M.Tech. (Engineering: Chemical) / South Africa has the second largest fluorspar reserves in the world, but about 95% of the mined fluorspar is exported without local beneficiation that would otherwise increase foreign exchange earnings., Creamer Mining Weekly G-Other Trade Topic- Investment, (2005). The first step of a possible local beneficiation process would be the feeding of fluorspar solid from a hopper fitted with a screw feeder, using nitrogen gas to transport the powder into a non-transfer plasma reactor system. This study had as a main goal the optimization of the applicable continuous feeding parameters. The objectives of the investigation were: (a) Evaluation of the feeding system. (b) Evaluation of pumping/vacuum generation requirements. (c) Evaluation of the effect of using solid powder with non - uniform particle size. (d) To develop a model to enable the design and preliminary costing of a fullscale plant. Tests were performed in a test rig constructed for this purpose using different pipe diameters and nitrogen flow rates for the transport of the powder. It was found that the level in the hopper would have to be kept constant or a control system would have to be implemented in order to maintain a constant powder feed rate. In addition, a model was developed for the transport of the powder, and was used to optimize the pipe diameter required. An initial estimate of the operating cost and earnings of a possible full scale plant indicated that the beneficiation process would be very profitable. It is therefore suggested that this process be investigated further for conditions closer to the optimum modelled in a mini-pilot plant operation that includes the plasma reactor system in preparation of full scale implementation
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:12326 |
| Date | 17 September 2014 |
| Creators | Ntetye, Langa |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Johannesburg |
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