TRANSACTION PAPER

The use of borehole radar in detecting disruptions in platiniferous horizons in the Bushveld Complex, South Africa - the financial implication

P. du Pisani^I; S. Coomber^I; G. Chitiyo^II; V. Daniso^II; S.Mampa^II

^IGeosciences Resource Group, Anglo TechnicalDivision, South Africa
^IIAnglo Platinum: Rustenburg Section, South Africa

SYNOPSIS

Robust borehole radar tools were developed for application in South Africa's gold mines in the late 1990s. These tools are needed to operate under extreme underground mining conditions characterized by high temperature, high humidity and corrosiveness. Once borehole radar was proved as a delineation tool for the flat tabular gold reefs, the technology was tested on similarly orientated platinum reefs. Due to the extremely favourable dielectric contrast of these platinum orebodies with their host rocks, borehole radar has been successful in identifying small-scale disruptions in these reefs that may affect mining them. Slim-line borehole radar tools are deployed in boreholes drilled parallel to sub-parallel to the platinum reefs to delineate disruptive structures such as dykes, faults, slumps (called potholes) and iron-rich ultramafic pegmatites (IRUPs), which change the normal reef composition. Advance knowledge of how the reef is displaced affects how the orebody is mined. Mine planning can be adapted to mine the ore body more economically and potential hazardous situations can be negated. This paper presents examples of where borehole radar was used to delineate disruptions to the reef plane in two platinum mines. It is shown that applying borehole radar prior to mining has a significant financial benefit. Finally, development directions for future borehole radar technology are recommended.

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References

1. CAWTHORN, R. G. The platinum and palladium resources of the Bushveld Complex. South African Journal of Science, vol. 95, 1999. pp. 481-489.         [ Links ]

2. VILJOEN, M. J. and SCHÜRMANN, L.W. Platinum Group Metals. Wilson, M.G.C. and Annhaeusser, C.R. (eds.), The Mineral Resources of South Africa. Council for Geoscience, South Africa, Pretoria, 1998. pp. 532-568.         [ Links ]

3. DE VRIES, P. and DU PISANI, P. Borehole radar delineation of the UG2 reef at Modikwa Mine. Ninth SAGA Biennial Technical Meeting and Exhibition, Cape Town. 2005.         [ Links ]

4. VAN SCHOOR, M., DU PISANI, P., and VOGT, D. High-resolution, short-range, in-mine geophysical techniques for the delineation of South African ore bodies. South African Journal of Science, vol. 102, 2006. pp. 355-360.         [ Links ]

5. EALES, H.V., BOTHA, W.J., HATTINGH, P.J., DE KLERK, W.J., MAIER, W.D. and ODGERS, A.T.R. The mafic rocks of the Bushveld Complex: a review of emplacement and crystallization history, and mineralization, in light of recent data. Journal of African Earth Science. vol. 16, 1993. pp. 121-142.         [ Links ]

6. VOGT, D. A borehole radar system for South African gold and platinum mines. South African Journal of Geology. vol. 109. 2006. pp. 521-528.         [ Links ]

7. BRAY, A., SINDLE, T., MASON, I.M., PALMER, K., CLOETE, J., STEENKAMP, J., DU PISANI, P. and TROFIMCZYK, K. Using slimline borehole radar from cover holes. Tenth SAGA Biennial Technical Meeting and Exhibition. Wild Coast Sun. 2007.         [ Links ]

8. ANGLO PLATINUM. Annual Report. Available at http://angloplatinuminvestoreports.com/angloplatinum_br_2007/index.php. 2007.         [ Links ]

9. DU PISANI, P., MASON, I.M. and DANISO, L.N. Borehole radar delineation of the Brakspruit regional pothole at Anglo Platinum's Rustenburg Section. Tenth SAGA Biennial Technical Meeting and Exhibition. Wild Coast Sun. 2007.         [ Links ]