Dual-listed Centamin produced 472 418 oz of gold in 2018 – a 13% year-on-year decrease.
The company, which operates the Sukari mine, in Egypt, had, during 2018, revised its full-year guidance downward in response to operational challenges, including lower grades from the openpit in the first half of the year.
As mining progressed through the transitional zone, disruption to the underground stoping sequence in the second quarter of the year resulted in a damaged rig, as well as unplanned dilution from the cascading stopes in the Amun underground area.
However, Centamin identified, evaluated and implemented solutions, and continues to work towards improving operational efficiencies, the company noted in a statement issued on Wednesday.
Although gold production was lower, a record 77.9-million tonnes of openpit material was moved and 23.1-million tonnes of ore was mined.
The London- and Toronto-listed miner mined underground ore tonnage equal to 1.24-million tonnes, while ore processed amounted to 12.6-million tonnes.
The company’s Cleopatra decline development reached 2 260 m during the period, which delivered 185 333 t of ore, resulting in 8 959 oz being produced.
During the fourth quarter, mining of Stage 4 progressed on schedule, the company said, adding that total material of 21.1-million tonnes was moved.
About five-million tonnes of ore was mined. This is a 24% reduction quarter-on-quarter, as mining progresses into the higher-grade sulphides at depth in Stage 4, resulting in improved mine grades, averaging 0.75 g/t, an 18% improvement quarter-on-quarter.
Milled grade was 0.92 g/t, a 12% improvement quarter-on-quarter.
The strip ratio, meanwhile, increased to 3.22 for the fourth quarter, for a total of 2.37 for the year. This, Centamin said, was in line with increased mining rates in Stage 4 on the north and west sides of the pit, coupled with the ore zones tightening up in the higher-grade zones.
Underground, meanwhile, total ore mined was 314 000 t, a 4% decrease quarter-on-quarter.
Overall mined grade averaged at 6.2 g/t, a 20% increase quarter-on-quarter. Ore mine from stoping was 199 000 t at 8 g/t.
Owing to increased dilution from the lower Amun stopes, which negatively impacted on the grade, the company has made good progress quarter-on-quarter to reduce unscheduled mining dilution. This, Centamin said, remains a core focus.
Ore mined from the development was 115 000 t at 3.1 g/t.
In terms of processing, the company processed a record 3.2-million tonnes through the plant, a 2% increase quarter-on-quarter, while head grade of 1.45 g/t was an increase of 12% quarter-on-quarter as a result of mining dilution and lower-grade underground development.
Additionally, improved metallurgical plant recoveries of 89.1% for the fourth quarter yielded an 88.7% recovery rate for 2018.
Commenting on the performance, CEO Andrew Pardey noted that the fourth quarter had delivered “further improvement in the grade from both the openpit and the underground stoping, while underground development focused on longer-term production access”.
He pointed out that the focus for 2019 would remain on ensuring the delivery of grade and, as such, gold production from Sukari, which is supported by “tight cost control across all areas of the organisation and returns for shareholders”.