Browsing by Author "Van der Westhuizen, Andries P P"

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    The evaluation of solids suspension in a pilot scale mechanical flotation cell
    (2004) Van der Westhuizen, Andries P P; Deglon, David
    The central step in flotation is particle collection, with solids suspension together with gas dispersion and reagent mixing as necessary preconditions for particle collection. Solids suspension is therefore often identified as an important subprocess for effective flotation. Yet, surprisingly little work has been published on solids suspension in mechanical flotation cells, especially more recent studies since the advent of round mechanical flotation cells and the subsequent dramatic increases in maximum cell sizes are largely lacking.
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    Investigation of operating parameters in a vertical stirred mill
    (2016) Edwards, Garren Chad; Van der Westhuizen, Andries P P
    Due to the depletion of coarser grained ores, more mineralogically complex ores are being treated. These complex ores usually have finer grained valuable minerals. Liberation of these finer grained valuable minerals lies in grinding finer. Grinding to these fine sizes is energy intensive and using standard ball mills are energy inefficient at these sizes (P80 < 75μm). Therefore, stirred mills are becoming increasingly prevalent in the mineral processing industry. In order to optimize these mills, the effects and mechanisms of the significant variables need to be understood. This project investigated operating parameters against performance in a laboratory scale vertical stirred mill (Deswik mill), in an ultrafine grinding (UFG) application of MG2 reef in the bushveld igneous complex. The operating variables that were investigated are stirrer speed, solids concentration, media size and media filling. The Kwade stress energy model was tested on the grinding results. The grinding performance was quantified in two ways, i.e. grinding efficiency and grinding rate. The grinding performance for this study was also investigated through a statistical analysis. The experiments was designed using a face centred central composite design (FCCD) and the results was statistically analysed using a design of experiments (DOE) software.