Late 19th – mid 20th century
Several small mining companies operated the Abontiakoon concession near Tarkwa town, leading to the sinking of eight vertical shafts and the excavation of numerous open pits. In 1882, operations at the underground Abosso mine exploited banket conglomerates to a depth of 850 metres. In 1920, Adjah Bippo and Cinnamon Bippo underground mines to the north were incorporated into the Abosso mine holdings. Abosso mine ceased operation in 1956 with recorded production of 2.7Moz at an average grade of 9.8g/t.
Late 20th – early 21st century
In 1989, Ranger Exploration (Ranger) began an investigation of retreating tailings from the Abosso mine. Following a drilling programme and subsequent feasibility study from 1993 to 1996, mining a mineralised quartz vein system to a depth of 200 metres was shown to be viable. Open pit operations commenced in August 1997 on the main pit, following the relocation of 3,000 people. Gold production started in November 1997 at the 3.0Mtpa capacity CIL plant. In 2001, Gold Fields and Repadre signed an agreement to purchase Ranger’s 90% interest in Damang. IAMGold and Repadre merged to give IAMGold an 18.9% interest in Damang and Gold Fields a 71.1% interest.
The Damang Expansion Project was initiated in 2004 to identify additional sources of ore from areas around the main pit. Following further drilling, a feasibility study was initiated to test the viability of a cut-back to extend the life of the main pit. Post approval of the necessary capital expenditure, the Damang pit cut-back (DPCB) and waste mining commenced in July 2005. A regional prospectivity study was completed in November 2005. In 2006, Mineral Resource estimation was carried out in the Rex, Tomento North, Tomento East, Tomento West and Huni areas. Amoanda Pit was finally depleted in August 2006. In 2010, drilling and Mineral Resource estimation was carried out at Amoanda North, Rex, Huni and Juno.
An updated conceptual extensional resource model was developed for the Greater Damang pit (Huni, Damang, Main and Juno) in 2011. Portions of the Damang pit down-dip extension drilling programme were completed and incorporated into the Greater Damang pre-feasibility study (PFS) with a resultant increase in Mineral Resource and Mineral Reserve ounces. During Q1 of 2011, the mine moved to owner mining and maintenance. GFG acquired the indirect 18.9% IAMGold interest in Damang and consequently holds 90% with the remaining 10% held by the Ghanaian government.
The pre-feasibility study for Greater Damang continued during 2012, following the completion of the Phase 2 drilling campaigns. Resource infill and geotechnical drilling programmes were completed on the Greater Damang Extension Project. Infill drilling and modelling of the Greater Amoanda Project was completed.
The fall in the gold price in 2013 resulted in the Greater Damang project being placed on hold, with the operation being restructured to maintain viability during the expected period of low gold price. The Damang turn around project in 2014 resulted in a return to profitability and positive free cash flow margin.
During 2015, infill drilling was completed at Huni-Saddle Bridge, Amoanda, Tomento North and Tamang with extensional drilling done at Juno East. Updates on the Damang Complex, Rex, Amoanda and Tomento North models were completed. The Damang Complex model was updated based on new drilling information, as well as reinterpretation of the existing five fault block model into six fault blocks.