Feasibility Study and Technical Report - Pretivm

OTHER FLOTATION TESTSPotential preg-robbing effects were noted during cyanide leaching tests; therefore, the2012 test program explored whether it was possible to remove the carbonaceousmaterial by pre-flotation. Although the tests showed that the pre-flotation should becapable of removing a portion of the carbonaceous material, the gold reporting to thecarbonaceous concentrate was high (approximately 35% of the gold reporting to thecarbonaceous concentrate from the VOK-1 composite sample) and significantcarbonaceous material still remained in the tailings of the pre-flotation step.Exploratory tests were conducted in 2013 to study the upgrading potential of headsamples by heavy media separation. No encouraging results were produced.GRAVITY CONCENTRATION TEST WORKMetallic gold determination tests and gravity concentration tests conducted during the2009 test programs showed that the Brucejack mineralization contains a significantamount of fine nugget gold grains. The metallic gold determination test results areshown in Table 13.16 to Table 13.18.The results indicate that free gold occurrence is substantially different from sample tosample. The VOK-3 and VOK-4 composite samples may contain significant amounts ofnative gold; however, the VOK-1 and VOK-2 composite samples may contain significantlyless nugget gold. Compared to the VOK Zone samples, the West Zone samples, onaverage, appear to contain less native gold grains. The 2009 to 2011 test results showsimilar gold occurrence patters as those identified in the 2012 test work.Table 13.16 Metallic Gold Test Results – Composite Samples (2012)SampleIDVOK-1CompositeVOK-2CompositeVOK-3CompositeVOK-4CompositeWZ-1CompositeScreen TylerMeshGrade (g/t) Distribution (%)Au Ag Au Ag Mass150 27.31 23.02 13.8 4.0 3.5-150 6.11 19.98 86.2 96.0 96.5Total 6.85 20.09 100 100 100150 13.12 35.76 10.6 17.1 8.0-150 9.59 14.96 89.4 82.9 92.0Total 9.87 16.62 100 100 100150 1,377.00 362.59 66.9 27.5 5.0-150 35.65 50.05 33.1 72.5 95.0Total 102.38 65.59 100 100 100150 23.86 24.77 41.4 3.0 5.2-150 1.83 43.5 58.6 97.0 94.8Total 2.97 42.54 100 100 100150 20.6 25.11 28.0 6.0 7.8-150 4.49 33.1 72.0 94.0 92.2Total 5.75 32.47 100 100 100table continues…Pretium Resources Inc. 13-23 1291990200-REP-R0012-02Feasibility Study and Technical Report on the BrucejackProject, Stewart, BC