FLOTATION simplifying coarse particle flotation, customers can unlock additional value from existing operations,” says Teemu Kaarniemi, Senior Vice President of Separation at Metso.
Traditional flotation circuits typically require extensive grinding to bring particles into an optimal range for efficient recovery. The coarse particle flotation changes this paradigm by expanding flotation performance to significantly coarser and less liberated particle sizes. The Sampo Cell design also simplifies coarse particle flotation flowsheets compared to other solutions.
The Sampo Cell does not inherently require feed classification, fluidisation water, or additional concentrate dewatering stages, reducing equipment requirements and supporting easier integration into existing plants. The technology is capable of efficiently floating the full particle size distribution, and its performance is not dependent on feed classification. In Sampobased circuits, classification may be applied for economic optimisation rather than operational necessity. When the fine fraction contains little recoverable value, a simple single-stage cyclone classification step can be used to remove these low-grade fines, enabling a smaller and more cost-effective circuit focused on the higher-value coarse fraction. The Sampo Cell uses familiar flotation controls and instrumentation, making implementation straightforward for plant operators. The Sampo Cell is part of the Metso Plus portfolio, supporting more efficient minerals processing through improved energy and water efficiency and higher resource recovery.
Since March 2026, the Sampo Cell has been in continuous 24 / 7 operation in industrial-scale scavenger duty at a copper mine in Chile – specifically as a scavenging technology for recovering copper from rougher tailings containing a high proportion of coarse and partially liberated particles at Grupo Minero Las Cenizas’ s Las Luces concentrator in Antofagasta, Chile. Approximately 30 % of the total tailings stream is processed, and the Sampo Cell has delivered a significant increase in overall copper recovery. In continuous industrial operation and across a broad range of operating conditions, the CPF cell consistently achieved copper stage recoveries exceeding 60 %, with recoveries above 80 % attained at moderate mass pulls.
Concentrate grades were at least twice higher compared to the main concentrator feed grade, enabling the recovered material to be returned to the circuit for regrinding and subsequent conventional flotation, with the objective of increasing overall recovery. Importantly, the Sampo concentrate has been directly sent to the regrinding circuit without the need to dewater it, with solids percentage between 25-35 %. These results were obtained without excessive mass pull, supporting selective recovery of valuable minerals while minimising the impact on
IM Editorial Director Paul Moore with Metso’ s Marly de Avila Carvalho( right), Product Manager, Coarse Flotation; and Antti Rinne, Vice President of Flotation( left)
auxiliary equipment and downstream capacity.
“ The industrial-scale operation in Chile has validated both the performance and scalability of the Sampo Cell. The results show how customers can improve overall plant recovery without major changes to the existing flotation circuit,” says Antti Rinne, Vice President of Flotation at Metso.
Metso says the launch of the Sampo Cell further strengthens its leadership in flotation technology. Metso offers one of the industry’ s most comprehensive flotation portfolios, covering mechanical flotation, pneumatic flotation, flotation services, process expertise, digital optimisation tools, and aftermarket support.
Combined with Metso’ s crushing, screening, grinding, filtration, thickening, and tailings solutions, customers benefit from an integrated approach that optimises performance across the entire minerals processing flowsheet.
IM Editorial Director Paul Moore travelled to Metso’ s headquarters in Helsinki and its Research Centre in Pori, to find out more about the technology – meeting in person with Antti Rinne and with Marly de Avila Carvalho, Product Manager, Coarse Flotation.
Rinne commented:“ We investigated several different options on how to best do coarse particle flotation and tried to look at the big picture, what is making the existing CPF alternatives complex, especially for brownfield operations. We considered that the additional equipment required for fluidised beds was what made these current technologies complicated, in our view – and we saw that there might be ways to overcome those issues.”
Rinne added that the drivers to develop Sampo without using fluidisation were the need for multiple stages of classification, and the amount of water used – which means large pumps and significant energy consumption.“ More classification also means greater height, which in turn requires more structural steel and additional pumping, making it very expensive from an overall project point of view.”
“ As a result, the Sampo Cell enables a remarkably compact circuit design, with significantly lower height requirements compared with conventional flotation and other coarse particle flotation solutions. While feed classification is not required for the Sampo Cell, it may be beneficial in certain applications depending on the project requirements and, when applied, only a single classification stage is typically sufficient. This compact configuration can significantly reduce building height and overall plant footprint, making the technology particularly attractive both for greenfield projects and for retrofits with space and structural constraints.”
Carvalho added:“ One other advantage that I think is crucial is that if you are adding a lot of water in the cell, that water needs to go somewhere. And in the fluidised bed based equipment, that water goes to the
International Mining | OCTOBER 2026