Record Year for Metso Stirred Mills as Mining Industry Opts for Energy-Efficient Comminution Technology

Metso saw record sales of stirred mills in 2025 as mining customers opted for more energy-efficient grinding solutions.

In minerals processing, there is growing demand for optimized technology combinations and multi-stage grinding to boost energy efficiency and reduce carbon emissions, as well as to improve productivity with optimized operating costs, according to Metso.

In milling, these can be achieved by using Metso's Vertimill and HIGmill stirred mills and high-pressure grinding (HPGR) technology. Overall throughput and recovery can be further enhanced by combining the stirred mills with concorde cell flotation technology, according to Metso.

Vertimills With Record Installed Power Deliver Significant Emissions Savings

In 2025, Metso sold more than 20 Vertimill grinding mills with a combined installed power of 67 MW. With these stirred mills delivering up to 35 percent energy savings compared to conventional ball mills, the total power saved amounts to approximately 36,550 kW.

This impressive reduction is equivalent to avoiding 135,000 tons of CO2 emissions annually, based on 8,500 operating hours per year. To put this in perspective, the emissions savings are comparable to the annual carbon footprint of approximately 20,200 people, using the Finnish per capita average of 6.7 tons of CO2.

"The growing preference for stirred milling technology extends not only to established markets but also to new regions where this technology has previously not been considered," said Alan Boylston, vice president, stirred mills of Metso. "Additionally, many existing concentrator plants are choosing to enhance their operations with add-ons to incorporate these solutions. Stirred mills are now increasingly being deployed in secondary and tertiary grinding applications, handling a wide range of ores including copper, gold and iron ore. Our comminution solutions portfolio is focused on future-oriented, energy-efficient technologies to meet our mining customers' diverse requirements and support them with value-adding services."

Comprehensive Stirred Mills Portfolio With Large Installed Base

Metso has a leading stirred milling technologies portfolio, consisting of Vertimill, HIGmill, stirred media detritor (SMD) mills, and vertical power mills (VPM). These mills are based on gravity-induced and fluidized technologies, allowing for an equipment solution for all comminution circuits in secondary, tertiary, fine, ultrafine, regrind and lime slaking applications.

Stirred mills are part of the Metso Plus offering — a qualified group of selected Metso products, services or digital solutions that provide significant environmental performance improvements. We also provide digital solutions as well as extensive support through a global network of service and repair centers.

With more than five decades of expertise in stirred mill technology, Metso has developed, tested and delivered approximately 1,000 stirred mills to hundreds of sites worldwide.

For more information, visit metso.com/mining/grinding/grinding-mills/stirred-mills/.