OZ Minerals' Prominent Hill copper-gold concentrator in South Australia was built in 2008 with commercial production commencing in early 2009. In addition to recovery of valuable minerals, the flow sheet for this iron oxide-hosted copper-gold deposit has to address the issue of producing a good quality saleable copper concentrate by high selectivity against non-sulfide gangue._x000D_
Detailed mineralogical studies integrated with the metallurgical test work highlighted that liberation of fluorine-bearing minerals and subsequent very efficient rejection in cleaner flotation was necessary to produce a commercial quality copper-gold concentrate._x000D_
Bench scale laboratory metallurgical tests and mineralogical studies identified the need to regrind rougher concentrate to a P80 of 20 -25 microns or finer for adequate liberation of the fluorine-bearing minerals._x000D_
Satisfactory separation of the fluorine-rich gangue material from the valuable copper sulfides requires highly efficient cleaner flotation. This is done by a combination of washed froth cleaning and conventional dilution cleaning._x000D_
Proven equipment developed to meet similar taxing liberation and separation duties for the treatment of the refractory zinc-lead-silver ores of the Carpentaria-Mount Isa Mineral Province have been selected._x000D_
The combination of Xstrata Technology's IsaMill and Jameson Cell technologies addressed both the liberation and separation issues in the Prominent Hill concentrator. The energy efficient IsaMill technology both regrinds the rougher concentrate while its inert grinding environment prevents contamination of mineral surfaces with 'debris' ensuring subsequent optimum flotation performance. Heading up the cleaner circuit with a 'scalping' Jameson Cell followed by conventional flotation equipment allows this section to take advantage of the Jameson Cell's high intensity flotation environment and froth washing capability to achieve maximum concentrate grade (at minimum fluorine levels) while maximising recovery through the use of conventional flotation machines._x000D_
This paper looks at the development of the Prominent Hill flow sheet from the initial mineralogical and laboratory test work to the design, scale-up and early operation of the Prominent Hill regrind and cleaner flotation circuits._x000D_
The mineralogically-based approach of domaining metallurgical ore types combined with the axiom of size-by-size mineral particle behaviour by liberation class gave a clear understanding of the liberation and separation issues involved in the processing of Prominent Hill ore._x000D_
Technologies developed to meet much more onerous liberation and separation duties for the treatment of the refractory zinc-lead-silver ores of the Carpentaria-Mount Isa Mineral Province were successfully used to improve concentrate quality by rejecting non-sulfide gangue containing impurities. An IsaMill and a Jameson Cell are included in the circuit for fine grinding and for additional concentrate cleaning._x000D_
Plant performance since commissioning has justified the approach for metallurgical test work and equipment choices for the flotation circuit.