4 th International Platinum Conference: Platinum In Transition ‘Boom or Bust’

1. Application of borehole radar to pothole identification and delineation ahead of the working face in platinum mines SPEAKER: Charles Golding, CEO, GEOMOLE AUTHORS: Carina Kemp, Senior Geophysicist, GEOMOLE Petro Du Pisani, Manager in-Mine Geophysics, ANGLO TECHNICAL SERVICES Mduduzi Shoke, Geophysicist, GEOMOLE 4th International Platinum Conference: Platinum In Transition ‘Boom or Bust’ 11th – 14th October 2010, Sun City, South Africa

2. Outline • Introduction • Efficient • Instrumentation • Deployment Methods • Effective • Borehole Radar Survey Design • Results and Interpretation • Economic • Financial Implications • Conclusions

3. Introduction • Borehole Radar (BHR) provides highly detailed, continuous ore body and structural delineation information for accurate resource definition and mine planning. • Borehole Radar has been delineating ore bodies for mine planning for over 10 years. • Improvements in technology over the last 3 years enable borehole radar to be deployed on the drill allowing for quick and easy surveying underground.

4. Efficient: Equipment • GeoMole BHR • 10 – 124 MHz Bandwidth • Resolution: less than1m • Range: up to 50m or more (depending on rock type) • Note: Borehole Radar will not work for all rock types but works very well in the Norites and Anorthosites in the Bushveld. • Probe diameter: 32 mm • Length 1.65 m • BHR Profiling at ~10 m/min • Omni directional antenna

5. t Efficient: Deployment The borehole radar system can be deployed by winch or on the drill rods similar to a gyro survey Data is acquired continuously as the rods are pulled and the radar ascends the drill hole Signal is sent radiallyoutwards into the surrounding rock The radar images the rock surrounding the drill hole. Final interpretation is produced. The radar is not directional. Neighboring drill holes and knowledge of stratigraphy aids interpretation.

6. Efficient: Forming a radargram Radar deployment Radargram

7. Efficient: Borehole radar process Radar survey Radargram Report & Surface Geology info Directional survey Database Interpretation

8. Thin seam Platinum Mining

9. BHR for Platinum Mining • Mine Planning: Removing uncertainty - DON’T develop blindly • Geo-technical information prior to development - shaft and raise planning • Mapping the extent and location of dilution zones before mining – knowing what to avoid or investigate further • Extending the life of the mine – greater confidence in resource estimation

10. Why Borehole Radar? • Tactical Mining Tool Removing uncertainty - DON’T mine blindly • Providing a means to “view” the space that lies ahead of the working face - mapping the extent of structures and uncertainties ahead of mining • Mapping complex deposits • Mapping man-made structures, e.g. old workings • Illuminating sources of physical instability to allow the miner to either anticipate or even avoid hazards altogether • Safety - locating potentially hazardous zones

11. Thin seam Platinum Mining Reef thinning <50cm Potholes

12. Effective: Thin seam Platinum Mining

13. Effective: BHR Survey Layout CROSS CUT RAISE BOREHOLES HOST ROCK HAULAGE

14. Effective: BHR Surface Generation CROSS CUT RAISE RADAR SURFACE BOREHOLES HOST ROCK HAULAGE

15. Effective: Survey Layout

16. Effective: Borehole Design ± 10m Anorthosite PxA Feldspathic Pyroxenite Triplets ~0.3m Leader Seam ~0.2m Main Seam (UG2) ~0.7m Pegmatoidal Feldspathic Pyroxenite ~0.6m Mela- to Leuconorite (BLESKOP MARKER) Pegmatoidal Feldspathic Pyroxenite ~0.9m Anorthosite ~0.9m Leuconorite 8mm Cr. Stringer Feldspathic Pyroxenite ~4m UG1 ~0.1 – 1m Anorthosite ± 7m ± 5m ± 25m Borehole ± 4m ± 5m

17. Effective: All Five Radargrams

18. Effective: Section

19. Effective: Interpretation

20. Example

21. Example: Conclusion • Fortunately no significant disruptions, other than a 2.2m pull down from a reef roll, were detected ahead of mining with the borehole radar for this panel. This meant that mining could continue with confidence. However…………

22. UG2 COLLAPSE INTO ~ 15m POTHOLE UG2 SHEARS & DROPS PULLING PxA ~2M UG1 Bleskop Marker UG2 PxA RADIAL DISTANCE FROM BOREHOLE (m) UG2 HANGING WALL PxA BREAK-AWAY DISTANCE FROM COLLAR (m)

23. Economic: Financial Implications • Borehole radar survey results which were the subject of a different paper (Du Pisani 2008) detected a significant reef roll in a nearby panel. The paper showed that borehole radar surveys ahead of mining could have saved over US$1M in unnecessary development in panels that contain un-mineable reef.

24. Economic: Financial Implications Financial impact summarised (after Du Pisani, 2008)

25. Economic: Financial Implications Impact of reduced dilution: • An average mine mines (say) 2 million tonnes per annum • Assume on-mine costs of approximately US$62.8 per tonne; 2 million tonnes will therefore cost US$125.7m • Geological losses ranges from 5% to 30% • Every 1% reduction in waste mined will save US$1.26m. 5% - US$6.29 • This is only the on-mine cost saving. There are significant additional costs incurred in processing waste.

26. Economic: Financial Implications Impact of reduced dilution (continued): • A 50 hole a year Self-Drive BHR program will cost: • A 1% reduction in waste because of geological certainty will pay for BHR!

27. Advantages of using BHR in Platinum • Intelligent development • Reduced dilution • Additional ore • More confidence in resource estimation – continuous ore body maps • Safety improvement; AND • It is inexpensive and easy to use

28. Conclusions • Borehole radar technology has come of age and provides a demonstrably efficient, effective and economic means of mining smarter. • Supply side constraints facing the platinum industry will be mitigated by being more efficient, BHR can help. • Successful implementation requires: • mine management to see BHR as an operational tool; and • a strong partnership between the supplier and the end user.

29. Acknowledgements The authors thank: • Anglo Platinum for allowing these results to be published and for their vision and support of the implementation of geophysical programs. • all the Rustenburg geologists, borehole radar surveyors and drilling contractor Rosond who have made these borehole radar surveys possible. • the mine staff of Anglo Platinum for their professional enthusiasm which made this study both possible and enjoyable. The authors gratefully acknowledge the scientific and technical contributions of the borehole radar research teams at: • The University of Sydney • The University of Stellenbosch • CRCMining