1. 1 Laser Scanning at Mogalakwena Platinum Mine-South Africa Presented by David van Rensburg Geotechnical Department Mogalakwena Platinum Mine AngloAmerican PLATINUM Geospatial World Forum 18-21 January 2011

2. PLATINUM 2 CONTENTS Overview, Mogalakwena Platinum Mine Regional Locality Mining Environment Riegl LPM321 Laser Deployment Slope Monitoring strategy used at Mogalakwena Mine The 6 th Dec 2009 bench failure event Conclusions

3. PLATINUM Mogalakwena Platinum Mine-Regional Locality 3

4. PLATINUM Mining Environment Brittle hard rock, highly jointed, toppling failure 4

5. PLATINUM Riegl LPM321 Laser Deployment Riegl control point Blast shelter High transmissivity glass 5

6. PLATINUM Riegl LPM321 Laser Deployment Mogalakwena Platinum Mine the first open pit in the world to use lasers for slope stability monitoring. Fully automated system developed in 2005. Forms part of an integrated risk monitoring system, used mainly to determine long term slope deformation trends and to identify high risk areas. Scanning locations determined by the mine Geotechnical Department. Manual mode medium range profiling of surfaces, at distances up to 600m, although designed to operate up to distances of 6 000m at accuracy of 20mm. Scanning of highwalls done during daylight hours only because of security concerns. 6

7. PLATINUM Slope Monitoring strategy used at Mogalakwena Mine GeoMoS Riegl Laser Photo- grammetry Daily Visual Inspections Identification of Critically Unstable Areas GroundProbe SSR Evacuation Procedures Special Areas Committee Management of Potentially Unstable Areas Detailed Inspections Must have human intervention to initiate evacuation Evacuation initiated automatically, without human intervention Routine daily functions Safety Critical Monitoring Management Control Specialised technical investigations Extensomet er Pit Alarms 7

8. PLATINUM The 6 th Dec 2009 bench failure event Localised bench failure (700 tonnes) occurred on 6 th Dec 2009, failure mode was Toppling failure. Initial slope movement (30m to the south of the failure) identified by the laser 3 rd week in November. Slope stability radar deployed immediately. 8

9. PLATINUM Scanning data East Highwall,recording of the 6 th Dec 2009 failure event, screen shot acquired 15 th February 2010 9

10. PLATINUM Scanning data East Highwall,recording of the 6 th Dec 2009 failure event, screen shot acquired 5 th Dec 2009 10

11. PLATINUM Scanning data East Highwall,recording of the 6 th Dec 2009 failure event, sharp deviation in the graph shows the failure event 11

12. PLATINUM Conclusions Although the laser did not locate any movement in the failure area, it identified the precursor to the event almost a month earlier. Slope stability radar was able to provide 20 hour warning of the failure event, personnel were timeously evacuated. The integration of laser together with slope stability radar provides an effective and appropriate risk management system. The reputational and economic cost to any mining organization when personnel are injured or killed or equipment damaged or destroyed, are immense. The Riegl laser system plays a vital role in Mogalakwena’s approach to open pit risk management. 12

13. PLATINUM 13 THANK YOU