Modern Mining October 2015

MINING News

Acacia production lower than expected in September quarter

London-listed gold miner Acacia, which operates three mines in Tanzania, has reported a lower than expected output of approximately 164 000 ounces for the quarter ended 30 September 2015. It attributes this to several short-term fac- tors negatively impacting output at the Bulyanhulu and Buzwagi mines over the period. The North Mara mine performed in line with expectations. As a result of the lower levels of pro- duction, cash cost per ounce sold and all-in sustaining cost per ounce sold (AISC) for the quarter will be above US$800 per ounce and US$1 200 per ounce respec- tively. Acacia predicts, however, a stronger fourth quarter performance, with produc- tion increases at all three mines. With the increase in fourth quarter pro- duction, the company expects to deliver full year production at around the level achieved in 2014 (718 851 ounces), com- pared to the initial guidance range of 750 000-800 000 ounces. Commenting on the update, Brad Gordon, CEO of Acacia, said: “I am person- ally very disappointed in the operational performance in the third quarter, which saw a succession of small issues impact Buzwagi and the ramp up at Bulyanhulu. We have addressed each of these to ensure they do not impact future performance. Importantly, key underlying metrics at Bulyanhulu, such as underground devel-

Bulyanhulu – which was commissioned in 2001 – is an underground mine with shaft access, which is transitioning to long-hole and drift and fill as its principal mining methods (photo: Acacia).

process, which will ensure that sufficient long-hole stopes are available as the mine moves into Q4 2015. Recoveries have been impacted by the lower grade together with instability in the plant caused by power interruptions and contamination of the elution circuit, which have both now largely been resolved. Furthermore, in order to better manage long term recoveries and processing costs, the mine is looking at options to separate the run of mine and the reclaimed tailings streams within the CIL circuit. At Buzwagi, production of approxi- mately 34 000 ounces for the quarter was impacted by the mining of lower than planned grades together with reduced mill throughput as a result of extended crusher downtime in September and an unplanned SAG mill re-line. Mining during the quarter was primarily focused on lower grade splay areas within the open pit; however, negative grade reconciliations from a higher grade zone, combined with limited flexibility resulting from slower than planned waste movement, led to mining below reserve grade for the quar- ter. The mine focused on additional waste movement in late September which will continue into early Q4 2015. At North Mara, production of approxi- mately 68 000 ounces was in line with plan. As expected, mined grade from the under- ground operation increased. This was due to the proportion of stoping ore of total underground ore production increasing over the quarter, and Acacia expects this trend to continue into the fourth quarter. 

opment rates, mining widths and stope availability are on track to sustain a step- up in production in Q4 2015.” At Bulyanhulu, the anticipated pro- duction ramp up did not materialise during the quarter, leading to production of approximately 62 000 ounces, with run- of-mine production of 55 000 ounces and reclaimed tailings production of 7 000 ounces. The reduced output was primarily due to delays in opening new high grade long-hole stopes, which led to lower ore tonnes mined than planned and reduced head grade together with lower plant recoveries. A specialist contractor has been brought in to undertake the stope opening

Acacia’s Buzwagi mine is a low grade bulk deposit with a single large open pit. The process plant is designed with a throughput capacity of 12 000 tonnes of ore per day (photo: Acacia).

6  MODERN MINING  October 2015