Ghana
Overview and Locality
The Iduapriem mine covers a 137km2 concession that includes Ajopa South West and is located in the western region of Ghana, some 70km north of the coastal city of Takoradi and approximately 10km southwest of the town of Tarkwa. It is bordered to the north by Gold Fields Ghana Limited (Tarkwa Mine) and to the east by the Ghana Manganese Company Limited (a manganese mine in existence since the 1920s).
Iduapriem is an open-pit operation with two circuits each comprising two-stage milling – a gravity circuit and a carbon-in-leach (CIL) plant. The gravity circuit recovers about 30% of the gold and the remainder is recovered by the 418ktpm capacity CIL plant.
A Brief History
A feasibility study was completed in 1990 and, in October 1991, the then owners, Golden Shamrock Limited, (Golden Shamrock) began construction of a 1.36Mtpa semi-autogenous milling circuit and carbon-in-pulp (CIP) plant.
Mining began in August 1992 with the first gold pour achieved in September of that year. Golden Shamrock was acquired by Ashanti Goldfields Company Limited in 1996.
In 2000, a portion of the non-operational Teberebie Goldfields Limited company (a subsidiary of Pioneer Goldfields Limited) was purchased, resulting in an increased Ore Reserve and LOM. In 2002, Ashanti upgraded the plant capacity to 4Mtpa and, in 2004, AngloGold merged with Ashanti to become AngloGold Ashanti.
In 2009, the plant capacity was further extended to the current 5.2Mtpa. A three-year investment plan is currently underway to revise and extend Iduapriem’s life of mine. The plan, which involves accelerated waste stripping, also includes increasing capacity of Iduapriem’s TSF to match the revised mine plan.
Overview and Locality
Obuasi is an underground operation with the main accesses into the mine consisting of shafts and a single access decline with interlevel development of between 15 and 30m. The Obuasi Deeps Decline, which is situated at the southern end of the mine, is designed to extend to a depth of about 1,500m. The Obuasi underground operation employs mostly the long hole open stoping (LHOS) mining method for ore extraction.
Existing infrastructure includes a 2.4Mtpa processing plant with flotation and bacterial oxidation (BIOX), underground development, hoisting shafts and associated infrastructure, power and water reticulation, office complexes, workshops and company housing estates. Power is supplied to the mine by the Volta River Authority and GridCo.
A Brief History
Production at Obuasi started in 1897 and stopped in the last quarter of 2014. Some aspects of the mine continued under limited operational conditions, including the development of the underground decline. A favourable feasibility study was completed in 2017 and indicated a strong technical and economical case with an anticipated 20-year LOM
In 2018, approval was received from the AngloGold Ashanti board to proceed with the project. The redevelopment project began in late 2018 and first gold was poured during the fourth quarter of 2019.
- Phase 1 of the redevelopment project was completed by end September 2020 and began commercial production on 1 October 2020.
- Phase 2, construction and mine development, was completed in 2021.
- Phase 3 of the redevelopment project is currently underway to develop the infrastructure necessary to support the planned ramp up in production to 5,000tpd by the end of 2023.