With ore grades declining and cost pressures rising, high-throughput circuits based on very large grinding mills are becoming an increasingly attractive option in mineral concentration applications. The new Outotec® Open Ended Discharge Grinding Mill (OED Mill) enables innovative and efficient high-capacity circuit designs through the removal of pulp lifters from the discharge arrangement, facilitating reductions in both CAPEX and OPEX.

Instead of using pulp lifters, the OED Mill discharges material directly through the grates, solving the throughput bottleneck problem often associated with comminution circuit design. The mill uses a novel grate-supporting spider to maximise slurry transport and minimise slurry pooling, increasing throughput capacity further and improving grinding efficiency.

The OED Mill enables novel circuit designs with significantly reduced equipment requirements and therefore lower CAPEX. Reductions in OPEX are made possible through a reduced – or even completely eliminated – need for grinding media. The OED Mill also incorporates innovative wear-part solutions that enable timely and safe servicing, including innovative outboard mounted grate panels which can be removed from the outside of the mill using a jib or overhead crane. Furthermore, the spider and discharge cone are segmented and removable. Together these solutions minimise the time and cost associated with mill relining and discharge-end servicing.

The mill also includes the Outotec Polymer HSB, which offers proven performance under even the toughest conditions to maximise mill availability.

Key benefits include the following:

• Highest possible discharge capacity through elimination of pulp lifters
• Maximised slurry transport and impact energy with lowest possible slurry pool level
• Reduced CAPEX with novel high-capacity circuit designs
• Minimised OPEX through the reduction or elimination of grinding media
• Optimised serviceability and availability with novel discharge wear package

“The Outotec Open Ended Discharge Grinding Mill takes high capacity discharge systems to the next level, enabling novel circuit designs with reduced CAPEX and OPEX. The completely open discharge end results in the lowest possible slurry pool level while simultaneously optimising serviceability and maximising availability,” says Damon Bordi, Mechanical Engineer, Grinding business line.