Metso Corporate Newsroom News 2023 Shaping the evolution of flotation: Metso celebrates 50 years in mechanical flotation
Product news September 1, 2023

Shaping the evolution of flotation: Metso celebrates 50 years in mechanical flotation

Metso Corporation’s press release on September 1, 2023, at 09:00 a.m. EEST

Flotation technology has played a pivotal role in Metso’s history for over 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.

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

During development of the larger flotation cells, the team noticed that 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,” says Antti Rinne, VP, Flotation at Metso. “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 m³. 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.

“Now, the biggest cell is almost 20 times larger than the original 38 cubic meters. 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 optimized with Metso’s HSC simulation tool, thus enabling optimization of total flotation cell volume and other key flotation parameters.

Reaching the unachievable recoveries with Concorde Cell™

Metso Concorde Cell, entering the market as recently as 2021, stands out as a significant milestone in flotation. 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. Both are part of Metso’s Planet Positive offering and ensure unmatched metallurgical performance.

“Combining the well-proven TankCell® technology with Concorde Cells is a low-risk and high-benefit approach,” says Rinne. “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.”

Upgrading older cells for maximized recovery

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. 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.

Visit Metso’s website to see the full flotation offering.

Further information:

Antti Rinne, Vice President, Flotation, Metso, tel. +358 40 523 9009, email: antti.rinne(at)

Helena Marjaranta, Vice President, Communications and Brand, Metso, tel. +358 20 484 3212, email: helena.marjaranta(at)

Metso is a frontrunner in providing sustainable technologies, end-to-end solutions and services for the aggregates, minerals processing and metals refining industries globally. By helping our customers increase their productivity, improve their energy and water efficiency and environmental performance with our process and product expertise, we are the partner for positive change.

Headquartered in Espoo, Finland, Metso employs over 16,000 people in close to 50 countries and sales for 2022 were about EUR 5.3 billion. The company is listed on the Nasdaq Helsinki.,

Metso TankCell TC e70 flotation cell
Metso Large OK-16 flotation machines