A new line of MH series mills from Outotec offers a range of SAG, ball and rod mills in standard sizes. Configurable options include shell, bearings, feed chute and rock box, as well as drive arrangements.

Outotec has introduced a new MH Series grinding mill range, claimed to offer flexible and easily deployable solutions that are cost-effective and easy to operate and maintain. Along with the new mill offering, Outotec also introduced a Polymer Hydrostatic Shoe Bearing (HSB) system, designed to maximize grinding mill availability and simplify maintenance.

The MH grinding mill series includes a range of SAG, ball and rod mills in standardized sizes with a capacity of up to 3.1-megawatt (MW) installed power. Although MH Series mills feature a standardized design in which certain parameters are fixed in order to control manufacturing costs and delivery lead times, the line still offers a range of configurable options for the shell, bearings, feed chute, and rock box, as well as drive arrangements. Add-on features such as bearing vibration and mill weight monitoring and automated lubrication system control are also available. MH Series mills are compatible with the optional Outotec mill control system.

The body module consists of a shell and cast integrated trunnion heads. The shell can include a transverse split as an option. A 180° split-ring gear with gear guard, an automated gear grease lubrication system, and an erection/maintenance cradle with jacks are included. The MH Series lining system can be ordered with rubber, steel and/or composites for various process conditions. The shells and heads are drilled to accommodate the selected lining.

MH Series mills use grease-lubricated spherical roller bearings with a v-ring and labyrinth seal to ensure a long lifetime. The free-end housing is equipped with rocker technology to accommodate axial movement of the mill. This means fewer spare parts to maintain and improved availability of parts, according to Outotec. The mill’s feed includes the trunnion liner and feed chute with support, as well as a feed seal. The standard discharge setup is a trunnion liner and reversible, disposable steel trommel with discharge housing.

The Polymer HSB system is included on all new Outotec grinding mills as standard equipment and is designed to maximize grinding mill availability and simplify maintenance, increasing revenue and reducing maintenance costs, according to Outotec, which said the system significantly improves the reliability and longevity of both radial and axial pads compared to bronze or white metal pad-bearing systems, eliminating failures associated with surface-to-surface contact caused by journal defects, frozen-charge starts or hydraulic system failures. The system’s self-aligning capability ensures that the pads are always precisely aligned with the mill journal, helping to protect the longevity of the mill by distributing stresses more evenly across the support structure and mill body.

Tuomas Tani, technical product manager for Outotec’s grinding business line, said Polymer HSB systems have “clocked over 7.5 million hours of production with zero hours lost due to bearing failure.”