The comminution process indicates that the most energy-efficient comminution system would be one where the particles leave the breakage field as soon as they reach product size. Contrary to the free falling gravitational (vertical) flow in crushers, the grinding mill's energy efficiency essentially depends on ore characteristics and the discharge rate of broken particles, which in turn depends on how efficiently the discharge pump (grate and pulp lifters) operates._x000D_
The essential function of a pulp lifter is to transport the broken material and slurry from the discharge grate out of the mill. Hence, the design optimisation of pulp lifters affects not only the energy efficiency and throughput of autogenous grinding/semi-autogenous (AG/SAG) grinding mills, but also contributes other process benefits such as improved wear life and operator-friendly steady and smooth mill operation._x000D_
Following its introduction in 2006, Outotec's patented Turbo Pulp Lifter (TPL) design has been retrofitted at existing sites and also installed in some new ones around the world. This paper will provide operational experience and data on how the TPL design has allowed AG and SAG mills to operate efficiently.