Open Pit Optimization - NPVS

Demonstration Guidelines – Open Pit Optimization

Open Pit Optimization -

“NPV Scheduler”

Demonstration Guidelines

Edition 1.0

Edition 1.0 1

Table of Contents

1 Introduction ................................................................................................................................ .. 1

2 Selling Points ................................................................................................ ............................... 2

3 Demonstration Topics ................................................................................................ ................. 4

4 Demonstration Procedures ................................................................................................ .......... 5

4.1 Getting Started ................................................................................................ ................... 6

4.2 Economic Model Generation ........................................................................................... 12

4.3 Ultimate Pit Creation ........................................................................................................ 23

4.4 Pushbacks Generation ..................................................................................................... 33

4.5 Scheduling ...................................................................................................................... 40

4.6 Case Study Management ................................................................................................. 49

4.7 Additional NPVS Functionality ..................................................................................... 51

4.8 Optimization and Scheduling Output ............................................................................. 52


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1 Introduction

This document is aimed at assisting you in giving an effective demonstration of the

software solution NPV Scheduler, used in the process of Open Pit Optimization and

Scheduling. It is recommended that you acquaint yourself with the items listed below,

which form part of the installed software, additional documentation is located on DaDS:

• Software

o NPV Scheduler+MFO v 3.2 (minimum)

o Help and Tutorials

• Additional Data

o Mine planning seminar (DaDS)


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2 Selling Points

The following list contains some of the major selling points of NPV Scheduler as a

software solution for the process of Open Pit Optimization and Scheduling:

• NPVS is a modular solution whereby the client can start with Maxipit and with

time, build up to a full Multimine Scheduler solution

• NPVS is a modern Windows interface providing the following basic features:

o Optimization to Scheduling process flow control by way of tab dialogs

o Summary parameter and output reports at all stages

o 3D visualization of the process results (surfaces, contours)

o Charting, Reserves and Reporting

o Scenario analysis management (Case Studies)

o Export of the various outputs (listed above)

• NPVS provides the following advanced features:

o Haulage Analysis

o Stockpile Optimization

o Mine Flow Optimization

o Multimine Scheduler (separate Product)

• NPVS is unique as a result of the following features:

o Practical Pushbacks

o

- pushbacks are derived from the Optimum Extraction

sequence (OES) and may deliver a better NPV and sequencing, while

taking into account constraints such as mining width

Optimized Blended Scheduling

o

- allows for creation of an optimized

blended schedule which is both practical and achievable blended e.g. iron

ore, industrial minerals & coal

Multimine Scheduler

• production quota – lbs copper

- allows for scheduling multiple pits (which may be

geographically remote) where common constraints and/or targets apply e.g.


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• common mining capacity limits e.g. same truck fleet used by two mines

• common blending targets – ore from two or three mines, ore blended to give defined qualities e.g. industrial minerals

• common haulage targets • Other NPVS features

o Graphical tools for digitizing Pit Limits, Slope Regions and Pushback

adjustments

o The quick repetition of the Import to Schedule stages

o Gap and sensitivity analysis by comparing ultimate pits, pushbacks and

schedules

o Generation of an Optimal Pit (using Optimum Extraction Sequence)

within the Ultimate Pit

o The Data Source Drivers provide Import/Export for a wide range of data

formats and 3D data from/to other technical mining systems


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3 Demonstration Topics

This demonstration will show you the power and flexibility of the suite of tools, found within

NPV Scheduler, which can be used in the process of Open Pit Optimization and Scheduling. The

demonstration will start with the creation of a new Project, the import of a mining block model

for the shallow, hydrothermal Cu-Au deposit and an overview of the basic solution. The

demonstration will then proceed by using an existing Project to show the various tools used in

the different steps of Open Pit Optimization and Scheduling i.e. creation of an economic model,

determination of an ultimate pit shell, generation of pushbacks and then scheduling. The

Demonstration will also show the features commonly used for creating and exporting charts,

reports, 3D views and output 3D data (for use in the next process – Pit Design). The results of

the different procedures will be shown with each stage.

It is suggested that you following the topics below, in the order shown, in order to give an

effective presentation of the various tools (follow the hyperlink, Ctrl + Click, to move to the

Demonstration Procedure for the specific topic). The approximate demonstration time is shown

in brackets. The guidelines below show how functions are accessed via the dialog buttons,

toolbar buttons or dropdown menus:

• Getting Started ( 5 min)

• Economic Model Generation ( 5 min)

• Ultimate Pit Creation ( 7 min)

• Pushbacks Generation ( 7 min)

• Scheduling ( 7 min)

• Case Study Management

•

( 3 min)

Additional NPVS Functionality ( 3 min)

• Optimization and Scheduling Output

( 3 min)


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4 Demonstration Procedures

Please note that all files (*.txt,*.dm, *.csv) that have a name

starting with a “_” (e.g. _vb_ultpit1.dm) are standard

demonstration files and should NOT be overwritten during the

demonstration process. The demonstration guidelines make use of

these standard files, although you may wish to use files that are

created during the demonstration process.

The ☺ indicates that there is a Studio script (included in the

standard project “Integrated Demo”) that can be used to assist in

the demonstration of the current topic, should the need arise.

These scripts only use the standard demonstration files. The

numbers in brackets (after the “Show” buttons in the script

dialog) indicate the prior script options that need to be run before

the current option. This is only necessary if the demonstration

guideline procedure has not been followed step by step.


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4.1 Getting Started (Back)

Overview

:

Starting a new Open Pit Optimization exercise involves creating a new NPV Scheduler

project and then importing a mining block model (regularized or subcelled) and any limiting

surfaces or perimeters (elevated if necessary) e.g. mining lease limits, road or rail reserves.

Labels (e.g. Ore1, Waste) are then assigned to each of the unique rock type codes that have

been used within the mining block model. These procedures are shown below, together with

an introduction into the NPVS interface:

Starting a new project

1. Start NPV Scheduler+ MFO > In the NPV Scheduler projects dialog select the Create

a new project option > click OK button

2. Define a new project name “Demo” > browse to the folder C : \ Database \ Integrated

Demo \ NPVS Projects\ > click OK button

NPVS Interface - Introduction

1. NPV Scheduler is a powerful, windows based, open pit optimization solution that

provides the following general functionality:

• Step by step control of the optimization process via the logical sequence of tab

dialogs (Input Model > … Scheduling) (tabs on left side)

• Case Study control for use in Scenario Analysis at any stage of the optimization

process (top left corner)


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• Parameters Report windows (bottom right, navigation tabs on bottom – click and

drag bottom window bar to open – by default closed)

• Output Report window providing summaries of output results for each stage (top

right, navigation tabs on bottom – by default open)

• Windows for viewing, at each stage:

o Block model

o Contours

o Surfaces

o Charts

o Model Reports (upper pane)

o Settings Reports (lower pane)

o Reserves

• Use of the Data Source Drivers for the following:

o Functionality for the Import of a wide range of formats of block models,

surfaces and perimeters

o Functionality for the Export of block models, surfaces, reports at each

stage and in a variety of formats

2. A modular solution that allows the user to start with Maxipit and build up to Multimine

Scheduler, as and when required

Importing a Block Model

1. Data Import (and Export) functionality is provided through the following options:

• Data Source Drivers – general import and export. Data > Import > DSD. Note the

wide variety of formats and especially the ability to access data from other general

mining packages

• Medsystem Data Import – specific Medsystem import functionality. Accessed by

menu Data > Import > Medsystem

• Custom Import – accessed by menu Data > Import > Custom


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2. The Data Source Drivers will be used to import the Studio format geological/mining

block model “_vb_mod1”. The block model contains the following information:

• Grades (fields AU and CU):

• Au [g/t]

• Cu [ %] (i.e. 0.1 = 0.1%)

• Numeric rock type codes (field NLITH):

• 1 = Sandstone (waste)

• 2 = Siltstone (ore)

• 3 = Breccia (ore)

• 4 = Basalt (waste)

• Rock densities (DENSITY)

• Mineralization zone codes (ZONE) (This field will not be imported):

• 1 = upper zone (predominantly Siltstone) – only Au extractable

• 2 = lower zone (predominantly Breccia) – both Au and Cu extractable

3. From the Input Model tab, the block model can be imported as follows:

• Select (check) the Studio model option > Click Import Model button

• In the Data Import dialog select Datamine from Driver Category and Block

Models from Data Type > click OK button

• In the Open Source File (Studio Block Model) dialog, browse to the folder C : \

Database \ Integrated Demo \ Data and select file _vb_mod1 > click Open

• In the Studio Block Model dialog select the following fields:

o NLITH

o DENSITY

o CU

o AU

• Check that the X, Y and Z coordinate fields are XC, YC and ZC respectively >

click OK button


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4. Continue importing the block model by using the parameter values, for each dialog, as

shown in the table below:

Parameter Setting

Assign Fields Dialog

Field:

NLITH

Assign to

Rock Type

DENSITY Density

CU Product

AU Product

Define Elements Dialog

Element:

CU

Data Type

Percentage

AU Grade

Define Units Dialog

General mass tonnes

Volume cu.m (cubic metres)

Element:

CU

Mass Unit

tonnes

AU grams

Define Defaults Dialog

Default density 0.0

Rock Mass formula = Volume x Density x 1

5. Click Finish button to import the block model

6. Check the Input Model Report in the Input Model report dialog noting:

• Input model statistics


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• Field assignments

• Units

• Average Au and Cu Grades

7. Save the project, File > Save. This is a temporary project file and can be discarded on

completion of this portion of the demonstration

Setting Parameter Labels

1. Set the rock type code parameter labels as follows:

• Select the Input Model tab sheet, select the Parameters Labels button and set the

following parameters:

Parameter Setting

Parameter Labels Dialog

Currency $

Code:

1

Rock Type Label:

Waste1

2 Ore1

3 Ore2

4 Waste2

Notes:

• A mining block model usually contains ore body blocks and surrounding waste

blocks, cut off against the topography and flagged with density information

• The labels used for Currency, Mass and Volume are used only as labels in the

output reports and are not recognized by NPVS as units of measure. The currency

label $ could be replaced by USD, without effecting any optimization calculations


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• The imported mining block model data is stored within NPVS and there is no link

with the original imported file. If changes are made to the mining block model it

needs to be reimported into NPVS – the model data it is not refreshed upon

opening the NPVS project

• The Reports tabs (Input Model, Economic Model, etc)(window on right, tabs on

bottom right - contain both an upper and lower pane). The upper pane contains the

Model Report and the lower pane the Settings Report. The default pane displayed

is the upper pane. To view both panes, select the report tab and raise the report

view split bar situated at the bottom of the window.

Once the Creation of a New Project and the importing of block

model data has been demonstrated, it is recommended that this

project be closed and that the existing project VikingBounty.ens

be used for the remainder of the demonstration. See 4.2

Economic Model Generation for further details.


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4.2 Economic Model Generation (Back)

Overview of Economic Model Stage

:

In the second stage of the optimization process, the imported block model (containing block

positions and dimensions, rock densities and product grades) is transformed into an

Economic Model. This economic model can be one of two types, either a Cost Model (more

commonly used or a Profit Model, and contains the following information (fields):

• Cost Model:

o Revenue – gross revenue

o Mining Cost

o Processing Cost

o Rock – total block tonnage

o Ore – total ore tonnage

o Fields defining ore tonnages classified by rock types and/or processing

methods

o Fields defining the mass of elements (products and attributes).

• Profit Model:

o Revenue – net revenue

o Rock – total block tonnage

o Ore – total ore tonnage

o Fields defining ore tonnages classified by rock types and/or processing

methods

o Fields defining the mass of elements (products and attributes).


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Working with an Existing Project

:

An existing project can be accessed at any time for viewing or further work. This can be

demonstrated by opening the existing project document VikingBounty.ens. The procedure is

as follows:

1. First Time

: Start NPVS > In the initial NPV Scheduler dialog tick option Open

another document > select More Files... option in the lower dialog > click OK button >

browse and select the existing NPVS project C:\ Database \ Integrated Demo \ NPVS

Projects \ VikingBounty \ VikingBounty.ens > click Open button

2. Thereafter

: Start NPVS > In the initial NPV Scheduler dialog tick option Open

another document > Select the project C:\ Database \ Integrated Demo \ NPVS

Projects \ VikingBounty \ VikingBounty.ens from the list of recent projects in the

lower dialog > click Open button

It is recommended that this project be used for the remainder of the

demonstration as reference is made to existing parameters and output.

The functionality at each of the different stages (Economic Model,

Ultimate Pit, …) can be demonstrated by:

• Reviewing the parameters in the Settings dialogs

• Displaying the relevant output (Reports, Surfaces, …)

It is generally recommended NOT to Run (regenerate) each of the

stages as some can take a few minutes to generate a solution. All

necessary results have been generated in the setup runs.


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Economic Model - Settings

:

1. The economic model settings are defined as follows:

• Select the Economic Model tab sheet > Select the Settings button and define the

following parameter values:

Parameter Setting

Copy Tab Sheet

No settings required

Options Tab Sheet

Cost Model select

Data for scheduling & reporting

Ore by rock type tick

Ore by processing method untick

Insitu products tick

Recovered products untick

By ore type untick

Notes on Parameters:

• The use of the Cost Model gives greater flexibility for adjusting Economic

Model parameters (costs, prices, adjustments) e.g. for scenario analysis, than

the Profit Model

• Ticking extra “Data for Reporting” options will not affect the results of

optimization process – reports will be structured differently (as per ticked

boxes). The process running time can however be effected – the selection of

more report options increases processing time


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• 1 g (gram) = 31.11 oz (ounce)

• 1 tonne (metric) = 2,204.62 lb (pound)

• 1 ton (short) = 2,000 lb

• Gold Price: $350/oz > $11.25/g

• Copper Price: 95cents/lb > $2094.34/tonne

• Prices and Costs are per mass of product

Parameter Setting

Prices Tab Sheet

Cu Price 2094.34 [$/tonne]

Cu Selling (cost) 126.5 [$/tonne]

Au Price 11.25 [$/gram]

Au Selling (cost) 1.22 [$/gram]

Process – reject cut-off test

Revenue exceeds rehab cost check


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• Mining Cost = Base Mining Cost + Capital Cost

0.95 = 0.80 + 0.15

• Default block mass not required

• Dilution and Recovery calculations - please note that the order of

application for calculations is Mining dilution factor then Mining recovery

factor

Parameter Setting

Mining Tab Sheet

Mining cost per mass unit check

Mining cost 0.95 [$/tonne]

Default block mass 0.00 [tonnes]

Mining dilution 3 [%]

Mining recovery 95 [%]


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Parameter Setting

Processing Tab Sheet

Waste1 *

Mining CAF 1.12

Rehab cost 0.17 [$/tonne]

Processing methods -

Ore1 *

Mining CAF 1.186


Processing methods Mill

Process Parameters - Cost: *

Unit cost 3.63 [$/tonne]

Above-Ground check

Process Parameters - CU: *

Recovery formula

=if(CU<0.2,4.4*CU,0.80

)

Additional processing cost 176.34 [$/tonne of Cu]

Process Parameters - AU: *

Recovery fraction 0.91 [%]

Additional processing cost 0.00 [$/gram of Au]

Ore2 *

Mining CAF 1.186


Processing methods Leach

Process Parameters - Cost: *

Unit cost 2.29 [$/tonne]

Above-Ground check

Process Parameters - CU: *


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Additional processing cost 308.65 [$/tonne of Cu]

Process Parameters - AU: *


Additional processing cost 0.00 [$/gram of Au]

Waste2 *

Mining CAF 1.00


Processing methods -

* Tabs are at the bottom of the Processing dialogs


• Waste2:

• Mining CAF = 1.00 (costs are equal to Mining Cost, defined in Mining tab

sheet)

• Waste1:

• Mining CAF = 1.12 (costs are higher than Mining Cost, defined in Mining tab

sheet, due to increased Drill&Blast costs for this material)

• Ore1: (upper mineralized zone – Siltstone ore)

• Mining CAF = 1.186 (increased mining costs due to selective mining)

• Processed by Milling, Flotation, Refining and Smelting

• Unit cost = 3.63 $/tonne ore

Calculation: Unit Cost = Processing Costs + Capital Cost

3.63 = 3.34 + 0.29

• Copper and gold recovered

• Copper recovery based on a formula where:

o Recovery = (4.4 x CU grade) if CU<0.2

o Recovery = 0.80 if CU>=0.2 (Note 0.80 = 80%)

• Gold recovery is fixed at 0.91


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• The Additional Processing Cost for Cu (176.34 $/tonne of Cu) covers the Cost

of Smelting

• Ore2: (lower mineralized zone – Breccia ore)

• Mining CAF = 1.186 (increased mining costs due to selective mining)

• Processed by Heap Leach methods

• Unit cost = 1.29 $/tonne ore

Calculation: Unit Cost = Leaching Costs + Capital Cost

1.29 = 1.24 + 0.05

• Copper recovered; no gold recovered due to the metallurgical nature of the ore

• Copper recovered by SXEW (Solvent Extraction and Electro-winning)

techniques

• Cost of SXEW placed under Additional Processing Costs (308.65 $/tonne Cu)


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• A reference bench of “0” is equivalent to 260m elevation

• Waste and ore blocks have the same incremental costs and reference bench i.e.

relative to the elevation of the highest block on the Northern limit of the pit

• Blocks mined below the reference bench attract the incremental mining cost

Economic Model – Generation

:

1. The economic model can be generated as follows:

• Note: This option can be run during a demonstration as it takes a short time (< 1 min)

to generate the economic model

• Select the Economic Model tab sheet

• Select the Run button

Viewing the Results

:

1. Once the economic model has been generated, the different results can be viewed

2. Economic Model Report:

Parameter

Select the Economic Model report tab (upper pane) and note

the following:

Setting

Adjustments Tab Sheet

Process: Reference Bench:

Default

Incremental Cost:

0 (260m elev) 0.01

Leach 0 (260m elev) 0.01

Mill 0 (260m elev) 0.01

Apply increments above

reference bench untick


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• These statistics are useful for checking the model for errors:

• General statistics

• Profit range

• Revenue range

• Processing cost range

• Mining cost range

• Ore tonnage by ore type (Ore1 and Ore2)

• Products contained in ore (Cu and Au)

• Product grades (Cu and Au)

• Cost adjustment factors check

• The contents of the page can be selected (left cursor click-and-drag) and copied

(dropdown menu Edit > Copy) for insertion into a document

• The report page can also be printed: File > Print

3. Model:

• The model is displayed as a Plan, two Section slices or a 3D slice

In the Economic Model tab sheet, select the Model button

• It is by default colored on Block Revenue (In the Plan view, the legend is displayed in

the top right)

• The views can be manipulated or enhanced with plot items (e.g. Legend boxes) using

the docked Toolbars (Digitizer, View Position, Format, Section Plane, Plot Items) at

the bottom of the NPVS window

• This can also be done using the main dropdown menu options (dialog context

sensitive menus)

• Model blocks can be queried as follows:

• Select block with cursor (left click)

• Right click > Properties

4. 3D Surface:

• The model surface (initial topography) is displayed as a surface

In the Economic Model tab sheet, select the Surface button

• Used to check initial topography


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5. Contours:

• The model surface (initial topography) is displayed as contours

In the Economic Model tab sheet, select the Contour button

• Used to check initial topography

• The display in the Pit Contours window can be manipulated using the Pit Contour

window’s dropdown menu Option > Surface Control

• The elevation of the position of the cursor is displayed at the bottom of the Pit

Contours window


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4.3 Ultimate Pit Creation (Back)

Overview

:

In the third stage of the optimization process, the ultimate pit shell and extraction sequence

(containing some or all blocks from the ultimate pit), is generated from the Economic Model and

the ultimate pit settings. The ultimate pit can be defined as the Lerchs-Grossman pit or the

Maximum Resource pit.

The extraction sequence can be optimized for NPV or for user defined blending targets. All

blocks in the extraction sequence define the Optimal Pit.

Ultimate Pit - Settings:

1. The economic ultimate pit settings are defined as follows:

• Select the Ultimate Pit tab sheet > Select the Settings button and define the

following parameter values:

Parameter Setting

Ultimate Pit Tab

Maximize cash flow check

Use top-down bench

discounting

uncheck


• None


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Parameter Setting

Sequencing Tab

Optimize NPV check

Parameters for Phases

Use price factors check

Max revenue factor 100 [%]

Incremental factor 1 [%]

Include all blocks from the

ultimate pit

uncheck


• LG Phases – a sequence of nested LG ultimate pits obtained by varying

economic parameters (Profit, Price or Mining Cost factors). The LG phases

help to create the extraction sequence and have no particular importance

afterwards


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Parameter Setting

Slopes Tab

Select Define Slope Region 1:

Slope filter dimensions:

X direction 8 [blocks]

Y direction 8 [blocks]

Azimuth

0

Slope

30

Select Define Slope Region 2:

Upper bound 3 (cells below topography)

Slope filter dimensions:

X direction 10 [blocks]

Y direction 10 [blocks]

Azimuth

1

Slope

41

34 41

93 41

118 45

275 43

Slope Modeling Option:

Include air blocks uncheck


• Two slope regions are defined here. The upper (Slope Region 1) weathered

material surface material approximately 60m (3 blocks) thick and requires less

steeply dipping slopes. The lower (Slope Region 2) unweathered material can

accommodate steeper slopes.


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• Slope filter dimensions – parameters that control the accuracy of slope

modeling; larger values give greater accuracy

• Up to 20 slopes can be defined per Slope Region

• Slope Regions can also be defined using:

o Imported surfaces

o An attribute field in the imported mining block model

• Unchecking “Include air blocks” prevents NPVS from mining (more than 1

block below surface) through the side of the block model

Parameter Setting

Time Tab

Annual discounting 10 %

Average ore output rate:

Tonnage 800,000 [tonnes]

Period 365 [days]


• Important: The Tonnage figure should read as 000,800,000 in the dialog box

i.e. check the positions of the commas


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Parameter Setting

Advanced Tab

Reblocking:

Ultimate pit:

X 1

Y 1

Z 1

Phases:

X 1

Y 1

Z 1

Initial Topography C:\Database\Integrated

Demo\VikingBounty\Case

Studies\Economic Model

1\InitialTopo.asc

No data points for charting

extraction sequence

100

Bench increment for ultimate

pit search

2

Status message interval 300


• None


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Ultimate Pit - Creation:

1. The ultimate pit can be generated as follows:

• Note: This option can be run during a demonstration as it takes a short time (approx.

1 - 5 min, depending on the PC specs) to generate the Ultimate Pit

• Select the Ultimate Pit tab sheet


Ultimate Pit – Viewing Results:

1. Once the economic model has been generated, the results can be viewed in various

formats, these are listed below.

2. Ultimate Pit Report:

• Select the Ultimate Pit report tab (upper pane)

• Note the following summary statistics, which are useful for checking and comparing:

• Optimization summary

• Ultimate Pit statistics

• Optimal Pit statistics

• Note the differences in NPV, ore tonnages and waste tonnages between the Ultimate

and the Optimal Pit.

• Important: the Ultimate Pit reflects a scenario where the pit is mined bench by bench

(the complete bench before starting the next bench below) whereas the Optimal Pit

reflects a scenario where the pit is mined according to the optimal extraction

sequence i.e. block by block. A practical solution would lie somewhere between the

two scenarios. The NPV results from the Pushbacks and Scheduling stages will be

more indicative of a practically achievable NPV


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• The format of the Ultimate Pit Report can be changed: dropdown Format > Report .

Ultimate Pit > select option (the default option “Ultimate pit and extraction sequence

summary” is normally displayed in the Report window)

3. Model:

• In the Ultimate Pit tab sheet: Select the Model button


• It is colored on Sequence with the legend displayed top right

• The views can be manipulated or enhanced with plot items using the docked Toolbars

or main dropdown menu options

4. Surface:

• The ultimate pit extents can be displayed as a 3D surface (either Ultimate Pit or

Phases surfaces)

• In the Ultimate Pit tab sheet: Select Ultimate Pit or Phases option > select the

Surface button

• Used to check extents of ultimate pit and to see if optimization extends to the limits

of the block model (block model may need to be extended)

• When displaying different Phase surfaces (option Phases needs to be selected in the

Ultimate Pit tab sheet), different surfaces can be selected for displaying : main

dropdown menu > Format > Surface > select surface number from to dialog OR

(faster option) use the Next Surface and Previous Surface buttons in the Surface

Control toolbar

5. Contours:

• In the Ultimate Pit tab sheet: Select the Contour button

• The ultimate pit extents are displayed as elevated contours

• The elevation of the position of the cursor is displayed at the bottom of the Pit

Contours window

• Used for visually querying depths within ultimate pit limits


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• Used to check extents of ultimate pit and to see if optimization extends to the limits

of the block model (block model may need to be extended)

• The display in the Pit Contours window can be manipulated using the Pit Contour

window’s dropdown menu Option > Surface Control

6. Ultimate Pit Reserves by Bench:

• In the Ultimate Pit tab sheet: Select the Reserves button

• The ultimate pit reserve (not Optimal Pit) is reported Bench by Bench within the

ultimate pit (Surface1) in a spreadsheet format

• The report includes the following information:

• Bench number

• Bench elevation (elevation of Toe position)\

• Profit

• Revenue

• Processing Cost

• Mining Cost

• Total Rock

• Total Ore

• Total Waste

• Ore1 (tonnes)

• Ore2 (tonnes)

• Cu insitu product (tonnes)

• Au insitu product (grams)

7. Charts (Sequence):

• In Ultimate Pit tab sheet: Check Sequence option > select Chart button

• The chart displays cumulative NPV, Profit and Total Ore for the Optimal Pit i.e.

extraction sequence optimized for NPV (and not values the Ultimate pit)

• The pit starts making a profit at approximately data point 20 (equiv. to 2.25

years)(100 data points = 11.29 years – Optimal Pit)


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• The chart Type (bar, line, …), Variables (NPV, Profit, Total Ore, …) or Settings can

be modified as follows:

• Open the chart in the NPVSChart window

• From main menu dropdown > Select Chart > Type, Variables or Settings

• Used for assessing when and how certain changes in variables (e.g. Total Ore tonnage)

effect NPV or Profit

• Charting can be done on an Incremental or Cumulative Variable basis

8. Reports (Sequence or Phase):

• In Ultimate Pit tab sheet: Check Sequence option > select Report button

• The Optimal Pit reserve is reported by Data Point(1 Point = approx 0.113 year)

within the ultimate pit (Surface1) in a spreadsheet format in both Incremental or

Cumulative data

• The report includes the following information:

• Point number

• Profit

• Revenue

• Processing Cost

• Mining Cost

• NPV

• Total Rock

• Total Ore

• Total Waste

• Strip Ratio

• Ore1 (tonnes)

• Ore2 (tonnes)

• Cu grade

• Au grade


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Notes:

• Charts and Reports can be generated by Phases: Ultimate Pit tab sheet > select bottom

Phases option > select Chart or Report button

• Pit Limits can be graphically defined using: Ultimate Pit tab sheet > Pit Limits button.

See Help for more details

• Slope Regions can be graphically defined: Ultimate Pit tab sheet > Slope Regions

button. See Help for more details


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4.4 Pushbacks Generation (Back)

Overview

:

In the fourth stage of the optimization process, practical, bench mineable stages of expansion or

interim pits (pushbacks) are generated within the ultimate pit shell taking into account access

space requirements and minimum pushback size (tonnage) settings.

Pushbacks - Settings:

1. The pushbacks settings are defined as follows:

• Select the Pushbacks tab sheet > Select the Settings button and define the following

parameter values:

Parameter Setting

Options Tab

General parameters:

Max no pushbacks to generate 10

Last pushback reach pit limit tick

Min dist. Between pushbacks:

Access space (units of length) 20

Min no blocks in a remnant 20

Pushbacks form cont. volumes tick

Limit final pit to subshell:

Limit pit to block untick


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• The system generally generates pushbacks numbering < Max No

• The access space is determined by the practical constraints of the mining

equipment

• Remnants smaller than minimum size are added to the previous pushback

• Ticking “Pushbacks form contiguous volumes” generates pushbacks where

each pushback, except the first one, includes the area of the previous

pushback

Parameter Setting

Control Tab

Define Variables:

MillOre

TotalOre 0

Attribute: Coefficient:

Ore1 1

Ore2 0

CU insitu 0

AU insitu 0

Define Pushback Variables:

Pushback 1

Defining variables MillOre: 390,000

Maximum depth 18 (-100)


• Note: The actual values of control variables (shown in the Pushback Report)

for a pushback will usually be greater than the defined Minimum Value

parameter, owing to access space requirements

• Define variables using button New


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• Delete variables using button Delete

• Edit variable parameters: select Variable in Define variables dialog >select

Parameters button

• Please see Help and Tutorial for details on how to set up Attribute

Coefficients

• Editing Pushback variables: Select pushback number > select Edit button

• Different Variable parameters and depths can be set for each Pushback;

setting only parameters for Pushback 1 will automatically give subsequent

pushbacks the same parameter values

Parameter Setting

Advanced Tab

Boundary correction factor 3

Max temporary pit number 200


• The “Boundary Correction factor” is a factor that controls the smoothing of

pushback boundaries: 1=less smooth; 4=very smooth

• The “Max temporary pit number” is an internal memory management

parameter. Change it only if the program gives a message saying that it is too

small


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Pushbacks - Generation:

1. The Pushbacks within the ultimate pit can be generated as follows:


1 min) to generate the pushbacks model

• Select the Pushbacks tab sheet


Pushbacks – Viewing Results:

Once the Pushbacks model has been generated, the results can be viewed in various formats,

these are listed below.

1. Pushback Report:

• Select the Pushback report tab (right window - upper pane)

• Note the following summary statistics generated for each Pushback. These are used

for checking the results of the process:

• Control variables (pushback control variables0

• Ore tonnage by type (Ore1 and Ore2)

• Products insitu (Cu and Au)

• Note that 8 pushbacks have been generated using the previous settings

2. Model:

• In the Pushbacks tab sheet: Select the Model button


• It is colored on Pushback with the legend displayed top right




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3. 3D Surface:

• In the Pushbacks tab sheet: Select the Surface button

• The extents of the different pushbacks are displayed as a surfaces

• Used to check positions, shapes and extents of individual and also relationships

between adjacent pushbacks

• When displayed, different Phase surfaces can be selected for displaying: main



Control toolbar

4. Contours:

• In the Pushbacks tab sheet: Select the Contour button

• The different pushback extents are displayed as elevated contours

• Used for visually querying depths within pushback limits and positions of the

pushback sequences

• The different pushback contour surfaces can be displayed in the Pit Contours

window: Select in the Pit Contour window’s dropdown menu: Option > Surface

Control > change the Surface Index number > select Apply button

5. Pushbacks Reserves by Bench:

• In the Pushbacks tab sheet: Select the Reserves button

• The pushbacks reserve is reported by Bench within each Pushback in a spreadheet

format

• The report includes the following information (by Pushback by Bench):

• Bench number


• Profit

• Revenue

• Processing Cost

• Mining Cost


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• Total Rock

• Total Ore

• Total Waste

• Ore1 (tonnes)

• Ore2 (tonnes)



6. Charts (Sequence):

• In Pushbacks tab sheet: Select Chart button

• The example displays Incremental NPV, Total Ore and Total Waste per Pushback






7. Reports :

• In Pushbacks tab sheet: Select Report button

• The Pushbacks are reported in a spreadsheet format in both Incremental and

Cumulative data

• The report includes the following information (note the extra MillOre variable –

parameter used to control the pushback generation):

• Pushback number

• Profit

• Revenue

• Processing Cost

• Mining Cost

• NPV

• Total Rock


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• Total Ore

• Total Waste

• Strip Ratio

• Ore1 (tonnes)

• Ore2 (tonnes)

• Cu grade

• Au grade

• MillOre

• Note that the total NPV (see last row in Cumulative Data from in the Report) for

these pushbacks is $ 41,981,416. As expected, it lies between the Optimal NPV value

($56,648,869) and the Ultimate Pit NPV value ($ -1,449,109)

Notes:

• Pushbacks can be adjusted: In the Pushbacks tab sheet > Check Edit and select the Adjust

button

• Pushback locations and shapes can be controlled using the following components:

o Polygonal boundary(s)

Digitized in the Adjustment (Surface Pushbacks) window

Imported

o Adjustment type

Global limits

Local limits

Local include

Local exclude

o Limiting Bench (for “global limits” and “local limits” only)

• This option can be used for scenario analysis in conjunction with case management tools

• As an example, Pushbacks may need to be limited (excluded) from a certain area in the

pit due to the temporary position of an in-pit crusher facility

• Please see the Help and Tutorial for further details


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4.5 Scheduling (Back)

Overview:

The fifth stage of the Open Pit Optimization and Scheduling process is the generation of a

practical schedule for mining, using the previously generated pushbacks. The schedule would

generally need to ensure a steady output of ore at manageable strip ratios and certain ore or

contamination control requirements. In order to achieve the defined targets under these

constraints, the program allows for the mining of two or more pushbacks at the same time.

Scheduling - Settings:

1. The Scheduling settings are defined as follows:

• Select the Scheduling tab sheet > Select the Settings button and define the following

parameter values:

Parameter Setting

Targets Tab

Time unit for shceduling:

No days 365

Define target variables:

Please select case study: “Schedules 2”

• See section 4.6 for further information on Case Study selection


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StripRatio untick (not used–example only)

Variable type Ratio

Rock

Target Variable Defn:

Ore1

Ore2

1 0

Numerator: Denominator:

-1 1

-1 1

Bounds and target values by period:

200 10 10 30

End Time: Target: Minimum: Maximum:

TotalRock tick

Variable type Rate per 365 days

Rock

Target Variable Defn:

1 Blank

Numerator: Denominator:

Bounds and target values by period:

1 15,000,000 7,500,000 20,000,000

End Time: Target: Minimum: Maximum:

200 10,000,000 8,000,000 11,500,000


• The scheduling time unit is typically 365 days; maximum number of time

units available within the program is 200 units

• StripRatio (not used) is an example of a Ratio type target variable

• TotalRock is an example of a Rate type target variable and has different

target values set for different periods (one set for Period=1, another for the

remainder of the schedule)

• The StripRatio is defined as a target variable – it is not necessary to define

Ore1 tonnes as a target variable as it is used as the Attribute for defining Time

(see next tab)


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Parameter Setting

Time Tab

Ore1

Attribute:

390,000

Rate:

Rate period (days) 365

Adjustments by Period:

1

End Time:

2

200

0.50

Adjustment:

0.75

1.00


• The Mill ore (Ore1) is used to define the production rate for the generation of

the schedule

• The adjustments for Period=1 and Period=2 reflect the buildup phase for the

plant i.e. the plant is planned to run at 50% capacity in year 1, 75% capacity in

year 2 and full capacity from year 3


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Parameter Setting

Options Tab

Generate mining sequence for

stockpile optimization or export

tick

Pushbacks file:

Default check

Optimization control:

Allow prestripping untick

Search breadth (1-4) 2

Maximum tree size (>50,000) 100,000

Rock unit parameter (1-10) 2


• The “Generate mining sequence …” option needs to be ticked in order to

generate data for exporting

• Increase the “Search breadth” parameter if a scheduling solution is not found

• The “Rock unit” parameter determines the number and size of “atoms” i.e. the

basic units of rock used for scheduling. Increasing the parameter increases the

number of units and provides a more accurate schedule. This increases the

processing time as the size of the schedule tree increases

• The “Re-schedule” button allows for the re-scheduling from a certain period

onwards


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Parameter Setting

Pushbacks Tab

All parameters 0

All Advanced parameters 0


• All settings are set to “0” as these options are not used

• This tab allows for the control of:

o Relative pushback progression rate

o Bench lags between pushbacks

o Prevention of mining pushbacks before a given period

• Advanced control of:

o Pushback dependencies


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Scheduling - Generation:

1. The schedules can be generated as follows:


<1 min) to generate the schedule output

• Select the Scheduling tab sheet


Scheduling – Viewing Results:

8. Once the scheduling model has been generated, the results can be viewed in various

formats, these are listed below.

9. Scheduling Report:

• Select the Schedules report tab (right window - upper pane)

• Note the following summary statistics. These are used for checking the process:

• Primary objective (here NPV maximization)

• Target variations (per period)

• Lifetime of the mine

• Prestripping set (Yes or No)

• NPV Estimate (it is now $ 40,494,123)

10. Model:

• In the Scheduling tab sheet: Select the Model button


• It is colored on Time/Period (TB2 i.e. latest period in which the block is mined) with

the legend displayed top right




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11. Surface:

• In the Scheduling tab sheet: Select the Surface button

• The extents of the different Periods are displayed as a surfaces

• Used to check positions, shapes and extents of individual and also relationships

between adjacent Periods of the schedule

• When displayed, different Period surfaces can be selected for displaying: main



Control toolbar

12. Contours:

• In the Scheduling tab sheet: Select the Contour button

• The different Period extents are displayed as elevated contours

• Used for visually querying depths within Period limits and positions of the Periods

• The different Periods contour surfaces can be displayed in the Pit Contours window:

Select in the Pit Contour window’s dropdown menu: Option > Surface Control >

change the Surface Index number > select Apply button

• Useful for viewing the progression of the Periods

13. Schedule Reserves by Bench:

• In the Scheduling tab sheet: Select the Reserves button

• The schedule reserve is reported by Bench within each Period in a spreadsheet format

• The report includes the following information (by Period by Bench):

• Bench number


• Profit

• Revenue

• Processing Cost

• Mining Cost

• Total Rock


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• Total Ore

• Total Waste

• Ore1 (tonnes)

• Ore2 (tonnes)



14. Charts (Schedule):

• In Scheduling tab sheet: Select Chart button

• The example displays Incremental Total Ore and Total Waste per Period






15. Reports :

• In Scheduling tab sheet: Select Report button

• The schedule is reported in spreadsheet format, Incremental and Cumulative data

• The spreadsheet also contains an Internal Rate of Return on Investment calculation

tool at the bottom of the sheet

• The report includes the following information (note the extra TotalOre variable –

parameter used as a Target in the generation of the schedule):

• Period number

• Profit

• Revenue

• Processing Cost

• Mining Cost

• NPV


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• Total Rock

• Total Ore

• Total Waste

• Strip Ratio

• Ore1 (tonnes)

• Ore2 (tonnes)

• Cu grade

• Au grade

• MillOre

• The above information is provided “by Period” and also “by Period and Pushback”.

See extra columns to the right of the spreadsheet

• Note that the total NPV (see last row in Cumulative Data from in the Report) for

these Scheduled pushbacks is $40,949,123. As expected, it lies below the NPV value

for the pushbacks ($ 41,981,416), between the Optimal NPV value ($56,648,869) and

the Ultimate Pit NPV value ($ -1,449,109)


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4.6 Case Study Management (Back)

Overview:

The process of Open Pit Optimization and Scheduling often involves the analysis of different

sets of parameters and their effect on the resultant output e.g. ultimate pit, schedule, etc. This

process of scenario analysis is facilitated within NPVS with the use of the Case Study manager.

1.

• The Case Study window is located in the top left corner of the NPVS project window

Locating the case Study window

• Select and drag down the window bar at the top of the NPVS processes window on

the left side to display the Case Study header, buttons and case studies list

• Expand the tree listed in the Case Studies List window, all the way down to the

Schedules, by clicking on the “+” signs

2.

• The currently selected Case Study header reads “… & Pushbacks 1 & Schedules 2”

Selecting a Case Study

• In the Case Study window > Select the tree item “Schedules 1”

• Click the Select Case button

• Check that the Case Study header reads “… & Pushbacks 1 & Schedules 1”

• The case is now selected and all parameters for this case are displayed in all the

Settings dialogs; the correct output for that case will also be displayed when the

relevant output is selected for viewing e.g. Model, Surface, Contours

3.

• In the Case Study window > Select the Edit Case button

Editing a Case Study (Scenario Analysis)

• In this dialog, the cases can be:

• Defined as new: Select case study tree item > New Case button


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• Renamed: Select case study tree item > Rename Case button

• Deleted: Select case study tree item > Delete Case button

• Extended: Select case study tree item > Extend case button

• The New Case option is used to create another case (current level only) at the same

level as the case item selected in the Edit Case Study Tree dialog

• This can be used in conjunction with the Copy Settings tabs in each stage of

the Open Pit Optimization and Scheduling process, for Scenario Analysis

• The Extend Case option is used to create another case (current and subsequent levels)

at the same level as the case item selected in the Edit Case Study Tree dialog

• This can be used in conjunction with the Copy Settings tabs in each stage of

the Open Pit Optimization and Scheduling process, for Scenario Analysis

• The Schedules 1 case is an example of an alternative scenario to the Schedules 2 case.

The former has , in the Scheduling parameters, only MillOre set as a scheduling

target variable, while in the latter, both MillOre and StripRatio are Target variables

4.

• Select the case

Adding Case Notes

• Add notes: Select Case Notes button > add notes to the dialog

5.

• Select the case which is to be worked on

Copying Case Settings

• Select the relevant NPVS stage tab e.g. Pushbacks sheet tab

• Click the Settings button

• Select the Copy tab

• Select the case which is the source of the settings that are to be copied

• Select Copy button

o Copying of settings will prompt before overwriting the current settings

o Case settings cannot be copied for the Input Model stage – a new NPVS project

needs to be created


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4.7 Additional NPVS Functionality (Back)

The following additional or advanced functionality is either fully integrated into NPVS or

available within the NPVS product suite as an extra product. Please see Help and Tutorial for

further details:

1.

• Feature within NPVS – see Stockpiling tab sheet

Stockpile Optimization

• Provides the ability to maximize NPV by optimizing the distributions of all types of

ore among processing methods, stockpiles and external material sources

2.

• Feature within NPVS – see Stockpiling tab sheet

Mine Flow Optimization

• Provides the ability to maximize the NPV by optimizing mining rates and cutoff

grades for all rock types and processing methods

3.

• Feature within NPVS – see main dropdown menu Tools > Define Destinations

(available when Ultimate Pit tab sheet is selected)

Haulage Analysis

• Provides the ability to optimize the haulage plan by optimizing the mining schedule

directly for truck hours. Haulage analysis and scheduling are combined and so

prevents the need for iteration. This allows scheduling objectives can to be met while

reducing the maximum truck fleet size and/or delaying expansion of the truck fleet

4.

• Additional product within the NPVS range

Multimine Scheduler

• Provides the ability to run the Optimization to Scheduling process on multiple pits

5.

• Feature within NPVS – see main menu Tools > Batch Optimization

Batch Runs

• Provides the ability to run any number of Economic Model runs or Optimizaation

runs (Ultimate Pit, Pushbacks, Scheduling, Stockpiling) based on the defined case

studies


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4.8 Optimization and Scheduling Output (Back)

Overview:

As shown in the above sections (4.1 – 4.5), the results for each stage of the Open Pit

Optimization and Scheduling process can be viewed in a variety of formats:

• Model

• Surface

• Contour

• Reserves

• Chart

• Report

These results can be output for use in reports, visualization and further open pit design. This can

be demonstrated by exporting the schedule Model and the final schedule Surface (Surface 11).

1. Export Model

• In the Scheduling tab sheet >Select the Model button

: the schedule Model can be exported as follows:

• From the main dropdown menu > Data > Export

• In the Data Export Objects dialog:

• Tick Result Model for export

• Driver category: Datamine

• Data Type: Block Models

• In the Studio Block Model dialog:

• Browse to the folder C:\ Database \ Integrated Demo \ Workarea \

• Save the export block model file as NPVSmod1

• Close the Model display window


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2. Export Surface

• In the Scheduling tab sheet >Select the Surface button

: the final schedule surface can be exported as follows:

• In the 3D Surface window display the surface Surface 11 > main dropdown menu >

Format > Surface > select surface number Surface 11 from the dialog

• Export the surface: From the main dropdown menu > Data > Export

• In the Data Export Objects dialog:

• Tick ONLY “3D Surface: Surface 11” for export

• Untick ALL other surfaces

• Driver Category: Datamine

• Data Type: Wireframes

• In the Studio Wireframe dialog:

• Browse to the folder C:\ Database \ Integrated Demo \ Workarea \

• Save the export wireframe triangles and points files as NPVSsurfTR and

NPVSsurfPT respectively

• Select elevation from the drop down menu under the Color Field label

• Close the 3D Surface display window

3. Viewing the output in Studio

• Run Studio in IntegratedDemo project

: the exported Model and Surface can be viewed (and used

as input into the Pit Design process ) in Studio as follows:

• Add the new export model and final schedule surface files to the Studio project:

• File > Add to Project

• Load the final schedule Surface, wireframe “NPVSsurfTR” / “…PT” into the

Design window

• ☺ Load the schedule Model “NPVSmod1” into the Design window and color on

NPV_TB (last Period in which a block can be mined) using the ☺Legends menu


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Notes:

• The exported schedule block model contains the following fields and information per

block:

o VALUE - value

o REVENUE - revenue

o PCOST - processing cost

o MCOST - mining cost

o SEQUENCE - optimized block extraction sequence number

o PHASE - pit phase number

o PUSHBACK - pit pushback number

o NPV_TA - period after which block is mined (optimal)

o NPV_TB - period before which block is mined (optimal)

o TOTAL_TA - period after which block is mined (target optimal)

o TOTAL_TB - period before which block is mined (target optimal)

• Please note that the NPV_TB value represents the period before which the block is

extracted according to the NPV optimal schedule while the TOTAL_TB value

represents the period before which the block is extracted according to the Target

TOTAL (Total Rock) optimal schedule (please see the NPV Scheduler Help >

Optimizing production schedules for further details)

It is recommended NOT to save the project

VikingBounty.ens (and overwrite demonstration

parameters with any changes or additions) either during or

on completion of the demonstration.

Documents

Open Pit Optimization - NPVS