Kansanshi mine sulphide ore circuit did not achieve target flotation recovery in
2016, hence it was deemed necessary to carry out a research aimed at optimizing
this circuit. The objective of the research was to optimise the Kansanshi milling
and flotation circuit processing a copper sulphide ore.
In line with this, samples were obtained around the circuit and processed in the
laboratory for moisture content, slurry concentration, particle size distribution,
and flotation response. This information was then used to build a computer-based
model of the Kansanshi milling and flotation circuit. This was done in MODSIM®,
a software package specialising in the design and simulation of mineral processing
operations. After careful appraisal, appropriate models were selected for the semi
autogenous grinding (SAG) and ball mills, SAG mill discharge screen,
hydrocyclones, pebble crusher, and the flotation cells. The calibrated model was
then used to simulate the effects of key operating parameters on flotation
recovery.
Analysis using the attainable region technique revealed that the SAG mill feed-rate
should be adjusted from 1719 tph to 2090 tph. This would lead to a better
utilisation of the pebble crusher that can process 358 tph of pebbles from the
current 198 tph. From the simulation work, it was established that rougher
flotation recovery can be improved from the current 80.0 % to 82.3 %. The technoeconomic benefits of the proposition are yet to be investigated.
Findings from the research concluded that the milling circuit optimum operating
parameter; which generated a final product falling predominantly in the range -
150 +38 μm were SAG and ball mills conditions of ball sizes 200 and 40mm
respectively, ball mill ball filling 32% and rotational speed between 75 and 80% for
both SAG and ball mills. The optimum hydrocyclone feed slurry concentration was
found to be 62% solids. Additionally, the SAG mill discharge screen aperture size
of 6 mm was the optimum. It must be noted that slurry concentration did not show any impact on both the SAG and ball mills performance. The SAG mill ball
filling did not show any significant improvement on performance. / College of Engineering, Science and Technology / M. Tech. (Chemical Engineering)
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:unisa/oai:uir.unisa.ac.za:10500/26692 |
| Date | 11 1900 |
| Creators | Lusambo, Martin |
| Contributors | Mulenga, Francois |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Format | 1 online resource (xiv, 151 leaves) : illustrations (chiefly color), graphs, map, application/pdf |
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