The effect of circuit configuration on regrind circuit performance

It was identified that potential improvements in recoveries were to be found in the better use of the regrind stages at a number of Anglo-Platinum concentrators. Historically, these concentrators used to operate in an open circuit configuration, over a relatively short period, the circuits were changed to closed circuit configurations because of the reported benefits of operating in this configuration. The effect of closing the circuit had, however not been quantified in these concentrators. This dissertation looks at quantifying the effects of each configuration with the purpose of drawing meaningful comparisons between them. The circuit configurations studied are open circuit, I-stage and 2-stage closed circuit configurations. The primary difference between these configurations is the network of hydrocyclones. This study pays special attention to the effect of cyclone performance on the regrind circuit performance. Comparisons were made between the open and the 2-stage closed circuits in three concentrators, and surprisingly the closed circuit did not show any improvement over the open circuit configuration from a combination efficiency perspective. The cyclones performance was analysed, and it was observed that the cyclones were operating inefficiently, most likely because the cyclones employed were not appropriate for regrind circuits. A further comparison was made between the I-stage and 2-stage circuit configurations and the I-stage closed circuit configuration proved to be more efficient than the 2-stage closed circuit configuration. Simulations were conducted to predict the performance of the circuit configurations by using more appropriate cyclones which are smaller in size. These cyclones are currently being used in a similar application in another concentrator. The simulations indicated that significant improvements in comminution performance could be realised with the utilisation of more appropriate cyclones, to achieve the closed circuit configuration.

Grantor dc:publisher.institution

Department of Mechanical Engineering

Year dc:date.issued

2004

Author dc:creator

• Mathye, Musa W

Advisors dc:contributor.advisor

• Powell, Malcolm
• Sweet, Craig

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/6762

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/6762