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Amulsar Gold Project
Crushing Circuit
Trade-off Study
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REVISION CONTROL
Issued for Internal Coordination
Issued for use
REVISION HISTORY
Revision Pages Revised Remarks
PB All Included Client’s Comments. Adjusted Capex battery limits to match the KDE Capex estimate.
PC All Various minor corrections.
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DISCLAIMER
This document contains the expression of the professional opinion of SNC-Lavalin
Australia Pty Ltd (“SLA”) as to the matters set out herein, using its professional
judgment and reasonable care. This document is written solely for the purpose stated
in the Agreement and for the sole and exclusive benefit of the Client, whose remedies
are limited to those set out in the Agreement. This document is meant to be read as a
whole and sections or parts thereof should thus not be read or relied upon out of
context.
SLA has, in preparing the cost estimates, followed methodology and procedures and
exercised due care consistent with the intended level of accuracy using its professional
judgment and reasonable care and is thus of the opinion that there is a high probability
that actual costs will fall within the specified error margin. However, no warranty
should be implied as to the accuracy of estimates.
Unless expressly stated otherwise, assumptions, data and information supplied by, or
gathered from, other sources (including the Client, other consultants, testing
laboratories and equipment suppliers, etc.) upon which SLA’s opinion as set out herein
is based have not been verified by SLA and SLA makes no representation as to its
accuracy and disclaims all liability with respect thereto.
To the extent permitted by law, SLA disclaims any liability to third parties in respect of
the publication, reference, quoting, or distribution of this report or any of its contents to
and reliance thereon by any third party.
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TABLE OF CONTENTS
1.0 EXECUTIVE SUMMARY .................................................................................... 7
2.0 INTRODUCTION ................................................................................................ 9
3.0 DEFINITIONS AND GLOSSARY ..................................................................... 11
4.0 SCOPE OF STUDY AND METHODOLOGY .................................................... 17
4.1 Scope of Work ............................................................................................. 17
4.2 Exclusions ................................................................................................... 19
4.3 Battery Limits .............................................................................................. 19
4.4 Process Streams ......................................................................................... 20
4.4.1 Inputs ............................................................................................................ 20
4.4.2 Outputs ......................................................................................................... 20
4.4.3 Reagents ...................................................................................................... 20
4.4.4 Utilities .......................................................................................................... 20
4.5 Study Methodology ..................................................................................... 20
4.5.1 Process Design Package .............................................................................. 20
4.5.2 Design Basis ................................................................................................. 21
4.5.3 Process Design ............................................................................................. 21
4.5.4 Engineering Design ....................................................................................... 22
4.5.5 Procurement ................................................................................................. 23
4.5.6 Capital Cost Estimate .................................................................................... 23
5.0 OPTIONS ANALYSIS ....................................................................................... 24
5.1 Circuit Options Discussion ........................................................................ 25
6.0 PROCESS PLANT DESCRIPTION .................................................................. 31
6.1 Area 2110 Primary Crushing ...................................................................... 32
6.2 Area 2120 Secondary Screening ................................................................ 35
6.3 Area 2130 Secondary Crushing ................................................................. 36
6.4 Area 2140 Tertiary Screening ..................................................................... 37
6.5 Area 2150 Tertiary Crushing....................................................................... 38
6.6 Area 2160 Product Loadout ........................................................................ 39
6.7 Area 2900 Plant Heating ............................................................................. 39
6.8 Fuel Supply.................................................................................................. 40
6.9 Personnel Accommodation and Transport ............................................... 40
6.10 Process Buildings and Facilities ............................................................... 40
7.0 CAPITAL COST ESTIMATE ............................................................................ 41
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7.1 Equipment ................................................................................................... 42
7.1.1 Bulk Earthworks ............................................................................................ 42
7.1.2 Plant Buildings .............................................................................................. 42
7.2 Structural - Concrete .................................................................................. 42
7.3 Structural – Steelwork ................................................................................ 42
7.4 Mechanical................................................................................................... 43
7.5 Piping ........................................................................................................... 43
7.6 Electrical ...................................................................................................... 43
7.7 Instrumentation ........................................................................................... 43
7.8 Miscellaneous Items ................................................................................... 43
7.9 Indirect Costs .............................................................................................. 43
7.10 EPCM Costs ................................................................................................. 43
7.11 Estimate Accuracy ...................................................................................... 44
7.12 Contingency ................................................................................................ 44
7.13 Battery Limits .............................................................................................. 44
7.14 Estimate Exclusions ................................................................................... 44
7.14.1 Commissioning ............................................................................................. 45
8.0 ESTIMATE COMPARISON .............................................................................. 46
APPENDIX A CRUSHING CIRCUIT OPTIONS ............................................................ 50
APPENDIX B CAPITAL COST ESTIMATE .................................................................. 51
APPENDIX C PROCESS DESIGN CRITERIA .............................................................. 52
APPENDIX D PROCESS FLOW DIAGRAMS .............................................................. 53
APPENDIX E PIPING AND INSTRUMENTATION DIAGRAMS ................................... 54
APPENDIX F MECHANICAL EQUIPMENT LIST ......................................................... 55
APPENDIX G ELECTRICAL LOAD LIST ..................................................................... 56
APPENDIX H PIPING, LINE AND VALVE LIST ........................................................... 57
APPENDIX I SINGLE LINE DIAGRAMS ...................................................................... 58
APPENDIX J LAYOUT AND PERSPECTIVE DRAWINGS .......................................... 59
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LIST OF TABLES
Table 3-1 Abbreviations, Acronyms and Terms ........................................................................ 11
Table 4-1 Study Deliverable List ............................................................................................... 17
Table 4-2 Crushing and Screening Plant Design Basis – Key Parameters ............................... 21
Table 5-1 Circuit Configuration Options Summary .................................................................... 24
Table 5-2 Installed vs Drawn Power - Crusher Summary ......................................................... 30
Table 7-1 Capital Cost Estimate Summary ............................................................................... 41
Table 8-1 Estimate Inclusions Comparison ............................................................................... 46
Table 8-2 Capital Cost Estimate Comparison ........................................................................... 47
LIST OF FIGURES
Figure 2-1 Amulsar Project Locality Map .................................................................................... 9
Figure 5-1 Option 1 Flowsheet ................................................................................................. 26
Figure 5-2 Option 10 Flowsheet ............................................................................................... 28
Figure 6-1 Crushing and Screening Plant Process Flow Diagram ............................................ 31
Figure 6-2 Crushing and Screening Plant Overall Layout ......................................................... 32
Figure 6-3 Primary Crusher Plant ............................................................................................. 32
Figure 6-4 Primary Crusher Plant ............................................................................................. 34
Figure 6-5 Example of a Primary Gyratory Crusher Installation ................................................ 34
Figure 6-6 Secondary & Tertiary Screening Plant ..................................................................... 35
Figure 6-7 Example of a Cone Crusher .................................................................................... 36
Figure 6-8 Example of a Double-Deck Banana Screen............................................................. 37
Figure 6-9 Secondary & Tertiary Crushing Plant....................................................................... 38
Figure 6-10 Example of a Typical Industrial Hot Water Boiler ................................................... 39
Figure 6-11 Example of a Typical Industrial Heater .................................................................. 40
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1.0 EXECUTIVE SUMMARY
Lydian International Ltd. commissioned SNC-Lavalin to conduct a crushing circuit
trade-off study for the Amulsar Gold Project located in Armenia. A feasibility study was
conducted earlier in 2012 for this project by KD Engineering.
The original concept was based on developing the project in two phases, each being
capable of crushing and screening 5 Mtpa of gold and silver bearing ore in preparation
for heap leaching. Following the feasibility study Lydian wished to examine an
alternative option of utilising a processing rate of 10 Mtpa from the start and as the
base case production scenario. To improve project NPV the proposed plant would be
designed to process 10 Mtpa of the ROM ore to produce a crushed product with the
particle size of less than 12 mm in preparation for heap leaching and the subsequent
recovery of gold.
The trade-off study summarised in this report aimed to:
• Conduct modelling of various configuration of the crushing and screening plant.
• Provide a summary of the selected equipment and operating parameters for each
option studied.
• Select a single option to be used as a basis for the development of the capital cost
estimate (CAPEX).
Ten different crushing and screening plant configurations were assessed and
compared. The options study examined various sizes and numbers of equipment used
in each of the three crushing and the associated screening stages. Option 10 was
selected for the development of the detailed capital cost estimate. This option consists
of one primary gyratory crusher (62/75), two secondary double-deck banana vibrating
screens, two secondary MP800st (or equivalent) cone crushers, three tertiary double-
deck banana vibrating screens and three tertiary MP800sh (or equivalent) cone
crushers. At this level of comparison, and following discussions with vendors, none of
the options considered appeared to have significant advantage in terms of operating
cost.
The proposed circuit configuration is expected to provide a robust plant with suitable
catch up and sprint capability to be able to cater for the adverse weather conditions.
Given the nature of heap leaching operations, the location of the project and the
climatic conditions in the area these factors are expected to be key components in
achieving the targeted plant throughput.
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The capital cost estimate for the selected crushing and screening plant, as per specified
battery limits, inclusions and exclusions, is provided in the following table.
Area Area Total Cost (USD) % of Cost
Crushing & Screening 71,442,822 50.4
Services 12,765,293 9.0
Sub-Total Direct Costs 84,208,115 59.4
Plant Wide Earthworks 10,861,910 7.7
EPCM 14,500,0000 10.2
Growth 8,800,000 6.2
Contingency 19,500,000 13.8
Spares 1,410,000 1.0
Vendor Reps 1,500,000 1.05
First Fill 1,000,000 0.7
Sub-Total Indirect Costs 57,571,910 40.6
Grand Total 141,780,025 100.0
The level of accuracy of the estimate obtained in this study is of the magnitude of
±15%.
It should be noted that this trade-off study was focused on the crushing and screening
plant component of the project. Any considerations associated with the relative location
of the mining area and heap leaching pads were outside of the scope of this study. As
such these factors may present potential opportunity for further optimisation of the plant
configuration.
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2.0 INTRODUCTION
The Amulsar gold project is located 170 km south of Armenia's capital Yerevan on the
border between the provinces (Marz) of Vayots Dzor and Sunnik. Lydian International
holds two Mineral Exploration Licences and a mining licence for the Artavasdes and
Tigranes open pit at Amulsar, through its 100% owned Armenian subsidiary Geoteam
CJSC. The Amulsar licences cover a total of 65 km2. The location of the project is
illustrated in Figure 2-1 below.
Figure 2-1 Amulsar Project Locality Map
Lydian International conducted a feasibility study carried out by KD Engineering in
Tucson, Arizona, USA. Various references are made in this document to this study.
The feasibility study was based on the plant concept consisting of two crushing and
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screening trains in parallel, with each train being capable of processing 5 Mtpa. The
proposed project would be brought online in two phases, commencing with a single
production train of 5 Mtpa and increasing to 10 Mtpa with the addition of another
production train in Year 4.
Following the above feasibility study completed by KD Engineering Lydian wished to
investigate an alternative option of utilising the ore processing rate of 10 Mtpa as a
base case production scenario. SNC-Lavalin Australia were commissioned to provide
a trade-off study to investigate the 10 Mtpa crushing and screening circuit option. The
study was based on evaluation and comparison of various configurations of the
crushing and screening circuit and developing engineering details and a cost estimate
for a selected configuration. The proposed project would be designed to process
10 Mtpa of the ROM ore to produce a crushed product with a P80 of 12 mm in
preparation for heap leaching and the subsequent recovery of doré.
The key objectives of the trade-off study were:
• To conduct modelling of various configuration of the crushing and screening plant.
• To provide a summary of the selected equipment and operating parameters for
each option studied.
• To select a single option to be used as a basis for the development of the capital
cost estimate.
This report provides a summary of the findings resulting from the trade-off study and a
capital cost estimate for the selected crushing and screening plant configuration.
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3.0 DEFINITIONS AND GLOSSARY
Various abbreviations, acronyms and terms used throughout this report are explained in
Table 3-1.
Table 3-1 Abbreviations, Acronyms and Terms
Abbreviation Explanation
C/I Civil and Infrastructure
CIF Cost Insurance Freight
CMMS Central Maintenance Management System
CPPC Contractor Progress Payment Certificate
CPU Central Processing Unit
CWi Crushing Work Index
CSS Closed Side Setting (Crusher Setting)
DCN Data Communication Network
DDU Delivered Duties Unpaid
DFS Definitive Feasibility Study
DOL Direct On-line
dP Differential Pressure
Dt/h Unit of mass throughput, dry tonnes per hour
E East
E/I Electrical and Instrumentation
EIA Environmental Impact Assessment
EPCM Engineering Procurement and Construction Management
EPB Emergency Push Button
ER Emergency Response
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Abbreviation Explanation
ESIA Environmental Statement and Impact Assessment
Ethernet A family of frame-based computer network technologies for local area networks
Excel™ Software application, Microsoft® Excel™
GST Goods and Services Tax
H Unit of time, hour
Ha Unit of area, hectare
HART Highway Addressable Remote Transducer
HV High Voltage
HVAC Heating Ventilation Air Conditioning
IEC International Electro-technical Commission
I/O Input/Output
IR Infrared
ISA Instrumentation Systems and Automation Society
ISO International Organization for Standardization
IT Information Technology
J/m3K Unit of heat capacity, joules per cubic metre degree Kelvin
Km Unit of length, kilometre
kN Unit of force, kilonewton
kPa Unit of pressure, kilopascal
kV Unit of electromotive force, kilovolt
kWh/t Unit of power consumption, kilowatt per hour per tonne
L Unit of volume, litre
LAN Local Area Network
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Abbreviation Explanation
LCB Local Control Board
LME London Metal Exchange
LOA Letter of Award
LV Low Voltage
M Unit of length, metre
m/s Unit of speed, metres per second
mA Unit of current, milliamp
MCC Motor Control Centre
MetSim Commercially available mass and energy balancing software
mg/m3 Unit of concentration, milligrams per cubic metre
Min Unit of time, minute
MIS Management Information System
Mm Unit of length, millimetre
MRR Materials Receiving Report
MPa Unit of pressure, megapascal
MSHA Mines Safety and Health Administration
MSDS Material Safety Datasheet
Mtpa Unit of mass throughput, mega (10 6) tonnes per annum
MTO Materials Take-Off
MV Medium Voltage
mV Milivolts
MW Unit of power, megawatt
N North
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Abbreviation Explanation
NB Nominal Bore
NDT Non-Destructive Testing
NFPA National Fire Protection Association
NL/min Unit of volumetric flow rate, normal litres per minute
Nm3/h Unit of volumetric flow rate, normal cubic metres per hour
NPV Net Present Value
On-Stream Factor Measure of time, expressed as a percentage, used to define the overall time equipment is expected to be operational
OCS Operator Control Station
OD Outside Diameter
P80 Size at which 80 per cent of the mass of a sample will pass a screen
P100 Size at which 100 per cent of the mass of a sample will pass a screen
P&ID Piping and Instrumentation Diagram
PAR Procurement Action Request
PC Personal Computer
PCS Plant Control System
PFC Power Factor Correction
PFD Process Flow Diagram
PID Proportional Integral Derivative
PIP Project Implementation Plan
PLC Programmable Logic Controller
PM Preventative Maintenance
PM+ SNC-Lavalin International proprietary project management tool
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Abbreviation Explanation
Project Amulsar Crushing Plant Options Study
PO Purchase Order
PPC Progress Payment Certificate
PPE Personal Protective Equipment
PRA Project Risk Analysis
PT 100 Temperature sensor made from platinum
PVC Poly Vinyl Chloride
Qf Heat loss, measured in Watts
QA/QC Quality Assurance/Quality Control
QMS Quality Management System
RCM Reliability Centred Maintenance
RFI Request for Information
RFQ Request for Quotation
ROM Run-of-Mine
RTD Resistance Temperature Detector
SCADA Supervisory Control and Data Acquisition
SCP Slave Processor Communication Program
SIL Safety Integrity Level
SNC-Lavalin SNC-Lavalin Pty Ltd, member of SLI
SLI SNC-Lavalin Inc
SOP Standard Operating Procedure
SQL Structured Query Language
T Unit of mass, metric tonne
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Abbreviation Explanation
t/a Unit of mass throughput, tonnes per annum
t/h Unit of mass throughput, tonnes per hour
t/t Unit of concentration, tonnes per tonne
TPL Third Party Logistics Provider
TV Television
µm Unit of length, micron
µs Unit of time, microsecond
VAC Unit of electromotive force, Volts, AC Power
VDU Video Display Unit
V/h Unit of turnover, volume per hour
VVVF Variable Voltage Variable Frequency
Word Software application, Microsoft® Word ™
W/m2/°C Unit of heat transfer, watts per unit area per degree Celsius
w/w Proportion of one unit compared to another on a weight basis
WBS Work Breakdown Structure
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4.0 SCOPE OF STUDY AND METHODOLOGY
4.1 Scope of Work
The following table provides a list of deliverables for the Amulsar Gold Project trade-off
study.
Table 4-1 Study Deliverable List
Item Document Number
Process & General
Study Report 140192-30RF-I-0001
Process Design Criteria 140192-0000-49EC-0001
Mass and Water Balance 140192-0000-49EB-0001
(included in drawing no.: 140192-2000-49D1-0001)
Crushing Circuit Options Summary 140192-0000-49EB-0002
Drawings
Process Flow Block Diagram 140192-2000-49D3-0001
Plant Flow Diagram – Schematic 140192-2000-49D3-0002
Stream Flow Data 140192-2000-49D1-0001
Primary Crushing 140192-2110-49D1-0001
Secondary Screening 140192-2120-49D1-0001
Secondary Crushing 140192-2130-49D1-0001
Tertiary Screening 140192-2140-49D1-0001
Tertiary Crushing 140192-2150-49D1-0001
Product Loadout 140192-2160-49D1-0001
Building Heating - hot water supply 140192-2960-49D1-0001
Building Heating 140192-2960-49D1-0002
Primary Crushing 140192-2110-49D4-0001
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Item Document Number
Secondary Screening - Sheet 1 140192-2120-49D4-0001
Secondary Screening - Sheet 2 140192-2120-49D4-0002
Secondary Crushing - Sheet 1 140192-2130-49D4-0001
Secondary Crushing - Sheet 2 140192-2130-49D4-0002
Tertiary Screening - Sheet 1 140192-2140-49D4-0001
Tertiary Screening - Sheet 2 140192-2140-49D4-0002
Tertiary Screening - Sheet 3 140192-2140-49D4-0003
Tertiary Crushing - Sheet 1 140192-2150-49D4-0001
Tertiary Crushing - Sheet 2 140192-2150-49D4-0002
Tertiary Crushing - Sheet 3 140192-2150-49D4-0003
Product loadout 140192-2160-49D4-0001
Building heating - hot water supply 140192-2960-49D4-0001
Building heating - Sheet 1 140192-2960-49D4-0002
Building heating - Sheet 2 140192-2960-49D4-0003
Building heating - Sheet 3 140192-2960-49D4-0004
Engineering
Mechanical Equipment List 140192-2000-45EL-1001
Electrical Load List 140192-6100-47EL-0001
Site layout – Plan 140192-2000-4LD1-0001
Site Layout – Perspective 140192-2000-4LD1-0002
Primary Crushing Building - Perspective 140192-2000-4LD1-0003
Secondary and Tertiary Screening Building - Perspective 140192-2000-4LD1-0004
Secondary and Tertiary Crushing Building - Perspective 140192-2120-4LD1-0005
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Item Document Number
Civil Layout - Plan 140192-2000-41D2-0001
Power Distribution Single Line Diagram – Sheet 1 140192-6100-47EL-0001
Power Distribution Single Line Diagram – Sheet 2 140192-6100-47EL-0002
Power Distribution Single Line Diagram – Sheet 3 140192-6100-47EL-0003
Estimating
Capital Cost Estimate 140192-0000-33KB-0001
Basis of Estimate 140192-0000-33KB-0002
4.2 Exclusions
The following items were excluded from the scope of work:
• Metallurgical test work
• Mining
• Geology
• Infrastructure
• Owner’s costs
• Project Financial Modelling
• Survey, geotechnical, hydrology, hydrogeology and site based investigations.
4.3 Battery Limits
The battery limits for the circuit studied were defined as follows:
• Inlet to the primary crusher
• Outlet of the tertiary crushing to the fine ore transfer conveyor
• Air, water and power defined as ‘over the fence’ and the battery limit conditions
stated.
There was some discussion between SNC-Lavalin and Lydian International following
the issue of the formal proposal regarding the back-end of the plant battery limit. It was
agreed that for the purpose of this study the effective battery limit will be the discharge
of the tripper conveyor feeding the crushed ore surge bin. SNC-Lavalin have proposed
two shuttle conveyors in lieu of the tripper conveyor to feed the crushed ore bins prior
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to the overland conveyor. However, for the capital cost estimate, in order to enable a
direct comparison with the KD Engineering estimate, the KDE’s estimate for the fine
ore bin and the lime silo were added to the SNC-Lavalin estimate to ensure that the
same battery limits are covered.
4.4 Process Streams
4.4.1 Inputs
• ROM ore.
• Raw water at a nominated point on the crushing plant boundary.
• Power at a nominated point on the crushing plant boundary.
4.4.2 Outputs
• Fine ore to the product loadout.
• Exhaust and vent gas/dust streams terminate at the limit of the building or
process equipment discharge line.
4.4.3 Reagents
The reagent associated with the part of the plant under consideration of this study is
lime. It was not included in the scope of the trade-off study, but the cost of the storage
silo and the associated equipment was added to the estimate using the KD
Engineering design and cost to ensure that both estimates cover the same battery
limits.
4.4.4 Utilities
• Electrical power at the HV inlet terminals of the plant distribution transformer for
electrical reticulation.
• Water supply (fresh, potable, fire, safety shower supply, etc.) to be defined.
• Storm water drains were not included in the scope of this study.
4.5 Study Methodology
4.5.1 Process Design Package
A number of crushing and screening circuit configurations were reviewed to determine
an optimum design to take forward to the engineering phase of the study. The range of
configurations and advantages and disadvantages of each option were reviewed with
Lydian in reaching a decision.
The crushing circuit was based on an engineering design produced by SNC-Lavalin
and presented in this report. The design includes the following information:
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• Block Flow Diagram
• Process Flow Diagrams
• Development of a mass balance for the proposed flowsheet
• Development of process design criteria
• Equipment list including equipment sizing
• Design calculations as required
4.5.2 Design Basis
The key design criterion provided by Lydian and used to guide the design philosophy
was the ore processing rate of 10 Mtpa. The primary operating parameters used in the
design are summarised in Table 4-2 below. The process design criteria document
number 140192-0000-49EC-0001 containing a full set of the relevant information is
appended for reference.
Table 4-2 Crushing and Screening Plant Design Basis – Key Parameters
Parameter Value Unit
Plant throughput rate, nominal 10 000 000 t/a
Plant throughput rate, design 11 500 000 t/a
Plant throughput rate, nominal 1 565 t/h
Plant throughput rate, design 1 800 t/h
Operating days per annum 355 days
Operating days per week 7 days
Operating hours per day 24 hours
Operating hours per annum (effective, feed on) 6 390 hours
Crushed ore particle size (P80) 12 mm
4.5.3 Process Design
Following discussions with Lydian on the various aspects of the flowsheet development
and the final circuit configuration selection, the proposed crushing plant design was
further modelled using Metsim software. The process design criteria were developed
based on SNC-Lavalin’s in-house database, information provided by the Client, and
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Bruno modelling results. In completing preliminary equipment design, the critical
design parameters, such as flows and compositions of streams, were compared with
typical plant practice to ensure that where assumptions have been made, that these
are reasonable. A summary of the critical operational parameters is shown at the start
of the design criteria.
The material balances, which incorporate solution and solids flows, were used for
sizing of equipment, bins, pumps and tanks. The mass balance is presented in the
Appendix D with flows relating to the stream numbers depicted on the stream data
PFD. The mass balance focuses on mass flows of solids within the overall flowsheet.
Preliminary and conceptual Piping and Instrumentation Diagrams (P&IDs) were
developed as part of this study. Piping, instrumentation and valve requirements were
also determined.
4.5.4 Engineering Design
The following preliminary information was generated in sufficient detail for a capital cost
estimate to the specified accuracy to be prepared:
• Mechanical Equipment List.
• Electrical load list, developed from the Mechanical Equipment List and vendor
data, used to calculate power consumption.
• Process Flow Diagrams.
• Design Calculations.
• General Arrangement Drawings.
• Bulk Materials Takeoffs from the plant model.
• Datasheets for major equipment.
4.5.4.1 Climatic Conditions
The climatic conditions in the area necessitated the following considerations:
• Crusher and screening buildings are enclosed and heated via hot water
system/hot air fan assisted heat exchangers.
• Access and egress between the crushing and screening plants undertaken via
enclosed walkways located in conveyor gantries to provide all weather access
within the plant.
4.5.4.2 Earthworks
The proposed plant is located in a high seismic zone, hence foundations for the
buildings and equipment must be founded on competent surfaces, significant cutting
into the rock faces to ensure competent surfaces will be necessary.
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Earthworks on this project will represent a significant capital cost. SNC-Lavalin at this
juncture have not been provided with complete survey details as indicated in the
feasibility study layouts undertaken for the project to date.
For comparison purposes a preliminary earthworks model has been developed which
indicates the proposed new layout of the crushing and screening plant will reduce the
cut and fill requirements by approximately 10% when compared with the previous
feasibility study layout.
Base data – KD’s scheme for crushing and screening plants cut to fill ratio 12.8:1,
current 11.5:1. The potential for a further reduction of the cut requirements exists with
extensive modification of the earthworks, hence providing a more balanced cut to fill
ratio, however this will require re-orientation of the plant and extensive engineering to
determine the cost benefit, hence currently these factors have not been considered in
this phase of the project development.
4.5.5 Procurement
Procurement packages were developed from the Mechanical Equipment List.
Datasheets were prepared for major equipment packages. Multiple source bids were
sought for major equipment packages from vendors known to provide cost competitive
bids for the equipment. For minor equipment packages, single source bids were
sought. Australian vendors only were approached but with representatives in Europe
where appropriate.
4.5.6 Capital Cost Estimate
The methodology employed in generating the capital cost estimate, including direct and
indirect costs for the project is provided in Section 7. On this basis, capital costs within
the specified level of accuracy were generated.
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5.0 OPTIONS ANALYSIS
The first step in the trade-off study was to model and analyse various circuit
configuration options. Different circuit configurations and equipment sizes as well as
equipment numbers were considered.
The simulations were performed using Metso’s Bruno software and as such the
equipment selection shown for comparative purposed is based on Metso equipment.
However, this does not indicate that SNC-Lavalin recommends using Metso equipment
and other crusher and screen vendors were invited to provide equivalent equipment
prices for the purpose of this study. An equivalent crusher and/or screen size would be
used where appropriate.
The details of all of the evaluated options are provided in the Appendix A. A summary
showing the major equipment in each option is presented in Table 5-1.
Table 5-1 Circuit Configuration Options Summary
Option Primary
Crushing Secondary Crushing
Secondary Screening
Tertiary Crushing
Tertiary Screening
1 1 x 62/75 1 x MP1000st 1 x 3661-2 2 x MP1000sh 2 x 3073 – 1
2 1 x 62/75 2 x MP800st 2 x 2461-2 2 x MP800sh 2 x 3673 – 1
3 1 x 54/75 1 x MP1000st 1 x 3661-2 2 x MP1000sh 1 x 3073 – 1
4 1 x 62/75 1 x MP1000st 1 x 3661-2 3 x MP800sh 3 x 1861 – 1
5 1 x 62/75 2 x MP800st 2 x 1861-2 3 x MP800sh 3 x 1861 – 1
6 1 x 50/65 2 x MP800st 2 x 1861-2 3 x MP800sh 3 x 1861 – 1
7 1 x 54/75 2 x MP800st 2 x 1861-2 3 x MP800sh 3 x 1861 – 1
8 1 x 54/75 2 x MP800st 2 x 1861-2 4 x HP800sh 4 x 3661 – 2
9 1 x 54/75 2 x MP800st 2 x 2461-2 2 x MP800sh 2 x 3673 – 1
10 1 x 62/75 2 x MP800st 2 x 3061-2 3 x MP800sh 3 x 3673 - 2
There were ten options considered, with some further minor variants, which were not
deemed suitable and thus are not reported. In addition to the plant throughput rate and
product particle size target, the common features of the ten options are:
• Each option consists of three stages of crushing.
• Each option includes secondary and tertiary screening.
• Each option utilises a single gyratory crusher in the primary duty, albeit
considering various crusher sizes in different options.
• All secondary screens used in calculations were double-deck screens.
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• In each option the secondary crushing and screening stage was configured as
open circuit. High level evaluation indicated that closing of the secondary circuit
is impractical in this case. It results in high recirculating load and leads to
uneven distribution of energy utilisation throughout the plant.
• Each option utilised a tertiary circuit in a closed circuit variant, with the tertiary
screen oversize being recirculated to the tertiary crusher feed bin.
• All secondary duty crushers were standard size head.
• All tertiary duty crushers were short head units (to enable tighter settings).
The key differences between the ten options are:
• The primary crusher size was ranged from 50/65 to 62/75.
• The number of secondary crusher units was either one or two.
• MP1000st and MP800st secondary crushers were used.
• Various sizes of double-deck screen sizes with various aperture sizes were
used depending on crusher types.
• Option 8 was set up to approximate the configuration selected by KD
Engineering.
• Three different types of crushers were used in the tertiary duty. These
included: HP800sh, MP800sh and MP1000sh.
• Between 2 and 4 crusher units were used in the tertiary duty.
• Screen sizes were varied and either single or double-deck screens were used.
• Options 1 to 6 used the tertiary circuit feed rate lower than the primary and
secondary, requiring larger intermediate buffer storage capacity.
• Option 10 was further modified by removing the material in the final size product
from the secondary screen undersize. In all other options the secondary screen
undersize was configured to be fed to the tertiary crushing and screening
circuit.
5.1 Circuit Options Discussion
A schematic simplified process flow diagram for the Option 1 is shown in Figure 5-1.
Option 1 utilises a 62/75 gyratory crusher followed by a single unit secondary crusher
and screening stage. In this configuration a MP1000st crusher was selected. The
tertiary crushing and screening stage includes two MP1000sh crushers. The primary
crusher will be fed at a design tonnage of 1 800 t/h. The crusher discharge will be
screened using a double-deck vibrating screen. The screen oversize will then report to
the secondary crusher and the undersize will be transferred to the tertiary crushing and
screening circuit. The tertiary circuit will be fed at a design tonnage of 1 400 t/h. This
indicates that a large intermediate buffer storage capacity would be required between
the secondary and tertiary parts of the plant.
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Figure 5-1 Option 1 Flowsheet
The configuration used in the Option 1 would not facilitate operating of the tertiary
circuit at the same rate as the primary and secondary part of the plant. The two tertiary
crushers will not have sufficient throughput capacity to be able to process 1 800 t/h. At
this tonnage screening would become inefficient and crushers would be overloaded.
The operating philosophy in this case would be to operate the tertiary circuit at a lower
throughput rate but over a longer period of time i.e. using higher overall utilisation of
the tertiary circuit. The configuration used in Option 1 will result in fewer secondary
and tertiary equipment numbers then the subsequent options, potentially leading to
reduced capital expenditure but, at the same time, it will require a relatively large
intermediate buffer storage capacity. At the same time, fewer equipment numbers
would reduce redundancy and cause inability to operate the plant at a reduced
throughput, for example when the secondary crusher is taken off line for maintenance
or any other reason. Additionally, the limited capacity of the tertiary circuit will reduce
the potential for catch up and sprint capability of the plant, but these factors may be
significant aspects of the plant operation given the climatic conditions and nature of
heap leaching operations.
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In Option 2 the single MP1000st secondary crusher was replaced with two MP800st
units. This configuration improves the operability of the secondary circuit and
increases the maximum theoretical capacity of the primary and secondary circuits.
However, with two MP800sh crushers in the tertiary duty the spare capacity of this part
of the circuit is limited above the design 1 400 t/h and the intermediate buffer storage is
required.
Option 3 is a variant of Option 1 with the primary gyratory crusher size reduced to
54/75. There is some capital expenditure benefit resulting from this selection.
However, the reduction in the size of the primary crusher necessitates an increase in
the close side setting to enable processing of the required tonnage throughput. The
effect of this is that the reduction ratio in the primary crusher is decreased implying that
more work will have to be done in the secondary and tertiary crushing stages in order
to achieve the required product particle size distribution.
Option 4 has the same primary and secondary configuration of Option 1. The
difference is that two MP1000sh crushers in the tertiary duty are replaced with three
MP800sh crushers. In this configuration it is possible to operate the whole plant at the
same throughput rate of 1 800 t/h without surge capacity, or one of the tertiary crushers
may be taken off line for maintenance, or other reasons, without the necessity to stop
the whole plant.
Option 5 is a modified Option 4. It contains the same primary and tertiary configuration
as Option 4, but a single MP1000st crusher in the secondary duty is replaced with two
MP800 st crushers facilitating operating of the circuit at reduced tonnage should any of
the secondary crushers need to be taken off line and in this way increasing the overall
plant utilisation. This circuit configuration may be operated with or without the
intermediate buffer storage capacity.
Option 6 has the same configuration as Option 5, but the primary gyratory crusher is
replaced with a smaller unit – 50/65. The reduced primary crusher would be expected
to result in some capital expenditure reduction, but the crusher would be operated
under a relatively high load with only limited spare capacity. Also, the size of maximum
particle that may be fed to the primary crusher would be reduced by 250 mm.
Option 7 has the same secondary and tertiary configuration as Option 6, but the
primary gyratory crusher is increased to 54/75, increasing the robustness of the circuit
and having an increased spare capacity relative to the Option 6.
Option 8 has the secondary and tertiary configuration based on the circuit proposed by
KD Engineering in the feasibility study. The difference is that the instead of two
primary jaw crusher a single 54/75 gyratory primary crusher is used. This option was
based on the concept of ramping up the production throughput in two phases and as
such it does not appear to be the most effective choice when aiming for the production
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target of 10 Mtpa from the start. Multiple (four) smaller tertiary crusher may have some
merit when intermediate buffer storage capacity is used, but when the whole plant is
operated at 1 800 t/h taking one tertiary crusher off line would result in the other three
becoming overloaded. Additionally, the installed power in this circuit is at least 20%
higher than for any of the other options, which were designed for the throughput of
10 Mtpa from the start.
Option 9 is a variation of Option 7, but with one tertiary crusher removed. Removal of
one crusher and screen results in the equipment cost reduction, but in this option
intermediate buffer storage capacity is required, as the tertiary crushing and screening
circuit would become overloaded if operated at the same rate as the primary and
secondary part of the plant. It would be expected that the reduction in cost due to the
elimination of one tertiary crusher and one tertiary screen would be negatively offset by
having to provide a significant intermediate buffer storage capacity in the form of a
stockpile or a large bin.
Figure 5-2 Option 10 Flowsheet
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Option 10 depicted in Figure 5-2 contains the equipment configuration that was
selected as a basis for the trade-off study and the subsequent development of the
capital cost estimate.
Option 10 consists of one primary gyratory crusher (62/75), two secondary double-deck
banana vibrating screens, two secondary MP800st cone crushers, three tertiary
double-deck banana vibrating screens and three tertiary MP800sh cone crushers.
Another feature of this option is that the secondary screen undersize will be routed
directly to the product stream rather than being first conveyed to the tertiary screening
section as is the case in Options 1 to 9. This is aimed to increase the flexibility of the
circuit by reducing the load to the tertiary crushing and screening and to prevent the
potential undesirable generation of fines resulting from rehandling of particles that are
already within the specified product particle size distribution. At present Lydian are
allowing 10 days of downtime per annum for adverse weather conditions during which
no mining operations are planned to occur.
The footprint of the Option 10 plant was reduced by eliminating the crushed ore
stockpile that would be typically used as a buffer storage facility either after the primary
or after the secondary crushing stages. Intermediate storage and buffer capacity is
particularly significant in operations that require a substantial period of operating time
to achieve steady state conditions and which are sensitive to stoppages that may
cause a decreased in efficiency or metal recoveries. A crushing and screening
operation, like the one proposed for the Amulsar project, is capable of achieving steady
state in a short period of time (within minutes). In the proposed plant configuration any
buffer storage requirements would be dealt with at both ends of the circuit – by
management of the mining fleet, ROM stockpile and by providing surge capacity at the
end of the circuit to cater for stoppages of the overland conveyor. The proposed circuit
configuration is expected to provide a robust plant with ample catch up and sprint
capability. Given the nature of heap leaching operations, the location of the project and
the climatic conditions in the area, these factors are expected to be key components in
achieving the targeted plant throughput.
Estimating of operating costs for each of the options considered was not carried out as
part of this study. However, power draws for major equipment considered in the
options comparison (crushers and screens) were estimated to vary by less than
240 kW between the ten options. Using a basis of 6 390 operating hours per annum,
10 Mtpa plant throughput and an assumed power cost of USD 0.05/kWh, the 240 kW
range would translate to a variation in the opex cost between the ten options of less
than 1 cent per tonne of ore processed. It is therefore anticipated that, under normal
operating conditions, none of the options considered would have a significant
advantage, or disadvantage, in terms of operating cost in relation to the other options.
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The following Table 5-2 provides a comparison of crushers power installed and power drawn for Option 8 (based KD Engineering feasibility study) and Option 10 (the selected flowsheet) for the current trade-off study.
Table 5-2 Installed vs Drawn Power - Crusher Summary
Stage
Option 8
(KDE Based Configuration)
Option 10
(Trade-off Study Selection)
Installed (MW) Drawn (MW) Installed (MW) Drawn (MW)
Primary Crusher 0.44 0.29 0.34 0.26
Secondary Crushers 1.20 0.66 1.20 0.62
Tertiary Crushers 2.40 0.65 1.80 0.71
Total 4.04 1.60 3.34 1.60
As discussed in preceding paragraphs, the difference in power drawn between the
options considered was found to be negligible, resulting in minor differences in terms of
expected impact on the plant operating cost. However, there are capital cost savings
to be realised in Option 10 as, in relation to Option 8, the installed crusher power is
17% lower in this flowsheet providing a more efficient configuration.
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6.0 PROCESS PLANT DESCRIPTION
The Crushing Plant Description should be read in conjunction with the Process Flow
Diagrams provided in the Appendix D. An overall plant process flow diagram is shown
in Figure 6-1.
Figure 6-1 Crushing and Screening Plant Process Flow Diagram
Figure 6-2 on the following page illustrates the general layout of the proposed crushing
and screening facility forming part of the overall Amulsar Gold Project.
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Figure 6-2 Crushing and Screening Plant Overall Layout
6.1 Area 2110 Primary Crushing
The Primary Crushing section is shown in the PFD number: 140192-2110-49D1-0001
in the Appendix D. The primary crusher plant is also illustrated in Figure 6-3 and
Figure 6-4.
Figure 6-3 Primary Crusher Plant
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It is planned to mine ore from a number of pits in order to achieve the required mine
production rate. The general process sequence for the Amulsar Gold Project will start
in the mine pits with loading of ROM ore into trucks which will take the ore to the ROM
pad, where it will be tipped into a Primary Crusher Dump Pocket (2110-BN-001).
Tipping will be from both sides of the dump pocket. From the dump pocket, ore will
gravitate into the Primary Gyratory Crusher which will reduce the ROM ore from a
nominal top lump size of 700 mm diameter to a top size of 355 mm and P80 of
approximately 130 mm. Some re-handle on the ROM pad to maintain plant utilisation
is expected.
At full production the total design feed rate will be 1800 t/h. The Primary Crusher has
been sized to process the largest pieces of ROM ore at 700 mm diameter. However,
the design of the selected crusher enables feeding particles of up to 1 260 mm if
required and as may be necessitated by the mining operations.
Coarse ore lumps which block the crusher throat will be broken up by a Rock Breaker
(2110-RB-001) located adjacent to the Primary Crusher Dump Pocket (2110-BN-001).
Ore which has passed through the crusher will enter the Primary Crusher Discharge
Bin from where the ore is withdrawn by a Primary Crusher Low Profile Belt Feeder
(2110-CV-001). The low profile belt feeder will discharge onto the Primary Crusher
Discharge Conveyor (2120-CV-001).
The primary crusher will be fitted with dust collection equipment (2110-PK-001) and the
production tonnage will be monitored by the Primary Crusher Discharge Belt
Weightometer (2110-WE-001).
When the primary crusher is out of service for maintenance, the ore from the pit will be
dumped on the adjacent ROM pad. From here it will be rehandled for feeding into the
Primary Crusher using front end loaders.
At the discharge end of the Primary Crusher Discharge Conveyor, any entrained tramp
metal will be collected by the Tramp Magnet (2110-MG -001). Recovered tramp metal
will be dropped at intervals via the Tramp Magnet Discharge Chute (2110-CH-004) into
a Tramp Magnet Bin (2110-BN-003). Ore from the Primary Crusher Discharge
Conveyor will gravitate via the Primary Discharge Conveyor Head Chute (2110-CH-
001) to the Secondary Screen Feed Conveyor (2120-CV-001) which will be fitted with a
Primary Crusher Discharge Weightometer (2110-WE-001). The Secondary Screen
Feed Conveyor will discharge via the Secondary Screen Feed Conveyor Head Chute
(2120-CH-001) to the secondary screen feed bin.
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An example of a typical primary gyratory crusher installation is shown in
Figure 6-5
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Figure 6-4 Primary Crusher Plant
An example of a typical primary gyratory crusher installation is shown in
5 Example of a Primary Gyratory Crusher Installation
Date: Page
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An example of a typical primary gyratory crusher installation is shown in Figure 6-5.
Example of a Primary Gyratory Crusher Installation
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6.2 Area 2120 Secondary Screening
The Secondary Screening section is shown in the PFD number: 140192-2120-49D1-
0001 provided in the Appendix D and it is also illustrated graphically in Figure 6-6.
Secondary Screen Feed Bins will have two discharge points, each of which will feed
ore to the secondary screening circuit comprising two parallel belt feeders, double deck
screens and product conveyors. Ore withdrawn from Secondary Screening Feed Bins
(2120-BN-201, 202) will be fed via Secondary Feed Bin Discharge Chutes (2120-CH-
101, 201) by Secondary Screen Belt Feeders (2120-FB-101, 201) onto Secondary
Double-Deck Screens (2120-SN-101, 201). Each screen will be fitted with two screen
decks. The upper screen will have 75 mm square apertures while the lower screen will
have 20 mm square apertures.
Secondary screen oversize will gravitate via the Secondary Screen O/S Chutes (2120-
CH-104, 204) to the Secondary Oversize Conveyor (2130-CV-001). The Secondary
Screens product will pass via Secondary Screen Discharge Chutes (2120-CH-103,
203) to the Secondary Screen U/S Conveyor (2160-CV-001).
Dust control will be provided by ductwork on all major transfer points.
The secondary screen O/S conveyor will discharge to Secondary Crusher Feed Bins
(2130-BN-101, 201). The secondary screen U/S conveyor will discharge to the Fine
Ore Bin. The secondary/tertiary screening equipment will be fitted with dust collection
equipment (2140-PK-001) comprising a dry baghouse, fan and associated ductwork.
Figure 6-6 Secondary & Tertiary Screening Plant
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6.3 Area 2130 Secondary Crushing
The Secondary Crushing section is shown in the PFD number: 140192-2130-49D1-
0001.
The Secondary Crushing Feed Bin will have two discharge points, each of which will
feed ore to the secondary crushing circuit comprising two parallel belt feeders, cone
crushers and crushed product conveyors.
Ore withdrawn from Secondary Crusher Feed Bins (2130-BN-101, 201) will be fed via
the Secondary Crushing Feed Bin Discharge Chutes (2130-CH-101, 201) by the
Secondary Crusher Belt Feeders (2130-FB-101, 201) via the Secondary Crusher Feed
Chutes (2130-CH-102, 202) into the Secondary Crushers (2130-CR-101, 201).
Secondary crusher discharge will gravitate via the Secondary Crusher Discharge
Chutes (2130-CH-103,203) to the Secondary Crusher Discharge Conveyor (2140-CV-
001).
Dust control will be provided by ductwork on all major transfer points.
The secondary crusher discharge conveyor will discharge to Tertiary Screening Feed
Bins (2140-BN-101,201,301).
An illustration of a typical cone crusher that would be used in the proposed duty is
shown in Figure 6-7.
Figure 6-7 Example of a Cone Crusher
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6.4 Area 2140 Tertiary Screening
The Tertiary Screening section is shown in the PFD number: 140192-2130-49D1-0001.
Tertiary Screening Feed Bins will have three discharge points, each of which will feed
secondary and tertiary crushed product to the tertiary screening circuit comprising three
parallel vibrating feeders, double deck screens and product conveyors. Ore withdrawn
from Tertiary Screening Feed Bins (2140-BN-101,201,301) will be fed via the Tertiary
Feed Bin Discharge Chutes (2140-CH-101,201,301) by the Tertiary Screen Vibrating
Feeders (2140-FV-101,201,301) onto Tertiary Double-Deck Screens (2140-SN-
101,201,301).
Tertiary screen oversize will gravitate via the Tertiary Screen O/S Chutes (2130-CH-
010,011,012) to the Tertiary Screen Oversize Conveyor (2140-CV-001). The Tertiary
Screen product (undersize) will be conveyed to the crushed ore surge been prior to
being transported via the overland conveyor to heap leach stacking. Each screen will
be fitted with two screen decks. The upper screen will have 32 mm square apertures
while the lower screen will have 18 mm square apertures.
Dust control will be provided by ductwork on all major transfer points.
Figure 6-8 Example of a Double-Deck Banana Screen
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6.5 Area 2150 Tertiary Crushing
The Tertiary Crushing section is shown in the PFD number: 140192-2150-49D1-0001.
The Tertiary Crushing Feed Bin will have three discharge cones, each of which will
feed ore to a tertiary crushing circuit comprising three belt feeders and three short head
cone crushers.
Ore withdrawn from the Tertiary Crusher Feed Bin (2150-BN-101, 201 & 301) will be
fed via the Tertiary Crushing Feed Bin Discharge Chutes (2150-CH-101, 301) by the
Tertiary Crusher Belt Feeders (2150-FB-101, 201 & 301) via the Tertiary Crusher Feed
Chutes (2150-CH-101, 201 & 301) into the Tertiary Crushers (2150-CR-101, 201 &
301).
Tertiary crusher discharge will gravitate via the Tertiary Crusher Discharge Chutes
(2150-CH-101, 201 & 301) to the Tertiary Crusher Discharge Conveyor (2140-CV-001).
Dust control will be provided by ductwork on all major transfer points.
The Tertiary Crusher Discharge Conveyor will discharge to the Tertiary Screening Feed
Bin (2140-BN-101,201,301).
Figure 6-9 Secondary & Tertiary Crushing Plant
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6.6 Area 2160 Product Loadout
The Product Loadout section is shown in the PFD number: 140192-2160-49D1-0001.
The Crushed Ore Surge Bin will be located adjacent to the Tertiary Screening Building,
and will be of an equivalent height. The crushed ore surge bin will have interconnected
walkways to allow operator access and for heating.
6.7 Area 2900 Plant Heating
The Plant Heating section is shown in PFDs number: 140192-2960-49D1-0001 & 0002
provided in the Appendix D.
The heating system design is based on a hot water supply. The hot water will be
supplied using a boiler package 2960-PK-001 and circulated to the plant building. Heat
exchanger and fan propelled heaters are proposed for this duty. Illustrations of a
typical boiler and heat-exchanger type heater that could be used in this duty are shown
in Figure 6-10 and Figure 6-11.
Figure 6-10 Example of a Typical Industrial Hot Water Boiler
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Figure 6-11 Example of a Typical Industrial Heater
6.8 Fuel Supply
Fuel, gas and lubricants will be dispensed as an “over-the-fence” supply contract by a
fuel supply company. These are outside of the scope of this study. An installation of
appropriately sized facility to match the Project demands will be required.
6.9 Personnel Accommodation and Transport
No allowance has been made in the crushing plant estimate for operating personnel
accommodation and transport.
6.10 Process Buildings and Facilities
Process-related buildings to be constructed on the plant site will include:
• Central control room housing the PLCs and SCADA system; including ablutions
for operational staff.
• Boiler house.
• MCCs and PLC rooms (equipped with filtered, forced air ventilation and fire
suppression system).
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7.0 CAPITAL COST ESTIMATE
A capital cost estimate (CAPEX) has been undertaken for the proposed revised layout.
The relevant estimating documentation, showing detailed breakdown of each area, is
provided in the Appendix B. The capital cost estimate summary for the revised
crushing and screening plant layout is summarised in Table 7-1. The crushing and
screening component contains an adjustment of USD 6,794,916 to allow for the
inclusion of the fine ore bin and lime silo and which is based on the KD Engineering
estimate as agreed in discussions between Lydian International and SNC-Lavalin.
Table 7-1 Capital Cost Estimate Summary
Area Area Total Cost (USD) % of Cost
Crushing & Screening 71,442,822 50.4
Services 12,765,293 9.0
Sub-Total Direct Costs 84,208,115 59.4
Plant Wide Earthworks 10,861,910 7.7
EPCM 14,500,0000 10.2
Growth 8,800,000 6.2
Contingency 19,500,000 13.8
Spares 1,410,000 1.0
Vendor Reps 1,500,000 1.05
First Fill 1,000,000 0.7
Sub-Total Indirect Costs 57,571,910 40.6
Grand Total 141,780,025 100.0
The level of accuracy obtained in this study is of the magnitude of ±15%, a summary of
the estimate build-up and parameters associated with the capital cost estimate are
provided in the Appendix B.
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7.1 Equipment
• Mechanical equipment: quotations sourced from the market via vendors with a track
record in the industry, sole sourcing from some vendors was adopted to reduce
overall study timeline, detailed specification driven multiple vendor bids may be
undertaken in the next study phase to maximize cost competitiveness.
• Electrical equipment: quotations sourced from the market via vendors with a track
record in the industry.
• Instrumentation and Controls: conceptual P&ID’s produced, costs factored utilising
in-house data.
7.1.1 Bulk Earthworks
• Terrain 3D model developed from SD contours provided by Lydian International
Ltd.
• Cut and fill quantity MTO developed from the earthworks 3D model.
7.1.2 Plant Buildings
• Control Room Building cost estimated by cost/m2 basis.
7.2 Structural - Concrete
Concrete foundation MTO’s are generated on a plant area basis:
• Preliminary design of main concrete footings, slabs and rafts. Concrete outline
models generated.
• Concrete is categorized by specific footing types and concrete volumes extracted
from the 3D model, rebar rates applied from database for specific footing types,
slab types etc.
7.3 Structural – Steelwork
Steelwork MTO’s are generated on a plant area basis:
• Preliminary structural design of main members, steelwork models generated.
• Steelwork tonnages extracted on area basis from the 3D model and grouped into
categories, light, medium, heavy and extra heavy members, grid mesh, handrail,
stairs and ladders.
• Preliminary design of fabricated steelwork, bins etc, platework and stiffeners by
manual MTO produced.
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7.4 Mechanical
• Mechanical equipment – refer to section 7.1.
• Mechanical platework items are assigned a unique equipment number e.g. chutes,
distribution boxes etc.
• Ductwork for dust extraction system and baghouses via manual MTO.
• Manual MTO’s are generated on a plant area basis.
7.5 Piping
• Piping for hot water system via manual MTO.
• Manual Valves: manual quantity take-off based on the conceptual P&ID’s.
7.6 Electrical
• Electrical Equipment, refer to section 7.1.
• LV distribution, cables schedules etc, based on overall layout and factored via
database.
• Medium Voltage (6.6kV) VSDs are used as soft starters.
• Cable trays, linear metres, manual take-off.
7.7 Instrumentation
Instrumentation interface and PCS I/O requirements was factored from similar project
via in-house database.
7.8 Miscellaneous Items
Manual MTO’s were produced to accommodate items where modelling has not been
undertaken.
7.9 Indirect Costs
Indirect costs include:
• Mobilization and demobilization costs of the construction workforce.
• Growth Allowance: quantities which are known to be required, but lacking in detail
have a growth allowance applied.
7.10 EPCM Costs
EPCM costs include:
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• Engineering – design, bid evaluation, shop detailing and spooling.
• Procurement - tenders, buying, expediting, inspection, warehousing.
• Project Management, scheduling, project controls, commercial management and
contract management.
• Construction Management, stores management and equipment hire management.
7.11 Estimate Accuracy
Estimate accuracy is in-line with estimating norms, for a Class 3 to 4 study estimate
with a magnitude of plus 15% minus 15%.
7.12 Contingency
Allowance for the unknown, which is included as an indirect cost.
7.13 Battery Limits
The battery limits for the capital cost estimate encompass:
• Retaining wall at the interface with the ROM (run of mine) Primary Crusher
Feed Bin.
• Shuttle feed conveyor chute discharge interface to the crushed fine ore bin.
However, it was agreed that KDE design and estimate will be used for the
purpose of the fine ore bin and lime silo costing to facilitate a direct comparison
with the SNC-Lavalin estimate.
• Incoming terminals of the HV distribution board 6100-HV-001 shown on
SLD140192-2000-47D1-0001 and located at the crushing and screening plant.
• All automated control functions will be performed on the plant PCS provided by
others. The battery limit for instrumentation is the I/O rack and a marshalling
panel located in the crushing and screening plant.
7.14 Estimate Exclusions
The following items are not incorporated in the process plant capital cost estimate.
The following items are excluded from this estimate:
• ROM pad and retaining wall.
• Roads and drainage.
• Crushed fine ore bins, support steelwork and concrete foundations are based
on the KD Engineering design and estimate.
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• Crushed fine ore bin building.
• Main Plant PCS.
• Utility pipework, inclusive of:
o Fire water system
o Potable water system
o Plant and instrument air system
o Process water system
o Raw water system
o Internal drainage pipework within the buildings and collection/distribution
system
7.14.1 Commissioning
No allowance has been made for a commissioning team or support from the
construction team with respect to commissioning and should be included as Owners
Cost.
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8.0 ESTIMATE COMPARISON
A comparison of inclusions and exclusions between the study estimate and the
feasibility study estimate prepared by KD Engineering are highlighted in Table 8-1.
Table 8-1 Estimate Inclusions Comparison
SNC-Lavalin Trade-off Study Estimate KD Engineering Estimate
Buildings heated for cold climatic
conditions.
Not stated in the information pack
provided.
Boiler building, boiler and heat exchanger
units and piping system allowed for in the
estimate.
Not stated in the information pack
provided.
Building, roof and side sheeting
composite sandwich construction for cold
climatic conditions.
Not stated in the information pack
provided.
Conveyors covered and walkways
allowed on enclosed conveyor gantries
allowing internal access to buildings.
Not stated in the information pack
provided.
Concrete raft concept design for all
buildings for seismic design
considerations.
Not stated in the information pack
provided.
Building purlins and girts designed for
snow load/additional loadings with
respect to the selection of composite
sheeting.
Not stated in the information pack
provided.
HV Transformers, concrete slab and blast
wall, foundation and bund wall
incorporated.
Not stated in the information pack
provided.
The following Table 8-2 provides a comparison of the original KDE Engineering
estimate, SNC-Lavalin estimate and the KDE estimate adjusted using various factors
and subsequently explained.
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Table 8-2 Capital Cost Estimate Comparison
Area KDE Original
Estimate (USD) SNC-Lavalin
Estimate (USD) Adjusted KDE
Estimate (USD)
Direct Costs
Primary Crushing &
Screening 12,994,231 12,831,201 12,994,231
Secondary Crushing &
Screening 23,017,856 19,647,155 23,017,856
Tertiary Crushing &
Screening 27,426,687 30,219,359 27,426,687
Product Loadout 8,856,745 1,950,191 8,856,745
Buildings Included above 12,765,293 Included above
Sub-Total Directs 72,295,519 77,413,199 72,295,519
Indirect Costs
Earthworks 11,765,000 10,861,910 11,765,000
EPCM 19,277,222 14,500,000 19,277,222
Owners Costs 6,000,000 Not itemised 6,000,000
Spare Parts 4,676,700 1,410,000 4,676,700
First Fill 1,185,900 1,000,000 1,185,900
Vendor Reps Not itemised 1,500,000 Not itemised
Mobile Equipment 1,855,000 Not itemised 1,855,000
Growth Allowance Not itemised 8,800,000 Not itemised
Contingency 19,069,206 19,500,000 19,069,206
Sub-Total Indirects 52,064,028 46,710,000 52,064,028
Total Cost 136,124,547 134,985,109 136,124,547
Adjustments
Concrete - - 10,000,000
Electrical & Instr. - - 8,500,000
Escalation - - 1,019,000
Product Loadout - 6,794,916 -
Adjusted Total Cost 136,124,547 141,780,025 155,643,529
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The column labelled “KDE Estimate” provides an extract from the original estimate
covering the crushing and screening plant. The column “SNC-Lavalin Estimate”
provides a summary of the crushing and screening cost as currently developed by
SNC-Lavalin. The adjusted total cost includes the product loadout section adjustment.
This adjustment was introduced to ensure that the two estimates are compared on the
same basis and using the same battery limits. Following discussions with Lydian it was
agreed that the cost estimate of fine ore bins and lime storage silo will be added to the
SNC-Lavalin estimate for this purpose.
SNC-Lavalin conducted a high level review of the KD Engineering estimate and
subsequently proposed a number of adjustments, which in SNC-Lavalin’s opinion
would result in a more realistic estimate. This is summarised in the column labelled
“Adjusted KDE Estimate”.
The first major consideration is the cost of concrete. KDE used a figure of USD 150
per cubic metre, which is considered to be significantly understated. Additionally, in an
email dated 19/10/2012 and entitled “KDE Concrete Costs”, Lydian International
provided SNC-Lavalin with information indicating that KD Engineering stated that the
original cost of concrete was underestimated by approximately USD 10M – thus the
concrete adjustment value shown in Table 8-2. For the purposes of this study it was
believed to be more appropriate to use KDE’s own adjustment since it was made
available.
In the capital cost estimate SNC-Lavalin applied factors to the mechanical equipment
cost to generate a series of costs for electrical and instrumentation associated with the
process plant areas. These factors are well understood and defined for similar plants.
However, the electrical and instrumentation costs in the KD Engineering estimate
indicate a much lower cost factor, which equates to the order of 6% of the mechanical
equipment cost. The differential between the SNC-Lavalin and KD Engineering
estimates is in the order of USD 8.5M. For comparison purposes SNC-Lavalin propose
that USD 8.5M be included in the KD Engineering estimate to make up for this
difference.
To further facilitate a direct comparison, SNC-Lavalin based the labour rates on the KD
Engineering rates, which include a productivity factor of 2.0. It is SNC-Lavalin’s opinion
that a more suitable productivity factor for the region where the project is to be
undertaken should be 3. This does not affect the comparison in this study and the
aspect can be addressed in the next phase of the project.
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The KD Engineering estimate is approximately 6 to 9 months old and SNC-Lavalin
therefore suggest that an escalation factor of 2.5% should be added to the KD
Engineering estimate to bring it in line with SNC-Lavalin’s estimate.