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Metso reflects on mechanical flotation technology evolution

Posted on 1 Sep 2023

Metso is celebrating 50 years of mechnical flotation this month, reflecting on the pivotal role flotation technology has played in the company’s history over the last five decades.

Evolving from humble beginnings at Outokumpu, and then further developed by Outotec, Metso has shaped the course of mechanical flotation and propelled the industry forward, it says.

The OK cell was taken into commercial use in 1973 with a capacity of 16 cu.m. At that time in flotation history, tanks were square-shaped when viewed from the top. As demand for even larger tanks escalated, a 38-cu.m version was introduced to optimise processes and achieve higher recoveries, and, ultimately, to enhance profitability.

During development of the larger flotation cells, the team noticed square-shaped tanks posed challenges in terms of load-bearing capacity at the corners. As a result, the entire industry shifted to round-shaped tanks. Thus, the TankCell® was born in 1995.

“TankCell is a great example of our history in flotation,” Antti Rinne, VP, Flotation at Metso, said. “Everybody who talks of TankCell flotation cells is speaking of our technology. We remain the original and leading provider of TankCell technology.”

Today, Metso TankCell boasts the world’s best flotation performance and offers a wide variety of cell sizes, currently ranging from 5 to 630 cu.m, the company says. This enables compact and cost-effective plant designs, even for high-tonnage operations. Fewer large units result in significant savings in construction costs, piping, cables, instrumentation and auxiliary equipment.

Rinne said: “Now, the biggest cell is almost 20 times larger than the original 38 cu.m. And, when we introduced the FloatForce® mixing mechanism in the TankCell design, it gave customers up to 30% savings in energy consumption and significantly better recoveries.”

Today’s flotation circuits are often designed and optimised with Metso’s HSC simulation tool, thus enabling optimisation of total flotation cell volume and other key flotation parameters, the company says.

Metso Concorde Cell, entering the market as recently as 2021, stands out as a significant milestone in flotation, according to Metso. The Concorde Cell is capable of recovering the unachievable fine and ultra-fine particles, increasing profitability while reducing operating costs, energy consumption and water usage.

This patented technology – the first of its kind – is tailored for finely disseminated and complex orebodies that were once considered inaccessible. For optimal results, it is best when used in conjunction with TankCell technology, Metso claims. Both are part of Metso’s Planet Positive offering and ensure unmatched metallurgical performance, it added.

“Combining the well-proven TankCell technology with Concorde Cells is a low-risk and high-benefit approach,” Rinne says. “The cell produces very high shear and extremely fine bubbles, which increases recovery in particles under 20 microns. Despite being the newest technology in Metso’s flotation portfolio, it has already been deployed at several operations globally.”

Since flotation is a continuous process, maintaining high availability and efficiency is crucial. Metso’s developments in flotation cell technology enable upgrading and retrofitting of older flotation equipment for enhanced performance, the company says. These advancements not only extend the lifespan of existing equipment, but also align operations with environmental and safety standards, ensuring long-term viability and compliance.

For more information on this flotation technology evolution, click here