Endeavour achieves first gold pour at Sabodala-Massawa expansion

The Sabodala-Massawa mine is located approximately 630 km east-southeast of Dakar, the capital of Senegal, and consists of several open pit operations on the highly prospective Birimian Greenstone Belt. Non-refractory ore is treated at a 4.0Mtpa CIL plant that achieved commercial production in November 2009.

In 2021, Endeavour completed initial upgrades at the existing CIL plant and simultaneously advanced the definitive feasibility study for the addition of a refractory ore processing plant. This confirmed the economic viability of processing the high-grade refractory ores from the Massawa deposits. In April 2022, Endeavour launched the construction of the 1.2Mtpa BIOX® circuit to process the large refractory ore resource.

The Metso BIOX^® Process was developed for the pre-treatment of refractory sulfide gold ores. The first commercial installation was at the Fairview mine in South Africa in 1986, and the technology has since grown to a mature and proven process. As of today, 13 commercial BIOX plants have been successfully installed. The process uses a mixed consortium of naturally occurring bacteria in stirred reactors to facilitate the oxidation of the sulfide minerals, thereby liberating the occluded gold particles for subsequent recovery in a conventional Carbon-in-Leach circuit. 

The Sabodala-Massawa BIOX plant is the 14^th successful delivery of the BIOX technology by Metso.  Several batch test programs as well as a comprehensive continuous BIOX pilot plant test program was completed during the development of the project, guiding the process design used by Metso for the design of the Sabodala-Massawa BIOX plant.

Delivered on schedule, on budget and with no lost time injuries

The BIOX Inoculum build-up began in 2023, in preparation for the wet commissioning that commenced in February 2024. Since then, approximately 50,000 tons of ore has been processed through the BIOX® Expansion, with the processing plant operating in line with expectations.

The first gold pour from the gravity circuit was completed in April 2024 and yielded approximately 112 ounces of gold. The first gold pour from the BIOX® circuit was completed in April 2024 as well, and it yielded approximately 612 ounces. The BIOX® Expansion is expected to achieve commercial production during the first half of 2024 and ramp up to its stable nameplate capacity of 1.2Mtpa later the same year.

“We are proud to have achieved our first gold pour at the Sabodala-Massawa BIOX® Expansion with over 3.5 million man-hours worked with no lost time injuries,” says Ian Cockerill, CEO, Endeavour Mining. “We have commissioned the project and delivered the first gold in only two years, marking the fourth capital project that we have completed in the last 10 years. All of these have been completed in two years or less, and have been delivered on schedule, on budget and with no lost time injuries. This is a testament to the quality of our projects team and the competitive advantage we have in West Africa.”

“At the Sabodala-Massawa BIOX® Expansion, we expect to achieve nameplate capacity in Q3-2024 driving stronger production at lower all-in sustaining costs through the year,” he continues. “Thus, sustaining the Sabodala-Massawa complex’s industry leading cost profile.”

“Producing the first BIOX gold at Sabodala-Massawa in budget and on time is the result of good cooperation between Endeavour as the project owner and Metso as the BIOX technology and major equipment supplier,” says Jan van Niekerk, Director, Gold Process Solutions at Metso. “We welcome Sabodala-Massawa as the 14th and newest member of the BIOX Users Group and look forward to our continued cooperation in the future.”