Low-grade concentrator regrind circuit upgrade at Newcrest's Cadia Valley operations.

Plant upgrades are described that were carried out in the Cadia Hill, New South Wales, circuit in April 2003 to improve concentrate quality and metal recoveries from the flotation circuit. The major changes involved circuit reconfiguration to allow all concentrates to be reground to less than 38 micrometres prior to final cleaning, increasing ball charge in the regrind mill to utilise fully all of the installed power, desliming of the cleaner scavenger concentrate to improve the circuit water balance and the inclusion of a gravity concentrator in the regrind circuit to recover more free gold to bullion. Once the flotation circuit had stabilised, concentrate launder modifications and increased froth crowding on the scavenger flotation cells permitted the introduction of stronger collectors without compromising concentrate quality or circuit stability. After 12 months, the Cu concentrate grade had increased by 2% and metal recoveries by 3% and 7% for Cu and Au, respectively. The project capital outlay has been repaid in less than three months.
Plant upgrades are described that were carried out in the Cadia Hill, New South Wales, circuit in April 2003 to improve concentrate quality and metal recoveries from the flotation circuit. The major changes involved circuit reconfiguration to allow all concentrates to be reground to less than 38 micrometres prior to final cleaning, increasing ball charge in the regrind mill to utilise fully all of the installed power, desliming of the cleaner scavenger concentrate to improve the circuit water balance and the inclusion of a gravity concentrator in the regrind circuit to recover more free gold to bullion. Once the flotation circuit had stabilised, concentrate launder modifications and increased froth crowding on the scavenger flotation cells permitted the introduction of stronger collectors without compromising concentrate quality or circuit stability. After 12 months, the Cu concentrate grade had increased by 2% and metal recoveries by 3% and 7% for Cu and Au, respectively. The project capital outlay has been repaid in less than three months.