In 2010, the collaboration between Terrafame and Metso started by addressing challenges caused by slippery ore in the primary crusher through a redesigned chamber profile. In the following years, targets were set and met to further optimize and extend the wear life of the primary gyratory wear parts. White iron was chosen for the two lowest concave tiers, and the mantle was made of a more ductile, high-grade manganese steel.
Building on the foundation
By 2017, the first MX mantles were tested, starting with an oversized mantle converted to MX and then later then to a standard size. By moving to the standard MX mantle, the lifetime was doubled, increasing to 7.1 million tons (Mt). This is compared to the average manganese mantle lifetime of approximately 3.5 Mt. The improvements have led to two MX mantles needed across the concave lifetime, achieving the target of reducing mantles from four to two.
Revisions have been made over time in the design to keep improving the production, supported by setting new targets, wear scanning and reporting, and regular meetings between Terrafame and Metso. The wear improvements bring concrete benefits to Terrafame with fewer mantles meaning more uptime, increased safety, and more produced tons. The current design lasts from 7.1 up to 8.8 Mt, also allowing flexibility for maintenance break planning.
