Following a successful trial of sorting technology on Cochrane Hill’s gold ore, St Barbara is undertaking an evaluation of an alternative design approach which would process the ore through the proposed 15-Mile process plant. 

• Cochrane Hill Ore Reserve is currently 15.4 Mt at 1.0 g/t Au for 510,000 ounces of gold. 
• Key design changes being considered include: 
  • A quarry-style satellite operation at Cochrane Hill, with sorted ore transported approximately 70 km by road to the proposed 15-Mile processing facility for conventional Carbon-in-Leach (CIL) processing for anticipated improved gold recoveries;
  • No processing plant or tailings management facility required at Cochrane Hill, resulting in a more capital efficient project that would also have reduced environmental and social impacts;
  • Utilisation of ore-sorting technology at Cochrane Hill to reduce overall ore haulage and processed tonnages, which appears possible after very successful bulk trials
  • Optimising the open pit design to eliminate the need for the relocation of a public road;
  • Significantly reduced water usage during construction, commissioning and operations; and
  • Optimised long term waste rock management plans to further reduce the footprint and improve the final landform design post-reclamation. 
• Ore sorting results to date are very promising: 
  • Ore sorting trial undertaken on an 840 kg sample using XRT (x-ray transmission) technology; 
  • Test work resulted in the concentration of 89.7% of the gold from the bulk sample into 54.3% of the sample mass for a reduction of approximately half of the material requiring transportation and processing with a 1.65 times uplift of the head grade in the resultant concentrate; and
  • Testing conducted with joint funding from the Nova Scotia Department
     

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