Engineering News and Mining Weekly
Wet commissioning started at Senegal plant
The Senegal-based Sabodala-Massawa Expansion project, which is making use of bacterial oxidation (BIOX) in its ore processing, has started wet commissioning activities, reports owner West Africa-focussed gold miner and developer Endeavour Mining.
The BIOX Expansion project is on budget, with construction now 91% complete, and the first gold pour being expected on schedule, in May.
Upon completion of the expansion project, the Sabodala-Massawa mine will become a true top tier asset with production this year expected to total up to 400 000 oz, mined and processed at an all-inclusive sustaining cost (AISC) of less than $850/oz. These costs, Endeavour reports, are expected to improve further in the coming years, “embedding the mine firmly in the lowest cost quartile”.
“This year, Endeavour is well positioned to transition from a phase of investment in organic growth, to a more cash flow generative phase in the second half of the year. This inflection point will allow us to focus our efforts on increasing our shareholder returns while de-levering our balance sheet, as we continue to execute on our strategy,” states CEO Ian Cockerill.
The addition of the 1.2-milliontonne-a-year BIOX Expansion, with an initial capital cost of $290-million, is expected to add 194 000 oz/y of incremental production over the first five years, lifting Sabodala-Massawa to toptier status with expected production of between 360 000 oz and 400 000 oz, at an AISC of between $750/oz and 850/oz. This production is expected to increase to above 400 000 oz from 2025.
Wet commissioning of the BIOX Expansion was delivered in less than 23 months after construction was launched in April 2022.
During construction activities, up to 1 300 employees and contractors were on site, 82% of whom were Senegalese nationals, successfully completing over three-million hours of work with zero lost-time injuries being recorded.
Growing Portfolio
The Sabodala-Massawa mine, of which Endeavour owns a 90% stake and the government of Senegal the remaining 10%, was acquired by Endeavour in February 2021 as part of its acquisition of gold miner Teranga Gold.
Located about 630 km eastsoutheast of Senegal’s capital, Dakar, the Sabodala-Massawa mine consists of several openpit operations on the highly prospective Birimian Greenstone Belt.
Non-refractory ore is treated at a 4-million-tonne-a-year carbon-in-leach (CIL) plant that achieved commercial production in November 2009.
In 2021, Endeavour expedited the completion of the initial upgrades at the existing CIL plant and simultaneously advanced the definitive feasibility study for the addition of a refractory ore processing plant to confirm the economic viability of processing the high-grade refractory ores from the Massawa Central Zone and Massawa North Zone deposits.
In 2022, Endeavour launched the construction of the 1.2-million-tonne-a-year BIOX circuit to process the large refractory ore resource, with first gold expected in early May.
As at the end of 2022, SabodalaMassawa’s proven and probable reserves totalled 62.8-million tonnes at a grade of 2.02 g/t, containing 4.1-million ounces of gold; while measured and indicated resources (inclusive of reserves) totalled 106.1-million tonnes at a grade of 1.86 g/t, containing 6.3-million ounces of gold.
In 2023, Sabodala-Massawa produced 294 000 oz, at an AISC of $767/oz; while this year, Endeavour forecasts producing between 360 000 oz and 400 000 oz, at an AISC of between $750/ oz and $850/oz.
From an exploration perspective, Sabodala-Massawa is also Endeavour’s largest focus this year, with exploration expenditure expected to amount to $21-million, which equates to 31% of total group exploration expenditure for the year.
During an exploration review, Endeavour identified and delineated more than 15 potential targets within 30 km of the Sabodala plant.
The exploration programme at Sabodala-Massawa is focussed on expanding non-refractory and refractory resources for the existing CIL processing plant and the new BIOX Expansion, respectively.
The exploration programme remains on track to achieve its five-year target of discovering an additional 2.3-million ounce to 2.7-million ounce of indicated resources by the end of 2025, at a discovery cost of less than $26/ oz.