maptek australia2012 sean dixon using rom in harp modelling

8/13/2019 Maptek Australia2012 Sean Dixon Using ROM in HARP Modelling

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To put it another way: how much coal can we dig up; and what does it taste

like?

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Hunter Valley regional overview

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Aerial view of the Integra complex.

Todays presentation will focus on the Northern Open Cut in particular,

although the geological features discussed are present throughout the entirelease area.

The Integra Open Cut is situated 10km North West of Singleton, New South

Wales in the Hunter Valley region. A thin seam mining operation, the mine is

managed and operated by Integra Coal Operations Pty Ltd on behalf of the

joint venture parties.

Vale Australia holds a 61.2% equity stake in the asset.

Two coal types are produced; comprising a semi-soft and a thermal product.

Vale Australia has been using Vulcan software at the Integra Open Cut coal

mine since 2009, for detailed geological modelling, survey and mine planning.

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Photo of the final wall of the South Open Cut during the early stage

overburden removal of the Western Extension

This photo illustrates the degree of seam splitting over short distances Geologically, this is not a simple deposit

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Close up view of the North Open Cut end wall, close to the Base of

Weathering

This slide illustrates the challenges in accurate geological modelling andprediction

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Structural generation includes roof, floor and thickness for seam and ply.

Coal quality parameters are modelled by ply.

Building the HARP model from the resource grids allows mine planningassumptions to be applied to the resource grids, without changing them.

The ROM HARP model contains the aggregated ply qualities, along with

volume / tonnage estimates based on mining horizons (working sections).

This model includes dilution, loss and moisture.

Version 8.1.4 improvements allow for Run of Mine calculations to be

performed on a HARP model, with no requirement for the generation of ROM

grids.

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This is rotated view of the North Open Cut at Vale Australias Integra mine

The triangulated surface is generated using pick ups by the site surveyors,

which is then cut into data derived from a LIDAR scan This surface is verified and used for monthly volume calculations and mine

designs

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This slide shows a cross section through the resource grids and borehole

database

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This slide shows a HARP block model generated for the North Open cut mine

area

The inputs to the HARP model were from the latest site resource statement Issues with using the resource grids for detailed mine planning include:

thin seams coalesce and split over a short area, causing mining, mine

planning and reconciliation problems

Seam dip is consistent at resource scale, however can change locally

due to presence of faulting or overlying channel conglomerates

Resource grids do not make allowances for loss or dilution, thus

making it difficult to make accurate short term mining decisions

Resource grids were clipped to a combined base of weathering and

topography surface including an active pit. This caused localdistortions where grid thickness and dips are either over or under

estimated. This can have an effect on the generation of the HARP

model.

The local distortions have prompted a change in workflow, where

unclipped grids are used to generate the HARP model. All material

above the base of weathering can then be assigned to overburden.

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Following on from the last slide, the thin seams coalesce and split over the

deposit

Two end of month surfaces (green and blue) are shown to illustrate thecomplexities of mining multiple thin seams

This diagram shows a section view along strike of the north open cut, the

thickest ply (red) is approximately 1.8m

Section width is ~500m

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Diagrammatic representation of the local seam splitting and coalescing found

at Integra

Although exploration boreholes are sufficient to allow most plies to beclassified as either Measured or Indicated, there is significant variation

observed once the coal is uncovered

This can be seen in the initial photo of the South Open Cut high wall

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While this method is effective, in the previous method you have to apply the

same aggregation rules across the entire model. In the new version, the rules

can be restricted allowing different parameters to be applied to each pit oreven each strip as required.

A large number of grids are generated through this process, effectively

creating a new ROM grid for every quality that is required (i.e. a minimum of

Relative Density, Raw Ash, Inherent Moisture, Total Sulphur, Specific Energy,

Product Ash, Product Yield etc). This means that at least 7 quality grids are

generated for every ply (7x70=490!). Additional grids are also created for the

ratio and burden calculations for each ply.

Unless a strict filing system and file nomenclature is followed, there are often

unintended consequences that occur when a completely new series of grids

are generated, thus the perennial question to the site geo Im confused, sowhich grids should actually I be using?

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The new ROM modelling tools available in 8.1.4 allow for mining assumptions

to be applied to the block model, thus there is no requirement for a new set of

grids to be produced. A new HARP model is generated during the process,simplifying the number of models generated and allowing for a clear audit trail.

The speed at which the HARP models may be generated allow for scenario

testing (such as re-running the ROM model after the monthly reconciliation

process has been completed, thus checking the quality and mining parameters

used).

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The new process available in 8.1.4

The following two slides are cross sections through the HARP ROM model for

Integra North Open Cut (same location as per slides 12 and 13)

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Integra North Open Cut section 1 down dip

This section illustrates the working sections derived by applying the quality and

mining parameters. The thinner seams have been combined into workingsections or set to zero thickness as per the mine planning assumptions.

An end of year surface has been include for reference, the resource grids

were clipped to a combined weathering and topography at the time of

modelling (nb a better outcome is generally achieved by using resource grids

that are not clipped to a surface).

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Integra North Open Cut section 1 along strike

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The ease of interrogation of the model allows for better informed mine

planning decisions

Examples of where this can be used at the Integra Open Cut include: Improved coal product allocation at the short term planning scale

Improved understanding of working section volumes and qualities

Assist with reconciliation processes

Scenario modelling may be completed to test the sensitivity of mining

parameters

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One suggested improvement on this process is to add a Block Selection

option to enable ROM modelling over specific pit areas (such as by pit, strip or

fault block).

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maptek australia2012 sean dixon using rom in harp modelling

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