Output at Acacia Mining's Bulyanhulu operations are being hampered by repeated overheating of the ball mill trunnion bearing.
Acacia - Tanzania's largest gold miner -undertook a planned two-week shutdown of the vertical shaft at the Bulyanhulu mine to refurbish and modernise the production and service winders. In parallel with this, it undertook a programme of works on the process plant over a similar time frame.
Acacia says the planned maintenance was concluded successfully and the recommenced full scale hoisting in early September, but it has not been able to run the plant consistently since the shutdown due to repeated overheating of the ball mill trunnion bearing.
A team of specialists is working with personnel on site in order to establish the root cause of the problem and a timeline for resuming normal operations.
Acacia says that while the plant has been down, it has built a surface stockpile of 11,300 ounces, with a further 7,400 ounces in stockpiles underground.
It has put stoping operations on hold until the plant is running and providing consistent paste fill.
The treatment of reclaimed tailings will continue, as will underground development and drilling activities.
Acacia says that due to a strong performance at North Mara, it continues to expect Q3 production to be broadly in line with Q1 2016, as guided at the interim results.
At this stage, full year guidance for both Bulyanhulu and Acacia remain unchanged.
At 8:07am: (LON:ACA) Acacia Mining Plc share price was -26.7p at 473.3p