1. Projects THE BASIL READ GROUP Mining and processing activities in Zimbabwe and some thoughts on mining the Great Dyke. Dr Michael Roberts, TWP SAIMM Zimbabwe Branch May 2010

2. Who are we? Basil Read Construction Buildings Roads Civils MiningDevelopmentsEngineering Basil Read Engineering TWP

3. Who are we?

4. A generic description of some project work undertaken in Zimbabwe by TWP. What do we do?

5. Pickstone-Peerless hydrothermal gold deposits. Activity

6. Location

7. Pickstone-Peerless hydrothermal gold deposits. A plant will be built on site to treat a sulphide dump. Later there might be consideration given to going underground. Activity

8. Unki declines on the Great Dyke. Activity

10. Unki declines on the Great Dyke. Declines completed. Activity

11. Evaluating and assisting with respect to efficient Chrome mining associated with the Great Dyke.

12. Activity Optimise mining and process engineering on the Great dyke with respect to Platinum group elements. How done. Optimise mineralogy, mining and process engineering by recognising that the ore body is not homogeneous.

13. The Bushveld complex

14. The Great dyke

15. There might be some commonality with respect to structure in the Bushveld and the Great Dyke. Mining on the Bushveld and Great dyke

16. Easy mining on the Great Dyke

17. Easy mining on the great dyke

18. Easy mining on the Great Dyke

19. Easy mining on the Bushveld

20. Difficult mining on the great dyke

21. Difficult mining in the Bushveld

22. Some commonality with respect to structure in the Bushveld and the Great Dyke. Flexural slip thrust faults. Great dyke

23. Flexural slip thrust fault

24. What is a flexural slip thrust fault? Ore body Section Flexural slip thrust fault Flat Ramp

25. Flexural slip thrust fault Flat Ramp

26. Flexural slip thrust fault on the Great Dyke ?????

27. Flexural slip thrust fault - origins

30. Flexural slip thrust fault - origin

31. Scientific description of a flexural slip thrust fault Part of the Platmine Research Programme funded by: Anglo Platinum Impala Platinum Lonmin Peer reviewed scientific paper referenced:  S. Perritt and M.K.C. Roberts “Flexural-slip structures in the Bushveld Complex, South Africa?” Journal of Structural Geology, Volume 29, Issue 9, September 2007, Pages 1422-1429. S. Perritt and M.K.C. Roberts “Flexural-slip structures in the Bushveld Complex, South Africa?” Journal of Structural Geology, Volume 29, Issue 9, September 2007, Pages 1422-1429.

32. Fall of ground fatalities over a set period Curved joint moved as a precursor to fall of ground Thrust fault or curved joint directly fell on deceased Seismic causes Other reasons for fall of ground 9/3215/322/326/32 Breakdown as to cause of 32 fall of ground fatalities

33. Pillar failure due to gouge on flexural slip thrust fault

34. Gouge

35. Pillar failure due to gouge on flexural slip thrust fault

36. Understanding the structures Understanding geological structures within the ore body. Rock mass ratings. Rock strengths Mining method. Appropriate mining span Excavation support Structural geology Rock engineeringMining engineering Knowledge gap

37. Understanding the structures Understanding geological structures within the ore body. Rock mass ratings. Rock strengths Mining method. Appropriate mining span Excavation support Structural geology Rock engineeringMining engineering Knowledge gap Expect surprises and production disruptions

38. Understanding the structures Understanding geological structures within the ore body. Rock mass ratings. Rock strengths Mining method. Appropriate mining span Excavation support Structural geology Rock engineeringMining engineering Expect smoother production profile No knowledge gap

39. TWP Plant Design Example

40. Thank you