Home Full portfolio Grinding mill upgrades
Whether old or new, we can help bring your grinding mill to the next level. Metso has a variety of upgrade options available to extend your equipment life, meet your sustainability goals and keep your mill performing at peak efficiency.

Why upgrade your grinding mill?


Upgrades provide additional safety for crew


Upgrades help you ramp up capacity


Upgrades help to increase equipment life


Upgrades help to simplify and speed up maintenance

Incorporating modern technology without major investment

Metso supplied their first grinding mill back in the late 1950s. Since then, we’ve delivered and serviced over 8,000 grinding mills globally, including some of the largest and most powerful mills in the world.

The mining industry has evolved since then, placing greater focus on sustainable performance and operations. We are proud to say that we have evolved along with it, providing sustainable services and wear parts to our customers.

With over 150 years of experience, we’ve learned that every mining operation has a unique grinding process and varying needs. Our team of grinding experts have curated many retrofit and upgrade solutions to achieve operational and sustainability targets such as increased capacity, improved energy efficiency, higher power, maintenance efficiency, better reliability, and more.

Polymer bearing pads for legacy Metso mills
Polymer bearing pads for legacy Metso mills

Traditional bearing pads with accumulator circuits comprised of a lube unit, gauges, and nitrogen tanks take up a large footprint and often cause downtime due to maintenance requirements or failure.

Metso polymer pads use advanced material technology to deliver long-lasting performance extending the operating life and improve the bearings' reliability in bearing-supported horizontal mills.

The pad design and the elastic properties of the polymer also ensure that an adequate film of oil is maintained throughout the mill operation.

The lubrication system is more efficient, as no accumulator circuit is required, which reduces space requirements, maintenance needs and improves safety.

Read more here >

Trunnion bearing lubrication systems
Maintaining oil temperature, flow, and cleanliness is vital for the health of your mill. If not controlled, fluctuations can shorten the life of key components.

Extend bearing and trunnion life with an automatic lubrication system. Our retrofit ensures that oil temperature, flow, and cleanliness are maintained with a custom-sized reservoir, filtration system and heat exchanger, as well as temperature, flow, and pressure instrumentation.
Trunnion bearing lubrication systems
Gear guard upgrade
Gear guard upgrade

Contamination, extreme heat, and insufficient lubrication all pose risks to your gears and pinions. If not prevented, these will cause accelerated wear and decreased operating life.

Ensure the health and longevity of your gears with a gear guard upgrade. This includes support columns for safer maintenance, a gear spray system for optimal lubrication, infrared monitoring to track health, and a pressured and sealed system to prevent contamination.

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Mill feed chute

A feed chute design that adds safety while improving serviceability and functionality at the same time. Our design features are proven to address the typical issues with feed chutes that often disrupt our customer's business.

Reduce downtime, improve safety and simplify access.

Features include:

  • Rock-box design (shown here)
  • Removable chute cover
  • Liner upgrades
  • Inflatable and labyrinth seals
  • Access platform
  • Access hatch
  • Carriage and trolley alignment upgrades

Read more here >

mill feed chute metso outotec
Inching drive upgrade
Inching drive upgrade
Positioning and rotating a loaded mill can be difficult. If not performed correctly, your equipment and team can be put at risk.

An inching drive slowly rotates your mill to ensure safety throughout maintenance work and prevent a dropped charge. Our retrofit includes a custom-designed drive and power unit, safety interlock system and accessory kits to make the inching drive portable and adaptable to suit all your mills.
Locked charge detection system
Dropped charge, also known as frozen or locked charge, happens when solidified material inside a horizontal grinding mill doesn’t cascade during rotating at start-up. Instead, the charge is lifted and then free falls onto the mill shell. 

A locked charge detection system can be used to prevent a dropped charge and structural damage to your mill. Our retrofit includes a pinion shaft encoder that measures mill velocity and position at start-up, as well as a control panel with a program logic to disengage the clutch when a locked charge is detected.

Locked charge detection system
Trunnion liner upgrade
Trunnion liner upgrade

Our trunnion liner upgrade replaces the existing single piece feed and discharge end trunnion liners with a two-piece design. The new design has proven to improve trunnion liner reliability, durability, and maintainability of the mill trunnion linings and bearings.

The main lining acts as a sleeve insert that is secured in the trunnion by a retaining ring. Dividing the trunnion liner into two pieces enables better distribution of the loading conditions. The improved load conditions reduce stress on the trunnion and fasteners to extend product durability and optimizes wear components.


Slurry wheel upgrade

The Metso slurry wheel upgrade is a retrofit sealing solution for the grinding mill feed end. The existing configuration is replaced with a new and improved slurry return system featuring a unique water-wheel design that significantly improves the material containment of the feed ends. More effective sealing helps to prevent excessive slurry spillage and reduces premature seal wear and its associated costs.

Read more here >

Slurry wheel upgrade
Hydrostatic bearing upgrade
Hydrostatic bearing upgrade

The Metso HSB upgrade is a modernization solution that helps maintain the optimal performance of grinding mill equipment. The proven design improves the durability and serviceability of both radial and axial hydrostatic bearing pads and is the standard arrangement in many new mill installations.

Existing bronze bearing pads are replaced with pads made from an advanced compound that significantly improves the maintenance, reliability, and longevity of both radial and axial pads. The upgrade solution helps reduce lost production time due to bearing-pad surface damage and decreases operational and maintenance costs.

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Spiral turbo pulp lifter

A pulp lifter is used in grate discharge mills to pump the ground ore from the mill. An inefficient pulp lifter can cause a slurry pool to build up in the mill, resulting in partial dissipation of charge (balls and rock) kinetic energy into the fluid, reducing the energy available for breakage.

This is particularly evident in larger mills, which have a reduced grate area relative to their grinding volume and power, and where the pulp is lifted further to reach the discharge through the trunnion. There are a number of causes of inefficiency in a pulp lifter, and these must be addressed together to design an efficient pulp lifter. 

Read more here >

Spiral turbo pulp lifter
Barricade trunnion bearing
Barricade trunnion bearing

Oil leakage from trunnion bearing seals can cause many environmental and administrative concerns. The Metso barricade seal arrangement solves the myriad of issues around the proper sealing of grinding mill main bearings. Our design incorporates protective properties superior to any arrangement yet brought to market. The barricade arrangement is now standard supply for all new Metso mill installations and can be retrofitted to many existing mills.


Many brands, many applications

  • Allis Chalmers
  • Allis Mineral Systems
  • Boliden Allis
  • Denver Equipment
  • Dominion
  • Hardinge
  • Hydralyft
  • Kennedy Van Saun (KVS
  • Koppers
  • Marcy
  • Metso 
  • Morgårdshammar
  • MPSI
  • NEI
  • Nordberg
  • Outokumpu
  • Outotec
  • Sala
  • Scanmec
  • STS (Svenson Technical Services)
  • Svedala
  • Thune
Horizontal grinding mills - Advancing an unrivaled innovation legacy

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