Metallurgy and Processing

The Boseto concentrator will be upgraded from its current 3.0 million tonnes per annum nameplate capacity to 3.6 million tonnes per annum to treat the Zone 5 ores. The ores respond well to conventional sulphide flotation, producing approximately 165,000 tonnes of high-grade copper concentrate at 40% Cu and 375g/t Ag. The concentrate will be road hauled to port for shipping and sale on the international market.

Boseto process plant design criteria summary

The project requires this plant to be upgraded to process 3.65Mtpa of sulphide copper ore, mined from the Zone 5 mining operation. The upgrades are predominantly required to cater for the Zone 5 ore characteristics and higher throughput, however, the replacement of the scalping and product screens and provision of a Larox filter is included to achieve tonnage and/or quality respectively.

This upgrade will be achieved through the following:

  • Modification to the ROM hopper to allow for direct unloading of 100 to 150t net payload road haul trucks.
  • Refurbishment and repairs to the existing primary crusher.
  • Replacement and/or upgrade of the scalping and product screens.
  • Reconfiguring the rougher and scavenger circuits to utilise overall capacity on sulphide only.
  • Existing regrind mills replaced with ultrafine regrind unit.
  • Cleaner 1 and 2 tanks cells replaced with new pneumatic cells.
  • Existing plate and frame filter replaced with a Larox vertical pressure filter.
  • Reconfigure and upgrade one of the existing concentrate thickeners.
  • Installing additional manual bagging plant to facilitate concentrate loadout.
  • Upgrading services where appropriate to support the previous upgrades.
  • Provision of a 20Ml raw water dam to feed the processing plant.
General upgrade to improve the condition and operability of the plant.
Process flow diagram for the proposed plant upgrade
Typical standard of upgrade design, modifications to the flotation circuit, addition of a new ultrafine regrind mill and two (2) new pneumatic cleaner cells.