A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2017 / The Merensky Reef vertical grade distribution is highly variable within Styldrift I Mine. The variable
nature of the Merensky Reef mineralisation necessitates regular and timeous updating of the planned
mining cut with sampling information so that the optimum can be applied during mining operations.
The current geochemical assay analysis that is used for the analysis of platinum group elements (PGEs)
has been proven to be accurate and precise however it is expensive with long turn-around times from
the laboratory. Portable X-ray fluorescence (pXRF) technology has been tested as an alternative to
measure the platinum group element content along the Merensky Reef. pXRF technology cannot
accurately measure PGE content directly. Copper and nickel are detectable by the pXRF analyser and,
like PGEs, copper and nickel mineralisation peaks along Merensky Reef horizon. Copper and nickel
were therefore tested as potential pathfinder elements to target PGE mineralisation along the
Merensky Unit. The testing of the pXRF analyser was undertaken by analysing the accuracy of the
results it produces as well as determining if a regression between copper/nickel to PGE content is
possible along the Merensky Unit. The pXRF did not produce results of adequate accuracy as a
consistent significant bias was detected with pXRF results which were consistently lower than
laboratory results. Calibration of the pXRF using site specific samples was not sufficient to overcome
the bias. Regressions from copper/nickel to PGEs were tested for the Merensky Footwall which could
be isolated as a single data population. Significant outliers exist that do not fit the regression analysis
due to the inconsistent PGE modes of occurrence along the Merensky Unit. Application of the pXRF to
the study area therefore does not meet the required conditions. An underground trial of the pXRF has
indicated that peaks in pXRF copper and nickel results often, but not always, coincide with peaks in
PGE mineralisation. The pXRF can therefore be used as a low confidence indicator of PGE
mineralisation however the user must be aware of the limitations of the instrument. pXRF analysis
cannot be used reliably therefore geochemical assay analysis remains the most reliable method to
analyse PGE content at Styldrift I Mine. / XL2018
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/23617 |
| Date | January 2017 |
| Creators | Moodley, Yusavia |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | Online resource (vii, 125 leaves), application/pdf, application/pdf |
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