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  • 8/2/2019 Anglo Coal

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    Geology and Conversion to

    Practical Parameters(Boreholes to Reserves)

    Ian de Klerk

    SACPS Conference Vryheid

    24 May 2006

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    COAL COAL

    RESOURCES RESERVESReported as in situ Reported as

    estimates Mineable In Situ,

    ROMand Saleable

    estimates

    INFERRED

    Increasing

    level of INDICATED PROBABLE

    geoscientific Mineable In-situ,

    knowledge ROM,

    and Saleable

    confidence

    MEASURED PROVED

    Mineable In-situ,

    ROM,

    Saleable

    Consideration of mining, coal processing, economic, marketing, legal

    environmental, social and governmental factors

    (the 'modifying factors')

    SANS 10320:2004 - The Guideline

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    GEOLOGICAL MODEL

    BUILDING

    GEOLOGICAL DATA

    EVALUATION

    REPORTED COAL

    RESOURCES

    Coal Resources per

    Classification Category

    GEOLOGICAL MODEL

    OPTIMISATIONAnalysis of data integrity,

    distribution, spatial data density

    and confidence classification for

    both Structural and Coal Quality

    Data Sets

    Confidence Classification into

    Measured, Indicated and Inferred

    Categories for both structural

    and coal quality models

    CLASSIFICATION

    Sub-seam definition,

    correlation and structural

    interpretation

    ROM DISCOUNT FACTORS

    SALES DISCOUNT FACTORS

    MINING AND SALES

    DISCOUNT FACTORS

    REPORTED COAL

    RESERVES

    Coal Reserves per

    Classification Category

    Classification into

    Proven and Probable Reserve

    Categories

    CLASSIFICATION

    LIFE OF MINE PLANMine Planning, Layouts,

    Schedule = Economic Life of

    Mine Model

    MTIS

    Application of Geological cut-

    offs and losses

    RESOURCE AND RESERVE ESTIMATION

    Geological Domains,

    Mining Horizon selection,

    Optimisation of Interpolators

    Confirmation of the estimated

    discount factors from GTIS to

    ROM and SALES within the

    area mined

    RECONCILIATION

    TECHNICAL

    MODIFYING FACTORSENVIROMENTAL, LEGAL

    GOVERNMENTAL, ECONOMIC

    INPUTS

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    The Geological Model - Resources

    Topographic DTM

    Borehole Collar Survey

    Seam / Sub-Seam Intervals and

    Correlation

    Sample Intervals, SampleRepresentivity

    Raw Coal Quality and Washability

    Data

    Selection of Mining Horizon Structural and Quality Modelling

    Definition of Geological Resource

    Blocks cut-off parameters

    Geological Loss Domains

    Resource Categories per Resource

    Block

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    Project Level and Resource Confidence

    68%33%35%33%Average

    20%0%20%80%> 20 years

    70%10%60%30%15 to 20 years

    80%50%30%20%Payback to 15 years

    100%70%30%0%0 to Payback

    M+IMeasuredIndicatedInferredPeriod

    Pre-Feasibility Estimate

    (Total Area Resource Data Confidence levels)

    0%

    10%

    20%30%

    40%

    50%

    60%

    70%

    80%

    90%

    100%

    0 to Payback Payback to 15

    years

    15 to 20 years > 20 years Average

    Inferred

    Indicated

    Measured

    50%8%43%50%Average

    0%0%0%100%> 20 years

    40%0%40%60%15 to 20 years

    70%10%60%30%Payback to 15 years

    90%20%70%10%0 to Payback

    M+IMeasuredIndicatedInferredPeriod

    25%Average

    0%> 20 years

    10%15 to 20 years

    40%Payback to 15 years

    50%0 to Payback

    MeasuredPeriod

    Increase in measured % from Pre-Feasibility to

    Feasibility

    Measured and Indicated

    0%

    20%

    40%

    60%

    80%

    100%

    0 to

    Payback

    Payback to

    15 years

    15 to 20

    years

    > 20 years Average

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    Coal Resource Statement

    Mineable Tonnes In-Situ (MTIS)

    1. Includes the coal seam at the theoretical mining height and

    between the relevant minimum and maximum mining heights

    and coal quality cut-offs.

    2. Includes dilution, but excludes contamination.

    3. Geological loss factors shall be applied.

    4. Tonnage quoted on a mineable in situ basis and coal quality

    reported on an in situ bed moisture or air-dried

    uncontaminated basis over the theoretical mining height.

    5. May be subdivided into different depth and thicknesscategories.

    MTISis reported per Resource Category(measured, indicated, inferred)

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    GEOLOGICAL MODEL

    BUILDING

    GEOLOGICAL DATA

    EVALUATION

    REPORTED COAL

    RESOURCES

    Coal Resources per

    Classification Category

    GEOLOGICAL MODEL

    OPTIMISATIONAnalysis of data integrity,

    distribution, spatial data density

    and confidence classification for

    both Structural and Coal Quality

    Data Sets

    Confidence Classification into

    Measured, Indicated and Inferred

    Categories for both structural

    and coal quality models

    CLASSIFICATION

    Sub-seam definition,

    correlation and structural

    interpretation

    ROM DISCOUNT FACTORS

    SALES DISCOUNT FACTORS

    MINING AND SALES

    DISCOUNT FACTORS

    REPORTED COAL

    RESERVES

    Coal Reserves per

    Classification Category

    Classification into

    Proven and Probable Reserve

    Categories

    CLASSIFICATION

    LIFE OF MINE PLANMine Planning, Layouts,

    Schedule = Economic Life of

    Mine Model

    MTIS

    Application of Geological cut-

    offs and losses

    RESOURCE AND RESERVE ESTIMATION

    Geological Domains,

    Mining Horizon selection,

    Optimisation of Interpolators

    Confirmation of the estimated

    discount factors from GTIS to

    ROM and SALES within the

    area mined

    RECONCILIATION

    TECHNICAL

    MODIFYING FACTORSENVIROMENTAL, LEGAL

    GOVERNMENTAL, ECONOMIC

    INPUTS

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    Run of Mine Coal Reserves

    Extractable Coal Reserve =Mineable Tonnes In-Situ Resource

    - Layout Loss and Barrier Pillar Loss(resources outside the mine layout)

    x In-Panel Extraction %(mining method, safety factors)

    - Mining Loss

    Run of Mine (ROM) Coal Reserve =

    Extractable Coal Reserve

    + Contamination(added as a thickness or a percentage)

    + ROM Moisture Correction Factor(surface moisture)

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    Saleable Coal Reserves

    Coal Product Interpretation Single stage or double stage wash

    Max and Min washing densities

    Relevant washtables (borehole, 25-0.5mm)

    Product specs

    Theoretical Practical Yield contamination borehole correlation factor (liberation) plant efficiency

    Loss of fines

    Beneficiation of fines coarse fines to spirals

    spirals yield and efficeincy

    ultra fines to floatation floatation yield and efficiency

    Fines added back to Product / Discard

    Effect of blending optimal cut-point density

    Product moisture correction factor

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    Saleable Coal Reserves

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    Reporting of Reserves

    Run of Mine Reserves (ROM)1. Tonnes are reported on a wet, contaminated basis

    2. Coal qualities may be reported as wet, contaminated or air-dried,

    contaminated or dry, contaminated

    3. The basis for reporting coal qualities must be stated

    Saleable Reserves

    1. Product tonnage is reported on a wet product basis (as delivered)

    2. Product qualities may be reported as wet product or air-dried product or

    dry product

    3. The basis for reporting product qualities must be stated

    ROM and Saleable are reported per Reserve Category(proven, probable)

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    Reconciliation

    To Define the short term Budget Plan with a high degree of

    confidence to ensure that we achieve budget tonnes, yield andrevenue predictions.

    To Define the Operational Life of Mine Plan with a moderate to

    high degree of confidence to ensure that we maximise reserve

    utilisation and optimise expected financial returns.

    To Define the new Project Life Of Mine Plan parameters with a

    high degree of confidence to reduce the risk of not making the

    expected financial returns.

    Why do we do Reconciliations?

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    Reconciliation - Operations

    GEOLOGICAL MODEL

    MINEABLE TONS IN-SITU

    With Geol Loss, min and maxmining heights and coal qualityCut-offs applied

    GEOLOGICAL FACTORS

    Structural Model

    Quality Model

    Resource Confidence

    Geol Loss

    ROM FACTORS

    Mining Loss, Dilution,Mining Recovery,Contamination andMoisture Adjustment

    SALES FACTORS

    Wash, Yield, Plant

    Factor, fines andMoisture Adjustments

    SALES MODEL

    ROM MODELFINAL BUDGET MODEL

    SURVEY AND

    PRODUCTION DATA

    Volumes

    ROM Tonnes

    Sales Tonnes

    Yields and QualitiesMoisture Adjustment

    MASS AND QUALITY BALANCES

    Volume, Tons, Coal Quality

    VARIANCE ANALYSIS

    Identify differences betweenthe predicted model and actualproduction values

    3

    4

    5

    FACTOR

    ADJUSTMENTS

    RECONCILIATION OF OPERATIONAL FACTORS

    SCHEDULEDRESERVES

    Geological Factors

    Mining Factors

    ROM Tonnes

    Sales Tonnes

    Moisture Adjustment

    1 2

    3

    FINANCIAL MODEL

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    Reconciliation - Projects

    What is different in the Project geology that can impactnegatively on the Project;

    What is different in the mineability and operability that can

    impact negatively on the Project;

    Are the production rates realistically based on the deposit

    geology?

    Are the factors used in the Project evaluation similar to knownoperations, and should they be?

    Are the factors used in the Project realistic and achievable?

    Does the original view of the project turn out to be the reality in

    the mine.

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    Project Risk

    1. Project factors can be significantly over- or under-estimated,

    encouraging imprudent investment (corrected only with

    difficulty)

    2. Uncertainty is best predicted as a probabilistic range, not a

    single deterministic forecast (this also helps geotechnical

    evaluations and improves predictions)

    3. The probability range is usually much greater than most

    geoscientists believe their predictive ranges are too narrow.

    4. Most statistical distributions are not normal (mean??)

    Exploration expenditure is often described as a gamble where thescience of geology is the only factor which does not make it an

    outright lottery

    Why Should we Consider Monte Carlo Simulations?

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    Project Risk

    Common Distributions

    Normal (Gaussian)commonly assumed

    average valuecentral limits theorem

    can result in < zero values

    LogNormalmore realisticno < zero values

    difficult statistics

    Convert data to Ln values

    Pertmaximum-minimum-expected

    non-natural parameters

    Better than triangular distribution

    Beta

    Beta (generalised)

    Beta (subjective)

    Binomial

    Chi-Squared

    Cumulative

    DiscreteError

    Erlang

    Exponential

    Extreme Value

    Gamma

    General

    Geometric

    Histogram

    HypergeometricInteger Uniform

    Inverse Gaussian

    Logistic

    Log-Logistic

    Lognormal

    Negative Binomial

    Normal

    Pareto

    Pearson Type V, VIPert (Beta)

    Poisson

    Rayleigh

    Students T

    Triangular

    Uniform

    Weibull

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    Project Risk

    Element Distributions

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    Project Risk

    Prediction of Financial Performance

    What is the

    probability of

    losing money on

    this project?

    8%

    What is the

    probability of

    making more thanR 300 m?

    33%