JOHANNESBURG (miningweekly.com) – As output from its newly expanded Moma mine jumps, Kenmare Resources has partnered with Mozambique’s State-owned power utility to combat unstable power supply.

The London-listed titanium minerals producer mined 7.65-million tonnes of ore at a grade of 6.3% during the fourth quarter of 2013 and increased its heavy mineral concentrate (HMC) output to 311 000 t from 157 000 t in the fourth quarter of 2012.

The 98% rise in HMC production was mainly attributed to the completion and ramp-up of the new dredge and concentrator plant in a second mine pond, which was part of Moma’s expansion during the second half of 2013, said MD Michael Carvill.

During the 12 months to December, the group mined 23.95-million tonnes of ore at an average grade of 5.9%, with HMC production almost doubling to 1.14-million tonnes, from the 772 300 t reported during the prior year.

The expansion of the mineral separation plant had also boosted ilmenite production by 69% from 123 600 t during the fourth quarter of 2012 to 209 400 t during the quarter under review. Ilmenite production for the full year increased 25% to 720 100 t.

“Expansion facilities were ramping up through the second half of 2013. All major facilities except for the zircon and rutile circuits have operated at or near design capacity levels. Utilisation levels are still below target levels, in large part owing to unstable power supply,” said Carvill.

A longer-than-expected ramp-up of the integration of the expanded zircon and rutile circuits, in addition to periods of unstable power supply, led to a decline in zircon output during the fourth quarter of 2013, which fell to 6 600 t compared with 10 600 t achieved during the fourth quarter of 2012.

Full-year output of Zircon declined 33% from 46 900 t in 2012 to 31 400 t during the year under review.

However, optimisation of the zircon and rutile circuits was ongoing, while a number of initiatives have been taken by Kenmare to enhance transmission capacity and deal with power instability issues.

Kenmare had partnered with State-owned utility Electricidade de Moçambique (EdM) to upgrade the transmission grid, including the installation of capacitor banks at Nampula and Alto Molocue and the upgrading of the Alto Molocue Static VAR Compensator  (SVC).

Kenmare also installed voltage stabilisation equipment and capacitor banks at the Moma mine.

However, despite these initiatives, Carvill said the electricity supply was subject to unplanned outages that had disrupted production.

“After investigation, it has become apparent that load growth on the northern network had been increasing more rapidly than EdM had anticipated. Consequently, especially with increased domestic load in the summer months, power demand at times exceeds the stable transmission capacity of the network, resulting in voltage instability,” he explained.

EdM would initiate a load management programme among EdM customers to prevent, at peak times, the line load rising above the stability limit of 118 MW at Nampula and had started the installation of series capacitors in the northern network and a SVC in Nampula, which was expected to be completed early next year, to significantly increase the transmission capacity of the network.

The power utility was also planning to build an additional 400 kV line as a long-term solution to the power supply issue.

“Kenmare is working closely with EdM to progress these projects and is providing support to further improve the operation of the network,” said Carvill.

Kenmare expected to publish its preliminary year-end results on March 12.