for
comments
01 August 24, 2012 T. L. August 24, 2012 J. H. August 24, 2012 J. H. August 24, 2012 Final report to BC Hydro

1052880100-REP-R0007-01
T A B L E O F C O N T E N T S
1.0 SUMMARY .......................................................................................................................... 1
1.1 KSM PROJECT BACKGROUND ............................................................................................... 1
1.2 WORK SCOPE ....................................................................................................................... 1
1.3 TEST WORK REVIEW ............................................................................................................. 2
1.4 ENERGY CONSUMPTION COMPARISON ................................................................................... 2
1.5 CONCLUSIONS ...................................................................................................................... 3
2.0 SCOPE OF WORK .............................................................................................................. 4
3.0 INTRODUCTION ................................................................................................................. 6
4.0 TEST WORK REVIEW ........................................................................................................ 7
4.1 SABC TEST RESULTS (2007 TO 2011) .................................................................................. 7
4.1.1 SULPHURETS MINERALIZATION ............................................................................. 8
4.1.2 KERR MINERALIZATION ........................................................................................ 9
4.2 SABC CIRCUIT SIZING SIMULATION (2008 TO 2011) ............................................................ 10
4.3 HPGR OPTION ................................................................................................................... 12
4.3.1 SGS LABORATORY-SCALE TESTING (2009) ........................................................ 12
4.3.2 KOEPPERN PILOT-SCALE TEST RESULTS (2010) ................................................. 13
5.0 PROCESS COMPARISON ............................................................................................... 16
5.1 DESIGN CRITERIA ............................................................................................................... 16
5.2 SABC OPTION .................................................................................................................... 16
5.2.1 EQUIPMENT SPECIFICATIONS ............................................................................. 16
5.2.2 PROCESS DESCRIPTION ..................................................................................... 17
5.3 HPGR OPTION ................................................................................................................... 17
5.3.1 EQUIPMENT SPECIFICATIONS ............................................................................. 17
5.3.2 PROCESS DESCRIPTION ..................................................................................... 17
5.4 FLOWSHEETS/LAYOUT ........................................................................................................ 18
5.5 EQUIPMENT/LOAD LIST ........................................................................................................ 18
5.6 ENERGY CONSUMPTION COMPARISON ................................................................................. 18
5.6.1 SABC OPTION ENERGY DATA ............................................................................ 18
5.6.2 HPGR OPTION ENERGY DATA ........................................................................... 19
5.6.3 ENERGY COST SAVINGS .................................................................................... 20
5.7 CAPITAL COSTS .................................................................................................................. 21
5.8 OPERATING COSTS ............................................................................................................. 21
5.9 SIMPLE PAYBACK ................................................................................................................ 23
5.10 SABC AND HPGR COMPARISON ......................................................................................... 23
ii 1052880100-REP-R0007-01
5.10.1 SABC OPTION ................................................................................................... 23
5.10.2 HPGR OPTION .................................................................................................. 24
5.11 PROPOSED METERING ........................................................................................................ 24
6.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................. 25

L I S T O F T A B L E S
Table 1.1 Total Energy Conservation Measures .............................................................. 2
Table 4.1 SMC Test Results ............................................................................................ 7
Table 4.2 BWi Test Results – Mitchell (2008) .................................................................. 8
Table 4.3 Bond Work Index – Mitchell (2009/2010) ......................................................... 8
Table 4.4 Bond Work Index Test Results – Sulphrets ..................................................... 9
Table 4.5 BWi Test Results - Kerr .................................................................................... 9
Table 4.6 SMC Test Results – Mitchell, Sulphurets, Kerr 2011....................................... 9
Table 4.7 JK SimMet Simulation Results for 60,000 t/d (One Stream), 2008 ............... 10
Table 4.8 Blended Ore Breakage (2008 and 2011) ....................................................... 11
Table 4.9 JK SimMet Simulation 1 Results, 60,000 t/d (One Stream) – 2011 .............. 11
Table 4.10 JK SimMet Simulation 2 Results for 60,000 t/d (One Stream) – 2011 .......... 12
Table 4.11 HPGR Average Test Results – LCTs (2009 – 2010) ..................................... 13
Table 5.1 Process Design Criteria ................................................................................. 16
Table 5.2 Estimated Electrical Power – SABC Option ................................................... 19
Table 5.3 Estimated Electrical Power – HPGR Option .................................................. 20
Table 5.4 Total Electrical Power Cost for SABC and HPGR Option ............................. 20
Table 5.5 Capital Cost Summary Comparison ............................................................... 21
Table 5.6 Comminution Circuit Operating Cost Comparison ......................................... 22

L I S T O F F I G U R E S
Figure 2.1 Simplified Flowsheet – SABC Option ............................................................... 4
Figure 2.2 Simplified Flowsheet – HPGR Option .............................................................. 5
Figure 4.1 HPGR Net Specific Energy Consumption vs. Cycle Number (2010) ............ 14
Figure 4.2 Specific Throughput (ts/hm3) vs. Cycle Number (2010) ................................ 15

L I S T O F A P P E N D I C E S
APPENDIX A SABC OPTION – FLOWSHEET
APPENDIX B SABC OPTION – LAYOUT
APPENDIX C SABC OPTION – COMMINUTION CIRCUIT LOAD LIST
iii 1052880100-REP-R0007-01
APPENDIX D SABC OPTION – CAPITAL AND OPERATING COST ESTIMATES
APPENDIX E HPGR OPTION – FLOWSHEET
APPENDIX F HPGR OPTION – LAYOUT
APPENDIX G HPGR OPTION – COMMINUTION CIRCUIT LOAD LIST
APPENDIX H HPGR OPTION – CAPITAL AND OPERATING COST ESTIMATES
APPENDIX I SGS HPGR AND KOEPPERN HPGR TEST REPORTS
G L O S S A R Y
TERM ABBREVIATION
abrasion index ................................................................ Ai
annum/year .................................................................... a
British Columbia Hydro and Power Authority ................. BC Hydro
Bond ball mill work index ................................................ BWi
cubic metre ..................................................................... m3
dollars – Canadian ......................................................... Cdn$
dollars – United States ................................................... US$
drop weight index ........................................................... DWi
effective grinding length ................................................. EGL
foot ................................................................................. ft
G&T Metallurgical Services Ltd. ..................................... G&T
gigawatt hour .................................................................. GWh
gram ............................................................................... g
grams per tonne ............................................................. g/t
High Pressure Grinding Rolls ......................................... HPGR
Hazen Research Inc. ...................................................... Hazen
hours .............................................................................. h
inch ................................................................................. in
JKTech Pty Ltd. .............................................................. JKTech
KHD Humboldt Wedag International Ltd. ....................... KHD
kilometre ......................................................................... km
Koeppern Machinery Australia Pty Ltd. .......................... Koeppern
Kerr-Sulphurets-Mitchell ................................................. KSM
kilowatt ........................................................................... kW
kilowatt hour per tonne ................................................... kWh/t
kilowatt second per hour ................................................ kWs/h
kilovolt ............................................................................ kV
kilovolt amps reactive hours ........................................... kVARh
iv 1052880100-REP-R0007-01
TERM ABBREVIATION
life of mine ...................................................................... LOM
locked cycle tests ........................................................... LCTs
megawatt ........................................................................ MW
metre .............................................................................. m
microns ........................................................................... µm
millimetre ........................................................................ mm
million ............................................................................. M
million tonnes ................................................................. Mt
million tonnes per year ................................................... Mt/a
Mitchell Treaty Tunnel .................................................... MTT
Newton per square millimetre ........................................ N/mm2
Treaty Ore Preparation Complex ................................... Treaty OPC
Polysius Corporation ...................................................... Polysius
preliminary economic assessment ................................. PEA
run-of-mine ..................................................................... ROM
semi-autogenous grinding .............................................. SAG
SAG mill-ball mill-pebble crushing ................................. SABC
Seabridge Gold Inc. ....................................................... Seabridge
semi-autogenous mill comminution ............................... SMC
SGS Minerals Services .................................................. SGS
tonnes seconds per hour metre cubed
(specific throughput constant) ........................................ ts/hm3
tonnes ............................................................................. t
tonnes per year .............................................................. t/a
tonnes per day ................................................................ t/d
tonnes per hour .............................................................. t/h
University of British Columbia ........................................ UBC
Tetra Tech Wardrop. ...................................................... Tetra Tech

v 1052880100-REP-R0007-01
1 . 0 S U M M A R Y
This energy study report evaluates the application of a cone crusher crushing/high
pressure grinding rolls (HPGR) ball mills circuit (HPGR option) as an alternative
technology to conventional semi-autogenous grinding (SAG)/ball mills circuit (SABC
option) for the Kerr-Sulphurets-Mitchell (KSM) Project owned by Seabridge Gold Inc.
(Seabridge).
1.1 KSM PROJECT BACKGROUND
The KSM Project will be a 130,000 tonnes per day (t/d) open pit operation with ore
processed in a conventional flotation and cyanide leach plant. The proposed
process plant will produce gold-silver doré, copper-gold concentrate, and
molybdenum concentrate from the porphyry mineralization. The produced
concentrates will be transported to the Port of Stewart for shipment to offshore
smelters. After receipt of construction and operating permits, the KSM Project will
take approximately five years of construction time to complete; with an additional
possible six months of start-up and commissioning activities. The overall life of mine
(LOM) will be approximately 55 years. Production is scheduled to commence at the
Mitchell pit, to be augmented by Sulphurets and Kerr pits and then underground
mines at the lower Mitchell deposit and Iron Cap deposit. The LOM average mill
feed grades are 0.207% copper, 0.0045% molybdenum, and 0.549 g/t gold.
Tetra Tech Wardrop (Tetra Tech) completed a preliminary economic assessment
(PEA) report for the KSM Project in 2008 for Seabridge, in which a SABC circuit was
used for the grinding process. Tetra Tech subsequently updated the PEA report in
2009 by choosing HPGR circuit as an alternative to the SABC milling option. In
2010, the KSM Project was further investigated at a prefeasibility level by Tetra Tech
and a HPGR circuit was again used in that evaluation.
1.2 WORK SCOPE
In this report, the SABC option is further compared with the HPGR option in terms of
energy consumption and capital and operating cost estimates using pre-feasibility-
level data and information. All currencies are expressed in Canadian (Cdn) dollars,
unless otherwise specified. When it is applicable, costs in US currency have been
converted using a fixed currency exchange rate of Cdn$1.00 to US$0.96. The
expected accuracy range of the capital cost estimate is +25/-15%.
Seabridge Gold Inc. 1 1052880100-REP-R0007-01
Kerr-Sulphurets-Mitchell (KSM) Comminution Circuit Energy Comparison
Between HPGR Circuit and SAG Circuit
1.3 TEST WORK REVIEW
The related test work for SABC option was conducted by Hazen Research Inc.
(Hazen) in 2008 and G&T Metallurgical Services Ltd. (G&T) in 2011. Contract
Support Services Inc. performed the circuit power requirement simulations based on
the semi-autogenous mill comminution (SMC) test results. For the HPGR option,
SGS Minerals Services (SGS) conducted a bench scale testing program in 2009,
which was followed by a pilot testing program conducted in the Koeppern Machinery
Australia Pty Ltd (Koeppern) facility at the University of British Columbia (UBC),
Vancouver.
The test work results, combined with industry experience, indicated that the KSM
Project mineralization is amenable to either SABC grinding or crushing using
secondary crushers and HPGR crushers followed by ball mill grinding.
1.4 ENERGY CONSUMPTION COMPARISON
The estimates showed that the total installed power requirement for the HPGR option
is approximately 106.7 MW with a running power of approximately 83.1 MW. The
energy consumption on a yearly basis is estimated to be 673 GWh/a. The SABC
option has a total installed power of 122.9 MW, with a running power 100.6 MW. The
SABC option requires additional 17.5 MW of running power when compared to the
total running power of the HPGR circuit. The annual energy consumption of the
SABC option is approximately 821 GWh/a, which is 147 GWh/a more than the HPGR
option.
The capital cost of the HPGR option will be approximately Cdn$141 million higher
than the SABC option. However, the total operating cost savings will be significant,
at approximately Cdn$33 million per year, which includes energy savings of
Cdn$14 million, and other non-energy savings of Cdn$19 million per year.
Considering only the energy savings, the simple payback period of the HPGR option
versus the SABC option is about 10 years. If considering the overall operating cost
savings, the simple payback will be just under five years.
Table 1.1 summarizes the energy conservation comparison between the SABC and
HPGR options, where the SABC option is the baseline option.
Table 1.1 Total Energy Conservation Measures
Energy Electricity Cost Capital Cost Incremental Capital Cost Simple
Savings Savings per Year (HPGR Option) Using HPGR Option Payback
(kWh/a) (Cdn$'000) (Cdn$'000) (Cdn$'000) (years)
147,221,666 14,109 819,831 140,919 10
Seabridge Gold Inc. 2 1052880100-REP-R0007-01
Kerr-Sulphurets-Mitchell (KSM) Comminution Circuit Energy Comparison
Between HPGR Circuit and SAG Circuit