Training Manual Block Modelling

Training Manual

BLOCK MODELLING

VULCAN 4 – Block Model Training Manual

Copyright 2002 Maptek Pty Limited

All rights reserved. No part of this manual shall be reproduced, stored in a retrieval system, or transmitted by any means – electronic, mechanical, photocopying, recording, or otherwise – without written permission from Maptek Pty Ltd. No patent liability is assumed with respect to the use of the information contained herein. Although every precaution has been taken in the preparation of this manual, the publisher and author(s) assume no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained herein.

Trademarks

Microsoft Windows is a registered trademark of Microsoft Corporation.

AutoCAD is a registered trademark of AutoDesk.

Conventions used in this manual

The following conventions are used throughout this manual.

Examples are written in bold italics.

Important points or references are written in bold.

Tip!

Hints, tips and warnings appear between horizontal lines.

i

Contacting Maptek

Corporate

Web: http://www.maptek.com.au

VULCAN product

Website: http://www.vulcan3d.com

Sales

Email: Australia: [email protected]

North America: [email protected]

South America: [email protected]

Europe: [email protected]

Web: http://www.maptek.com.au/contact/contact.html

Telephone: Australia: 61-8-8338 9222

North America: 1-303-763 4919

South America: 56-2-234 4608

Europe: 44-115-947 2000

Support

Email: Australia: [email protected]

North America: [email protected]

South America: [email protected]

Europe: [email protected]

Web: http://www.maptek.com.au/services/services_email.html

Telephone: Australian: 61-8-6211 0000

North America: 1-303-763 4919

South America: 56-2-234 4608

Europe: 44-115-947 2000

ii

http://www.maptek.com.au/services/services_email.html

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http://www.vulcan3d.com/

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Contents

Table of Contents

VULCAN 4 – Block Model Training Manual iCopyright 2002 Maptek Pty Limited iTrademarks iConventions used in this manual iContacting Maptek iiCorporate iiVULCAN product iiSales iiSupport ii

Table of Contents iiiTable of Figures vii

CHAPTER 1 - BLOCK CONSTRUCTION IN VULCAN 1

What is a Block Model? 2

Why do we use Block Models? 2Advantages of using block models 2

How do you create a block model in VULCAN? 2

Block Construction 31.1 Create a Block Definition File (.bdf) 3

1.1.1 Origin and Orientation 31.1.2 Block Model Offsets, Parent Block Size and sub-blocking 41.1.3 Variable Names and Default Values 51.1.4 Define the Limits of the Block Sizes by Variables 51.1.5 Boundaries 6

1.1.5.1 Inversion Examples: 61.1.5.2 Projection Axes: 6

1.1.6 Exceptions 71.1.7 Saving the Block Definition File 8

1.2 Create the Block Model 8

Workshop: Creating your first model 81. The model origin and orientation (Orientation Panel) 84. Creating the model: 10

CHAPTER 2 – VIEWING BLOCKS IN VULCAN 11

VULCAN Block Viewing Methods 12

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Contents

Reasons for Viewing Block Models 12

Getting Information about your Block Models 122.1 Getting a List of your Block Models 122.2 Opening Your Block Model 132.3 Displaying the Block Model Header Information 13

Block Viewing 132.4 Generating Contours of the Block Model 13

CHAPTER 3 – BLOCK MANIPULATION 163.1 Editing a Block Model 163.2 Performing a Calculation on the Block Model 163.3 Mining the Block Model 163.4 Using Scripts 17

3.4.1 Why use scripts in VULCAN? 173.4.2 Scripting Constructs 173.4.3 Operators 18

3.4.3.1 Comparison operators: 183.4.3.2 Logical operators: 183.4.3.3 Assignment operators 183.4.3.4 Mathematical operators 18

3.4.4 Example Script: 18

Workshop Exercise: Scripts 191. Plan your calculation 202. Document your work: 203. Document Temporary Variables 203.5 Adding Block Model Variables 203.6 Deleting Variables from a Block Model 213.7 Renaming Variables in a Block Model 213.8 Translating a Block Model 213.9 Rotating a Block Model 213.10 Indexing a Block Model 223.11 Assigning Values to a Block Model 22

CHAPTER FOUR – BLOCK TRANSFER 254.1 Importing a Regular Block Model 254.2 Importing a Sub-blocked Block Model 254.3 Importing Attributes into a Block Model 264.4 Exporting a Block Model 274.5 Export Variables to a Map File 284.6 Intersect a Drill Hole Database 304.7 Block Model Addition 31

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Contents

Creating a New definition File 31Defining the Parent Scheme 32Adding New variables 32Determining which variables to include (Variable Constraining) 33Creating the new Block Model 33

Workshop - Block Manipulation, Add 344.8 Regularising a block model 344.9 Deleting Blocks from a block model 404.10 Extracting Blocks to a new Block Model 42

CHAPTER 5 - INVERSE DISTANCE GRADE ESTIMATION 43

Grade Estimation in VULCAN 43What is Grade Estimation? 43Why use Grade Estimation? 43How do we use Grade Estimation in VULCAN? 43

CHAPTER 6 – BLOCK RESERVES 44

Overview – Reserves submenu 446.1 Simple Reserves 44

6.1.1 General 446.1.2 Calculate Reserves based on POLYGONS 47

6.2 Block Reserves 486.2.1 Setup the specification 486.2.2 Select the data regions 506.2.3 Define the data source 506.2.4 Save the reserve specification 526.2.5 Calculate the reserves 526.2.6 Display the report 52

6.3. Advanced Reserves 556.3.1 Open the specification file 566.3.2 Specify the Variables (from the block model on which to report) 566.3.3 Define Regions 61

6.3.3.1 Select Polygons as Regions 616.3.3.2 Select triangulations as regions 63

6.3.4 Specify Block Selection Conditions 646.3.5 Save the Parameters 656.3.6 Calculate the Reserves 656.3.7 Reporting the Reserves 66

6.3.7.1 Open report specification file 666.3.7.2 Define General Report Details 676.3.7.3 Define Column specs. 68

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Contents

6.3.7.4 Define Table Details. 716.3.7.5 Save the specification file 736.3.7.6 Reporting the reserves 73

Workshop - Block Reserves 74

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Figures

Table of Figures

Figure 1-1: Block Model Slice............................................................1Figure 1-2: Regular Block Model.......................................................2Figure 1-3: Block Menu.....................................................................3Figure 1-4: Block Model Utility - Orientation Panel...........................3Figure 1-5: Block Model Utility – Schemes Panel..............................4Figure 1-6: Block Model Utility – Variables Panel..............................5Figure 1-7:Block Model Utility – Limits Panel....................................5Figure 1-8: Block Model Utility – Boundaries Panel...........................6Figure 1-9: Inversion with 3D (Solid) Triangulations.........................6Figure 1-13: Projection along the Y axis...........................................7Figure 1-15: Block Model Utility – Exceptions Panel.........................7Figure 1-16: Block Model Orientation Panel......................................9Figure 1-17: Add Schema Panel........................................................9Figure 1-18: Add Variable Panel.....................................................10Figure 1-19: Block Create Panel.....................................................10Figure 2-1: Multiple Block Model Slices..........................................11Figure 2-3: Report Window showing block model details...............14Figure 2-4: Block Contours panel....................................................15Figure 3-1: Block Edit panel............................................................16Figure 3-2: Block Calculation Panel................................................16Figure 3-3: Stope Mining Panel.......................................................17Figure 3-4: Add Block Model Variable panel...................................20Figure 3-5: Block Model Change Variable Name Panel...................21Figure 3-6: Block Model Translation Panel......................................21Figure 3-7: Block Model Rotation Panel..........................................22Figure 3-8: Index Block Model Panel...............................................22Figure 3-9: Assign Block Values Panel............................................22Figure 2-4: Regular Import Panel....................................................25Figure 4-2: Sub-blocked Import Panel............................................26Figure 4-3: Import Attributes into Model Panel...............................27Figure 4-4: Block Model Export Panel.............................................27Figure 4-5: The Mask Block Model panel........................................28Figure 4-6: Load Samples Database Panel.....................................30Figure 4-7: Intersect Drilling Panel.................................................30Figure 4-8: DB Intersection Record Panel.......................................30Figure 4-9: DB Intersection Fields Panel.........................................31Figure 4-10: New Definition Panel..................................................31Figure 4-11: Block Model Parent Scheme Panel.............................32Figure 4-12: Add Variable Panel.....................................................32Figure 4-13: Block Model Add Panel...............................................33Figure 4-14: Model Reblocking Panel..............................................34Figure 4-15: Reblocking Dimensions Panel.....................................34Figure 4-16: Resulting Variables Panel...........................................35Figure 4-17: Common Blocks..........................................................36

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Contents

Figure 4-18 –Regular Block (R), sub-blocks (S1, S2, S3 and S4) and common blocks (C1, C2, C3 and C4)......................................38

Figure 4-19: Block Selection Panel.................................................40Figure 4-20 Block Extraction Panel.................................................42Figure 6-1: Reserves submenu.......................................................44Figure 6-2: Reserves Calculation Panel..........................................45Figure 6-3: Reserves Cut-offs panel...............................................45Figure 6-4: Block Selection Panel...................................................46Figure 6-6: Reserves Report...........................................................47Figure 6-7: Polygon Reserve Panel.................................................47Figure 6-8: Confirm box..................................................................48Figure 6-9: Data Sources................................................................49Figure 6-10: Grade Names Panel....................................................49Figure 6-11: Breakdown Names Panel............................................49Figure 6-12: Grade Cut-offs Panel..................................................49Figure 6-13: Solid Model List Panel.................................................50Figure 6-14: Solid Model List panel with triangulations..................50Figure 6-15: Pick Data Source Panel...............................................51Figure 6-16: Block Model Panel......................................................51Figure 6-17: Block Model Grade Variables Panel............................51Figure 6-18: Block model breakdown variables Panel....................52Figure 6-19: Save Report Format Panel..........................................52Figure 6-20: Complete Report Panel...............................................52Figure 6-21: Reserve Listing Showing a Complete Report..............53Figure 6-22: Reserve Listing Showing an Above Cut-off Report.....53Figure 6-23: Unformatted Dump Panel...........................................54Figure 6-24: Reserve Listing Showing a Dump Report...................54Figure 6-25: Open Reserves Specification File Panel......................56Figure 6-26: Breakdown Fields Panel..............................................56Figure 6-27: A Block inside a reserve region that has been 0.3

mined (70% available)...........................................................58Figure 6-28: A block 50% inside a reserve region that has been 0.3

mined (70% available)...........................................................58Figure 6-29: Second Breakdown fields panel..................................58Figure 6-30: Grade Variables panel................................................59Figure 6-31: Grade Cut-offs Panel..................................................60Figure 6-32: Define Regions by Polygon Panel...............................61Figure 6-33: Multiple Selection Box................................................62Figure 6-34: Confirm box................................................................62Figure 6-35: Rename Region Panel................................................62Figure 6-36:Select Triangulations Panel.........................................63Figure 6-37: Set Group Name Panel...............................................63Figure 6-38: Reserve Region Report Panel.....................................63Figure 6-39: Block Selection Panel.................................................64Figure 6-40: Save Reserves Specification File Panel......................65

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Contents

Figure 6-41: Calculate Reserves Panel...........................................66Figure 6-42: Open Report Specification File Panel..........................66Figure 6-43: Global Report Parameters Panel................................67Figure 6-44: Report Columns panel................................................68Figure 6-45: Report Tables Panel...................................................71Figure 6-46: Save report Specification File Panel...........................73Figure 6-47: Create report Panel....................................................73

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Chapter 1 Block Construction

Chapter 1 - Block Construction in VULCAN

Figure 1-1: Block Model Slice

1

Use conditions (exceptions) to remove blocks

Use sub-blocking to increase accuracy along contacts

Define regions using Triangulations

Use large parent blocks to minimise the block model size.

Limit the maximum block size within regions

Automatic block optimisation

What is a Block Model? A block model is a series

of "blocks" or "cells" that collectively define a larger block. Each block defines an exact piece of 3D space.

Each cell can be assigned a series of attributes, eg grade, geological code, metallurgical code or geotechnical code that represent the physical properties of the deposit. In this way a complete "model" of the deposit can be produced.

Figure 1-2: Regular Block Model

Why do we use Block Models?Advantages of using block models

A block model is a very efficient data structure in

which to store a large amount of information.

Very flexible construction methods allow you to create a model that accurately represents the geological and mining conditions.

Allows excellent visualisation of geological zones or grade trends within an orebody.

The increased use of geostatistical methods to express grade distribution requires a block model structure to store the results of the estimation.

Rapid calculations between the values within variables allow effective resource/reserve estimates to be undertaken.

How do you create a block model in VULCAN?Creating a block model in VULCAN typically consists of the following steps:

1. Construct the model (Construction submenu).

2. Verify the model by slicing contouring etc. (Viewing submenu).

3. Perform calculations, add variables, etc. (Manipulation submenu).

4. Interpolate grades into the model (Grade Estimation submenu).

2

5. Report the Resource (Reserves submenu).

Figure 1-3: Block Menu

Block ConstructionThe block construction process typically consists of two steps;

1. Create a block definition file (.bdf) (Block > Construction > New option).

2. Create the block model (Block > Construction > Create Model option).

1.1 Create a Block Definition File (.bdf)

The New Definition option allows you to create a new block definition file (.bdf). This file stores all the parameters required for the construction of a VULCAN block model. When the option is selected, the Block Model Utility is started.

Figure 1-4: Block Model Utility - Orientation Panel

1.1.1 Origin and Orientation

The origin is commonly either the minimum point of the model or the map grid origin (0, 0, 0). It can, however, be any value.

Orientating the model to match the overall orientation of the deposit will generally result in better edge definition between geological zones, producing fewer blocks.

Orient the model by entering absolute and relative rotations about the three axes.

Notes:

3

All rotations are measured anti-clockwise. If clockwise rotations are required, then use negative angles.

Bearing, Plunge and Dip are not used with their geological definitions, but rather refer to rotations around the axes.

For a rotated model it is easier to use the minimum co-ordinates of the model for the origin.

For Block Addition the models must have the same orientation.

1.1.2 Block Model Offsets, Parent Block Size and sub-blocking

The Schemes panel allows you to define the model extents, i.e. the start and end offsets that define the 3D aerial extent of the model, parent block size and extent, and block size of any sub-block areas.

Figure 1-5: Block Model Utility – Schemes Panel

The first row in the table must be the Parent Scheme.

Notes:

If the model origin is (0,0,0) then the start and

end offsets are the co-ordinates of the minimum and maximum points of the model. If the model origin is the minimum point of the model, then the start and end offsets are the distances relative to the origin in order to define the 3D extent of the model.

The parent block size must be a divisor of the model extent. If the parent block size does not fit exactly within the model extent, you are notified and prompted to adjust the extent.

Subsequent rows in the table are for any sub-block areas. Specify the minimum block sizes in the “Block X, Y and Z” fields. If the sub-blocking is to take place in a sub-region of the block model, then enter start and end offsets.

Additional sub-blocking extents may be defined within the model if required.

The sub-blocking extents must not exceed the model extents.

Sub-blocking minimum sizes should be kept to a reasonable resolution to define the boundaries. The smaller the sub-blocking size the larger the model. This will affect computer performance and the time

4

taken to create or modify the block model.

Sub-blocking maximum sizes must not exceed the parent block size.

Sub-blocking sizes must be a divisor of the parent block size.

1.1.3 Variable Names and Default Values

The Variables panel allows you to specify all variables to be created in the model. You must also specify the data type and a default value for each variable. The description is optional.

Figure 1-6: Block Model Utility – Variables Panel

Notes:

Variable names should never start with a numeric value.

Keep variable names as short as possible.

Select the data type most appropriate to the requirements of the variable. As some data types use more memory than others, selecting an inappropriate data type could result in much larger

block models than necessary.

Variables used for estimation must be either "float" or "double" data type.

1.1.4 Define the Limits of the Block Sizes by Variables

The Limits panel allows you to specify a maximum block size for blocks of predefined values. Values are assigned using the Boundaries panel.

For example, within a particular ore zone the block limits may be 5, 2.5, 2.5. Whereas in another ore zone the block limits may be 1,1,1.

Figure 1-7:Block Model Utility – Limits Panel

Notes:

A block will have this limit applied if the variable value is equal to that specified in the panel. You may therefore use many different limit values to define accurately the zones in the model.

The maximum block size must lie between the smallest sub-block size

5

and the parent block size. Hence you must have defined sub-blocks.

The maximum block size must be a divisor of the parent block size.

1.1.5 Boundaries

The Boundaries panel allows you to apply attributes to blocks based on their position relative to triangulations. This option also allows sub-blocking to be performed.

For example, a geological code may be applied if a block lies within a solid triangulation defining the geological region.

Priority levels are assigned to resolve areas of conflict between triangulations; the higher the value the higher the priority. The highest value allowable is 9999.

Inversion and projection along an axis are used to determine the area of interest relative to a triangulation.

Figure 1-8: Block Model Utility – Boundaries Panel

Notes:

Wildcards may be used when listing triangulation names.

Partial inversion is only used with surface triangulations.

The higher priority value takes precedence over the lower.

1.1.5.1 Inversion Examples:

Figure 1-9: Inversion with 3D (Solid) Triangulations

Figure 1-10: Inversion with 2D (Surface)

Triangulations

1.1.5.2 Projection Axes:

The projection axis defines the direction for a surface and has no effect when working with solids. The projection axis option is used in situations where steeply dipping structures define regions.

6

Figure 1-11: Projection Axes

If No inversion is selected the negative side of the triangulation is the area of interest. If Partial or Complete inversion is selected the positive side of the triangulation is the area of interest.

For triangulations (ore bodies) that are steeply dipping, it may be necessary to project along the X or Y axes to ensure the correct inversion is applied.

Figure 1-12: Projection along the X axis

Figure 1-13: Projection along the Y axis

For triangulations (ore bodies) that are near to horizontal i.e. lying in the XY plane, a projection along the Z axis may be more suitable. The area of interest is then below the triangulation if No inversion or above if Partial or Complete is selected.

Figure 1-14: Projection along the Z axis

1.1.6 Exceptions

The Exceptions panel allows you to specify conditions that will result in those blocks that match the condition being removed.

For example, if the exception, topo eq "air", is used then all blocks where the variable

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"topo" has the value "air" will be removed from the model.

Figure 1-15: Block Model Utility – Exceptions Panel

Notes:

Removing unnecessary blocks from the model will reduce the size of the model resulting in better computer performance.

Remember that if you simply use the topography triangulation to remove blocks, then you may be discarding some blocks that are required for accurate reserves, scheduling etc. To avoid this, make a copy of your topography triangulation, translate it to a height about twice the block height above the topography triangulation and then use this copy for the exception.

1.1.7 Saving the Block Definition File

The Block Model Utility > File > Save As option allows you to save the block definition file. The maximum size of the definition file name is 20 alphanumeric characters.

1.2 Create the Block Model

The Create Model option (either the Block > Construction > Create Model or the Block Model Utility > Model > Create Model) allows you to build the model.

Once all the required parameters have been entered using the New Definition option, simply specify the block definition file name (.bdf) and the name for the model. By default the definition file that is currently loaded is displayed in the panel and a block file name that matches the definition file name is suggested.

The index model option should be selected to allow the generation of a block model index. A block model index will allow much faster access to the model for future processing. If the block model is large, then the creation of the index may take some time.

The block model creation process is run in a shell window, thus allowing you to continue working within VULCAN.

Workshop: Creating your first modelThe aim of this workshop is to create a number of models that demonstrate the various options available. We will create a simple regular model and then introduce some simple viewing techniques so

8

that you may verify the model.

Work at your own pace. Use the manual if required or ask the MAPTEK staff for assistance.

1. The model origin and orientation (Orientation Panel)

Enter the origin co-ordinates and the Rotation angle:

X origin coordinate:

77900.000

Y origin coordinate:

4300.000

Z origin coordinate:

300.000

Bearing:

62

Figure 1-16: Block Model Orientation Panel

This will create a model trending 62, with horizontal plunge and dip.

2. The model dimensions (Schemes Panel)Enter the start offset:

Start X Offset:

0.000

Start Y Offset:

0.000

Start Z offset:

0.000

Enter the End offset:

End X Offset:

810.000

End Y Offset:

330.000

End Z Offset:

600.000

Enter the parent block size:

Block X Size:

30.000

Block Y Size:

30.000

Block Z Size:

30.000

Figure 1-17: Add Schema Panel

This will define a model 810 330 600 metres.

Select File > Save As.

Enter the block definition file name:File Name:

first

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3. Adding variables (Variables Panel)

Enter:

Variable name:

geol

Select the data type:

name

Enter the default value:

air

Enter the description:

geological code

Figure 1-18: Add Variable Panel

This model will only have one variable called ‘geol’ with a value equal to ‘air’.

Select File > Save.

4. Creating the model:

Select Model > Create Model.

Enter the model name:

first

Enter the definition file name:

first

Figure 1-19: Block Create Panel

Select OK to build the model.

When the model has been created use the Block Viewing - slice and blocks options to verify the model.

Now that you have created your first model you may like to experiment with the other options available. Try the following examples. Either build on previous models by editing the .bdf or create new block definition files.

A regular model with origin at model minimum

A regular model - rotated

A regular model - plunged

A regular model - dipped

A sub-blocked model using solid triangulations

A sub-blocked model using surface triangulations

A sub-blocked model using both solid and surface triangulations

A sub-blocked model using limits

A sub-blocked model using exceptions

Finally create a model, which we will use for grade estimation, using some or all of these options.

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Chapter 2: Block Viewing

Chapter 2 – Viewing Blocks in VULCAN

Figure 2-1: Multiple Block Model Slices

11

VULCAN Block Viewing MethodsVULCAN allows you to display the block model in a variety of ways.

You may:

Display the block model extents.

Slice the model at any orientation.

Slice the model dynamically.

Display multiple slices. Load blocks as 3D boxes,

rectangles or crosses. Contour the model. Interrogate the model

directly.

Reasons for Viewing Block ModelsAfter a block model has been created it must be verified. Common types of checks performed include:

Blocks have been created in the correct place.

Blocks are of the correct size.

Sub-blocking has performed as expected.

Variable values have been assigned correctly.

Check for "leaks".

After grade estimation the model is viewed again to verify the estimation process. The model may be viewed at any time to gain information.

Getting Information about your Block ModelsThe Block menu contains options that allow you to

List the block models in your working directory (Block > Directory).

Open a block model (Block > Open).

Display the block model header information (Block > Header).

2.1 Getting a List of your Block Models

The Directory option allows you to display a list of the block models in your working directory.

Figure 2-2: Report Window showing block model directory listing

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2.2 Opening Your Block Model

The Open option allows you to open a block model. You

can also use the Open button on the Standard

toolbar or the Open Block Model button on the Open toolbar to Open Block models.

The standard Windows Open Panel is displayed.

Use the Look in field to navigate to the directory in which the block model is stored.

From the Files of Type field select Vulcan Block Models. Note this is only necessary if you used the Open button on the Standard toolbar.

Select the block model to open and select Open.

Note:

You can only have one block model open at a time.

2.3 Displaying the Block Model Header Information

The Header option allows you to view general information about the model.

The information includes:

Model name Number of blocks Number of variables Model origin Model orientation

Creation/Edit date Variable defaults Translation tables Model schemes

Block Viewing2.4 Generating Contours of the Block Model

The Contour option allows you to contour any variable in the model in any plane. One or more sections may be contoured at any time. Zonal contours may be created.

Note:

Contours are restricted to values in the plane being contoured.

Use "continuous contours" to take care of blocks with default values.

Displaying contours as underlays will assist in graphics performance.

Contour intervals are controlled by those set out in the contour legend scheme. See Analyse > Legend Edit if you do not have a contour legend scheme.

13

Figure 2-3: Report Window showing block model details

Figure 2-4: Block Contours panel

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Chapter 3: Block Manipulation

Chapter 3 – Block ManipulationThe Manipulation submenu allows you to:

Edit variable values. Perform one-line

calculations. ‘Mine’ the block model

using triangulations. Perform multi-line

calculations using scripts. Add, delete and rename

variables. Translate or rotate the

block model. Index the block model for

faster access. Assign values to a block

model.

3.1 Editing a Block Model

The Edit option allows you to edit the value of a variable in any block within the model.

Simply click on the block you want to edit, select the variable name and enter the new value in the edit panel.

Figure 3-1: Block Edit panel

3.2 Performing a Calculation on the Block Model

The Calculation option allows you to perform a one-

line calculation on any block within the model.

Simply select the variable on which to perform the calculation and enter the equation to perform.

For example, you might want to determine the dollar value of each block.

Consider:

Variables:

au = gold grade (grams per tonne)

sg = density (tonnes/m3)

volume = volume (m3)

dollar = dollar value of block

Calculation:

(tonnes au) gold value per tonne – (tonnes mining cost per tonne)

i.e. ((sg * volume) * au) * 34.00 - (sg * volume) * 40.0

Figure 3-2: Block Calculation Panel

3.3 Mining the Block Model

The Mine option allows you to mine out the block model against solid triangulations that represent the mined out zones of an ore body. This value can then be used in the advanced block reserve options.

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A variable is required to store the mined value. You have the choice of storing the percentage of the block remaining or the fraction of the block mined. You also have the option of selecting blocks using the full cell or proportional cell evaluation methods.

Use full cell evaluation if you want to include those blocks whose centroid falls within the region. The entire block is selected.

Use proportional cell evaluation if you want to include those blocks that are (either fully or partially) in the region. The selected blocks are scaled according to the proportion of the block's volume that lies within the region.

Note:

The proportional cell evaluation method applies only when restricting blocks using a bounding box, closed triangulation or bounding surfaces.

Figure 3-3: Stope Mining Panel

3.4 Using Scripts

3.4.1 Why use scripts in VULCAN?

allows you to perform complicated calculations on the block model.

scripting can be used to modify existing variables in the model by acting on one or more variables at a time.

examples of using scripts include calculating dollar values for use in Whittle 3D, establishing percent of block mined and creating classification fields for reserve reporting.

scripts can be stored as a record of the modifications to a block model and thus rerun or used as an audit trail.

3.4.2 Scripting Constructs

Scripts follow the basic construct shown below.

if ( expression ) then

statement

elseif ( expression ) then

statement

elseif ...

else

statement

endif

Note:

"If" statements may be nested, but remember

17


that each "if" must have its own "endif".

Spaces and indents are optional, but help in legibility and debugging.

The "elseif" and "else" statements are optional.

3.4.3 Operators

The operators below are just some that can be used with scripts.

3.4.3.1 Comparison operators:

Numeric:

eq equal to

ne not equal to

le less than or equal to

lt less than

ge greater than or equal to

gt greater than

Character:

eqs equal to string

nes not equal to string

3.4.3.2 Logical operators:

Use "and", "or" for complex conditions.

For example,if ( au gt 0.5 and au le 2.5 ) then

3.4.3.3 Assignment operators

= to assign a value

3.4.3.4 Mathematical operators

+ add

- subtract

/ divide

* multiply

abs absolute

sqrt square root

sin sine

cos cosine

Note:

See the Online Help > Envisage > Core Appendices > Appendix D and H for additional information on scripting syntax and operators.

3.4.4 Example Script:

The example below assigns different values for "recovery" based on the value of the "geo" and "weathering" variables.

* demorecover.bcf

* block model calculation script to define a recovery

* factor based on "geo" and "weathering".

*

* This script assumes that the "recovery" variable has been added to the block model

*

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* rec_103 = recovery expected in geo = 3 and weathering = 100




* rec_0 = recovery expected in non-ore zones

*

* Assign variable values

rec_103 = 0.833

rec_105 = 0.85

rec_203 = 0.97

rec_205 = 0.92

rec_0 = 0.00

if ( geo eq 3.0 ) then

if ( weathering eq 100.0 ) then

recovery = rec_103

elseif ( weathering eq 200.0 ) then

recovery = rec_203

else

recovery = rec_0

endif

elseif (geo eq 5.0 ) then

if ( weathering eq 100.0 ) then

recovery = rec_105

elseif ( weathering eq 200.0 ) then

recovery = rec_205

else

recovery = rec_0

endif

else

recovery = rec_0

endif

Note:

Scripts are executed for each cell in turn.

Any variable names may be used, but only those variables defined in the block model will save the results. i.e. Scripts allow the use of temporary variables to make the calculations easier to understand and implement.

Comment lines may be used freely throughout the script. Simply begin the line with an asterisk.

Scripts provide a good permanent record, or audit trail, of calculations performed on the block model.

Sequence of events:

Geology supply block model with geology and grade variables.

Add the required engineering and economic variables.

19


Execute scripts to calculate the values of economic and engineering variables to aid in mine planning.

Workshop Exercise: ScriptsUse one of the block models constructed earlier to calculate a dollar field for reporting and evaluation purposes.

1. Plan your calculation

a. What variables will you need?

b. What logic will best suit the calculation and cell selection?

c. You may have to add your variable(s) first.

Note:

Use units analysis to confirm that the value you are calculating is actually the quantity you want. i.e. Do you wish to calculate the total dollar value of each cell or the $/t value of the material?

2. Document your work:

a. Include details such as your name, the date, the name of the script (so that if the script is printed out it can be identified), the purpose of the script

and the model at which it was targeted.

b. You may also include details of where this script fits into the mine planning data flow, and what variables were added to the "original" model to allow the script to run.

Note:

Make the calculation as complex as you wish, but be liberal with comments (for your and other people’s reference). Also build the complex calculation up from a simple one. Confirm that each new part runs before doing more.

3. Document Temporary Variables

a. Define all constants to be used as temporary variables at the head of the script. This makes editing and re-running scripts easier.

b. Don’t forget to document different versions of scripts for reference.

Note:

If you will be doing a complex calculation on a large or huge block model, then it may pay to extract a small section on which to test the scripts before you edit the real model.

20


3.5 Adding Block Model Variables

The Add Variable option allows you to add variables to the block model.

Figure 3-4: Add Block Model Variable panel

You must:

Enter a new variable name.

Select the type of data to be stored in the variable.

Enter a default value. And enter an optional

description for the variable.

On completion of the Add Block Model Variable panel, it is redisplayed, so that additional variables may be defined. When all variables are defined, cancel out of the panel. The variables will be added to the model.

3.6 Deleting Variables from a Block Model

The Delete Variable option allows you to delete variables from a block model.

Simply select the variable to be deleted from the variable list and select OK.

Note:

All data associated with the deleted variable is also removed.

3.7 Renaming Variables in a Block Model

The Change Name option allows you to rename any existing variable in the block model:

Select the variable to be renamed from the variable list.

Enter the new name. Enter an optional variable

description. Enter an optional default

value.

Figure 3-5: Block Model Change Variable Name

Panel

3.8 Translating a Block Model

The Translate option allows you to move a block model.

Enter the X, Y and Z translation distances. The block model will then be

21


moved (translated) the appropriate distance along each axis.

Figure 3-6: Block Model Translation Panel

3.9 Rotating a Block Model

The Rotate option allows you to rotate a block model about its origin. Simply enter the rotation angles for the X, Y and Z axes. All rotation angles are anti-clockwise. If clockwise rotation is required, then enter negative rotation angles.

Figure 3-7: Block Model Rotation Panel

Note:

The rotation axes are the same as defined in the block construction area. Therefore the Bearing, Plunge and Dip do not have their normal structural definitions.

3.10 Indexing a Block Model

The Index option allows you to index a block model. Indexing a block model writes a spatial index of the block locations to the block model file, consequently allowing for faster access to the block model. If the structure of the block model changes in any way, the block model must be indexed again. Adding or deleting variables has no effect on the index of the block model.

Figure 3-8: Index Block Model Panel

Note:

The index procedure requires an amount of disk space equal to the amount that the model already occupies. This means that if the model is 4Mb in size and only 3Mb is free you won't be able to index the model.

When indexing the model you can choose to use the fast method, which is CPU intensive and stops you working in Envisage, or the slower method, which allows you to continue working in Envisage.

22


3.11 Assigning Values to a Block Model

The Assign Values option allows you to assign block variable values from an input model to an output model. The block variable values are assigned based on their common block overlap and the calculation method chosen.

The open block model (remember you can only have one block model open at a time) is the input model. You specify the output model on the Assign Block Values panel. You also specify the name of the block definition file (.bdf) that is to be created or edited in the assignment process.

Figure 3-9: Assign Block Values Panel

Note:

The input and output model must have the same orientation (i.e. bearing, plunge and dip) and their parent (primary) block extents must overlap. If the output model extent is beyond the input model extent, input blocks on the edge will be assigned incorrect values due to the difference in volume.

All definition files are displayed in the definition file list, however, only those files created in a previous assign values procedure should be selected.

Load only an existing assignment definition file if it was created with the same input and output block model so that variable details match.

Figure 3-10: Assignment Variables Panel

Name variable values in the output model are ignored, i.e. you cannot assign a value from the input model to a name variable in the output model. For this reason, the Assignment Methods are not displayed for output name variables.

Use the Next button to step through each output variable's panel.

The name, default value and data type of the output

23


variable is displayed at the top of the panel.

For each output variable, specify the assignment calculation method:

Use default value - uses the default value of the output variable (shown in the top half of the panel).

Majority variable - allows you to enter or select an input variable for which the majority value will be calculated and placed in the output variable.

Total variable - allows you to enter or select an input variable for which the total will be found and placed in the output variable.

Average variable - allows you to enter or select an input variable for which the average will be found and placed in the output variable.

Percentage variable - allows you to enter an input variable and an ordinal value. The percentage of variable values equal to the ordinal value is calculated and placed in the output variable.

Select the Weight blocks using density option to weight output variables by density. You can either use a density value or an input density variable.

Once all output variables have been assigned, you are prompted whether to continue with the assignment process or to change the definition.

If you select Change definition, you are returned to the first output variable's panel. If you select Continue, the external block assignment program is run in a shell window. Once this is finished, press Enter to remove the window.

Note:

The block assignment program processes the output model in strips of X-Y blocks with the Z depth of the output model. Where these strips overlap the input model, the input model blocks are re-blocked and the calculated volume and (possibly density weighted) values are assigned to the output model blocks.

To run the block assignment program from outside Envisage, start a Hamilton C Shell, navigate to your working directory and execute the block assignment program bassign from the VULCAN_EXE directory. Use your input and output block models and a previously created assignment definition file (the definition file must

24


match the input and output models). For example:

$VULCAN_EXE/bassign demoinput demooutput demoassign.bdf

or, if VULCAN_EXE is not defined

$VULCAN_BIN/exe/bassign demoinput demooutput demoassign.bdf

Chapter Four – Block TransferThe Transfer menu allows you to:

Import regular and sub-blocked models.

Import attributes from an ASCII file.

Export the block model to an ASCII file.

Mask a block model.

Write block values to a map file (drilling).

Add two

block models.

Regularise a block model.

Delete sections of a block model.

Export a block model.

4.1 Importing a Regular Block Model

The Regular option allows you to import an ASCII file that represents a regular block model. You must set up a definition file to match the ASCII file.

Within the ASCII file, the fields must be in a specific order with each line representi

25


ng a block. It must have an X, Y and Z centre, then the grade or model fields, in the same order as defined in the definition file. The block co-ordinates must be in real world co-ordinates.

See the Online Help > Envisage > Block Model > Appendix A for more details on the ASCII file format and the corresponding definition file.

Enter the name of the block model to be created, the name of the

definition file and the name of the ASCII file to be imported in the Regular Import panel.

Figure 1-4:

Regular Import Panel

Note:

Use an alphabetic character as the first character of the block model identifier.

The block model name may have a maxim

um of 20 characters. The block model extension (.bmf) will be added automatically.

The ASCII model file name should contain the full name (including the file extension) of the ASCII file to be imported.

4.2 Importing a Sub-blocked Block Model

The Subblock option allows you

to import an ASCII file that represents a sub-blocked block model. You must set up a definition file to match the ASCII file.

Within the ASCII file, the fields must be in a specific order with each line representing a block. It should have an X, Y and Z centre, X , Y and Z size, and then the grade or model fields in the same order as defined in the definition file. The block co-ordinates must be in real world co-ordinates.

26


See the Online Help > Envisage > Block Model > Appendix A for more details on the ASCII file format and the corresponding definition file.

Figure 4-2: Sub-blocked Import Panel

You specify the name of the block model to be created, the name of the definition file and the name of the ASCII file to be imported on the

Sub-blocked Import panel.

Note:

Use an alphabetic character as the first character of the block model identifier.

The block model name may have a maximum of 20 characters. The block model extension (.bmf) will be added automatically.

The ASCII model file name should

contain the full name (including the file extension) of the ASCII file to be imported.

4.3 Importing Attributes into a Block Model

The Attributes option allows you to import an ASCII file containing block model details and grade estimation results, into a pre-existing block model.

The format of the ASCII file must be: X centre Y centre

Z centre data1 data2 data3 ……

where X, Y and Z centre, is a point in space.

Whatever block encloses the point, gets data1, data2, data3 inserted into the specified fields. If two data points exist for the same co-ordinate point, or two co-ordinate points lie in the same block, then the last co-ordinate read in the ASCII file will overwrite any previous ones.

27


The data variables in the ASCII file do not have to be in the same sequence as the block model. Not all the variables within the block model have to be in the ASCII file. However, all the data variables within the ASCII file must be imported, otherwise errors will occur when reading the file. Therefore, if the ASCII file has eight data variables and only three of them are to be imported, the file

must be stripped of the excess columns.

Figure 4-3: Import Attribute

s into Model Panel

The open block model name is displayed at the top of the panel Import Attributes into Model panel.

Enter the ASCII file name in the Insertion file name field. The full file name must be entered, including the file extension. If the file is not in your working directory, precede the file with the required path (paths may be relative or full).

Up to 30 variables can be imported at a time.

Centroids can be imported as real world co-ordinates or as relative offsets. Real world co-ordinates are an

actual location in space. Relative offsets are the distances in the X, Y and Z directions with respect to the origin of the block model.

Note:

This option does not require a definition file.

4.4 Exporting a Block Model

The Export ASCII option allows you to export a block model to an ASCII file.

The name of the open block model is

28


displayed at the top of the Block Model Export panel.

Enter the destination file name in the Export file name field. Include a file extension if required. For example, <file name>.asc. The maximum file name size is 20 alphanumeric characters. The file will be placed in your working directory.

Figure 4-4: Block Model Export Panel

To export the block identification numbers, select the Export block ids check box. Don’t tick this box if you want to import the model back into Envisage.

To export the physical volumes of the blocks, select the Export block volumes check box. Don’t tick this box if you want to import the model back into Envisage.

To export all variables in the block

model select the Export all variables radio button.

Alternatively you can choose to export a subset of the variables in the block model. If this is the case, select the Export individual variables radio button. A maximum of 30 variables may be exported using this method.

Centroids can be exported as real world or as relative offsets.

4.5 Export Variables to a Map File

The Export Mask option allows you to export variables from the open block model, corresponding to the X, Y and Z locations of a specified map file (this may be an ISIS database or ASCII map file).

This option creates a new map file that includes all fields from the "old" map file (the file being read) plus up to 6 new fields.

The data that will be exported is specified in the <proj><na

29


me>.bmm parameter file. This parameter file can be used with the Hamilton C Shell bmask command, e.g.

bmask <proj><name>.bmm

This option is useful if you want to write the estimated grade values to a map file for validation purposes and bivariate analysis (see the Online Help Envisage > Analyse > Statistics 11 section). It is also useful to map the geological domains

defined in the block model to a map file, so that domain restrictions can be used in grade estimation.

Figure 4-5: The Mask Block Model panel

The open block model name is displayed at the top of the Mask Block Model panel.

Enter the name of

the parameter file to be created or modified in the Parameter Identifier field. The maximum size of the name is 10 alphanumeric characters. As the project code and extension are added automatically, you do not need to enter these values.

To import from or export to an ISIS database, select the Use samples database option. Specify the design name and the database identifier.

To import from or export to an ASCII map file, enter MAP in the Design Name field.

Up to 6 variables can be selected. You'll also need to specify an appropriate default value.

Note:

The design names for the "old" and new database must not be the same (unless using map files, in which case they will both be MAP).

If exporti

30


ng data to an ISIS database, the data may be grouped in the resultant database file. ISIS databases may contain multiple groups. ASCII map files may consist of one group only. To create a new group, enter a unique name in the Group field. The maximum size of the group name is 12

alphanumeric characters.

You may want to enter an optional 40 alphanumeric character description of the map or database. The description appears in the header of the new map file.

If exporting to an existing ISIS database or map file, selecting the Append to existin

g group check box will allow you to append the specified group to the same group(s) in the existing database or map file.

If the Use Fortran Format option is selected, specify the map file identifier (<mfi>) in which the existing sample data is stored.

Note:When

using Fortran formats, data will be appended to the specified map file instead of a new map file being created.

The FORTRAN format statement identifies the location of the X, Y, and Z co-ordinates. Envisage expects a character variable indicating the

31


number of columns to be skipped before the first location is reached plus three real numbers. The three real numbers represent the X, Y and Z co-ordinates. For example, 12X, 3F13.3 means that the co-ordinates are located starting in the 13th column (first 12 columns are skipped). The maxim

um size of the format is 80 alphanumeric characters. The fields supported in a FORTRAN format statement are listed in the Online help, Envisage > Core Appendixes.

If the Use samples database option is selected, a panel will be displayed allowing you to enter the group name and field information required.

Figure 4-6: Load Samples Database

Panel

Enter the name of the group to be loaded from the source file.

Wild cards (* multi character and % single character) may be used if you can't remember a group's name. However, only one group will be loaded- this is the first group in the file that matches the entered criteria. For example,

A* loads the first group in the map file that starts with an A.

Specify the names of the fields containing the X, Y and Z co-ordinates.

The sample data will then be exported and a map file will be created or, if using a FORTRAN format, the data will be appended.

The export occurs in a Shell window. This window also displays error messages.

When the export is finished press [Enter] to

32


remove the window.

4.6 Intersect a Drill Hole Database

The Export Drilling option allows you to intersect a drillhole database with variables of the open block model that correspond to the X, Y and Z locations of the database.

This option is useful if you want to write the estimated grade values to a drillhole database for validation and analysis purposes analysis

(see the Online Help Envisage > Analyse > Statistics 11 section).

Note:

The drillhole database fields will be overwritten with the block model variables unless destination fields have been created in which the intersection results will be stored.

Figure 4-7:

Intersect Drilling Panel

The open block model is displayed at the top of the Intersect Drilling panel.

Enter the design (datasheet) name (.<dsn>) of the drill hole database and the optional database identifier.

Figure 4-8: DB

Intersection

Record Panel

Enter the drill hole database table

(record) to be intersected.

Figure 4-9: DB

Intersection Fields

Panel

Select the From and To fields in the specified table (record). Up to 10 block model variables can be matched to drillhole fields.

Note:

The block model variables and drillhole database fields must be real

33


numbers (4 bytes).

4.7 Block Model Addition

The Addition Parameters option allows you to create a block definition file to be used when combining two block models into a new model. The models to be combined may:

Totally overlap each other.

Partially overlap.

Not overlap.

Have different parent block sizes.

Contain different variables.

They must be of the same orientation, i.e. bearing, plunge and dip.Some specific uses for this option include:

Adding two adjacent models so that a resource calculation may be performed on the total model.

Extracting a portion of a model for modification, i.e.

adding in a variable or updating the grade estimation, then adding it back into the original.

Creating a new empty model that may contain a surface or solid which was not present in the old model. Then combining this model with the original to create a new model that now include

s the surface or solid zones.

Creating a New definition File

Figure 4-10: New

Definition Panel

Specify the two block models to add. Also enter the name of the new block model that will be created when this option is run.

Hints:

It does not matter which model you select as the first or

34


second one. Only the variables are stored in the definition file (.bdf) - the names of the block models are not stored.

The new block definition file name will be taken from the new block model name. For example, if you enter FINAL as the new block model name, your block

definition file will be named <proj>FINAL.bdf.

Defining the Parent Scheme

The two models may be combined into a new one, using:

Either model scheme.

A combined scheme.

A new scheme.

Figure 4-11: Block

Model Parent Scheme Panel

Columns in the Block Model Parent Scheme panel are ordered X, Y and Z. The offsets are the offset distances relative to the origin point.

Hints:

A new block definition file is created for the new model.

The new model extent is dependent on the scheme entered on this panel.

If your final model does not cover the expected area, check the scheme used.

The model 1 and model 2 parent schemes must be multiples of each other. The resultant model's parent scheme must encompass both other parent schemes.

Adding New variables

New variables

35


may be added into the resulting block model and/or existing variables in either model can be manipulated for use in the new model.

Figure 4-12: Add Variable

Panel

If new variables are required in the final block model, which do not exist in either of the two original models, they may be added

using the Add Variable panel. See the Block Manipulation – Add Variable section for details on adding variables.

If no new variables are required or all variables have been added, cancel this panel.

Determining which variables to include (Variable Constraining)

There are a number of options regarding how existing variables are used in the new model:

Variable Dominance -

Variables from both models are used. Select which model variables will be used in areas of overlap.

Average of Variables - Uses the average of the two model variables in areas of overlap.

Direct Variable Mapping - Allows the use of variable values from one

model only.

Use scripts – Allows variable values to be determined by a script.

The Variable Constraining panel will be displayed for each variable. You must choose whether or not to include the variable in the final model.

If a variable exists in both original models and is not selected for inclusion in the final model when displayed as a

36


variable in the first model, it will appear again when displaying variables from the second model. If the variable is selected from the first model, it will not appear for the second model.

When using Variable Dominance a block addition script file is generated automatically. For example:

IF (m1:material NE “-9999999999”) THEN

m3:mineralisation = m1:material

ELSE

m3:mineralisation = “WASTE”

ENDIF

END

Note:

All block model scripts created by the block addition routine have the extension “.bcf”.

Creating the new Block Model

The Perform Addition option allows you to create a new block model by adding two existing models. The process uses the block model addition

definition file and block model addition variable constraining script files created in the Block > Transfer > Addition Parameters option.

You must specify the two existing block models and the new block addition definition file name.

Figure 4-13: Block

Model Add

Panel

Note:

It does not matter which model you select

as the first or second one.

Workshop - Block Manipulation, AddThe aim of this workshop is to experiment with the Block Addition options to become familiar with the consequences of each.

Try the following:

Add two models that do not overlap.

Add two overlapping models.

Extract part of

37


a model, modify it, and then add it back to the original.

Add a waste model to an ore model.

4.8 Regularising a block model

The Regularise Parameters option allows you to create or edit a block definition file (<proj><name>.bdf). This file is then used by the Perform Regularisation option to regularise a block model.

Hints:

Block definition files are also created by other block model options, e.g. the Block > Transfer > Addition Parameters option and the Block > Construction > New Definition option. If you use the Regularise Parameters option to edit these types of .bdf files, a warning message will be

displayed informing you that the .bdf file is not a reblock definition file.

Figure 4-14: Model Reblocking Panel

The Parameter file to copy option allows you to copy and then modify an existing definition file.

Enter the name of the new parameter file in the New parameter file field. The project code and extension are added

automatically. The maximum size of the parameter file name is 20 alphanumeric characters and this includes the project name and file extension (.bdf).

Figure 4-15:

Reblocking

Dimensions Panel

The Reblocking Dimensions panel

38


requires you to set the regular model's origin, start and end (minimum and maximum) X, Y and Z offsets for its extent, and its X, Y and Z regular block sizes.

The regular model can sit completely inside, outside or partially inside the sub-blocked model.

The block sizes do not have to be aligned with the sub-blocked model's sizes. The model’s dimensions are completely independe

nt of the sub-blocked model being regularised.

On completion of this panel, the Resulting Variables panel is displayed. This panel needs to be completed for each variable required in the new model.

Figure 4-16:

Resulting Variables

Panel

Enter the name of the variable you want to create in the new model in the Variable Name field. The maximum size is 20 alphanumeric characters.

The Default value is only required if using the default, total or average regularisation methods (see below). The following characters may be used in combination with the default value, but not on their own:

[ ] ( )

{ }% , + - * / &

For each variable you must specify a data type and regularisation method.

Available data types:

Float - A real number accurate to 7 significant figures. It is generally used for grades and densities.

Double - A floating point number accurate to 14 significant figures. It is generally used for

39


sensitive grades. Use of this data type will result in large block model files that are slower to process.

Integer - A fixed point number in the range [-2 000 000 000 to +2 000 000 000].

Byte data - A fixed point number in the range [0 to 255].

The regularisation

methods (listed below) calculate variables using sub-blocks, regular blocks and common blocks. Common blocks are generated when a regular block intersects sub-blocks. In the example, R indicates the regular block, S the sub-blocks and C the common blocks. The number of sub-blocks intersected by a regular block is denoted by NSB.

Figure 4-17: Common Blocks

Available regularisation methods:

Use default value - This method uses the default value specified at the top of the panel.

Majority variable - This method calculates the ordinal value that occupies a majority of the regular block's volume. The input and output variable types should be byte or integer. Floating point variables will be truncated. The calculation may be defined as follows:

where

Total variable - This method calculates the total of the variable from the sub-blocks intersected by the regular block. The calculation may be defined as follows:

40


where,

and

Average variable - This method calculates the average of the variable from the sub-blocks intersected by the regular block. The calculation may be defined as follows:

where.

and

Hint:

If density weighting is not used, the density value defaults to 1. Otherwise, the specified density value or sub-block density variable is used.

Percentage variable - This method calculates

the percentage of the regular block volume occupied by sub-blocks matching a specified ordinal value. The input variable type should be byte or integer, and the output variable type should be floating point. The number of sub-blocks intersected by a regular block and also matching the given ordinal value is denoted by NSB. The calculation may be defined as follows:

where,

and

The Weight blocks using density option is applicable only if you are averaging or totalling a field's contents (i.e. density

weighted averages - e.g. grams/ton; density multiplied totals - e.g. tonnages).

Examples - Regularisation

41


Methods (2D only)

Figure 4-18 –

Regular Block (R),

sub-blocks

(S1, S2, S3 and S4) and common blocks

(C1, C2, C3 and

C4)

When regular block R intersects sub-blocks

S1, S2, S3, S4 it generates common blocks C1, C2, C3, C4. See Figure 4-18 and Tables 4-1 and 4- 2.

Table 4-1: Sub Blocks

Sub-block

Volume

S1 400.0

S2 400.0

S3 400.0

S4 400.0

Table 4-2: Common Blocks

Common Block

C1

C2

C3

C4

Default Variable - No calculation performed.

Majority Variable - Refer to Figure 4-18, Table 4-1 and Table 4-2.

Majority for zone variable in regular block:

hence, the majority = A

Total Variable - Refer to Figure 4-18, Table 4-1 and Table 4-2.

Total for gold variable in regular block:

hence, the total = 2.5

Average Variable - Refer to Figure 4-18, Table 4-1 and Table 4-2.

Average for gold variable in regular block:

42


NOTE:

Density weighting is not used for this example.

Percentage Variable - Refer to Figure 4-18, Table 4-1 and Table4-2.

Percentage of regular block volume filled by sub-blocks with a zone value of A:

Fill Percentage Variable (fillpc) - Reblock option - Refer to Figure 4-18, Table 4-1 and Table 4-2.

Filled percentage for regular block:

4.9 Deleting

Blocks from a block model

The Delete cells option allows you to delete blocks from a block model. When this option is selected, the block selection panel is displayed allowing you to choose the blocks to be deleted.

Figure 4-19: Block Selection

Panel

Either all blocks or specific

blocks can be selected. If you select specific blocks, you can specify one or more of the following selection criteria:

By variable - To restrict blocks by a variable, specify the variable and a particular value. For example, all blocks where the Material variable equals Ore.

By bounding triangulation - To select blocks within a particular solid triangulation, e.g. a stope. If there is more than

43


one triangulation loaded, you'll be prompted to select the required one.

By bounding box - To restrict the selected blocks to those contained within a cube. The cube is defined in Interactive or Co-ordinate mode. The required mode is selected from the panel displayed upon completion of the current panel.

If you select Interactive mode, you'll be prompted to create the box by indicating

the lower left corner and then dragging the "rubber" band rectangle to the upper right corner.

If you select Co-ordinate mode, enter the minimum and maximum co-ordinates for the box.

By section - To restrict the blocks to a defined section plane. You can then enter its associated thickness. The section plane can be selected by line, points, grid co-ordinates

or 3 points (the panel for this information is displayed as soon as the current panel has been accepted).

By condition - To use a field constraint, for example, Fe gt 10.0

(iron value greater than 10.0). A list of available operators/functions is provided in the Online Help (in Appendix D of the Core Appendices.

By bounding surfaces - To restrict the blocks by a bounding

surface. A panel in which to specify the top and bottom surface triangulations is displayed once this panel is completed.

Reverse matching - To reverse the block selection, that is, to select the blocks that were not selected by the other selection criteria.

Cells can be evaluated using either full or proportional cells.

Use full cell evaluation (that is select the Use Block Centres option) to

44


select those cells where the centroid falls within the region.

Use proportional cell evaluation (that is leave the Use Block Centres option unticked) to select the exact proportion of a block or sub-block that is intersected by the region.

Hints:

The proportional cell evaluation method applies only when restricting blocks using a bounding box, closed triangul

ation or bounding surfaces.

Make a copy of the block model and use the copy for deletion if you don't want the original to be affected!

4.10 Extracting Blocks to a new Block Model

The Extract cell option allows you to extract specified blocks from a block model and save them to another block model file.

Figure 4-20 Block Extraction Panel

Enter the block model identifier of the block model into which the extracted blocks will be saved in the Destination model field.

Hint:

Use an alphabetic character as the first character of the block file identifier.

Select the Record block IDs in

destination model option to extract the block identification numbers as well.

The Block IDs variable option is only applicable if you are extracting block identification numbers. It allows you to store the block identification numbers into a nominated (existing) variable.

On completion of this panel, the Block Selection panel is displayed, so that any extraction can be restricted

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to blocks matching a particular condition. For example, where the geology matches a certain value or the grade within a particular range. Refer to 4.9 Deleting Blocks from a Block Model for information on this panel.

Upon completion of the Block Selection panel, the blocks are extracted and saved into the nominated block model file (.bmf).

Hints:

If you are selecting

blocks by section, the Plane definition panel will be displayed before any blocks are extracted and saved.

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Chapter 5: Grade Estimation

Chapter 5 - Inverse Distance Grade Estimation

Grade Estimation in VULCANThe Grade Estimation submenu allows you to:

Use multiple estimation techniques.

Run single or multiple estimation passes.

Match ellipsoid orientation to known structures.

Display the ellipsoid onscreen.

What is Grade Estimation?

Grade Estimation is the process of interpolating values from a database or file into the blocks of a block model.

The technique covered in this course is the inverse distance method. This technique assigns weights to the samples that are inversely proportional to their distances from the points being estimated.

Why use Grade Estimation?

The aim of block modelling is to model the deposit as accurately as possible. This not only applies to its structural characteristics, but also to its grade distribution.

Grade estimation techniques provide a

better solution than classical ore reserve methods as they attempt to account for the spatial relationships between the samples.

How do we use Grade Estimation in VULCAN?

Grade Estimation in VULCAN is accomplished by entering the parameters that control the estimation pass into an estimation parameter file (.bef). This file contains information such as:

The type of estimation method.

The estimation variable. Variables, which contain

statistical information, to aid in analysis.

The search ellipsoid orientation and size.

Type of sample weightings.

The sample database or file for use.

Sample manipulation specifications.

Block selection criteria.

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Chapter 6: Block Reserves

Chapter 6 – Block ReservesThere are four different reserving options; three of the options are grouped under the Reserves submenu and the fourth under the Advanced Reserves submenu.

Overview – Reserves submenu

Figure 6-1: Reserves submenu

6.1 Simple Reserves

6.1.1 General

The General option allows you to calculate quick and simple reserves on the open block model, using multiple block selection criteria, grade cut-offs and report

breakdown by a zone variable.

Although up to 6 grade variables may be specified, General Reserves is really only useful for reporting tonnes and the grade of a single grade variable. You

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This section allows for titled reserve reports.Use the Setup option to define report titles, geologic breakdowns and cut-offs.

This section contains options for generating quick and unsophisticated reports.

Select triangulations or polygons that define the regions from which the reserves will be derived.

Match report titles to data.

Calculate reserves. Use this section

to report the reserve between cut-offs, above cut-offs or in spreadsheet format.


have little control over the format of the reserves report.

Figure 6-2: Reserves Calculation Panel

Up to 6 grade variables may be used in the calculation.

Select the Use zone breakdown option to use a zone variable, e.g. the geology variable in the reserves calculation.

The density can either be a variable within a density field in the block model or a constant (value).

Select the Save report to file option to save the calculated reserves. Specify a file name. The maximum size is 20 alphanumeric characters. The file will be placed in your working directory. The file extension .brf (block model report file) is automatically added.

The Spawn reserves calculations in window option is only applicable if the Save report to file option

was selected. It allows you to run the reserves calculations in another window thus freeing the current window for further Envisage work.

Figure 6-3: Reserves Cut-offs panel

Select the Use cut-off grades option to use cut-off grades. Enter the number of cuts and the cut-off values (up to 13). The reserves report will only include those cut-offs for which values have been supplied, e.g. if you specified 13 cuts, but supplied only values for the first 5, only the first 5 cuts will be reported.

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Figure 6-4: Block Selection Panel

Either all blocks or specific blocks can be selected. If you select specific blocks, you can specify one or more of the following selection criteria:


By bounding triangulation - To evaluate reserves within a particular solid triangulation, e.g. a stope. If there is more than one triangulation loaded, you'll be prompted to select the required one.

By bounding box - To restrict the selected blocks to those contained within a cube. The cube is defined in Interactive or Co-ordinate mode. The required mode is selected from the panel that is displayed upon completion of the current panel.

If you select to use Interactive mode, you'll be

prompted to create the box by indicating the lower left corner and then dragging the "rubber" band rectangle to the upper right corner.

If you select to use Co-ordinate mode, you enter the minimum and maximum co-ordinates for the box.

By section - To restrict the blocks to a defined section plane. You can then enter its associated thickness. The section plane can be selected by line, points, grid co-ordinates or 3 points (the panel for this information is displayed as soon as the current panel has been accepted).


(iron value greater than 10.0). A list of available operators/functions is provided in the Online Help (in Appendix D of the Core Appendixes.

By bounding surfaces - To restrict the blocks by a bounding surface. A panel in which you specify the top and bottom surface triangulations is displayed once this panel is completed.

Reverse matching - To reverse the block selection, that is, to select the blocks that are not selected by the other selection criteria.

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Use full cell evaluation (that is select the Use Block Centres option) if you want the average grade of those cells where the centroid falls within the region.

Use proportional cell evaluation (that is leave the Use Block Centres option unticked) if you want to use the exact proportion of a block or sub-block that is intersected by the region. This calculates the weighted average of those portions and is the most precise method.

Hints:


The reserves are then calculated and displayed. If the Zone Breakdown option has been selected, then both grades and zones are included in the report.

Figure 6-6: Reserves Report

Note:

The total grade is a cumulative sum of the values in the grade variable.

6.1.2 Calculate Reserves based on POLYGONS

The Polygon option allows you to calculate reserves in a similar manner to the General option, but based on a polygon.

This option is designed to take a polygon, which represents a section of a mining block or bench, and define the bench by specifying the height, bearing, and dip adjustment and position of the polygon.

Figure 6-7: Polygon Reserve Panel

Enter the thickness of the bench or block in the Height field.

The String Position defines the position of the string (polygon) within the bench or mining block. The position can be top, middle or base.

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Select the Use bearing and dip adjustment option to set the orientation of the bench strings (polygons) within the bench. Enter the bearing and the dip.

Select the Project onto plane option to project the bench string onto a plane. Once this panel is completed, you will be prompted to select the bench string, and the Section Plane panel is displayed. See the General option for an explanation of the fields on this panel.

Select a bench string once the Polygon Reserves panel is accepted. A temporary solid triangulation, defined by the polygon, and a Confirm box (refer to Figure 6-8) are displayed.

Figure 6-8: Confirm box

Select Incorrect solid to exit the option.

Select Correct solid, if you are satisfied with the triangulation. The Reserve Calculation panel is displayed. See the General option for an explanation of the fields on this panel.

Once the Reserve Calculation panel has been completed, the Reserve Cut-off panel is displayed. This panel is also described in the General option.

Upon completion of the Reserve Cut-off panel, the reserves are calculated and displayed. An example is given at the end of the General option's description.

6.2 Block Reserves

The Block Reserves options (Block Reserves Setup, Save Parameters and Load Parameters) provide you with greater flexibility to control the formatting of the reserve report than the General or Polygon options.

The Block Reserves options allow you to generate reserves for up to 5 different block models.

6.2.1 Setup the specification

The Block Reserves Setup option allows you to create a specification file to store all the required parameters for the block reserves report.

The report parameters consist of the titles to appear in the report plus cut-off values. The titles are for the data sources, grades and breakdowns.

Once the report parameters have been set up, use the Regions (Triangle or Polygon) and the Assign

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Data options to specify the regions in which to calculate the reserve report and the block models and variables to be used in the reserves calculation.

The titles for the report are entered in the Data sources panel.

Figure 6-9: Data Sources

For example, if you want to report on more than one model enter their names in title #1 and title #2. A maximum of 5 data source titles may be entered. This means you can calculate reserves for up to 5 block models simultaneously.

The Grade titles, e.g. copper, gold etc, are entered in the Grade Names panel. A maximum of 10 grade titles may be entered.

Figure 6-10: Grade Names Panel

The breakdown titles are entered in the Breakdown Names panel. Breakdowns are used to calculate reserves within each breakdown value. For example, you may want to break the report down by the "geology".

Figure 6-11: Breakdown Names Panel

The grade cut-off titles are entered in the Grade Cut-offs panel. For example; 0, 0.5, 1.0 .... 10.0

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Figure 6-12: Grade Cut-offs Panel

A maximum of 9 numeric grade cut-off values may be specified. The values are used by the Above Cut-off option.

Note:

Only the first grade variable is used for the cut-offs. All others are calculated within the cut-off grade range for the first grade variable.

The next step is to select the regions in which to calculate the reserve.

6.2.2 Select the data regions

The Triangle Regions option allows you to select the solid triangulations to use for the reserve calculation. Alternatively you may use polygons (and the Polygon Regions option) to define the region for the reserve calculation. The regions will have the same name as the

triangulations from which they were derived.

Figure 6-13: Solid Model List Panel

Select the Add button to select triangulation(s). The common open dialog is displayed. The usual Windows selection methods apply to this panel, i.e. use [Ctrl] and the left mouse button to select multiple non-adjacent files and [Shift] and the left mouse button to select adjacent files. Once the triangulations are highlighted

use the button to move the files to the selection area of the panel and then select Open. The triangulations will be added to the Solid Model List panel (see Figure 6-14).

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Figure 6-14: Solid Model List panel with triangulations

Selected triangulations are displayed in the list with a green tick, deselected with a red cross (the deselected triangulations will be removed from the list once the OK button is selected. Double click on a triangulation to toggle its selection state.

6.2.3 Define the data source

The Assign Data option allows you to match the data source titles to the block model(s) and block model variables that are to be used in the reserve calculation.

Figure 6-15: Pick Data Source Panel

The Pick Data source panel will contain all of the data sources that you specified in

the Block Reserves Setup option.

Select the data source you want to assign to a block model.

Note: All data sources listed

must be assigned a block model (this may be the same one).

Figure 6-16: Block Model Panel

Enter the name of the block model in the Block model name field.

The Density can be a single value (Use supplied density option) or a variable (Use stored density option).


Use full cell evaluation to reserve those blocks where the centroid falls within the region.

Use proportional cell evaluation to use reserve exact proportion of a block or sub-block that is intersected by the region.

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Note: The proportional cell

evaluation method applies only when restricting blocks using a bounding box, closed triangulation or bounding surfaces.

The Block Model grade variables panel is displayed. All grade variable titles that were specified in the Block Reserves Setup option are listed on this panel.

Figure 6-17: Block Model Grade Variables Panel

For each grade variable title, specify a grade variable. All variable titles listed must be assigned a grade variable.

If Breakdown variables were specified in the Block Reserves Setup option, the Breakdown variables panel is displayed.

Figure 6-18: Block model breakdown variables

Panel

For each breakdown variable title, specify a breakdown variable. All variable titles listed must be assigned a breakdown variable.

The Pick Data Source panel is then redisplayed if you have any unassigned data source titles.

Once all data sources have been assigned to a block model and all other titles to block model variables, the parameters can be saved.

6.2.4 Save the reserve specification

Select the Save Parameters option to store the reserve parameters in a specification file. The file will automatically be given the file extension of .bpf.

Note:

As the regions are not saved in the spec file, each time you want to generate a new reserve using the spec file, you must define the region(s) of interest.

Figure 6-19: Save Report Format Panel

6.2.5 Calculate the reserves

Select the Calculate option to generate the report. The calculations are carried out using the specifications

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detailed in the currently loaded reserves parameter file <project code><spec file name>.bpf.

6.2.6 Display the report

Select the Complete option to display the report. The report is displayed showing the tons/grades between cut-offs.

Figure 6-20: Complete Report Panel

Select the Ignore zero tonnages option to exclude zero tonnages.Select the Save report to file option to save the report to a file. The maximum size of the report name is 20 alphanumeric characters. No file extension is added.

Figure 6-21: Reserve Listing Showing a Complete Report

Select the Above cut-off option to display the report by cut-off grade.

You will be prompted with a panel similar to the Complete Report Panel (see Figure 6-17). Select the options required and a report will be displayed.

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Figure 6-22: Reserve Listing Showing an Above Cut-off Report

The Units column in the report is the product of the Tonnage column with the Average Grade column, that is, reports the mass of metal contained for each breakdown field. If, for example, Tonnage was expressed in Tonnes, and Grade was expressed in grams per Tonne, the units in this case would be grams.

Select the Dump option to display the report without titles. This output is suitable for importing into a spreadsheet package.

Figure 6-23: Unformatted Dump Panel

Select the Save report to file option to save the report to a file. The maximum size of the report name is 20 alphanumeric characters.

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Figure 6-24: Reserve Listing Showing a Dump Report

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6.3. Advanced Reserves

The Advanced Reserves submenu provides you with total flexibility in formatting the titles and content of a block model reserves report. You can report on a range of breakdown fields, including being able to generate product codes by nominating specific conditions.

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1. Use Open Parameters to create the reserves parameter file.

2. Use Variables to specify the block variables, cut-offs, density, product codes and partially mined blocks.

3. Use Polygons or Triangles to define the regions for the reserve.

4. Use Block Selection to apply the selection criteria to the block model.

5. Use Calculate to generate the reserves dump file.

6.3.1 Open the specification file

Advanced block reserves are calculated according to the parameters set up in a reserves calculation specification file (.res). A specification file must be opened (Open Parameters option) before the parameters can be specified.

Figure 6-25: Open Reserves Specification File Panel

Specify the name of the Reserves specification file. The maximum size for new file names is 80 alphanumeric characters (the size includes the .res file extension, which is automatically added to the file name).

6.3.2 Specify the Variables (from the block model on which to report)

The Variables option allows you to specify the variables to be used when calculating the reserves. Each variable will be saved to the reserves dump file (.dmp) as a column.

Note:

A Block model must be open before you can specify the variables. If no block model is open, you'll be prompted to open one before the panels associated with the

variable specification are displayed. Similarly, you will be prompted for a calculation reserves file if there is none open.

Figure 6-26: Breakdown Fields Panel

The Classification fields allow the specification of a breakdown variable. In this way the reserves can be broken down according to fields, such as GEOLOGY or ORE_TYPE. For example, GEOLOGY could be a field in the block model with the values: TQ1, TQ2, TQ3. Each of these different codes could form the basis for a breakdown of the reserves, with grades reported for each of the three geological types.

A breakdown variable may be of data type Name, Byte, Short or Integer, but not of type Float or Double (see the Online Help Envisage > Block > Transfer > Edit for an

explanation on data types). If the breakdown variable is of data type Name it will be left justified in the dump file, otherwise it is right justified.

Some block models have a number of variables, which define the fraction of each material type. For example, two variables FORE and FWST might contain the fraction (0.0 to 1.0) of ORE and WASTE in each block respectively. The reserves for material ORE are calculated based on the fraction of the volume (for each block) specified in the FORE field, and the reserves for material WASTE would be calculated using the fraction of the volume (for each block) specified in the FWST field. The Material type by fractions fields can therefore be used to classify reserves according to material type.

Classifying reserves according to material type will also be affected by the use of the mined out field. If a block has been mined out, then the volume is adjusted correspondingly before the fraction field value is applied to the volume (see also the description of the Mined Out Field). Blocks with unknown (missing) values for the fraction field, will contain "unknown material" in the material column of the dump file.

The remaining options on this panel apply to fields in the block model that contain

percentages or fractions related to the volume of each block.

The options are typically used to process the results of the Mine option (Manipulation submenu) or the Execute option (Transfer submenu).

In the Mined out (or fillpc) field enter the name of the field in the block model that contains the mined out or fillpc value.

You can either select the percentage for each block (volume) available for mining or the fraction of each block (volume) that has already been mined.

For example, if the mined out field for a block has a value of 70%, 70% of the block's volume is used in determining reserves. If the mined out field for a block has a fraction value of 0.7, 0.3 of the block's volume is used in determining reserves.

When a block is evaluated against a region (triangulation) the proportion of the block inside the region is determined. If the block has been partially mined, as indicated by a mined fraction or available percentage field, the treatment of the mined part has two cases:

Case 1 - Incremental Pits

If a previous pit has been used to set a mined field, then the mined part of a block can reasonably be assumed to lie inside the new pit. Hence select the Mined portions assumed

inside regions option. In this case the proportion inside region volume is determined and then the mined out volume of the block subtracted. This method can be used to obtain accurate incremental pit volumes without the need to reblock the model. See Figure 6-27 for an example.

Figure 6-27: A Block inside a reserve region that has been 0.3 mined (70%

available).

where,

RV=reserve volumeVR=volume in regionVM=volume minedV =Total volume

Case 2 - Underground Stope with Development

Triangulations of development may be used to set a mined field in a block model. In this case when evaluating a stope region the mined part of a block

partly inside the region needs to be assumed equally distributed. Hence Do not select Mined portions assumed inside regions option. In this case the reserve volume is the product of the proportion in region volume and the percentage not mined. See Figure 6-28 for an example.

Figure 6-28: A block 50% inside a reserve region that

has been 0.3 mined (70% available)

where,

RV=reserve volumeVR=volume in regionF=fraction not minedV =Total volume

Figure 6-29: Second Breakdown fields panel

Select the Generate product codes option to use product codes and apply conditions. If unselected, no product codes can be specified. Each block in the model can be classified according to product, based on whether it satisfies the condition for that product. Each product must have an associated condition and the first condition satisfied will determine the product for each block. Blocks that don't meet the conditions for any of the products specified will contain "unknown product" in the product column of the dump file.

For example;

Product Code

Condition

Lg cu lt 0.5 and au lt 1.0

mg cu ge 0.5 and cu lt 2.0 and au ge 1.0 and au lt 3.5

hg cu ge 2.0 and au ge 3.5

The next panel (Grade Variables) allows you to enter a density and up to 15 grade variables for the reserve calculation.

Figure 6-30: Grade Variables panel

The density variable allows the mass to be calculated from the volume values. The default density is used in the tonnage calculation for those blocks where the density field value is 0 (zero) or negative.

Up to 15 grade variables can be specified for the calculation of reserves. Each variable can be specified as wt by mass, wt by vol or sum.

Sum - Sum is used for variables containing units (e.g. grams of gold) that should be cumulated rather than averaged.

Wt by Vol - Weight by volume is used for grade variables containing values based on volume-weighted averages (e.g. grams of gold per cubic metre).

Wt by Mass - Weight by mass is used for grade variables that should be treated as a weighted average based on mass (e.g. grams per tonne of gold).

Grade values are sent to the dump file according to type and appropriate entries are placed in the VARIABLE_TOTALS block.

Select the Use Average box to use the average grade value of the selected blocks in the reserve calculation.

Warning! Do not tick this box if any of the blocks do not have a specific grade assigned to them (i.e. they have a default grade instead) as the resulting reserves will be incorrect.

Supply a Default for Missing value to replace the default creation value of the selected blocks during the reserve calculation.

If no default is specified and the Use Average box is unselected, the total volume and tonnage values for that grade variable may be different to the values for the breakdown. In that case the total tonnage and total volume for the grade variable are also reported and the grade value is based only on the blocks with known values.

Specify the number of decimal places to be included in the report.

The final panel in the Variables series is the Grade Cut-offs panel.

Figure 6-31: Grade Cut-offs Panel

Grade cut-off values may be specified by:

Range and increment. Specific values.

Select the Use grade cut-offs option to use a grade cut-off variable to breakdown the reserves. Specify the cut-off variable. New breakdowns are defined based on the specified grade cut-off values (see below).

The Below cut-off value is used in the "below cut-offs" column in the dump file if the value of the grade cut-off variable is less than the first (lowest) cut-off value.

The Unknown cut-off value is used in the dump file for missing values in the grade cut-off variable if no default grade

value has been specified. However, if the average grade is to be applied for the grade cut-off variable, then the average grade is calculated based on the matching breakdowns (i.e. across the cut-off values) and the values are incorporated into the breakdown with the appropriate cut-off value.

Grade cut-off values may be specified as a range (first and last values), increment or explicitly by value.

6.3.3 Define Regions

6.3.3.1 Select Polygons as Regions

The Polygons option allows you to specify polygons, which are converted to triangulations, to be used in the reserve calculation. Specify the height of the bench and the location of the polygon within the bench (i.e. top, middle or bottom) and the orientation of the polygon within the bench, or project the polygon (forwards and/or backwards) to create the triangulation.

Note:

The polygon must be displayed on the screen.

Figure 6-32: Define Regions by Polygon Panel

Select the Bench height option to convert the polygon to a triangulation using bench height. Specify the height of the bench and the location of the polygon relative to the bench (top, middle or base). The Use directional adjustment on sides option is only applicable to the bench height conversion method. It allows you to apply a directional adjustment, in the form of a bearing and gradient, to the sides of the bench (used for benches with non-vertical sides). The Project polygons onto plane option is also only applicable to the bench height conversion method. This option allows you to project the polygons onto a plane, which is defined after this panel is completed.

Select the By projection option to convert the polygon to a triangulation using projection. Specify a back and forward projection distance.

Select the Confirm each polygon option to view each triangulation before it is saved and added to the regions list.

This is particularly useful when multiple polygons are being converted into triangulations.

Region triangulation files are named according to the polygon object name and the number of regions that have been selected for determining reserves. Select the Allow duplicate object names option if you don't want duplicate object names to be detected. If unselected, you'll be prompted to rename any region found to have the same polygon object name as another region.

Region triangulations created using this option are automatically included in the list of selected regions in the Triangles option.

Note:

If you are converting by bench height and projecting the polygons onto a plane, the Section Plane panel will be displayed before the Multiple Selection box (which is used to select the method of selecting the polygons). Refer to Reserves > General for information on this panel.

Figure 6-33: Multiple Selection Box

Select the method for selecting the polygons and select the polygons. If selecting by group, feature or layer, you'll be prompted to confirm that the correct objects have been selected. No prompt appears if selecting by object.

The polygon is then converted to a triangulated region. You will be asked if the conversion created the correct region.

Figure 6-34: Confirm box

Select Correct region to accept the triangulation. If you were selecting by object, you will be prompted to select another object. Right click to return to the Multiple Selection box. If you were selecting by group, feature or layer, then

you are returned to the Multiple Selection box when you accept the region. Right click to cancel when you have finished creating regions. Incorrect region returns you to the “Select object” prompt. That is, you’ve selected your method of selecting the strings and now you need to select the strings.

Use the Save Parameters option to save the regions.

Note: If you selected not to have

duplicate names (see Allow duplicate object names option), you'll be prompted to rename any duplicates found.

Figure 6-35: Rename Region Panel

Enter the name of the region. The maximum size is 10 alphanumeric characters

6.3.3.2 Select triangulations as regions

The Triangles option allows you to select the triangulations (solids) to use as regions in the reserve calculation.

Figure 6-36:Select Triangulations Panel

Select the Select triangulations by picking off screen option to pick the triangulations off the screen. Triangulations that are already regions are automatically selected. To remove these regions, simply left click on the triangulation. To select a triangulation, left click on the triangulation (you will need to confirm the selection). To assign or alter the group code, left click again on the selected triangulation. The Set Group Name panel is then displayed.

Figure 6-37: Set Group Name Panel

Enter the group code for the selected triangulation.

Note:

To edit the group code of existing regions, you will need to deselect them first and then reselect them.

Select the Select triangulation by name option

to access the standard open dialog. From this dialog, highlight the triangulations – the standard windows selection methods apply (i.e. [Ctrl] + Left mouse button to select non-adjacent files and [Shift] + Right mouse button to select adjacent files.) Once

highlighted, use the button to move the files into the selection section of the panel. Select Open.

The Reserve Region Report panel is displayed.

Figure 6-38: Reserve Region Report Panel

This panel lists the names of the selected triangulations. To specify the group, highlight the name(s) in the list, enter the group name in the Edit Group field and select Set Group.

Select the Deselect all triangulations option to remove all triangulation regions from the parameters.

Use the Save Parameters option to save the triangulations.

6.3.4 Specify Block Selection Conditions

The Block Selection option allows you to specify block selection criteria for the reserve calculation.

Figure 6-39: Block Selection Panel

Either all blocks or specific blocks can be selected. If you select specific blocks, you can specify one or more of the following selection criteria:


By bounding triangulation - To evaluate reserves within a particular solid triangulation, e.g. a stope. If there is more than one triangulation loaded, you'll be prompted to select the required one.

Note:

If regions are being used, the block selection triangulation will be ignored. Therefore we recommend

that a triangulation only be used in block selection when not including regions.

By bounding box - To restrict the selected blocks to those contained within a cube. The cube is defined in Interactive or Co-ordinate mode. The required mode is selected from the panel displayed upon completion of the current panel.

If you select to use Interactive mode, you'll be prompted to create the box by indicating the lower left corner and then dragging the "rubber" band rectangle to the upper right corner.

If you select to use Co-ordinate mode, enter the minimum and maximum co-ordinates for the box.

By section - To restrict the blocks to a defined section plane. You can then enter its associated thickness. The section plane can be selected by line, points, grid co-ordinates or 3 points (the panel for this information is displayed as soon as the current panel has been accepted).


(iron value greater than 10.0). A list of available operators/ functions is provided in the Online Help (in Appendix D of the Core Appendices).

By bounding surfaces - To restrict the blocks by a

bounding surface. A panel in which you specify the top and bottom surface triangulations is displayed once this panel is completed.

Reverse matching - To reverse the block selection, that is, to select the blocks that are not selected by the other selection criteria.


Use full cell evaluation (that is select the Use Block Centres option) if you want the average grade of those cells where the centroid falls within the region.

Use proportional cell evaluation (that is leave the Use Block Centres option unticked) if you want to use the exact proportion of a block or sub-block that is intersected by the region. This calculates the weighted average of those portions and is the most precise method.

Hints:


6.3.5 Save the Parameters

The Save Parameters option allows you to save the open reserves specification file. This must be done before the Calculate option is used as the reserves calculations are based

on the contents of the reserves specification file.

Figure 6-40: Save Reserves Specification File Panel

Enter the name of the specification file (the open specification file name is displayed as the default). The maximum size is 80 alphanumeric characters (including the .res extension).

6.3.6 Calculate the Reserves

The Calculate option allows you to calculate the block reserves for the open specification file. The results are stored in a dump file (.dmp).

When calculating reserves, the block creation default value will be ignored when calculating the grade value. The estimation default value, if it is different from the block creation default value, will be included when calculating the grade value. All blocks that satisfy the selection criteria are used for the tonnage calculation regardless of their default grade value.

Note:

As the block creation default values are ignored when calculating reserve grades, blocks with these values are effectively treated as if they

had the average grade of the blocks selected for that reserve breakdown zone.

If there are many regions being used or the block model is large, then the calculation may take a while. It is recommended that you perform the calculation in another window so that further work in Envisage can proceed. However, the block model cannot be accessed until the reserves calculation is complete.

Choose spawn reserves calculation in window to make the calculation run in a separate window.

Figure 6-41: Calculate Reserves Panel

Enter the name of the dump file. The default is the name of the open parameter file. The maximum size is 40 alpha-numeric characters (this includes the .dmp file extension). Select the Spawn reserves calculations in window option to run the calculation process in another window, thus freeing the current window for further Envisage work. 6.3.7 Reporting the Reserves

Use the Open Report option to create the

reserves report parameter file.

Use the Global option to store global settings, such as report titles and layout.

Use the Column option to set up column formats and user defined variables.

Use the Tables option to set up table formats and choose which columns to report in the table(s).

Use the View Report option to report the reserves and select the tables to use.

6.3.7.1 Open report specification file

The Open Report option allows you to open a report specification file (<name>.tab).

Note: The block model does not

need to be open to perform any report setup functions.

Figure 6-42: Open Report Specification File Panel

Enter the name of the specification file. The maximum size is 80 alphanumeric characters. The size includes the .tab file extension.

Hint: It is highly recommended

that you are consistent with your filenames. It is best to

give the same unique name to all four files, that is, the .res file, the .dmp file, the .tab file and finally the .rep file are all given the same file name. You will then be able to distinguish between them by their different file extensions.

Select the Read columns from .dmp file option to create the report based on the column information that exists in the header of the dump file (.dmp). Specify the name of the dump file.

If reading columns from a dump file, the column name, width, type and totals calculation classification for each dump file column/variable are read in from the dump file header and each column is added to the end of the columns list. Columns present in the columns list with the same name as dump file columns are not replaced.

6.3.7.2 Define General Report Details

The Global option allows you to set the general parameters that apply to all tables in a report. You may:

Enter page length Enter margin widths Enter page header Enter page footer

Figure 6-43: Global Report Parameters Panel

Enter the maximum number of Lines per page. The default is 60 (standard for an A4 portrait page). A page break is automatically inserted when the maximum is reached.Enter the margins. The left margin is the number of spaces before the text starts (the default is 10). The top margin is the number of lines before the text starts (the default is 4). This number is in addition to the maximum number of lines per page.

Tick the Use box to separate rows and optionally columns. Enter the separating character in the Row and Column fields.

Tick the Use Tab box to use tabs instead of a character to separate the columns.

Up to 5 lines of page header information can be specified. The maximum size of each line is 80 alphanumeric characters. The page header appears at the top of each page. The header lines are included in the maximum number of report lines specified earlier.

Note: The page header may

include the variables $page (current page number), $date (current date), $time (current time) and $blocksel (block selection information from dump file). These variables are substituted when the report is created. The variables may be in either upper or lower case.

Up to 15 lines of page footer information can be specified. The maximum size of each line is 80 alphanumeric characters. The page footer appears at the end of the report. The footer lines are included in the maximum number of report lines specified earlier.

Note: The same variables as

mentioned above may be included in the page footer.

6.3.7.3 Define Column specs.

The Columns option allows you to add, delete, or edit columns in the report column list. You may change:

The header Width Number of decimals Class

Note:

Columns may also be derived, i.e. calculated, from values in other columns.

Figure 6-44: Report Columns panel

The column name must be unique within the list of columns. The maximum size is 20 alphanumeric characters. Spaces are not allowed. The maximum number of columns per specification file is 50.

The heading appears at the top of the column. The maximum size is 20 alphanumeric characters. Spaces are allowed. The heading will be centred within the width specified below. It must not contain more characters than the column width.

The width defines the number of characters that the column

entries will take up in each row. If a character column value exceeds the width of the column, it will be truncated to fit. If a numeric column value exceeds the column width, the column will be expanded for that row to accommodate the value. This is to avoid undefined numeric values in reports. Numeric column values are right justified, character column values are left justified.

The decimals value determines how numeric columns are displayed. If the value is negative, no decimal places are displayed and the column values are rounded.

For example, a value of -1 rounds to the nearest 10, -2 to the nearest 100 etc. The rounding of numeric columns does not affect the original column values used in calculations; only the displayed values are rounded.

Tick the Derived column checkbox to derive the column from other columns. If unselected, the column must be from the dump file.

The Calculate on output option is only applicable if you have selected the Derived column option. It allows you to calculate the derived column on output.

Calculations are based on the actual dump file column values for each row, except for columns that are to be calculated on output. Columns that are calculated on output

use the column values displayed for that row.

For example,

Column 1 and Column 2 have the following input values:

Column 1 Column 2

Value 1 10.0

Value 1 20.0

Value 3 30.0

Value 4 40.0

Column 3 and Column 4 are both derived from values in column 2:

Column 3

Derived Yes

Derived on output

No

Expression 1 1.0/column2 condition 1: column2 gt 0.0

Expression 2 0.0

type sum

Column 4

Derived Yes

Derived on output

Yes

Expression 1 1.0/column2 condition 1: column2 gt 0.0

Expression 2 0.0

type sum

And the table is ordered and reported by column 1:

TableOrder_by Column 1Report_by Column 1

Results in the following being reported:

Col 1 Col 2 Col 3 Col 4Val 1 30.0 0.1500

00.0333300

Val 2 70.0 0.05833

0.0142857

100.00 0.20833

0.0476157

Note: The values in column 3 are

different to column 4 because column 4 has been derived from the column 1 output values of 30.0 and 70.0, whereas column 3 was derived from the values 10.0, 20.0, 30.0 and 40.0

The Expression/Condition options are only applicable for derived columns. An expression will only be used (in the calculation of the column) if a condition is associated with the expression and that condition is met. The first condition to be met determines the expression to use and an expression

without a condition will always evaluate to TRUE.

To avoid undefined column values, it is very important that there is always an expression that can be used, especially in the case when none of the conditions are met (see example on the previous page). Take care also to avoid division by zero, numeric underflow and numeric overflow errors in expressions.

Expressions for derived columns may include:

Arithmetic operators logical operators string operators numeric functions logical functions string functions column names* column internal function

names**

See the Online Help, Envisage > Core Appendices > Appendix D for a description of the available operators/functions.

* Never use operators in column names or give columns the same name as any of the functions.

**Three types of column internal functions are available for use in deriving columns. This is done by prefixing the name of a numeric column with Sum_, Max_ or Min_. These are the cumulative sum, maximum and minimum column internal functions respectively.

The functions can be used to derive column values in the same way as column names.

Specify the class for numeric columns. The class options are: Value, Average, Sum, Maximum, Minimum, and Weighted average. These options determine how the column values are to be calculated and displayed. Each variable column is generally treated as a sum, average, maximum, minimum or weighted average based on another column's value (e.g. grade based on tonnage). Specify that other column in the Weight By Column field. The Value option is used for columns that are not to be subtotalled, but rather have their actual values reported. For example, columns using the column internal functions Cumulative Sum, Maximum and Minimum.

The Display final total option is only applicable if the Value option was selected. It allows you to display the final total.

6.3.7.4 Define Table Details.

The Tables option allows you to add, delete, and edit tables used in the report. For each table you may specify:

Columns to be reported Columns to order by Columns to report by

Conditions to apply to columns.

Note:

When you are finished defining the tables save the specification file.

Figure 6-45: Report Tables Panel

The table name must be unique within the list of tables. The maximum size is 20 alpha-numeric characters. Spaces are not allowed.

Select the Descending to sort column values (rows) in descending order. If unticked, values will be sorted in ascending order.

The Order by column allows you to specify the column(s) by which to order. If entering more than one, separate each column with a comma. The total number of characters for the columns specified here must not exceed 80 characters. If no columns to order by are specified, the rows remain unsorted (i.e. in the same order as the dump file).

If using a column to order by that is also a column to be subtotalled (see Report by option), that column must be the last entry.

Note: Columns based on column

internal functions or columns calculated on output cannot be used, as sorting is performed before column subtotalling.

Select the Only Display Totals option to only report total values.

The Report by option allows you to specify a column for which subtotals will be reported. Every time the column value changes a subtotal row will be displayed in the table. If also ordering by this column, make sure that the column is the last one specified in the Order by field.

Note: As subtotalling is performed

before reporting column values, columns calculated on output cannot be used.

Character columns will be excluded from the report if they are not used for ordering or subtotalling. Numeric columns are always included except if the Display final total option is unselected (see Report Columns panel in the Columns option).

The condition fields allow you to select which rows to include in the table based on whether certain column conditions are met. For example, the following condition will select only the rows with a copper grade between 1.4 and 6.0:

cu_ivd gt 1.4 and cu_ivd lt 6.0

Up to 5 conditions may be entered. To access the conditions panel, click on the icon at the right of the field. All conditions must be true before a row is included in the table. See the Online Help, Envisage > Core Appendices > Appendix D for a full list of available operators/functions.

Note: Any column name can be

used in the row selection conditions, but row selection is performed before the sorting and subtotalling of columns, so columns based on column internal functions or columns calculated on output cannot be used.

Either all columns can be used in the table or a subset (select columns).

If the Select All columns option is selected, the columns appear in the table as in the columns list.

To select a subset of the columns, untick the Select All columns option and enter the names (separated by a comma) of the columns you want to include in the Selected Columns field.

Note: If subsets are selected, the

columns used to order and report by must be included

in the subset. Selecting a column does not necessarily mean that it will be displayed in the table. See the description of the Report by option.

6.3.7.5 Save the specification file

The Save Report option allows you to save the open report specifications file. This must be done before the View Report option is used as the report creation is based on the contents of the report specification file.

Figure 6-46: Save report Specification File Panel

Enter the name of the report specification file. The default name is the name of the open report specification file (<name>.tab). This can be overwritten with a new name if you don't want the "old" file to be affected. The maximum size is 80 alphanumeric characters. The size includes the .tab file extension.

6.3.7.6 Reporting the reserves

The View Report option allows you to generate a report using the open report specification file.

The resulting report is stored in a report file (.rep).

The results may be posted to the screen if required.

Note:

The report is automatically sent to the Report Window, but will be limited to the width of that window so some columns may not be displayed. If this is the case, save the report and view it in a text editor.

Figure 6-47: Create report Panel

Enter the name of the dump file containing the required calculation results.

Enter the name of the resulting report file. The default is report.rep. The maximum size is 40 alphanumeric characters (this includes the .rep file extension).

Either all tables or selected tables can be included in the report. If you select All tables, the tables appear in the report in the same order as they do in the table list. If you select Select tables, the tables appear in the order that they are selected. Use the drop-down lists to select the particular tables.

Select the Post report in graphics option to display the report in the Primary window.

Once this panel is completed, you will be prompted to specify a layer for the report (if no layer is currently open) and the name of the report to be loaded into that layer. A colour for the report text is also specified. You are then prompted to indicate the text origin, i.e. the left hand corner where the report text will start, and the text extent.

The report is displayed in the Report Window or, if posting in graphics, displayed as a layer. In the latter case you can use the Text Edit options under Design for any text editing functions.

Workshop - Block ReservesThe aim of this workshop is to use both of the block reserves submenus to gain an understanding as to what each offers.

Try producing a few simple reports first and then progress to more complex reports.

Training Manual Block Modelling

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