The yearly maintenance shutdown at Jubilee’s Roan concentrator operations, in Ndola, Zambia, was completed in May, with operations successfully resuming at full capacity and with a run-of-mine throughput target of 30 000 t a month.

Jubilee CEO Leon Coetzer says he expects the operation's performance for June to provide a clearer indication of sustainable operating capacity and recovery efficiencies with the addition of the fines concentrate from Roan now being processed at the company’s Sable refinery in Kabwe, Zambia.

“As previously noted, the monthly fines concentrate production contains about 140 t of copper previously stockpiled at Roan,” he notes.

The success of the interventions to further improve copper efficiencies will be known over the coming week as Roan’s in-circuit inventory is rebuilt at stable operations, and Roan holds the option to further increase throughput with the inclusion of the front-end dense medium separation (DMS) circuit which will be considered in June.

The commissioning of the company’s new fine copper concentrate dewatering facility has reached successful completion, with the calibration of performance measures under way to achieve stable continuous operations.

Jubilee used the scheduled downtime to implement key interventions to counter the sharp rise in global fuel and acid prices.

Key interventions included the expansion of the copper oxide recovery circuit to further improve copper efficiencies by a targeted 5%, partly offsetting the near 80% increase in local fuel prices. This directly impacts the transport costs associated with the run-of-mine (RoM) delivered to Roan and copper oxide concentrate transported to the Sable refinery.

Acid consumption and transport costs currently account for about 20% and 16% of monthly expenditure, respectively.

The main activities of the yearly maintenance period focused on the RoM feed circuit and maintenance of the internal pumping mechanisms of the flotation units, as well as final modifications to the new dewatering circuit for the fines concentrate.

The fines concentrate stream accounts for about 25% of the contained copper within the total RoM feed to Roan and the new concentrate dewatering circuit has demonstrated sufficient operating capacity at throughput rates above current fines concentrate production levels.

Further, optimisation work is focused on refining the operating parameters required to maintain the stable continuous operation of the circuit under varying feed density conditions. Roan also currently holds significant stocks of fine concentrate material that has naturally dried during the current dry weather period, allowing transportation to Sable to supplement any temporary interruptions in dried fine concentrate production.

“The successful progression of the Roan dewatering circuit through commissioning and ramp-up marks another important milestone in the expansion of our Zambia copper operations.

“The ability to process both newly generated fine concentrate material together with the historical stockpile provides increased operational flexibility and supports the continued scaling of our integrated copper strategy,” says Coetzer.