OPTIMISING THE GRINDING PROCESS Metso Corporation notes the grinding mill has efficient drive and polymer hydrostatic shoe bearing systems to improve radial, axial bearing reliability and longevity
Finland-based industrial machinery company Metso Corporation has been awarded an order to deliver an 18 MW semi-autogenous grinding (SAG) mill for the Phase 2 expansion at Canadian mineral exploration and development company Orezone Gold Corporation’s Bomboré gold mine, in Burkina Faso.
Bomboré, situated 85 km east of the capital city of Ouagadougou, is 90% owned by Orezone, while the government of Burkina Faso holds the remaining 10%.
Orezone highlights that the region the Bomboré mine is located in, is readily accessible through “excellent infrastructure and simple logistics”.
In highlighting the features of this mill, Metso notes an efficient drive system and a polymer hydrostatic shoe bearing system, is intended to markedly improve radial and axial bearing reliability and longevity.
Further, this mill is equipped with the Metso MillSense mill charge sensor system, which stabilises and optimises the grinding process, thereby ensuring increased productivity and reliable operation.
Metso says that it offers the mining industry’s widest range of horizontal grinding mills. Inclusive of the Premier and Select Mills, the company adds that its horizontal grinding mills can be easily integrated with its mill relining equipment and is supported by its extensive services network to ensure optimisation during the mill’s lifespan.
Metso also offers a comprehensive mill linings range and relining services, with materials and designs optimised for each specific application.
According to Orezone, Bomboré is generally considered the largest undeveloped gold deposit in Burkina Faso.
Orezone plans to develop the project in stages, the first of which is intended to focus on the oxides as a carbon-in-leach (CIL) operation, while the second stage will focus on the underlying sulphides, with a separate crushing and grinding circuit feeding the same CIL circuit as the oxides.
“The Premier SAG mill to be delivered to Bomboré is part of our Planet Positive offering, thanks to its energy efficiency. This high-capacity SAG mill, which will be one of the largest gear-driven mills installed in Africa, is based on proven technology,” says Metso Corporation grinding business senior VP Christoph Hoetzel.
According to an expansion study, Orezone, in October 2023, floated plans to incorporate a 4.4-million-tonne-a-year hard rock plant with the 5.9-million-tonne-a-year oxide plant for a total processing rate of 10.3-million tonnes a year – a significant increase in gold production at a low incremental capital cost.
Construction of the new standalone 4.4-million-tonne-a-year hard rock processing facility will enable Bomboré to produce an average of 209 000 oz/y at an all-inclusive sustaining cost of $1 121/oz.
First gold from the hard rock plant is scheduled for the third quarter of 2025.