Blasthole Sampling at Newmont Boddington Gold Sampling 2013 – Brisbane May 2013

Newmont Boddington Gold 00/00/00 Place title of presentation here

Geological Setting 00/00/00 Place title of presentation here

Boddington Open Pit North Pit South Pit Waste Dump 00/00/00 Place title of presentation here

Ultimate Pit Ultimate Pit Dimensions Length: ~4,000 m Width: ~1,000 m Depth: ~700 m If notes are needed they are Arial 10pt. Image of the skyscraper, Burj Khalifa Dubai, to depict the future depth of the Boddington pit. 00/00/00 Place title of presentation here

Pit Geology Generally good vertical continuity of grade zones (sub vertical contacts) Clear lithological boundaries to Dolerites, If notes are needed they are Arial 10pt. 00/00/00 Place title of presentation here

Mining Fleet Placeholder for Rope shovel Main dig units – 3 x Bucyrus 795HD Rope Shovels, 1 x Terex RH340 Truck Fleet – 40x 795D/F Production at ~4500-5000t/hr from each shovel Targeting 100mt/yr.

Shovel Dipper Indicator of Bucket Size – 3 pass load of a 795 truck Selectivity as a function of bucket size – similar scale to blasthole sample separation Single pass of 12m bench – no need to take 2 samples from hole 00/00/00 Place title of presentation here

Drill and Blast Fleet Needs decent picture with dust skirts 9 x DML 2 x PV271 5 x D65 If notes are needed they are Arial 10pt. 00/00/00 Place title of presentation here

Boddington Mill Text starts here, Arial 20pt. Level 2, Arial 20pt Boddington Mill – 35-40mt/yr. Very hard rock, 3 stage crushing with 4 Ball Mills, Float Circuit to 2 CIL trains Low Grade, throughput is king but grade elevation important If notes are needed they are Arial 10pt. 00/00/00 Place title of presentation here

Grade Control Requirements 55% of 2014 total movement is Ore 00/00/00 Place title of presentation here

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 00/00/00 Place title of presentation here

Blasthole Spacing and Minimum Mining Size 5m x 6.2m Kriged Blocks 5m x 5m x 6m Minimum Mining Size 20m x 20m x 12m Bench Height Large number of samples to SMU (14 in this example, usually more) Precision of boundaries below the drill spacing not important at NBG – bucket size 00/00/00 Place title of presentation here

Blasthole Sampling Systems Considered On Rig Samplers – Weight and Reliability Pie Trays – Safety Sectioning – Segregation and Bias, Manual Handling Spears – Manual Handling, Rocket Sampler Mammoth 00/00/00 Place title of presentation here

Auger Sampling - Augers Two types of Augers – Lipped and unlipped History; Kennecott -> Antamina -> Boddington Auger on an electric cordless drill. 00/00/00 Place title of presentation here

Auger Sampling - Technique Under Control of Geologists, no extra equipment on drills, allows metadata on collar to be collected (wet, blown out, run over) “After the fact” – not working around rotating drill strings/rigs Auger action allows sample to reach bottom of the pile. Single sample per hole removes vertical mixing issues, (refluxing, sloughing) 00/00/00 Place title of presentation here

Auger Sampling - Theory Text starts here, Arial 20pt. Level 2, Arial 20pt Level 3, Arial 14pt Level 4, Arial 14pt Level 5, Arial 14pt H Multiple cuts from the pile (at least 8, target 6kg sample size) radial towards blasthole Reduces issues of lateral segregation, Subdrill material thin Irregular collars can be accounted for by varying pattern. If notes are needed they are Arial 10pt. 00/00/00 Place title of presentation here

Electronic Data Capture Pocket Acquire, PDAs, Barcodes Barcode number used in lab. 00/00/00 Place title of presentation here

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 00/00/00 Place title of presentation here

Sample Protocol Testing If notes are needed they are Arial 10pt. Auger Possibly Biased low at low grades (<0.2g/t) Generally within the variability of the lot 00/00/00 Place title of presentation here

Ongoing QAQC - Field Duplicates Text starts here, Arial 20pt. Level 2, Arial 20pt Level 3, Arial 14pt Level 4, Arial 14pt 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 If notes are needed they are Arial 10pt. 00/00/00 Place title of presentation here

Particle Size Sensitivity Small Project in 2012 checking where the grade sit sin the bulk sample. Worried by the peaks in higher grade samples. Checked Metal – looks good for the auger. Discovered were in the middle of bit trial giving 2 completely different particle populations, and very different to protocol test work 00/00/00 Place title of presentation here

Mill Reconciliation 00/00/00 Place title of presentation here

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. If notes are needed they are Arial 10pt. 00/00/00 Place title of presentation here

RC – Blasthole Comparison pattern Tight spaced RC drilling on 10m Centres(Green) with 2m Samples Blastholes Sampled (Red) Poor target selection (all ore grade) 00/00/00 Place title of presentation here

RC – Blasthole Comparison - Nearest Hole Nearest neighbors reasonable correlation (~0.8) BH biased slightly higher and higher variance Note: No Change of Support conducted 00/00/00 Place title of presentation here

RC – Blasthole Comparison Complete Blast BH slightly higher, however targets high grades better as wide spaced drilling at southern end over actinolite vein Note: No Change of Support conducted 00/00/00 Place title of presentation here

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 If notes are needed they are Arial 10pt. Is there an issue to resolve? 00/00/00 Place title of presentation here

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% 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 00/00/00 Place title of presentation here

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. 00/00/00 Place title of presentation here

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. 00/00/00 Place title of presentation here

Globally the Industry needs an automated, reliable blasthole sampling system. 00/00/00 Place title of presentation here

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. 00/00/00 Place title of presentation here