FLOTATION
Metso describes its new Sampo™ Cell as a breakthrough innovation in coarse particle flotation that enhances recovery of coarse particles without compromising fine particle recovery
Floating forces
The most significant flotation development this year was from Metso, which in September 2026 introduced the Sampo™ Cell, which it describes as a breakthrough innovation in coarse particle flotation that enhances recovery of coarse particles without compromising fine particle recovery, helping mining companies improve the efficiency, profitability, and sustainability of their operations. In Finnish mythology, Sampo is a magical device forged by the blacksmith Ilmarinen that brings riches and good fortune to its holder.
Based on a froth-feeding principle, the Sampo Cell technology gently feeds slurry directly into the froth phase, where separation takes place under lowturbulence conditions. This minimises particle detachment and enables efficient recovery of particles that are typically lost in conventional flotation circuits. The Sampo Cell can be applied for front-end gangue rejection or as a scavenger stage to recover valuable particles from intermediate or final tailings.
The Sampo Cell is a pneumatic flotation cell operated using standard flotation control variables such as superficial gas velocity, froth height and reagent addition. Because these parameters are commonly used in conventional flotation circuits, the technology can be readily implemented within existing process control systems while targeting improved recovery of coarse particles. By avoiding high turbulence and feeding the slurry directly to the froth environment, the cell promotes stable
Paul Moore looks at a major coarse particle flotation technology introduction plus other key developments in this critical part of the flowsheet
bubble-particle aggregates and reduces detachment of coarse particles. In addition, the absence of fluidisation water simplifies the flowsheet, reduces process water demand, and minimises the need for auxiliary equipment. According to Metso, this makes the technology particularly attractive for coarse particle recovery and scavenging applications.
“ Mining companies are under increasing pressure to process more complex ores, improve recovery while reducing their environmental footprint. The Sampo Cell represents a significant leap forward in flotation technology. By expanding the recoverable particle size range and 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
40 International Mining | OCTOBER 2026