Shelley, Davies, Olivier and Atta Danso
This paper reflects on how measurements from inside an operating SAG mill might be used to better understand throughput, mill wear and energy dissipation within the mill. The paper discusses how the measurements might influence and enhance approaches to energy and wear efficient mill operation when compared with current day modelling techniques. Insights are drawn from measurement inside two operating SAG mills in Australia using sensors inserted into grinding media and sensors fixed to the rotating mill shell. Energy and wear efficiency are typically important to these operations.
Both energy and wear efficient comminution is a pre-occupation of mineral processing researchers and practitioners. This is because the process of SAG milling is very energy inefficient and the cost of energy and consumables to process ore is significant. In the milling process ore and media are literally thrown into each other at high speed by specifically designed lifter bars. Ball, liner and energy are sacrificed by design in the process of reducing large size rocks to much smaller particle sizes. This violent environment has resulted in serious deficiencies in modelling the internal dynamics of the mill and thus hindered great operational improvements for decades.
Given the status of current SAG milling models and the hindered progress toward measuring inside mills, it is reasonable to think that successfully combining real time data from inside the mill with mill optimizing mathematical models might provide an industry step-change to the efficacy of energy and wear efficient mill operation. This paper shows results of measurements inside a mill and explores the possibilities that the measures have in mill optimization.
Paul Shelley1*, Eugene Davies2, Jacques Olivier3 and Mark Atta Danso4
1. VP Innovation, Molycop, Global
2. Innovation engineering, Molycop, Global
3. Western Australian School of Mines, Curtin University
4. Senior Processing Superintendent, Westgold Resources, Australia