COMMINUTION & CRUSHING
unlocking the full energy-efficiency potential of HPGR technology,” Mackert explains.
This approach contrasts with so-called“ finish grinding” setups in dry processing circuits, which have historically faced operational challenges. Controlling wear, maintaining process stability and managing operational variability can be demanding in such configurations, as practical experience has shown, he adds.
Perhaps more revolutionary is the use of HPGRs in applications beyond established industry norms.
FLS is currently involved in a copper project featuring a 4 m diameter by 1 m wide HPGR to be installed downstream of an AG mill – effectively acting as a pebble crusher.
“ We see this as a genuine step change,” Mackert says.“ It will be the first time an HPGR is used as a pebble crusher without conventional crushers pre-conditioning the feed size.”
The machine will process feed material of up to 100 mm. The unusually large roll diameter ensures a sufficiently wide operating gap to accommodate the coarse feed.
Equipped with Rotating Side Plates( RSPs), oil-lubricated bearings and the latest HPGR Pro technology features, the unit reflects how far the technology has evolved from its early mining applications, Mackert says.
While greenfield projects continue to drive capital sales, brownfield optimisation is emerging as an equally important growth area for the company.
Close cooperation between FLS’ s product and service teams has resulted in several retrofit and upgrade projects – including conversions of competitor machines.
“ We are seeing strong interest from operations looking to increase throughput without expanding footprint,” Mackert notes.“ In many cases, upgrading to RSPs can increase capacity by up to 20 % within the existing installation.”
Introduced commercially with the HPGR
Pro in 2020, RSP technology replaces conventional cheek plate designs. In addition to throughput gains, FLS reports energy savings of up to 15 %, along with a more uniform pressure profile across the operating gap. The result is improved grinding performance and significantly more even roll tyre wear, extending tyre life by 30 % or more.
For mines with 10-15 years of remaining life, debottlenecking the comminution circuit often becomes a strategic priority.
“ That’ s typically when operators approach us,” Mackert says.“ And in many cases, we can retrofit RSP technology within just a few days on site.”
With decarbonisation targets tightening and energy efficiency becoming a decisive project metric, HPGR technology appears to be moving beyond incremental optimisation toward structural change in comminution design, according to Mackert.
If the current project pipeline materialises, 2026 may well mark the beginning of a new chapter – one in which HPGRs are no longer viewed as an alternative, but as a central pillar of next-generation mineral processing flowsheets.
Process pairs offering performance
Metso dedicated a whole segment of its most recent capital markets day program to a presentation focused on improving energy efficiency in comminution, with Giuseppe Campanelli, President, North and Central America market area, highlighting this trend to investors and other stakeholders during the event.
Comminution is the largest energy consumer in mining, so improving the efficiency of this process is a powerful lever for improved profitability and sustainability, the OEM says.
For a 100,000 t / d copper concentrator, a 5 % reduction in total comminution energy can translate into annual savings of around € 3-5 million($ 3.6-5.9 million), according to Campanelli’ s presentation, adding that primary and secondary grinding represented the most impactful areas for energyefficiency gains within the concentrator.
Christoph Hoetzel, Senior Vice President, Grinding, at Metso, followed this train of thought when IM spoke to him in early- February.
“ It might be controversial for a grinding guy to say, but in a concentrator the real value generation happens downstream, we are just preparing the material for that value stage,” he said.“ If we as an industry could separate the valuable mineral from the gangue without comminution, we would. Liberation without any grinding would make a marked difference from a global energy perspective.”
This vision is unlikely to be realised across the industry soon, but the more immediate inclination towards holistic flowsheet thinking is helping reduce grinding’ s energy-intensive credentials. It starts before the mill, with traditional drill and blast optimisation programs as well as ore characteristic trackers such as Smartag now being complemented with preconcentration methods and material analysis occurring in the pit prior to crushing, rejecting below cut-off grade material or material that may cause the comminution circuit issues; it also happens further downstream, with solutions that offer coarse particle flotation or a new generation of fine and ultra-fine particle recovery for complex orebodies.
“ We continue to have conversations with clients about how to integrate a sorting opportunity at the front end of the flowsheet and what impact that will create further downstream,” Hoetzel said.“ At the same time, the downstream teams in flotation are keeping us updated with developments on that side and the positive ramifications for the grinding process.”
Against this backdrop, Hoetzel and his team continue to see the success of offering holistic technology combinations. Customers are ordering new pairings of equipment to achieve energy-efficiency gains. It could be an HRC™ HPGR into a ball mill in a copper
Metso’ s sales of stirred mills, such as the Vertimill, HIGmill, Stirred Media Detritor mill and Vertical Power Mill, have increased in recent years
30 International Mining | MARCH 2026