Metso Introduces a New Concept in Mill Liners

Metso’s Megaliner mill-liner shell element requires fewer attachment points than conventional liners.
Metso Mining and Construction’s new Megaliner shell liner has been designed to reduce downtime for large grinding mills to a minimum, employing an innovative design that allows faster replacement. According to the compa-ny, it also improves worker safety dur-ing maintenance, as the liners are bolt-ed into position from the outside of the mill and workers are not required to stand within the ‘drop-zone’ area of the liners.

Mill availability is improved through faster liner replacement. Megaliner, said Metso, uses larger than average liners yet these can still be placed with the same 6- to 8-axis liner handlers commonly used with large AG mills. Using larger liners means mills require fewer of them and Megaliner also has fewer attachment points compared with conventional liners, speeding up instal-lation even further. Liners are easily and accurately positioned before bolt-ing with the aid of highly visible, col-ored guiding markers.

Metso said it designed the system to make removal and replacement of liners as quick, safe and easy as installation. Bolting and unbolting is straightfor-ward, as the threaded portion of the standard hex-head liner bolts is pro-tected from dust, corrosion and general mechanical damage. Once loosened, it is often possible to remove the liner bolts simply by hand-turning them. Pneumatic or recoilless hydraulic ham-mers are not needed to dislodge worn Megaliners, as gravity alone is general-ly sufficient.

Workers fasten the liner’s attachment bolts from the
outside of the mill, improving personal safety.

The Megaliner is suitable for large AG mills with large trunnions and where modern liner handlers are available. Each Megaliner element integrates multiple lifter and shell plate rows, and covers an area up to 4 m 2 (43 ft 2 ). The rubber-and-metal composite liner weighs 30% to 60% less than metallic liners of a similar size.

Overall, said Metso, installing and replacing mill liners with the Megaliner system creates a much safer and less stressful environment for the liner han-dler operator and the installation team.

As featured in Womp 2012 Vol 05 -