JSE-listed AngloGold Ashanti has advised that underground mining activity remains suspended at the Obuasi gold mine, in Ghana, following a fall-of-ground incident on May 18.

The company on May 26 confirmed that mine rescue teams continue to search for a missing miner who was drawn down into ground that gave way.

Investor relations senior VP Stewart Bailey said the company holds on to hope of finding the missing worker alive.

Once the search for the missing mineworker concludes, AngloGold will progress with detailed site work to determine amendments, if necessary, to the mine design plan.

Early indications are that the fall-of-ground incident was likely caused by the failure of a horizontal, or sill pillar, in one of the mine’s smaller mining stopes. A thorough investigation into the event has been initiated, AngloGold explained.

It said it would undertake an in-depth area-by-area assessment of the mine design, mine schedule and ground management plans before progressively releasing mining areas for a phased resumption of production.

Although the company said Obuasi’s guidance for this year was likely to be impacted by the standstill, it could not say to what extent.

Obuasi’s estimated contribution to 2021 guidance was between 300 000 oz and 350 000 oz. The mine had produced 46 000 oz in the first quarter of the year, while production in the second quarter, up to May 18, was 34 000 oz.

AngloGold interim CEO Christine Ramon stated that changes to Obuasi’s contribution to guidance would come to light once areas of the mine start being declared safe for work.

Planning and technical executive VP Graham Ehm noted that the investigation could take from two weeks to two months to conclude, depending on the findings and how the investigation proceeds.

“Even though the incident occurred in a small area of the overall mine, we did want to pause and review, having a look at each of the mine’s production areas before resuming stoping and mining activity.

“When we designed Obuasi’s redevelopment, we were careful to consider what is involved in resuming mining in a mine that has a lot of history. We designed the operating systems, ground management system and mining schedule to cater for being in a historical mine,” Ehm explained.

He added that the company would take into account any learnings and recommendations that come from the investigation and amend its ramp-up and mining plans accordingly.

While the company has voluntarily suspended all underground mining activity at the mine, the infrastructure refurbishment and construction related to Phase 1 of the mine’s redevelopment project continues.