Boroo Gold Mine

Boroo Gold Mine


Project Category:



Centerra Gold Inc








Scope of Work

OMC’s scope of work was to undertake an optimisation of the comminution circuit and carry out a general audit of plant performance. Recommended changes to the circuit where made to increase plant capacity based on the audit, collection of survey data and modelling. A follow up audit was then undertaken a year and a half later and these are now scheduled annually.



The Boroo 2.4Mtpa plant comprises a jaw crusher, overflow surge bin with static stockpile, SAG Ball and CIP ircuit. The SAG mill is 8.53 m ∅ x 2.6 m EGL with 2.8 MW drive and a 4.8 m ∅ x 7.6 m EGL, 3 MW Ball mill.



Significant credit must be given to site personnel for this achievement through their ownership and application of the recommendations made following the 2005, 2007, 2008 Audits. This involved:

  • Increasing the SAG mill ball charge from 4% to 8% to improve power efficiency. A reduction in the SAG mill ball size from 125 mm to 100 mm to minimise lump degradation. Production increased by 8.8% while achieving a 27 μm finer grind size giving a 9.5 % increase in efficiency for a total improvement of 18.3%.
  • New cyclone cluster; Cavex cyclones are suited to the coarser grind size. Improved operation of the classification to minimise fines misreporting to underflow.
  • Upgrade of the mill discharge pumps with larger capacity units.
  • Modifications to gravity circuit to increase gravity recovery from 45 to 57%.
  • Improvements in operation of CIL circuit.