Tonopah Metallurgy

Column Leach Testwork

Column leach testwork completed 4 composite samples ranging in grade from 0.38g/t to 1.98g/t head grade and divided by rock type.

  • Coarse Crush –RC chips used as samples, crushed to 80% minus 10 mesh and agglomerated with cement  
  • Tests not driven to completion in 60 days – additional time needed to increase recovery  
  • Impact of slow-leaching free gold content noticed on recovery 
  • +83% recovery on argillite (Opa) sample representing ~ 50% of resource base.  
  • +58% recovery expected with additional time in Tertiary Volcanics
  • 71% average recovery expected 
  • Additional testwork required to optimize process route  

Metallurgical Testwork

  • PQ Core (8.5 cm) drilled to produce representative metallurgical test samples 
  • Testing program underway at KCA lab in Reno, Nevada 
  • HPGR crushing testwork complete: bottle roll, column leach, stacking and agitation leach tests ongoing