Implementation of regrind–flotation pre-treatment of the CIL feed in a copper–gold plant

•A copper–gold plant implemented regrind–flotation pre-treatment prior to the CIL.•Plant scale flotation recovery was lower than laboratory study expectations.•Plant scale pre-treatment increased gold recovery inline with the laboratory study.•Plant scale copper recovery increased without also increasing cyanide consumption.

A regrind–flotation pre-treatment method developed to improve performance of a CIL circuit at copper–gold concentrators has been implemented at plant scale at the Newcrest Telfer mine. Low gold recovery in the CIL circuit due to the occlusion of gold by iron sulphide gangue minerals was overcome by the fine grinding of the CIL feed. A post-regrind copper flotation stage recovered liberated copper sulphide minerals allowing lower cyanide consumption in the subsequent CIL circuit than by regrinding alone. Gold recoveries achieved during the laboratory development of the regrind–flotation pre-treatment method have been replicated during the commissioning of the full-scale plant.

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