Modern Mining May 2021

GOLD

The redevelopment project will see Obuasi transformed into a modern, mechanised mine.

an average head grade of 8,1 g/t. In the following 10 years, average annual production of 400 000 oz to 450 000 oz is forecast.” Phase 2 operational readiness includes ramping up the mining operation, including the start of mining in Block 8 lower, commissioning the KRS shaft, GCVS vent shaft and paste fill plant, and installing under- ground paste systems. Project milestones Ehm refers to government agreements as one of the key project milestones in the redevelopment of Obuasi. “Right from the start, agreements underpin- ning an operation of 20+ years were crucial,” he says. “The redevelopment plan, as well as a tax concession agreement, were ratified by the Ghana parliament in June 2018, while key environmental permits for the project and the reclamation security agreement were secured in the same year.” The official launch of the Obuasi Redevelopment Project on January 22, 2019 was another milestone of note. “The completion of Phase 1 was quite a milestone. We undertook our first blast on February 1, 2019 and poured first gold in December the same year,” explains Ehm. “Phase 2 construction ran throughout 2019 and 2020, and at the end of 2020 we started commission- ing the newly-built mill and the new shaft. Both the new plant and the shaft are quite different from what they used to be; they are both highly automated.” Construction of new infrastructure and further work (processing plant and underground) under Phase 2, including new tailings storage, is another key mile- stone. Upgrading of the processing plant doubles production from 2 000 t of ore per day to 4 000 t. As

African brownfield project updates This year and next year will be key investment years for AngloGold Ashanti as it boosts production from brownfield projects to increase its overall reserve base and the life of its mines. At Geita in Tanzania, the expansion of the underground operations continued during Q1 with development of the newly established Geita Hill Underground mine progressing. “We are on track to achieve our target of consistently having three to four years of reserves ahead of us at the right balance between development and ore extraction,” explains Ehm. With the approval of the Nyamulilima and Geita Hill projects, the four mining sources being Geita Hill, Nyankanga, Star & Comet and Nyamulilima, have now all been approved and are underway. These four projects pro- vide access to exciting ore bodies and great optionality in the mine plan. “At the current pace, operational ore access at Geita Hill is planned for mid-2022. Exploration drilling will continue as access increases and we will begin to declare new reserves at the end of 2021,” he says. Meanwhile, Nyankanga underground continues to show further poten- tial, and together with Star & Comet, provides a large share of ore tonnes fed to the plant. “Overall, Geita continues to prove itself as a world-class asset, and while we move through an underground and open pit development period, the ore body continues to expand and show its strength, and we look forward to a beneficial operation as Geita sets itself up for a promising future,” says Ehm. AngloGold Ashanti planned to declare a significant increase in reserves at Geita. The final declaration pre-depletion amounted to 1,45 moz, of which 1 moz is attributable to Nyamulilima. “This confirms the strength of the ore body and the team on the ground as they managed to take Nyamulilima into reserve in under a year, and at the same time increase post-depletion reserves by 55% to 2,3 moz,” says Ehm. At the Siguiri project in Guinea, the Block 2 project implementation reached various milestones during the first quarter of this year, including final permitting. Road construction and open pit topsoil removal have com- menced subsequently. 

16  MODERN MINING  May 2021