Paper presented by Richard Whittering at Procemin-Geomet 2019 Conference, Santiago, Chile, 21 November, 2019
Mill liners are the primary barrier protecting the mill shell from excessive damage or wear. Over the years, the mill liner design and selection had focused on the operation’s maintenance requirements of improving the life of liners; thus, increasing the overall availability of the grinding circuits. With an increasing treatment of complex ore bodies with variable competencies, SAG mill liners and discharge systems are proving to be crucial components controlling the power draw and the resulting throughput and grinding performance.
This paper explores examples of operations with poor SAG mill liner and discharge system designs. It is shown, that poor design of SAG mill liner and discharge system can negatively affect the SAG mill operation, whereby throughput increase is restricted due to the SAG mill constraints. Examples are presented to support Ausenco’s practical approach to SAG mill liner design and grinding optimisation with a focus on production – i.e. throughput.
Ausenco’s comminution optimisation tool, Ausgrind, was used to benchmark and analyse plant data with empirical models, predict circuit performance for varying ore characteristics, evaluate liner wear and predict the life for varying operating parameters. Variances between the actual and the predicted values were assessed in detail to identify missed opportunities and help guide operations with re-defined operating parameters to maximise throughput and productivity.