boddington gold blasthole sampling at newmont boddington gold sampling 2013 – brisbane may 2013

Boddington Gold

Blasthole Sampling at Newmont Boddington Gold

Sampling 2013 – Brisbane May 2013

00/00/00 Place title of presentation here 2

Newmont Boddington Gold


Geological Setting

Boddington Open Pit


North Pit

South Pit

Waste Dump


Ultimate Pit

If notes are needed they are Arial 10pt.

Ultimate Pit Dimensions Length: ~4,000 m Width: ~1,000 m Depth: ~700 m

Image of the skyscraper, Burj Khalifa Dubai, to depict the future depth of the Boddington pit.


Pit Geology


Mining Fleet

Placeholder for Rope shovel


Shovel Dipper


Drill and Blast Fleet

Needs decent picture with dust skirts



Boddington Mill

Text starts here, Arial 20pt.Level 2, Arial 20pt

Level 3, Arial 14ptLevel 4, Arial 14pt

Level 5, Arial 14pt



Grade Control Requirements

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Tonn

es

Month

ROM

MG

Waste

55% of 2014 total movement is Ore

Key Challenges for Sampling

• Safe – Minimise Exposure to High risks

• Costs – High Volume Low Cost

• Accuracy – Low Head Grade, requires Accurate, Precise Sampling. 1-2% increase in mill head grade delivers big benefits

• Fast – Keep the Pit working.


• Auger Sampling Selected


Blasthole Spacing and Minimum Mining Size

Blasthole Spacing 5m x 6.2m

Kriged Blocks 5m x 5m x 6m

Minimum Mining Size 20m x 20m x 12m Bench Height


Blasthole Sampling Systems Considered


Auger Sampling - Augers

Auger Sampling - Technique



Auger Sampling - Theory



Level 5, Arial 14pt


Electronic Data Capture



Sample Protocol Testing

• Hole drilled through Tarpaulin to prevent contamination.

• 5 Auger Samples taken (1 for Production, 4 for test work)

• 2 Spear Samples for comparison

• Remainder Alternate Shovelled to 5 piles

• 1 Pile Selected at random (post shovelling) and dispatched for rotary splitting.

• 11 sub samples split and assayed.

• Remainder of pile reserved for CRM generation


Sample Protocol Testing


0.10

1.00

10.00

0.10 1.00 10.00

Rota

ry S

plit

Au (g

/t)

Auger Sample Au (g/t)

Sample Protocol Test Results

• Auger Possibly Biased low at low grades (<0.2g/t)• Generally within the variability of the lot


Ongoing QAQC - Field Duplicates



Level 5, Arial 14pt


• 2,434 Field Duplicates in 2012 (~8% of samples duplicated)

• Between 0.1g/t and 1g/t Au • 85% of Samples <0.1g/t error• 95% of Samples <0.2g/t error

0.01

0.1

1

10

100

0.01 0.10 1.00 10.00 100.00

Log

of F

ield

Dup

licat

e

Log of Primary Sample

Log-Log Chart of Field Duplicate Results 2012

Particle Size Sensitivity


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

12.59.56.74.753.352.360.850.425<0.425

Au G

rade

(ppm

)

Size Fraction (mm)

Au Grade by Size Fraction

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

35.00%

40.00%

45.00%

50.00%

12.59.56.74.753.352.360.850.425<0.425

Au M

etal

(%)

Size Fraction (mm)

% Au Metal by Size Fraction


Mill Reconciliation

90%

95%

100%

105%

110%

Jan-12 Feb-12 Mar-12 Apr-12 May-12 Jun-12 Jul-12 Aug-12 Sep-12 Oct-12 Nov-12 Dec-12

Delivered to Mill/Recieved at Mill 3 Month Rolling

Oz 5% Lines 5% Lines


Boddington and RC drilling

• Rock Strength – 150-250Mpa

• Historic Low Penetration rates (>15 years experience on site with multiple contractors)

• Diamond almost same meterage cost for Resource Definition drilling.



RC – Blasthole Comparison pattern

• Tight spaced RC drilling on 10m Centres(Green) with 2m Samples

• Blastholes Sampled (Red)


RC – Blasthole Comparison - Nearest Hole

0.1

1

10

100

0.1 1 10 100

14m

Com

posi

te R

C Au

(g/t

)

Blasthole Au (g/t)

RC 14m Composite vs. nearest BH

Note: No Change of Support conducted


RC – Blasthole Comparison Complete Blast

Note: No Change of Support conducted


RC vs. BH Drilling Business Case

Technical Excellence is not a Business Case(Dunham 2012)


Estimated Cost increase requires ~3-5% mill head grade increase to cover.

Operational Impact of 4-5 Grade Control RC rigs

Is there an issue to resolve?

Blasthole Sampling Delivery


Total Percentage

Assayed 303,919 95.06%

Safety or Loaded 956 0.30%

Trashed 3,430 1.07%

Contaminated 999 0.31%

Sampling Issues 4,745 1.48%

Not Sampled 5,680 1.78%

Total 319,729

• 95% of blastholes with sampling assigned sampled project to date.

• Minimal Sampling issues (Wet holes/Small collars)

• Minimal Shovel downtime “Waiting for Markup” (<30hrs in 2012)

• Good Reconciliation


Blasthole Sampling Summary

• Blasthole Sampling can work given;• The Right Deposit• The Right Sampling System – tested and verified at

that site• Ongoing test work and evaluation

• Ensure it is supported by RC drilling where required

• Management Buy-In.If notes are needed they are Arial 10pt.


Are Augers the answer?

• Potential Overextension Injuries in Samplers/Technicians if poor techniques employed.

• Experienced at 3 mines where system is used.

• Can be managed but limits time in role and recruiting pool.

Globally the Industry needs an automated, reliable

blasthole sampling system.


Thanks and Acknowledgements

• Dominique François-Bongarçon .

• Newmont Boddington Gold Ore Control Team, past and present, especially Letitia Scott, Alison Compton and Jodie Gray.

• Newmont Boddington Gold Drill and Blast department.


boddington gold blasthole sampling at newmont boddington gold sampling 2013 – brisbane may 2013

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