
Performance targets:
Safety first
We design with safety as the top priority
Increased uptime
Shorter and fewer maintenance stops
Lower maintenance costs
Reduced cost of operation, quick and easy maintenance
Maximized throughput
Maximized yearly production

Continuous improvement
A mill lining is a customized wear part. Identifying the appropriate type of lining and design is vital for optimizing mill throughput and total grinding costs, including costs for energy, grinding media and maintenance. Furthermore, the design must be constantly optimized to meet your needs. We work closely with our customers and carefully follow their process to make sure the lining we supply is always optimized for current operating conditions.
Metso Outotec offers mill linings with materials and designs optimized for each specific application. We can design and supply mill linings for all types of mills - for Metso Outotec mills as well as for competitor mills - and for all parts of the mill. Our wide product range, innovations, knowledge and experience makes us unique. Our approach to lining design is focused on grinding performance, mill uptime and safety.

At Metso Outotec, cooperation with our customers and availability to offer support and service are of key importance. We have local support close to our customers, several expertise hubs as well as research facilities focused on wear parts development. Metso Outotec's global laboratory network offers unmatched testing and material development. Our wear parts are manufactured in Metso Outotec's global factory network, utilizing the latest technologies and adhering to stringent quality standards. Today we have eleven production units focusing on rubber and Poly-Met wear parts and five foundries for metallic wear parts.


Metso Outotec is widely recognized as a technology leader in mill manufacturing, which makes us much more than a service and wear parts supplier – we are true grinding experts. We know the functional parameters, mechanics, kinematics and forces the mill is subjected to in operation. Thinking long term already when buying a mill provides greater opportunities to achieve lower maintenance and operating costs. This, in combination with knowledge about your current operation conditions and targets, is crucial when designing a mill lining.
Developing new materials and solutions together with our customers is at the heart of what we do. By choosing Metso Outotec, you gain access to the latest innovations and can participate in the process of creating them.
We pioneered the use of rubber linings and invented Poly-Met, Megaliner and Orebed mill linings. New products are constantly being developed to enhance our customers’ ever more advancing processes. Our recent innovations include wear reading solutions, Megaliner™ for heads, Liner Positioning System upgrade, digitalization etc.


By working with a partner who understands the variables affecting grinding performance, you have a great opportunity to maximize mill performance and availability.
We are constantly working to optimize your mill lining design according to your targets and current conditions. Our simulation software allows us to predict the performance of the customized lining extremely accurately, which ensures that we deliver the gains we promise. With Metso Outotec, you can be sure that your mill lining is always designed according to your targets, ore and grinding process.

Finding the balance between grinding and discharging requires in-depth knowledge of the grinding process. It is often challenging, as efficient grinding is dependent on many separate parts and parameters.
Metso Outotec designs mill linings for all parts of the mill; shell lining, head lining, discharge system and trommel. We can offer a holistic approach to your whole grinding circuit, and we look at how your different wear parts function together
Head linings
As part of a system solution, the head lining is designed with consideration to the shell lining design. All components must be in balance to minimize the number of maintenance stops. We try to keep the number of individual parts to a minimum, and to ensure that parts do not interfere with each other during installation. Liners that are most subject to wear are made more robust, and whenever possible these high wear parts are designed to be independently replaceable.
Shell linings
The shell lining has a major influence on grinding efficiency. It transforms the mill rotation into charge motion and both profile and spacing must be carefully selected to suit each specific mill. When designing a shell lining, Metso considers the type of grinding, mill size and speed, maintenance schedules, safety, impact levels, efficient use of materials, and many other parameters.
Discharge systems
Metso’s wear-resistant rubber-covered or cast dischargers come in two general designs – radial and curved. The larger the mill, the longer the distance the material must travel before being discharged into the trunnion. A curved discharger design will initiate a flow towards the center of the mill at an earlier stage and ensure that the discharger pan is emptied and ready to be refilled during the next pass through the charge. Prompt removal of material and less backflow will allow the energy to be more efficiently utilized for grinding fresh ore. As less material is recirculated, wear life increases. In addition, increased flow can also contribute to increased throughput and decreased power consumption.
Trunnion linings
Metso trunnion liners are custom-made to protect your mill trunnions from internal wear. Fit is critical, and our trunnion liners can be made to almost any size or shape. Typical design features include internal spirals or dams to control material flow, flanges for the mounting of trommel screens, inclusion of threaded holes for jacking screws, inspection ports, etc. Metso trunnion liners are grouped into three categories; One-Piece, Replaceable Sleeve and Bolted Wear Elements.
Mill trommel screens
Mill trommels, whether used for sizing or scalping, play a vital role in your grinding circuit. Metso’s robust but light-weight trommel frames consist of carefully selected welded profiles that are covered in a protective layer of wear resistant rubber or polyurethane. Adapting flanges, if required are available to suit the design of virtually any trunnion or trunnion liner interface. There are two main types of screen panels – modular and customized. The modular trommel panel with snap-on attachment comes in a standard size of 305 x 610 mm. Installation and replacement of the snap-on screen panels is easily accomplished and results in minimal if any impact on mill availability.
Head linings
As part of a system solution, the head lining is designed with consideration to the shell lining design. All components must be in balance to minimize the number of maintenance stops. We try to keep the number of individual parts to a minimum, and to ensure that parts do not interfere with each other during installation. Liners that are most subject to wear are made more robust, and whenever possible these high wear parts are designed to be independently replaceable.
Shell linings
The shell lining has a major influence on grinding efficiency. It transforms the mill rotation into charge motion and both profile and spacing must be carefully selected to suit each specific mill. When designing a shell lining, Metso considers the type of grinding, mill size and speed, maintenance schedules, safety, impact levels, efficient use of materials, and many other parameters.
Discharge systems
Metso’s wear-resistant rubber-covered or cast dischargers come in two general designs – radial and curved. The larger the mill, the longer the distance the material must travel before being discharged into the trunnion. A curved discharger design will initiate a flow towards the center of the mill at an earlier stage and ensure that the discharger pan is emptied and ready to be refilled during the next pass through the charge. Prompt removal of material and less backflow will allow the energy to be more efficiently utilized for grinding fresh ore. As less material is recirculated, wear life increases. In addition, increased flow can also contribute to increased throughput and decreased power consumption.
Trunnion linings
Metso trunnion liners are custom-made to protect your mill trunnions from internal wear. Fit is critical, and our trunnion liners can be made to almost any size or shape. Typical design features include internal spirals or dams to control material flow, flanges for the mounting of trommel screens, inclusion of threaded holes for jacking screws, inspection ports, etc. Metso trunnion liners are grouped into three categories; One-Piece, Replaceable Sleeve and Bolted Wear Elements.
Mill trommel screens
Mill trommels, whether used for sizing or scalping, play a vital role in your grinding circuit. Metso’s robust but light-weight trommel frames consist of carefully selected welded profiles that are covered in a protective layer of wear resistant rubber or polyurethane. Adapting flanges, if required are available to suit the design of virtually any trunnion or trunnion liner interface. There are two main types of screen panels – modular and customized. The modular trommel panel with snap-on attachment comes in a standard size of 305 x 610 mm. Installation and replacement of the snap-on screen panels is easily accomplished and results in minimal if any impact on mill availability.

There are two types of stirred media mills: Vertimills and Stirred Media Detritors. In a stirred media mill, the mill body is static and the charge motion is created by an agitator such as a rotating spiral or impeller.
We provide both original body liners and spiral/impeller liners designed as a system for each of the mill sizes of Metso’s extensive range of stirred media mills. Our product range includes all the consumables in your mill e.g. body liners, screw liners, impeller arms, retaining screens and attachment hardware.
Combine for better results
The lining material should be distributed in such a way that the thick portions protect the areas with high wear and the thinner portions are used on the areas with lower wear. A certain lining thickness is required to achieve the desired wear life, and the lining must also have a profile suited to the desired type of charge movement but without occupying too much volume. Moreover, a good lining design will keep a good profile throughout its service life, providing enough traction to sufficiently lift the charge.
More than a lining
Metso Outotec offers a full portfolio of parts, services and equipment to ensure that you get the best out of your grinding process and reach your production goals.
More than a lining
When buying a mill lining from Metso Outotec, you get more than just a wear part. We always do a pre-study and design the lining based on your conditions and targets. Wear and performance monitoring are regularly done to better understand your grinding process and to optimize the lining accordingly. Technical support is offered, and we arrange product and process trainings as well as technical development meetings for our loyal customers.
Installation and reline
Our experienced engineers oversee the safe and timely installation of Metso Outotec-supplied parts. Our experts adhere to the most stringent safety standards and are highly trained in OEM workmanship, allowing for a high-quality installation. If necessary, Metso Outotec can also guarantee the amount of downtime needed to perform wear part changeouts. Read more on Maintenance and repairs.
Grinding circuit optimization
Metso Outotec process experts help in solving complex operational issues using analytical techniques, laboratory testing, and advanced control systems. Whether you need to optimize a piece of equipment, a circuit, or your entire plant, we have the tools and technology to help you make it happen. Read more on Process optimization and controls.
Life Cycle Services
Metso Outotec's pre-packaged solutions are designed to assist you in meeting your business goals, from start-up to shutdown to end-of-life. We can support you on a specific activity or over a larger scope, combining elements from our large portfolio of services with unique commercial models. Read more on Life Cycle Services.